Warning to anyone who’s had Covid as scientists discover symptoms that can last for TWO YEARS

Authors: Vanessa Chalmers, Digital Health Reporter May 11 2022  May 12 2022

DOCTORS have discovered the symptoms of Covid that can last for two years or more. 

Their research has shown that half of patients admitted to hospital are still likely to have at least one persistent problem two years later.

The study, published in The Lancet Respiratory Medicine, has the longest follow-up period of patients to date. 

Researchers are only able to analyse what symptoms exist after two years given the coronavirus emerged in late 2019.

So it’s possible problems like fatigue and anxiety could stick around even longer.

Lead author Professor Bin Cao, of the China-Japan Friendship Hospital, China, said: “Our findings indicate that for a certain proportion of hospitalised Covid-19 survivors, while they may have cleared the initial infection, more than two years is needed to recover fully from Covid-19.”

The study involved almost 1,200 patients, aged 57 on average, who were infected with the bug in the early phase of the pandemic.

They had all been treated in Wuhan, China, then assessed six months, 12 months and two years after discharge.

Researchers looked at their walking abilities, mental health, quality of life and more.

Covid patients were generally found to be in poorer health than those in the general population two years after infection.

They reported:

  • Fatigue or muscle weakness (31 per cent of Covid patients compared to five per cent in the general population)
  • Sleep difficulties (51 per cent compared with 14 per cent)
  • Pain or discomfort (23 per cent compared with five per cent)
  • Anxiety or depression (12 per cent compared with five per cent)

Joint pain, palpitations, dizziness, and headaches were also more common among previously hospitalised Covid patients.

Not all of those hospitalised were affected, however.

More than half (55 per cent) of participants had at least one symptom of Covid at two years, and were therefore considered “long Covid” patients.

The researchers then compared the long Covid group with the group of participants who had endured Covid, but gotten better. 

Those with long Covid had more pain (35 per cent vs 10 per cent), and mobility issues (five per cent vs one per cent) than their fully recovered counterparts.

Some 13 per cent showed symptoms of anxiety and 11 per cent depression, compared with three per cent and one per cent in non-long Covid patients, respectively. 

The researchers said it’s not possible to say whether problems like these are specific to Covid, or whether other hospital patients experience them.

Long Covid is defined as someone who still battles symptoms beyond four weeks in the UK.

It may be defined as ongoing Covid (four to 12 weeks), or post-Covid syndrome (more than 12 weeks) by medics.

The symptoms may include fatigue, a cough, breathlessness, muscle or joint pain, loss of taste of smell and brain fog.

Post Covid-19 complications: Skin issues, joint pain becoming increasingly common, say experts

People should seek good rehabilitative care, exercise every day, maintain good posture, and follow a healthy diet to manage joint and muscle pain

Authors: By: Lifestyle Desk | New Delhi |

The list of post-Covid complications seems to be only increasing with doctors now saying that there has also been an increase in skin conditions like herpes, and joint pains in patients

What is causing joint issues?

There is about four-five per cent increase in arthritis cases post Covid-19 infection, said Dr Narendra Vaidya, joint replacement surgeon and managing director, Lokmanya Hospital Pune.

“During Covid, inflammatory molecules break muscle protein and decrease its synthesis causing muscle fatigue; this also damages cartilage, causing arthritis. Arthritis can also arise as sequele of steroid and antiviral drugs used to treat Covid-19. Musculoskeletal symptoms like stiffness of joints, muscle pain are commonly seen in post-Covid patients along with decreased muscle strength. Many people complain of joint and muscle pain, and have also come with new onset of autoimmune arthritis,” he said.

According to Dr Vaidya, patients complain of joint pain or arthralgia, muscle pain or myalgia, extreme fatigue, reactive arthritis, and vasculitis (inflammation of the blood vessels). “Joint pain can be temporary or continue for months,” he said.

One more reason to develop joint pain could be the overdose of steroids or a faster. This might develop osteonecrosis of bones, leading to faster degeneration and joint pains, said Dr Richa Kulkarni, chief consulting physiotherapist, KINESIS – Sports Rehab and Physiotherapy Clinic, Pune.

How to prevent and treat the condition?

People should seek good rehabilitative care, exercise every day, maintain good posture, and follow a healthy diet to manage joint and muscle pain, said Dr Vaidya.

What are the skin conditions?

Covid has induced many autoimmune and dormant infections in people with low immunity, such as herpes and warts. “Treatment with monoclonal anti–TNF alpha antibodies can cause herpes. Since the beginning of the pandemic, many people reported herpes, joint pain, and even warts. These problems are commonly seen in females when compared to males. People come with complaints like skin rash, redness, shingles around eyes nose, lips. These infections are common among senior citizens, and pregnant women. Herpes and other skin complications are getting triggered in patients who have a previous history. Do not ignore any signs like rashes, redness of the skin, and patches, seek immediate medical attention,” said Dr Vishwajeet Chavan, orthopedic surgeon, Apollo Spectra Pune.

Dr Saurabh Shah, dermatologist at Bhatia Hospital Mumbai has been seeing about one case of herpes zoster (covid related) every week. “The reason could be low immunity since  Covid attacks the immune system of the body. Herpes Zoster (also known as shingles) virus (Varicella Zoster virus) is present in the body of almost every individual. When our immunity gets compromised or jeopardised, herpes zoster, which lies dormant in the body (dorsal nerve root ganglion), becomes active and flares up. Usually this skin infection is seen in patients with poorly controlled diabetes, patients with chronic renal failure, patients on chemotherapy, post medical and surgical illness and other diseases that compromise our immunity,” he explained.

There is also an uncanny increase in the incidence of urticaria in a lot of patients, said Dr Shah. “These rashes appear as itchy, red, evanescent raised areas on most parts of the body, usually after an infection (post-Covid). These invariably disappear in a few hours,” Dr Shah told indianexpress.com.

By: Lifestyle Desk | New Delhi |
Updated: February 21, 2022 4:22:15 pm

Multivariate profile and acute-phase correlates of cognitive deficits in a COVID-19 hospitalized cohort

Authors: AdamHampshireaDoris A.ChatfieldbAnne ManktelowMPhilbAmyJollyaWilliamTrenderaPeter J.HellyeraMartina DelGiovaneaVirginia F.J.NewcombebJoanne G. Outtrimb BenWarneb JunaidBhattid LindaPointond AnneElmere NyarieSitholebf JohnBradleybgh NathalieKingston lStephen J.Sawceri Edward T.Bullmorecdj…David K.Menonbck1

eClinicalMedicine

Volume 47, May 2022, 101417

Summary

Background

Preliminary evidence has highlighted a possible association between severe COVID-19 and persistent cognitive deficits. Further research is required to confirm this association, determine whether cognitive deficits relate to clinical features from the acute phase or to mental health status at the point of assessment, and quantify rate of recovery.

Methods

46 individuals who received critical care for COVID-19 at Addenbrooke’s hospital between 10th March 2020 and 31st July 2020 (16 mechanically ventilated) underwent detailed computerised cognitive assessment alongside scales measuring anxiety, depression and post-traumatic stress disorder under supervised conditions at a mean follow up of 6.0 (± 2.1) months following acute illness. Patient and matched control (N = 460) performances were transformed into standard deviation from expected scores, accounting for age and demographic factors using N = 66,008 normative datasets. Global accuracy and response time composites were calculated (G_SScore & G_RT). Linear modelling predicted composite score deficits from acute severity, mental-health status at assessment, and time from hospital admission. The pattern of deficits across tasks was qualitatively compared with normal age-related decline, and early-stage dementia.

Findings

COVID-19 survivors were less accurate (G_SScore=-0.53SDs) and slower (G_RT=+0.89SDs) in their responses than expected compared to their matched controls. Acute illness, but not chronic mental health, significantly predicted cognitive deviation from expected scores (G_SScore (p=​​0.0037) and G_RT (p = 0.0366)). The most prominent task associations with COVID-19 were for higher cognition and processing speed, which was qualitatively distinct from the profiles of normal ageing and dementia and similar in magnitude to the effects of ageing between 50 and 70 years of age. A trend towards reduced deficits with time from illness (r∼=0.15) did not reach statistical significance.

Interpretation

Cognitive deficits after severe COVID-19 relate most strongly to acute illness severity, persist long into the chronic phase, and recover slowly if at all, with a characteristic profile highlighting higher cognitive functions and processing speed.

Funding

This work was funded by the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre (BRC), NIHR Cambridge Clinical Research Facility (BRC-1215-20014), the Addenbrooke’s Charities Trust and NIHR COVID-19 BioResource RG9402. AH is funded by the UK Dementia Research Institute Care Research and Technology Centre and Imperial College London Biomedical Research Centre. ETB and DKM are supported by NIHR Senior Investigator awards. JBR is supported by the Wellcome Trust (220258) and Medical Research Council (SUAG/051 G101400). VFJN is funded by an Academy of Medical Sciences/ The Health Foundation Clinician Scientist Fellowship. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Evidence before this study

A PubMed search for articles using the terms ‘COVID-19′, ‘chronic’ and ‘cognitive impairment’ returns 85 results between 2020 and 2022, reflecting growing concern that people may suffer persistent cognitive problems after SARS-CoV-2 infection. However, most of these studies have built on either subjective report of cognitive problems or brief pen-and paper assessment scales that lack sensitivity to mild deficits and precision regarding affected cognitive domains.

Added value of this study

Using precision computerised cognitive assessment tools, we observed that 46 COVID-19 patients matched for age, gender, education and first language, 6–10 months after admission for care at Addenbrookes hospital perform less well than controls in terms of cognition. Critically, the scale of their cognitive deficits correlated with acute illness severity as recorded during the hospital stay, but not fatigue or mental health status at the time of cognitive assessment.

Implications of all the available evidence

These results suggest that the patients who have recovered from severe COVID-19 may need longer term support for cognitive deficits that persist into the chronic phase. More research is required to understand the basis of these deficits. Future work will be focused on mapping these cognitive deficits to underlying neural pathologies and inflammatory biomarkers, and to longitudinally track recovery into the chronic phase.

Introduction

There is growing evidence that COVID-19 can cause lasting cognitive and mental health problems. Recovered patients reporting psychological symptoms including fatigue, cognitive difficulties (“brain fog” and “problems finding the words”), sleep disturbances breathlessness and psychiatric disorders months after infection.1 In the UK alone, 13.7% of 20,000 individuals reported having symptoms inclusive of cognitive difficulties 12 weeks after a positive COVID-19 test (UK Office for National Statistics, April 2021). Mild cases can report persistent cognitive symptoms; however, prevalence is higher in severe cases,2 with ∼33–76% of patients suffering cognitive symptoms 3–6 months post hospitalisation.3,4

The neurobiological and psychological bases of these deficits remain unclear. Imaging biomarker studies indicate multiple likely candidates. Indeed, drawing parallels with serious acute respiratory syndrome (SARS), middle eastern respiratory syndrome (MERS) and post-critical illness/intensive care syndrome, a range of neurological/ central nervous system (CNS) complications can arise from infection.5,6 Most notably, encephalitis, ischaemia, haemorrhage, microstructural and functional changes and cerebrovascular disease (CVD) have been observed in COVID-19 patients, and more recently, evidence of brainstem inflammation using 7 Tesla magnetic resonance imaging (MRI) has been reported.7 There has been concern regarding whether cognitive deficits will remain for years as a chronic syndrome, and whether patients who develop CVD as a result of infection will experience neurodegeneration and dementia in the long-term,789 despite recovery of other acute and sub-acute symptoms.10

Key limitations for much of this early work include a reliance on self-report as opposed to objective assessment of cognitive deficits, the application of neuropsychological scales that lack sensitivity to detect subtle deficits in the formerly unimpaired or precision to differentiate deficits across cognitive domains, and uncertainty regarding longevity of deficits. Furthermore, depression, anxiety, fatigue and post-traumatic stress are elevated post COVID-19 illness,11 which might mediate the association with cognitive sequelae.

Recently, we provided preliminary results addressing some of these limitations. Specifically, we used computerised cognitive assessment technology,12,13 which has superior sensitivity and precision to gold-standard neuropsychological scales,14 to investigate objectively measurable deficits across multiple cognitive domains in a large online cohort15,16 that incidentally included people who reported infection with COVID-19 of varying severity.17 Higher cognitive functions such as spatial planning and analogical reasoning appeared to be disproportionately impaired, especially in hospitalised patients. However, our earlier analyses lacked clinical-record corroboration of self-reported illness severity or hospital treatment. Furthermore, participants primarily were in the early chronic phase ∼2–3 months post illness, which limited insight into the longevity of deficits.

Here, we use the same technology to assess patients at timepoints ranging from between ∼1 and 10 months post admission to hospital for severe COVID-19. We sought to determine whether (i) the finding of higher cognitive deficits after COVID-19 infection can be replicated in a hospital confirmed cohort, (ii) the cognitive deficits relate to features of acute illness vs. mood, anxiety, tiredness or post-traumatic stress disorder (PTSD) at the point of assessment, (iii) the deficits negatively correlate with time since illness and (iv) the scale and profile of deficits is qualitatively comparable to that observed in normal age-related decline or dementia.

Methods

Data collection

All patients admitted to Addenbrookes Hospital with COVID-19 between 10th March 2020 and 31st July 2020, who survived and consented to take part were eligible for this cohort study. This comprised 489 patients, of whom 49 were consented to the NIHR COVID-19 BioResource to participate in the study and were administered the follow up battery. The study was approved by the Cambridge Central Research Ethics Committee (17/EE/0025 0025 & IRAS ID: 220277). Of these, 46 patients (27 females, 19 males, age mean=51 years standard deviation (SD)=14 years, range 28–83 years) completed the study protocol adequately to allow analysis (Tables S1–3). Based on the effect size observed in our previous citizen science dataset,17 where people were assessed using the same technology, expected effect size for critically ill hospitalised patients would be >0.5 standard deviations. At n-46, power was sufficient to detect with one-tailed alpha at p < 0.05 a 0.5SD effect size difference as gauged by DfE scores from the linear model at 96% relative to zero and at 94% relative to the matched control group. There was statistical power of 95% to detect medium strength correlations of r = 0.50 at two tailed alpha p < 0.05. Participants completed a custom computerised cognitive assessment battery under supervised conditions via the Cognitron platform,17,18 comprising 8 tasks deployed on an iPad (Supplemental Methods), as well as standard mood, anxiety and post-traumatic stress scales, specifically, the Generalized Anxiety Disorder 7 (GAD-7),19 the Patient Health Questionnaire 9 (PHQ-9)20,21 and the PTSD Checklist for Diagnostic and Statistical Manual of Mental Disorders 5 (PCL-5)22 in a return visit to the hospital on average 179 days after illness onset (SD=62 inter-quartile range=81).

Statistical methods

All analyses were conducted in MATLAB R2020a. To enable correlation of deficit magnitude with clinical and mental health measures whilst accounting for population variables, accuracy and median reaction times were extracted for each task, comprising 16 measures (Table S4), were transformed to deviation from expected (DfE) scores (see below definition) relative to N = 66,008 normative datasets (Table S5), comprising individuals who had performed the same set of tasks. Specifically, to calculate DfE scores, linear models were trained to predict performance for each task within the normative dataset from age decade, sex (male, female, other), education level, handedness (left, right ambidextrous) and first language (English, other). The trained models were then applied to the patient demographics, to which they were naive, providing expected scores for each individual. DfE score was quantified as the difference between observed minus predicted score divided by the control standard deviation. Non-compliant individuals from the normative dataset already had been identified and removed based on responding unfeasibly fast given the response time distribution; applying the same threshold identified no non-compliant participants within the patient dataset. Four patients could not complete Verbal Analogies and one could not complete Spatial Planning as they found them too challenging. Control and patient datasets were concatenated, and composites were then calculated by taking the first unrotated principal component (Table S6) across the eight summary score measures (G_SScore), focused on accuracy, and across the eight response time scores (G_RT), focussing on speed of response. Component scores were calculated for each subject via regression of the component loadings matrix across the above measures, excluding any unavailable datapoints, and transformed to DfE score as described above. For further comparison, a set of matched controls was identified from within the normative database and processed in the same manner as the patients. Specifically, for each patient, ten unique control datasets were randomly selected who exactly matched them in terms of age decade, sex, handedness, first language and education level.

All statistical analyses applied a prior significance cut-off set to p < 0.05. T-tests, performed one-tailed with family wise error (FWE) correction for multiple comparisons, evaluated whether patient composite and individual task DfE scores were consistently poorer than expected relative to the matched normative group. Multiple regression determined whether G_SScore and G_RT DfE scores could be predicted from clinical features during the acute hospital stay or mental health measures at the time of assessment. Clinical features were World Health Organisation (WHO) COVID-19 severity score,23 highest C-reactive protein (CRP), mechanical ventilation, extrapulmonary support, days ventilated, tracheostomy, and highest D-dimer; as well as age, sex and time since illness. Mental health scores were the GAD7, PHQ9 and PCL5. Due to high correlations between some of these clinical features, the feature matrix was reduced by applying Principal Component Analysis with varimax rotation, where the number of components was defined according to the Kaiser convention of retaining components with eigenvalues >1. The relationship between G_SScore and G_RT to time since illness was further examined in isolation using bivariate correlations with one-tailed significance.

To qualitatively gauge whether the profile of COVID-19 related cognitive deficits was similar in pattern or scale to age-related decline, standard deviation differences were extracted from the normative models (that is, accounting for the other population variables listed above) for each task between people at ages aged 70–79 minus those 20–29 or 50–59 within the control dataset. For further qualitative comparison, performance data from a previously collected group of 28 early-mid stage dementia patients were submitted to the same DfE pipeline as described above and effect sizes plotted (clinical and demographic details provided in Table S7).

Role of the funding source

The funder of the study had no role in the design of the study, data collection, data analysis, interpretation or writing of the report. All authors had full access to all data within the study. The corresponding authors had final responsibility for the decision to submit for publication.

Results

T-tests of global summary score and response time composites (Figure 1a) confirmed that participants who had been hospitalised due to COVID-19 scored significantly lower and were slower in their responses than would be expected given the control population as gauged by DfE scores (G_SScore estimate=-0.538 SDs, t=-4.214 p < 0.0001; G_RT estimate=0.726SDs, t = 4.507, p < 0.0001). Repeating the analysis for the 43 chronic-phase patients >90 days post symptom onset showed a similar result (G_SScore estimate=-0.524 SDs, t=-3.875 p = 0.0004; G_RT estimate=0.715SDs, t = 4.194, p < 0.0001). Contrasting the DfE scores directly against 460 precisely matched individuals (Figure 2), 10 per patient, from the control database reinforced this observation (mean difference in G_SScore estimate=-0.525SDs, t=-4.327, p < 0.0001; mean difference in G_RT estimate=0.887SDs, t = 5.803, p < 0.0001).

Fig 1
Fig 2

Application of Principal Component Analysis to the matrix of clinical and mental health features identified three components with eigenvalues >1 capturing 74% of the variance (Figure 1b). After varimax rotation, Component 1 captured variance pertaining to general severity of acute illness, including heavy positive loadings from WHO COVID-19 severity score, highest CRP, and requirement for mechanical ventilation, extrapulmonary organ support and days ventilated, moderate positive loading with age and requirement of tracheostomy and moderate negative loading for days since illness. Component 2 had heavy positive loading of requirement for tracheostomy and days ventilated, moderate positive loading for highest D-dimer and mechanical ventilation and extrapulmonary support, and moderate negative loading for females vs. males and time from illness onset. Component 3 had heavy positive loadings for the three mental health scales.

Multiple regression of the component scores onto DfE performance composites (Figure 1c) showed a significant negative correlation between G_SScore and Component 1 (Estimate=-0.346, F(1,42)= 9.392 p = 0.00380), but not Component 2 (Estimate=0.140, F(1,42)=1.841 p = 0.18208) or Component 3 (Estimate=-0.153, F(1,42)=1.855 p = 0.18041). There was also a threshold level negative correlation between G_RT and Component 1 (Estimate=0.305, F(1,42)=4.008 p=​ 0.05178), but not Component 2 (Estimate=-0.177, F(1,42)=1.791 p = 0.21044) or Component 3 (Estimate=0.111, F(1,42)=0.592 p = 0.46861).

Bivariate correlations (Table S8) showed significant associations between G_SScore and Severity WHO COVID-19 ordinal scale, mechanical ventilation, extrapulmonary organ dysfunction support and highest CRP during admission at the one tailed uncorrected threshold. However, the hypothesised trends towards reduced underperformance over time were of small effect size and were statistically non-significant (G_SScore r = 0.15 p = 0.1542, G_RT r=-0.16 p = 0.1486 one tailed and uncorrected). Reanalysing the data focusing exclusively on either those who were or were not ventilated relative to their respective controls showed significant cognitive deficits in both sub-groups (Fig. S1 & Table S9).

Finally, DfE scores were examined at the individual task level. There was a broad pattern of reduced accuracy and slowed response compared to the 460 matched controls (Table 1Figure 2a), with multiple tasks surviving the p < 0.05 one-tailed and family wise error (FWE) corrected for multiple comparisons threshold. As predicted,17 underperformance was more substantial for tasks challenging higher cognitive functions such as Analogical Reasoning (score -0.85SDs RT +1.34SDs) and Spatial Planning (score +0.28SDs RT +0.89SDs), as well as 2D Manipulations (score -0.58SDs RT +0.57SD) and word recall (immediate score -0.43SDs RT +0.43SDs delayed score -0.051SDs RT +0.46SDs).

Table 1. T-tests contrasting patients vs. 460 matched controls (one-tailed and FWE corrected for multiple comparisons).

Empty CellEmpty CellEffect size (DfE)tp (corrected)
AccuracyVerbal analogies-0.854-6.205<0.00001
2D manipulation-0.575-4.2210.00026
Words immediate-0.432-2.8690.03863
Spatial span-0.405-3.6050.00309
Target detection-0.176-1.4501.32876
3D rotation-0.076-0.9962.87946
Words delayed-0.051-0.4585.82405
Spatial planning0.2831.5101.18614
LatencySpatial span0.2311.5431.11135
Words immediate0.4313.0350.02276
Target detection0.4442.5680.09468
Words delayed0.4632.9420.03070
2D manipulation0.5703.8790.00107
3D rotation0.6203.5220.00421
Spatial planning0.8884.7790.00002
Verbal analogies1.3377.018<0.00001
GlobalG_SScore-0.525-4.3270.00016
G_RT0.8875.803<0.00001

For comparison (Figure 2), the pattern of mean age-related differences in performance of people in their 70s minus 20s or 70s minus 50s was quite distinct, with age related differences being most pronounced for 2D Manipulations, Spatial Span and Target Detection as opposed to Spatial Planning or Verbal Analogies. Furthermore, the 28 dementia patients who undertook 6 of the tasks showed the greatest DfE score on the Word Memory task with notably higher effect size.

Discussion

Individuals who survive severe COVID-19 illness have objectively measurable cognitive deficits, lasting many months, with respect to age- and demographic-adjusted norms.17,24252627282930 Taking Cohen’s notion of effect sizes as a gauge, the scale of those deficits was large; on average the 0.52SD and 0.89SD levels of underperformance on global accuracy and response time composite measures span the medium to large effect size range. For individuals who required mechanical ventilation, both composites were in the large range at 0.90SDs and 1.0 SDs, respectively, which is somewhat larger than our previous online study using the same assessment tools.17 The deficits within specific cognitive domains were even greater, e.g., Verbal Analogies response times were 1.3SDs longer on average for all patients and 1.7SDs for those who had required mechanical ventilation. Notably, when analysing only those individuals for whom English was the native language, the same pattern of deficits was still evident. Furthermore, our analyses accounted for both first language and education level. These results accord with self-reported problems ‘finding words’31 and neuropsychological case studies indicating verbal fluency deficits in severe COVID-19 patients post recovery.32

By using a large pre-existing normative dataset to correct for normal population variability in cognitive performance, we were able to begin the process of disentangling potential contributors to cognitive deficits post COVID-19. In particular, measures of mood, post-traumatic stress and mental health at the point of assessment were sufficiently dissociable from acute illness severity to be evaluated within the predictor matrix. This distinction is critical, because it is now well established that people who have recovered from severe COVID-19 illness can have a broad spectrum of symptoms of poor mental health11 as do those suffering from Long Covid,1 which could conceivably contribute to both self-perceived and objectively measured cognitive deficits. These include problems with depression, anxiety post-traumatic stress, low motivation, fatigue, low mood, and disturbed sleep. Here, it was clearly the case that acute illness severity was the better predictor of objectively measurable global cognitive deficits during the chronic phase. At the level of individual clinical features, WHO COVID-19 severity score, highest CRP and the requirement for mechanical ventilation and multiple organ support were predictive of poorer cognitive performance.

All patients were recruited from the same hospital and following illness within a narrow timeframe, which given differences in patient treatment and virus variants across time limits our confidence when generalising these results. We believe that this limitation is somewhat mitigated by the concordance between the results presented here and our previous citizen science dataset, published in this journal.17 Nonetheless, future research should seek to determine the relationship between variants, treatment strategies and cognitive outcomes at larger scale.

Regarding how representative the cohort was, the recruited population were younger, and more frequently female, and with a higher proportion of critical care admissions (WHO Ordinal Scale >6) than those who came through the centre (Tables S10–S14). A significant proportion, though not all, of these differences is attributable to the mortality of 24% in the overall admitted population, since non-survivors were older (median age=80 inter quartile range =73–87), more often male (64%), and may have included patients in whom treatment limitation decisions may have been in place.

Our analysis of fatigue post COVID-19 illness was not in the original analysis plan. However, scores capturing self-report of fatigue in the months post illness were available for 38 patients (Tables S1–3) from the Post-Intensive Care Unit Presentation Screen, a brief functional screening tool to inform the rehabilitation needs after treatment in intensive care settings. 28 of them endorsed some level of fatigue. Fatigue score correlated robustly with the mental health composite score (r=-0.45 p = 0.005) but not with the acute illness composite score (r = 0.03 p = 0.852) or either of the cognitive composite scores (G_ACC r = 0.19 p = 0.240; G_RT r=-0.16 p = 0.343). These results indicate that although both fatigue and mental health are prominent chronic sequalae of COVID-19, their severity is likely to be somewhat independent from the observed cognitive deficits.

A further limitation was that the acute clinical features were too highly correlated with each other to dissociate. All but two of the participants requiring mechanical ventilation also required multiple organ support, and the requirement for mechanical ventilation correlated with highest CRP, a measure of inflammation, at r∼=0.8. The observed correlation with a marker of acute inflammation may reflect a causal relationship beyond the severity of respiratory problems; however, given the high correlation to other clinical features of the acute phase, work seeking to disentangle underlying clinical causes of the observed cognitive deficits will require either substantial sized cohorts with sufficient power to delineate highly correlated predictors or additional data types, such as brain imaging in order to detect associations with markers in specific types of neuropathology.

Some previous studies have observed significant recovery across time in terms of cognitive symptoms18 and imaging measures of brain function.33 In accordance with these studies, we did observe slow and non-significant trends towards reduced deficits in both accuracy and response latency as a function of time from illness. We conclude that any recovery in cognitive faculties is at best likely to be slow. It also is important to consider that trajectories of cognitive recovery may vary across individuals depending on illness severity and the neurological or psychological underpinnings, which are likely complex. Plotting recovery trajectories and untangling their multivariate relationships to clinical features will require multi-timepoint studies in larger cohorts.

At a finer multivariate grain, the profile of deficits replicates our previous report in an online cohort of disproportionate underperformance within certain cognitive domains. In concordance with a previous large scale online study this pattern includes tasks designed to assess performance accuracy of attention, memory, difficult word-based reasoning and planning.17 However, we also observed slowed processing speed. On a neurological level, this pattern of impairment aligns with the observation of sub-acute phase hypometabolism within frontoparietal systems after COVID-19 illness26 that are known to be recruited in different combinations and configurations during the performance of these tasks.12,13,34

In this latter respect, the application of an assessment battery that provides a dimensional profile spanning multiple cognitive domains is of value when offering interoperability across studies. Indeed, it was informative to note that this profile of cognitive dysfunction was quite distinct to the normal pattern of age-related decline and to the pattern of deficits observed in early-stage dementia patients. On average, the scale of deficits was most similar to that observed in normal cognitive decline between the ages of 50–70; however, when examined in more detail the pattern of cognitive deficits was most pronounced for different tasks than either age-related decline or the dementia group. These more detailed results highlight the potential value of cross comparing multivariate profile of COVID-19 cognitive deficits to a wider variety of populations in order to identify potential similarities to other neurological conditions. Future work should also expand the repertoire of disorders, especially populations who have recovered from other critical illnesses, and cross relate these detailed cognitive profiles to imaging and blood biomarker measures of neuropathology and tracking recovery and decline trajectories over a longer temporal scale.

In summary, severe COVID-19 illness is associated with significant objectively measurable cognitive deficits that persist into the chronic phase. The scale of the deficits correlates with clinical severity during the acute phase as opposed to mental health status at the time of assessment, shows at best a slow recovery trajectory and the multivariate profile of deficits is consistent with higher cognitive dysfunction as opposed to accelerated ageing or dementia.

Funding

This work was funded by the National Institute for Health Research (NIHR) Cambridge Biomedical Research Centre (BRC), NIHR Cambridge Clinical Research Facility (BRC-1215-20014), the Addenbrooke’s Charities Trust and NIHR COVID-19 BioResource RG9402. AH is funded by the UK Dementia Research Institute Care Research and Technology Centre and Imperial College London Biomedical Research Centre. ETB and DKM are supported by NIHR Senior Investigator awards. JBR is supported by the Wellcome Trust (220258) and Medical Research Council (SUAG/051 G101400). VFJN is funded by an Academy of Medical Sciences/ The Health Foundation Clinician Scientist Fellowship. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Contributors

AH and DKM had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Concept and design: AH, JB, ETB, JBR, DKM

Acquisition, analysis, or interpretation of data: AH, DAC, AM, AJ, WT, PH, MDG, VFJN, JGG, JB, LP, AE, NS, JB, NK, SJS, DKM.

Drafting of the manuscript: AH.

Critical revision of the manuscript for important intellectual content: All authors.

Statistical analysis: AH.

Obtained funding: JB, JBR, ETB, DKM.

Supervision: AH, ETB, JBR, DKM.

Data sharing statement

Requests for data should directed to the corresponding authors. Data will be available upon reasonable request.

Declaration of Interests

Dr. Hampshire reports grants from UK Dementia Research Institute, grants from NIHR Imperial Biomedical Research Centre, and grants from NIHR, outside the submitted work; and is Co-director and owner of H2 Cognitive Designs Ltd and director and owner of Future Cognition Ltd, which support online cognitive studies and develop custom cognitive assessment software, respectively. Ms. Chatfield has nothing to disclose. Ms. Manktelow has nothing to disclose. Dr. Jolly has nothing to disclose. Mr. Trender has nothing to disclose. Dr. Hellyer reports being Chief Executive of H2 Cognitive Designs LTD, which provides a platform for online cognitive tests for remote assessment and receives remuneration for role. Ms. Del Giovane has nothing to disclose. Dr. Newcombe reports grants from Academy of Medical Sciences / The Health Foundation Clinician Scientist Fellowship during the conduct of the study. Ms. Outrim has nothing to disclose. Mr. Warne has nothing to disclose. Mr. Bhatti has nothing to disclose. Ms. Pointon has nothing to declare. Ms. Elmer has nothing to disclose. Dr. Sithole has nothing to disclose. Dr. Bradley reports grants from Funding for NIHR BioResource (IS-BRC-1215-20014) during the conduct of the study. Dr. Kingston has nothing to disclose. Dr. Sawcer has nothing to disclose. Dr. Bullmore reports personal fees from GlaxoSmithKline, personal fees from Sosei Heptares, outside the submitted work; and is Honorary Treasurer and member of Council for the Academy of Medical Sciences. Dr. Rowe reports grants from Wellcome Trust, grants from NIHR, grants from Medical Research Council, during the conduct of the study. Dr. Menon reports grants from Lantmannen AB, grants from GlaxoSmithKline Ltd, personal fees from Calico LLC, personal fees from GlaxoSmithKline Ltd, personal fees from Lantmannen AB, other from Integra Neurosciences, outside the submitted work; and reports leadership and fiduciary roles for Queens’ College, Cambridge, Intensive Care National Audit and Research Centre, London, and European Brain Injury Consortium.

Acknowledgments

We thank NIHR BioResource volunteers for their participation, and gratefully acknowledge NIHR BioResource centres, NHS Trusts and staff for their contribution. We thank the National Institute for Health Research, NHS Blood and Transplant, and Health Data Research UK as part of the Digital Innovation Hub Programme. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

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References

1A. Nalbandian, K. Sehgal, A. Gupta, et al.Post-acute COVID-19 syndromeNat Med, 27 (4) (2021), pp. 601-615 View PDFCrossRefView Record in ScopusGoogle Scholar2D. Huang, X. Lian, F. Song, et al.Clinical features of severe patients infected with 2019 novel coronavirus: a systematic review and meta-analysisAnn Transl Med, 8 (9) (2020), p. 576 View PDFCrossRefView Record in ScopusGoogle Scholar3C. Huang, Y. Wang, X. Li, et al.Clinical features of patients infected with 2019 novel coronavirus in Wuhan, ChinaLancet, 395 (10223) (2020), pp. 497-506ArticleDownload PDFGoogle Scholar4V. Chopra, S.A. Flanders, M. O’Malley, A.N. Malani, H.C. PrescottSixty-day outcomes among patients hospitalized with COVID-19Ann Intern Med, 174 (4) (2021), pp. 576-578 View PDFCrossRefView Record in ScopusGoogle Scholar5S. Inoue, J. Hatakeyama, Y. Kondo, et al.Post-intensive care syndrome: its pathophysiology, prevention, and future directionsAcute Med Surg, 6 (3) (2019), pp. 233-246 View PDFCrossRefView Record in ScopusGoogle Scholar6M.H. Lam, Y.K. Wing, M.W. Yu, et al.Mental morbidities and chronic fatigue in severe acute respiratory syndrome survivors: long-term follow-upArch Intern Med, 169 (22) (2009), pp. 2142-2147 View PDFCrossRefView Record in ScopusGoogle Scholar7S. Miners, P.G. Kehoe, S. LoveCognitive impact of COVID-19: looking beyond the short termAlzheimers Res Ther, 12 (1) (2020), p. 170View Record in ScopusGoogle Scholar8D. Bougakov, K. Podell, E. GoldbergMultiple neuroinvasive pathways in COVID-19Mol Neurobiol, 58 (2) (2021), pp. 564-575 View PDFCrossRefView Record in ScopusGoogle Scholar9E. Goldberg, K. Podell, D.K. Sodickson, E. FieremansThe brain after COVID-19: compensatory neurogenesis or persistent neuroinflammation?EClinicalMedicine, 31 (2021), Article 100684ArticleDownload PDFView Record in ScopusGoogle Scholar10L.A. Jason, M.F. Islam, K. Conroy, et al.COVID-19 symptoms over time: comparing long-haulers to ME/CFSFatigue Biomed Health Behav (2021)Google Scholar11S.R. Chamberlain, J.E. Grant, W. Trender, P. Hellyer, A. HampshirePost-traumatic stress disorder symptoms in COVID-19 survivors: online population surveyBJPsych Open, 7 (2) (2021), p. e47View Record in ScopusGoogle Scholar12E. Soreq, I.R. Violante, R.E. Daws, A. HampshireNeuroimaging evidence for a network sampling theory of individual differences in human intelligence test performanceNat Commun, 12 (1) (2021), p. 2072View Record in ScopusGoogle Scholar13A. Hampshire, R.R. Highfield, B.L. Parkin, A.M. OwenFractionating human intelligenceNeuron, 76 (6) (2012), pp. 1225-1237ArticleDownload PDFView Record in ScopusGoogle Scholar14H. Brooker, G. Williams, A. Hampshire, et al.FLAME: a computerized neuropsychological composite for trials in early dementiaAlzheimers Dement, 12 (1) (2020), p. e12098(Amst)View Record in ScopusGoogle Scholar15Hampshire A. Great British intelligence test protocol. Research Square. 2020.Google Scholar16A. Hampshire, P.J. Hellyer, E. Soreq, et al.Associations between dimensions of behaviour, personality traits, and mental-health during the COVID-19 pandemic in the United KingdomNat Commun, 12 (1) (2021), p. 4111View Record in ScopusGoogle Scholar17A. Hampshire, W. Trender, S.R. Chamberlain, et al.Cognitive deficits in people who have recovered from COVID-19EClinicalMedicine (2021), Article 101044ArticleDownload PDFView Record in ScopusGoogle Scholar18Zhao S, Shibata K, Hellyer PJ. et al. Rapid vigilance and episodic memory decrements in COVID-19 survivors. medrXiv 2021.Google Scholar19R.L. Spitzer, K. Kroenke, J.B. Williams, B. LoweA brief measure for assessing generalized anxiety disorder: the GAD-7Arch Intern Med, 166 (10) (2006), pp. 1092-1097 View PDFCrossRefView Record in ScopusGoogle Scholar20K. Kroenke, R.L. Spitzer, J.B. Williams, B. LoweThe patient health questionnaire somatic, anxiety, and depressive symptom scales: a systematic reviewGen Hosp Psychiatry, 32 (4) (2010), pp. 345-359ArticleDownload PDFView Record in ScopusGoogle Scholar21R.L. Spitzer, K. Kroenke, J.B. WilliamsValidation and utility of a self-report version of PRIME-MD: the PHQ primary care study. Primary care evaluation of mental disorders. Patient health questionnaireJAMA, 282 (18) (1999), pp. 1737-1744Google Scholar22C.A. Blevins, F.W. Weathers, M.T. Davis, T.K. Witte, J.L. DominoThe posttraumatic stress disorder checklist for DSM-5 (PCL-5): development and initial psychometric evaluationJ Trauma Stress, 28 (6) (2015), pp. 489-498 View PDFCrossRefGoogle Scholar23WHO Working Group on the Clinical Characterisation and Management of COVID-19 infectionA minimal common outcome measure set for COVID-19 clinical researchLancet Infect Dis, 20 (8) (2020), p. e192-e7Google Scholar24V. Beaud, S. Crottaz-Herbette, V. Dunet, et al.Pattern of cognitive deficits in severe COVID-19J Neurol Neurosurg Psychiatry, 92 (5) (2021), pp. 567-568 View PDFCrossRefView Record in ScopusGoogle Scholar25J. Hellmuth, T.A. Barnett, B.M. Asken, et al.Persistent COVID-19-associated neurocognitive symptoms in non-hospitalized patientsJ Neurovirol, 27 (1) (2021), pp. 191-195 View PDFCrossRefView Record in ScopusGoogle Scholar26J.A. Hosp, A. Dressing, G. Blazhenets, et al.Cognitive impairment and altered cerebral glucose metabolism in the subacute stage of COVID-19Brain, 144 (4) (2021), pp. 1263-1276 View PDFCrossRefView Record in ScopusGoogle Scholar27A. Jaywant, W.M. Vanderlind, G.S. Alexopoulos, C.B. Fridman, R.H. Perlis, F.M. GunningFrequency and profile of objective cognitive deficits in hospitalized patients recovering from COVID-19Neuropsychopharmacology (2021)Google Scholar28K.W. Miskowiak, S. Johnsen, S.M. Sattler, et al.Cognitive impairments four months after COVID-19 hospital discharge: pattern, severity and association with illness variablesEur Neuropsychopharmacol, 46 (2021), pp. 39-48ArticleDownload PDFView Record in ScopusGoogle Scholar29B. Raman, M.P. Cassar, E.M. Tunnicliffe, et al.Medium-term effects of SARS-CoV-2 infection on multiple vital organs, exercise capacity, cognition, quality of life and mental health, post-hospital dischargeEClinicalMedicine, 31 (2021), Article 100683ArticleDownload PDFView Record in ScopusGoogle Scholar30M.S. Woo, J. Malsy, J. Pottgen, et al.Frequent neurocognitive deficits after recovery from mild COVID-19Brain Commun, 2 (2) (2020), p. fcaa205View Record in ScopusGoogle Scholar31J. Seessle, T. Waterboer, T. Hippchen, et al.Persistent symptoms in adult patients one year after COVID-19: a prospective cohort studyClin Infect Dis (2021)Google Scholar32D.M. Whiteside, V. Oleynick, E. Holker, E.J. Waldron, J. Porter, M. KasprzakNeurocognitive deficits in severe COVID-19 infection: case series and proposed modelClin Neuropsychol, 35 (4) (2021), pp. 799-818 View PDFCrossRefView Record in ScopusGoogle Scholar33G. Blazhenets, N. Schroeter, T. Bormann, et al.Slow but evident recovery from neocortical dysfunction and cognitive impairment in a series of chronic COVID-19 patientsJ Nucl Med, 62 (7) (2021), pp. 910-915 View PDFCrossRefView Record in ScopusGoogle Scholar34A.E. Jolly, G.T. Scott, D.J. Sharp, A.H. HampshireDistinct patterns of structural damage underlie working memory and reasoning deficits after traumatic brain injuryBrain, 143 (4) (2020), pp. 1158-1176 View PDFCrossRefView Record in ScopusGoogle Scholar

COVID-19 infection could age brain by 20 years, lower IQ significantly

Authors: Chris Melore Study Finds May 3, 2022

A severe coronavirus infection could leave patients with the brain of a 70-year-old, lowering someone’s IQ by 10 points, according to a new study. Researchers from the University of Cambridge and Imperial College London found that COVID patients are dealing with levels of cognitive impairment which are similar to the decline a healthy person sees between the ages of 50 and 70. Disturbingly, the team warns that this damage may never fully heal.

Long-term cognitive and mental health problems have been a growing issue during the pandemic. Even after the infection passes, a large number of patients continue to experience “brain fog,” problems recalling words, sleep issues, PTSD, and dozens of other symptoms for months — a condition doctors call long COVID. A recent study found that up to six in 10 recovering patients develop long COVID.

Even a mild case of the virus can lead to lingering cognitive issues. Study authors say as many as three-quarters of hospitalized COVID patients could suffer from some level of brain damage and cognitive decline.

Brain aging 20 years — in 6 months

Their new study examined 46 coronavirus patients entering the hospital or an intensive care unit between March and July 2020. Sixteen of these individuals ended up needing mechanical ventilation due to severe infection.

Six months later, the team conducted a series of computerized cognitive tests using the Cognitron platform. The system measures different aspects of brain health, including memory, attention, and reasoning skills. Researchers also examined each person’s levels of anxiety, depression, and PTSD following their infection.

In comparison to over 66,000 healthy people from the general public, results show severe COVID patients were less accurate and had slower response times on cognitive tests. These deficits were even worse among patients needing ventilation while in the hospital.

Estimates show that the damage from a COVID-19 infection led to the same amount of cognitive decline that the average person sees after 20 years of aging — between ages 50 and 70. That’s also the equivalent of losing 10 IQ points during their illness and the months following.

Specifically, COVID survivors did poorly on tasks involving verbal analogical reasoning — which translates to problems with finding the right words in conversation. The patients also displayed slower processing speeds, which the team says connects to the decreases in brain glucose consumption within the frontoparietal network of the brain doctors are seeing during the pandemic. This area of the brain controls a person’s attention span and complex problem-solving skills. It’s also important to their working memory.

“Cognitive impairment is common to a wide range of neurological disorders, including dementia, and even routine ageing, but the patterns we saw – the cognitive ‘fingerprint’ of COVID-19 – was distinct from all of these,” Professor David Menon says in a university release.

Some COVID-19 patients will ‘never fully recover’

Although studies continue to find ties between long COVID and lingering mental health issues, the study authors say they’ve discovered a clearer link between the severity of someone’s infection and cognitive decline. Concerningly, the team found that patients are only gaining some of these skills back over time.

“We followed some patients up as late as ten months after their acute infection, so were able to see a very slow improvement. While this was not statistically significant, it is at least heading in the right direction, but it is very possible that some of these individuals will never fully recover,” Prof. Menon adds.

As for what’s causing COVID to take such a toll on the human brain, researchers say there are a number of possibilities. COVID could be directly infecting the brain, but the team notes this is not a major cause. It’s more likely that a combination of inadequate oxygen or blood supply to the brain, blood clots, and microscopic bleeds are all contributing to the brain damage in coronavirus patients.

There is also growing evidence that COVID-19 produces inflammation which is similar to what people experience while developing Alzheimer’s disease.

“Around 40,000 people have been through intensive care with COVID-19 in England alone and many more will have been very sick, but not admitted to hospital. This means there is a large number of people out there still experiencing problems with cognition many months later. We urgently need to look at what can be done to help these people,” concludes Professor Adam Hampshire from the Department of Brain Sciences at Imperial College London.

The study is published in the journal eClinicalMedicine.The contents of this website do not constitute advice and are provided for informational purposes only.

Extensive thrombosis after COVID-19 vaccine: cause or coincidence

Authors: Luís Lourenço Graça ,1 Maria João Amaral ,2 Marco Serôdio,3 Beatriz Costa2

SUMMARY
A 62-year-old Caucasian female patient presented with abdominal pain, vomiting and fever 1 day after administration of COVID-19 vaccine. Bloodwork revealed anaemia and thrombocytosis. Abdominal CT angiography showed a mural thrombus at the emergence of the coeliac trunk, hepatic and splenic arteries, and extensive thrombosis of the superior and inferior mesenteric veins, splenic and portal veins, and the inferior vena cava, extending to the
left common iliac vein. The spleen displayed extensive areas of infarction. Etiological investigation included assessment of congenital coagulation disorders and acquired causes with no relevant findings. Administration of COVID-19 vaccine was considered a possible cause of the extensive multifocal thrombosis. After reviewing relevant literature, it was considered
that other causes of this event should be further investigated. Thrombosis associated with COVID-19vaccine is rare and an etiological relationship should only be considered in the appropriate context and after investigation of other, more frequent, causes.

BACKGROUND
During the COVID-19 pandemic, the pharmaceutical industry is under immense pressure to develop effective and safe vaccines, and as such clinical trials have been expedited in order to make them available to help fight this health crisis. In this context, timely communication between healthcare institutions and regulatory entities is especially important. Reports of thrombosis due to administration of these vaccines have been causing an important
discussion in the scientific community as well as social alarm. However, it is important to note that this is a rare complication and more frequent causes of extensive arterial and venous thrombosis should be considered and investigated.1

CASE PRESENTATION
A 62-year-old Caucasian female patient, with personal history of obesity (body mass index of
30kg/m2), asthma and rhinitis, presented to the emergency department with abdominal pain,
nausea, vomiting and fever (38°C) 1day after administration of the first dose of COVID-19 vaccine(from AstraZeneca). On physical examination, she presented epigastric and left iliac fossa tenderness as the only abnormal finding. The patient denied recent epistaxis and gastrointestinal or genitourinary blood loss.

INVESTIGATIONS
Blood tests revealed microcytic hypochromic anemia (hemoglobin 7g/L), thrombocytosis (780×109/L),increased levels of inflammatory parameters (leucocytes 13×109/L; C reactive protein 31.07mg/dL) and slightly increased levels of liver enzymes and function (AST 36, ALP 126U/L, GGT 72U/L, LDH 441U/L, total bilirubin 1.3mg/dL, direct bilirubin 0.5mg/dL). The patient was tested for COVID-19 with nasopharyngeal PCR tests at admission and on the fifth day of hospitalization. Both tests were negative. Abdominal CT angiography (CTA) showed a mural thrombus at the emergence of the coeliac trunk, with total occlusion (figure 1), as well as at the hepatic and splenic arteries. There was also extensive thrombosis of the superior and inferior mesenteric veins and its tributaries, splenic and portal veins, including the splenoportal confluent (figure 2). There was a filiform thrombus at the distal portion of the inferior vena cava, extending to the left common iliac vein, non-occlusive (figure 3). Spleen presented extensive areas of infarction (figure 1). Coeliac trunk occlusion due to paradoxical embolism was excluded by transthoracic echocardiogram. No interatrial communication was detected. Re-evaluation CTA 5days after the diagnosis was identical. Etiological investigation included assessment of congenital coagulation disorders and acquired causes. Regarding congenital disorders, personal and family history of important thrombotic events, thrombosis in unusual sites and abortions were assessed with no relevant findings. Molecular testing for factor V Leiden mutation and prothrombin gene20210 G/A mutation were both negative. Acquired causes of a coagulation disorder, such as neoplastic, infectious and autoimmune disorders, like antiphospholipid syndrome (APS), were also investigated. Thorax, abdomen, pelvic and brain CT did not detect any suspicious lesions. Tumor biomarkers—carcinoembryonic antigen, alpha fetoprotein, carbohydrate antigen 19-9, cancer antigen 125, cancer antigen 15-3, neuron-specific enolase and chromogranin A—were negative. The patient refused to undergo upper digestive endoscopy and colonoscopy. Despite increased levels of inflammatory parameters at admission (leukocytosis and C reactive protein), these values decreased during the hospitalization period. Blood and urine cultures were also negative. Anticardiolipin IgG and IgM and antibeta-2-glycoprotein IgG and IgM were negative, excluding APS.

DIFFERENTIAL DIAGNOSIS
In the presence of venous and arterial thrombosis, the etiological investigation should include

assessment of congenital and acquired coagulation disorders, as well as the presence of interatrial communication that could explain the coeliac trunk occlusion due to paradoxical embolism. As previously stated, these etiological factors were assessed with no specific findings, with the exception of digestive endoscopic study, which was refused by the patient. In this context, and given the fact that the presentation took place 1day after administration of the first dose of COVID-19 vaccine, we hypothesize that the vaccine might be the cause of the extensive arterial and venous thrombosis. This case was immediately reported to INFARMED, the Portuguese authority for drugs and health products. Vaccine-induced thrombotic thrombocytopenia (VITT) was also considered a differential diagnosis. However, the patient did
not present with thrombocytopenia, which is a key criteria for VITT, and therefore the presence of this syndrome was unlikely.COVID-19 tests at admission and on the fifth day of hospitalization were negative; however, she was not tested prior to the onset of the event and therefore it was not possible to exclude

recent COVID-19 infection, which may predispose to thrombosis, even during the convalescent phase.
TREATMENT
At presentation, there were no signs of organ ischemia that required revascularization procedure or intestinal resection. Considering the anemia, the patient was not a candidate for
fibrinolysis. The treatment was empiric endovenous antibiotherapy and transfusion of two units of red blood cells. Anticoagulation with low molecular weight heparin (LMWH) 1mg/kg
two times per day was initiated and maintained during hospitalisation, with monitoring of anti-Xa levels. After hospitalization,in an outpatient setting, the patient was initiated on edoxaban.

OUTCOME AND FOLLOW-UP
Re-evaluation CTA 28 days after presentation revealed a portal vein with a filiform caliber, with a cavernomatous transformation. There was only permeability of the left branch of the portal
vein, with venous collateralization in the hepatic hilum. Coeliac trunk was still occluded, with permeability of the gastroduodenal artery and the right hepatic artery, and apparent occlusion at the emergence of the left hepatic artery, although with distal repermeabilisation. Partial thrombus persisted in the lumen of the left common iliac vein and inferior infrarenal vena cava. At the follow-up consultation, 1month after discharge, the patient was clinically asymptomatic.

DISCUSSION
Venous and arterial thrombotic disorders have long been considered separate pathophysiological entities due to their anatomical differences and distinct clinical presentations. In particular, arterial thrombosis is seen largely as a phenomenon of platelet
activation, whereas venous thrombosis is mostly a matter of activation of the clotting system.2
There is increasing evidence regarding a link between venous and arterial thromboses. These two vascular complications share several risk factors, such as age, obesity, diabetes mellitus, blood Figure 1 CT angiography arterial phase, axial image: a mural thrombus is observed at the coeliac trunk emergence, with total occlusion. Splenic parenchyma without enhancement after contrast administration can also be observed, translating to extensive infarct areas.
Figure 2 CT angiography portal phase, coronal image: portal vein thrombosis (A) extending to the splenoportal confluent (B) can be observed. Figure 3 CT angiography portal phase, coronal image: a non-occlusive filiform thrombus at the distal portion of the inferior vena cava can be observed, extending to the left common iliac vein. on April 13, 2022 by guest. Protected by copyright. http://casereports.bmj.com/ BMJ Case Rep: first published as 10.1136/bcr-2021-244878 on 16 August 2021. Downloaded from Graça LL, et al. BMJ Case Rep 2021;14:e244878. doi:10.1136/bcr-2021-244878 3

Case report hypertension, hypertriglyceridaemia and metabolic syndrome.3 Moreover, there are many examples of conditions accounting for both venous and arterial thromboses, such as APS, hyperhomocysteinaemia, malignancies, infections and use of hormonal treatment.3 In this case, in accordance with the literature, the patient is 62 years old and obese, with no other findings. Hyperhomocysteinaemia and digestive tract malignancies were not excluded. Recent studies have shown that patients with venous thromboembolism are at a higher risk of arterial thrombotic complications than matched control individuals. Therefore, it is speculated that
the two vascular complications may be simultaneously triggered by biological stimuli responsible for activating coagulation and inflammatory pathways in both the arterial and the venous system.3 The modified adenovirus vector COVID-19 vaccines (ChAdOx1nCoV-19 by Oxford/AstraZeneca and Ad26.COV2.S by Johnson & Johnson/Janssen) and mRNA-based COVID-19 vaccines(BNT162b2 mRNA by Pfizer/BioNTech and mRNA-1273 by Moderna) have shown both safety and efficacy against COVID-19 in phase III clinical trials and are now being used in global vaccination programmes.4Rare cases of postvaccine-associated cerebral venous thrombosis(CVT) from use of COVID-19 vaccines which use a viral vector, including the mechanism of VITT, have emerged in real-worldvaccination.4 On the other hand, the incidence and pathogenesis of CVT after mRNA COVID-19 vaccines remain unknown. However Fan et al4
presented three cases and Dias et al5reported two cases of CVT in patients who took an mRNA vaccine (BNT162b2 mRNA by Pfizer/BioNTech). In both cases, causality has not been proven.
In a recent editorial, three independent descriptions of persons with a newly described syndrome, VITT, were highlighted, characterized by thrombosis and thrombocytopenia that developed 5–24 days after initial vaccination with ChAdOx1 nCoV-19 (AstraZeneca), a recombinant adenoviral vector encoding the spike protein of SARS-CoV-2.6VITT is also characterized by the presence of CVT, thrombosis in the portal, splanchnic and hepatic veins, as well as acute arterial thromboses, platelet counts of 20–30×109 /L, high levels of D-dimers and low levels of fibrinogen, suggesting systemic activation of coagulation.6 In our case, similarities were found with VITT regarding thrombosis in the portal, splanchnic and hepatic veins, as well as acute arterial thromboses and high levels of D-dimers. On the other hand, timing of the event (1day after vaccination), high levels of fibrinogen and absence of thrombocytopenia, which is a key criteria for VITT, point to a different direction. Moreover, the
presence of thrombocytosis allowed for a safe use of LMWH for anticoagulation, with monitoring of anti-Xa levels. Most of the cases reported so far of venous and arterial thrombosis as a complication of AstraZeneca’s COVID-19 vaccine have occurred in women under the age of 60 years, associated with thrombocytopenia, within 2weeks of receiving their first dose of the vaccine.7As for the mechanism, it is thought that the vaccine may trigger an immune response leading to an atypical heparin-induced thrombocytopenia-like disorder. In contrast with the literature, our patient presented with thrombocytosis, not thrombocytopaenia.7 Smadja et al8reported that between 13 December 2020 and
16 March 2021 (94 days), 361734967 people in the international COVID-19 vaccination data set received vaccination and795 venous and 1374 arterial thrombotic events were reported in
Vigibase on 16 March 2021. Spontaneous reports of thrombotic events are shared in 1197 for Pfizer/BioNtech’s COVID-19 vaccine,325 for Moderna’s COVID-19 vaccine and 639 for AstraZeneca’sCOVID-19 vaccine.7 The reporting rate for cases of venous (VTE) and arterial (ATE) thrombotic events during this time period among the total number of people vaccinated was 0.21 cases of thrombotic events per 1million person vaccinated-days.7For VTE and ATE, the rates were 0.075 and 0.13 cases per 1million persons vaccinated, respectively, and the timeframe between vaccinationand ATE is the same for the three vaccines (median of 2days),
although a significant difference in terms of VTE was identified between AstraZeneca’s COVID-19 vaccine (median of 6days) and both mRNA vaccines (median of 4days).8 The first paper addressing this issue was published in the New England Journal of Medicine and described 11 patients, 9 of themwomen.9 Nine patients had cerebral venous thrombosis, three had
splanchnic vein thrombosis, three had pulmonary embolism and four had other thromboses. All 11 patients, as well as another 17 for whom the researchers had blood samples, tested positive for antibodies against platelet factor 4 (PF4). These antibodies are also observed in people who develop heparin-induced thrombocytopenia. However, none of the patients had received heparin before their symptoms started.9Our patient did not present thrombocytopenia, so anti-PF4 antibodies were not tested. Thus, considering the anemia, thrombocytosis and thrombosis diagnosed 1day after the first dose ofCOVID-19 vaccine, it seems prudent to continue investigation for other causes of this event, such as hematological malignancies or others.

REFERENCES
1 Burch J, Enofe I. Acute mesenteric ischaemia secondary to portal, splenic and superior
mesenteric vein thrombosis. BMJ Case Rep 2019;12:e230145.
2 Singer DE, Albers GW, Dalen JE, et al. Antithrombotic therapy in atrial fibrillation:
American College of chest physicians evidence-based clinical practice guidelines (8th
edition). Chest 2008;133:546S–92.
3 Ageno W, Becattini C, Brighton T, et al. Cardiovascular risk factors and venous
thromboembolism: a meta-analysis. Circulation 2008;117:93–102.
4 Fan BE, Shen JY, Lim XR, et al. Cerebral venous thrombosis post BNT162b2 mRNA
SARS-CoV-2 vaccination: a black Swan event. Am J Hematol 2021. doi:10.1002/
ajh.26272. [Epub ahead of print: 16 Jun 2021].
5 Dias L, Soares-Dos-Reis R, Meira J, et al. Cerebral venous thrombosis after BNT162b2
mRNA SARS-CoV-2 vaccine. J Stroke Cerebrovasc Dis 2021;30:105906.
6 Cines DB, Bussel JB. SARS-CoV-2 vaccine-induced immune thrombotic
thrombocytopenia. N Engl J Med 2021;384:2254–6.
7 AstraZeneca’s COVID-19 vaccine: EMA finds possible link to very rare cases of unusual
blood clots with low blood platelets. Available: https://www.ema.europa.eu/en/news/
astrazenecas-covid-19-vaccine-ema-finds-possible-link-very-rare-cases-unusual-bloodclots-low-blood [Accessed Apr 2021].
8 Smadja DM, Yue Q-Y, Chocron R, et al. Vaccination against COVID-19: insight from
arterial and venous thrombosis occurrence using data from VigiBase. Eur Respir J
2021;58:2100956.
9 Wise J. Covid-19: rare immune response may cause clots after AstraZeneca vaccine, say
researchers. BMJ 2021;373:n954.

Intestinal Damage in COVID-19: SARS-CoV-2 Infection and Intestinal Thrombosis

Authors: Xiaoming Wu1Haijiao Jing1Chengyue Wang1Yufeng Wang1Nan Zuo1Tao Jiang2*Valerie A. Novakovic3 and Jialan Shi1,3,4* Front. Microbiol., 22 March 2022 | https://doi.org/10.3389/fmicb.2022.860931

The intestinal tract, with high expression of angiotensin-converting enzyme 2 (ACE2), is a major site of extrapulmonary infection in COVID-19. During pulmonary infection, the virus enters the bloodstream forming viremia, which infects and damages extrapulmonary organs. Uncontrolled viral infection induces cytokine storm and promotes a hypercoagulable state, leading to systemic microthrombi. Both viral infection and microthrombi can damage the gut–blood barrier, resulting in malabsorption, malnutrition, and intestinal flora entering the blood, ultimately increasing disease severity and mortality. Early prophylactic antithrombotic therapy can prevent these damages, thereby reducing mortality. In this review, we discuss the effects of SARS-CoV-2 infection and intestinal thrombosis on intestinal injury and disease severity, as well as corresponding treatment strategies.

Introduction

COVID-19 has become a worldwide pandemic causing widespread illness and mortality. SARS-CoV-2 mainly infects the respiratory tract through attachment to angiotensin-converting enzyme 2 (ACE2) receptors (Lan et al., 2020). ACE2 is also highly expressed on intestinal epithelial cells, allowing SARS-CoV-2 to infect the intestinal tract (Xiao et al., 2020a). Recent meta-analyses show that 48%–54% of fecal samples from COVID-19 patients have tested positive for viral RNA, and 15%–17% of patients have gastrointestinal (GI) symptoms (Cheung et al., 2020Mao et al., 2020Sultan et al., 2020). Additionally, live virus can be isolated from fecal samples of COVID-19 patients (Wang et al., 2020). Some studies have proposed fecal–oral transmission as the cause of intestinal infection (Guo et al., 2021). However, direct evidence for fecal–oral transmission is still lacking. Meanwhile, the virus has been detected in the blood of both symptomatic and asymptomatic patients (Chang et al., 2020), and disseminated virus could infect extrapulmonary organs (Jacobs and Mellors, 2020). Thus, the potential that intestinal infection occurs via blood transmission should be carefully considered.

Pulmonary infection triggers cytokine storm and induces a prothrombotic state (McFadyen et al., 2020Moore and June, 2020). Venous and arterial thrombosis are common in COVID-19 (Moore and June, 2020). Systematic reviews estimate that 14%–31% of in-hospital patients develop a clinically apparent thrombotic event (Suh et al., 2021Tan et al., 2021), while autopsy reports show a high prevalence of microthrombi in multiple organs, including lung, heart, liver, kidney, and gastrointestinal tract (Bradley et al., 2020Polak et al., 2020). A cohort study showed that COVID-19 patients with intestinal ischemia had markedly elevated D-dimer levels and poor outcomes (Norsa et al., 2020). Additionally, recent studies have shown that mesenteric thrombosis often results in intestinal resection and significantly increases mortality (Bhayana et al., 2020El Moheb et al., 2020). Therefore, it is essential to outline the mechanisms of intestinal thrombosis and its contribution to intestinal damage and disease progression.

In this review, we discuss blood transmission as a potential route for intestinal infection. We then summarize the characteristics and mechanism of intestinal thrombosis formation in COVID-19. Next, we focus on the effects of intestinal infection and thrombosis on intestinal damage and disease severity. Finally, we discuss therapeutic strategies to prevent intestinal damage.

Gastrointestinal Symptoms and SARS-CoV-2 Infection

Multiple studies have reported GI symptoms in COVID-19 patients, including diarrhea, nausea, vomiting, anorexia, and abdominal pain (Cheung et al., 2020Mao et al., 2020Sultan et al., 2020). According to a meta-analysis comprising 10,890 COVID-19 patients, the pooled prevalence estimates of GI symptoms were: diarrhea (7.7%), nausea or vomiting (7.8%), and abdominal pain (2.7%; Sultan et al., 2020) with 10% of these patients reporting GI symptoms as being their initial symptoms (Cheung et al., 2020). These data indicate potential gastrointestinal infection by SARS-CoV-2, which is reported to infect and replicate in epithelial cells of human small intestinal organoids (Zang et al., 2020). Both viral nucleocapsid proteins and viral particles have been detected in infected patient intestinal biopsies (Livanos et al., 2021). Additionally, SARS-CoV-2 RNA and live virus can be found in the stool of patients (Wang et al., 2020). More importantly, SARS-CoV-2 subgenomic mRNA is transcribed in actively replicating cells and has been detected in fecal samples (Wölfel et al., 2020). Further, rectal viral shedding persists for longer than that of the respiratory system (Zhao et al., 2020). All these data demonstrate that SARS-CoV-2 directly infects and replicates in intestinal epithelial cells of patients.

Intestinal Infection and Transmission Routes

With the deepening understanding of COVID-19, GI symptoms have been recognized as early signs of the disease. The high expression of ACE2 in the GI tract, isolation of live virus from fecal samples, and a subset of patients presenting with only GI symptoms seem to suggest fecal–oral transmission. However, problems with the feasibility of this mode of transmission remain. First, studies have shown that SARS-CoV-2 loses infectivity in simulated gastric acid within 10 min (Chan et al., 2020Zang et al., 2020Zhong et al., 2020). Secondly, SARS-CoV-2, as an enveloped virus, is largely unable to withstand the detergent effect of bile salts and the activity of digestive enzymes in the duodenum (Figure 1). Although some studies have suggested that highly viscous mucus in the gastrointestinal tract protects SARS-CoV-2, allowing the virus to retain its infectivity (Guo et al., 2021Zhang H. et al., 2021), there is still a lack of direct evidence. Bushman et al. (2019) had previously investigated the links between the structures of viruses and routes of transmission and found a strong association between fecal–oral transmission and the absence of a lipid envelope. Lastly, although some studies have isolated intact viruses from feces (Wang et al., 2020Zhang Y. et al., 2020Zhou et al., 2020Xiao et al., 2020b), most of them have not further confirmed the infectivity of these viruses (Wang et al., 2020Zhang Y. et al., 2020Xiao et al., 2020b). Zhou et al. (2020) confirmed viral propagation by RT-PCR, but only in a single fecal sample. Previous research has shown that SARS-CoV-2 is completely inactivated in simulated human colonic fluid over the course of 24 h, which may explain the sporadic detection of infection-active SARS-CoV-2 from feces samples.FIGURE 1

Figure 1. Intestinal infection and transmission routes. ① Direct evidence for fecal–oral transmission is still lacking. SARS-CoV-2 may be unable to enter the small intestine from the stomach due to gastric acid, bile and digestive enzymes. ② SARS-CoV-2 released from type II alveolar cells infects alveolar capillary endothelial cells (ECs). The virus replicates in ECs and is released into the blood to form viremia. ③ SARS-CoV-2 is released from infected ciliary cells of the nasal cavity and breaks through the basement membrane, infecting the vascular ECs and eventually entering circulation. ④ Blood transmission after alveolar or nasal infection is a potential route of intestinal infection. Eventually, SARS-CoV-2 is released into the gut and infects surrounding intestinal epithelial cells along the intestinal tract. ⑤ SARS-CoV-2 in the gut can also enter the capillaries and cause viremia, leading to recurrence of disease.

Several lines of evidence suggest that SARS-CoV-2 may infect the intestinal tract via the bloodstream. Deng et al. (2020) detected SARS-CoV-2 RNA in anal swabs from intratracheally but not intragastrically infected rhesus macaques, suggesting blood transmission. Indeed, SARS-CoV-2 RNA has been detected in blood and urine samples of patients (Wang et al., 2020). The virus can also be detected in multiple organs (including heart, brain, and kidney) and is associated with organ injury, indicating that the virus can reach and infect extrapulmonary organs (Puelles et al., 2020). Another study showed that SARS-CoV-2 viremia was associated with intestinal damage, independent of disease severity (Li Y. et al., 2021). Thus, blood transmission could be the cause of intestinal infection. Specifically, SARS-CoV-2 replicating in alveolar epithelial cells and capillary ECs is released into the bloodstream and infects new vascular ECs. The capillary network is then the main route by which the virus enters and infects extrapulmonary organs. The extensive surface area of intestinal capillaries makes intestinal epithelial cells more susceptible to infection than other extrapulmonary organs. Following infection of intestinal capillaries, SARS-CoV-2 is released into the gut and infects surrounding intestinal epithelial cells along the intestinal tract (Figure 1). Once established in the gut, SARS-CoV-2 can also reenter the capillaries, potentially leading to recurrence of disease. Consistent with this, in patients who experienced recurrence, the phylogenetic analysis of infection samples has shown that recurrent virus evolves from the original parent virus (Hu et al., 2020).

Additionally, SARS-CoV-2 RNA can also be detected in the blood and urine of asymptomatic patients, suggesting a second pathway to viremia through the nasal cavity (Chang et al., 2020Hasanoglu et al., 2021). The abundant blood vessels, thin mucous membrane, and higher levels of ACE2 (Huang et al., 2021) make it possible for the virus to initiate viremia from the nasal cavity. Specifically, SARS-CoV-2 is released from infected ciliary cells of the nasal cavity and breaks through the basement membrane, infecting the vascular ECs and eventually entering circulation (Figure 1). Blood transmission after nasal infection is therefore another potential route of intestinal infection.

Intestinal Damage, Malnutrition, and Poor Outcomes

A recent study has shown that a fecal sample positive for SARS-CoV-2 RNA at any time during hospitalization was associated with higher mortality [HR: 3.4 (1.2–9.9); Das Adhikari et al., 2021]. Similarly, another study showed that small-bowel thickening on CT was strongly associated with ICU admission (Wölfel et al., 2020). This relationship did not hold for colon or rectal thickening. These data indicates that small-bowel damage contributes to poor outcomes. As the main organ for nutrient absorption, damage to the small intestine will result in malabsorption and malnutrition, both of which commonly occur in COVID-19 patients (Di Filippo et al., 2021Lv et al., 2021) and are associated with disease severity (Luo et al., 2020Zhang P. et al., 2021). A fecal metabolome study showed that feces of COVID-19 patients were enriched with important nutrients that should be metabolized or absorbed, consistent with malabsorption (Lv et al., 2021). A prospective study showed that 29% of COVID-19 patients (31% of hospitalization patients and 21% of patients quarantined at home) had lost >5% of body weight [median weight loss, 6.5 (5.0–9.0) kg or 8.1 (6.1–10.9) %; Di Filippo et al., 2021]. Those patients with weight loss had greater systemic inflammation, impaired renal function and longer disease duration. A large, multicenter study (including 3,229 patients with GI symptoms) showed that 23% of patients had malnutrition, of whom 56.4% were unable to gain weight after 6 months follow-up (Rizvi et al., 2021). Studies also showed that malnutrition was associated with higher incidences of acute respiratory distress syndrome, acute myocardial injury, secondary infection, shock, and 28-day ICU mortality (Luo et al., 2020Zhang P. et al., 2021). Overall, malabsorption and malnutrition due to damaged small intestine increased disease severity and mortality.

Nutrient absorption in the small intestine is mainly through ATP-dependent active transport. Intestinal infection, hypoxemia, and intestinal ischemia contribute to malabsorption. SARS-CoV-2 adhesion depletes ACE2 levels on intestinal epithelial cells, which alters the expression of the neutral amino acid transporter B0AT1, reducing the intake of tryptophan and the production of nicotinamide (D’Amico et al., 2020). Meanwhile, uncontrolled viral replication consumes large amounts of ATP and nutrients, resulting in decreased nutrients entering the bloodstream. More importantly, anaerobic glycolysis caused by hypoxemia and intestinal ischemia significantly decreases ATP and active transport, leading to malabsorption. Additionally, hypoxemia and intestinal ischemia can also cause anorexia, nausea, vomiting, and enteral nutrition intolerance, reducing food intake. A prospective multicenter study showed that reduced food intake was associated with higher ICU admission and mortality (Caccialanza et al., 2021).

Intestinal Ischemia and Thrombosis

Intestinal ischemia is a common manifestation in COVID-19 patients. Autopsy results have shown that 31.6% of deceased patients had focal ischemic intestinal changes (Chiu et al., 2020). In a separate imaging study, bowel wall thickening and pneumatosis intestinalis, which indicate intestinal ischemia, were found on 38.1% (16 of 42) of abdominal CT images (Bhayana et al., 2020). Of these, 4 (9.5%) patients with pneumatosis intestinalis developed severe intestinal necrosis and needed resection. In another cohort study, 55.8% (58/104) of ICU patients developed an ileus (Kaafarani et al., 2020). Although mechanical factors cannot be ruled out, insufficient intestinal motility due to intestinal ischemia was more likely to be the cause of ileus in COVID-19 patients. In these patients with ileus, 4 (3.8%) developed severe intestinal ischemia and require emergency surgery. Both studies found microthrombi in these resected intestinal samples, which were the main cause of intestinal ischemia and increased mortality.

Additional intestinal ischemia and necrosis follows the formation of mesenteric thrombosis. However, there is currently relatively little data of mesenteric thrombus in COVID-19. Therefore, we have summarized the characteristics of 40 patients in 39 case reports published on PubMed (Supplementary Table 1). The median age of these patients was 50 (20–82) years, 26 (65%) were male, 38 (95%) developed bowel ischemia or necrosis, 30 (75%) needed bowel resection, 7 (17.5%) required no surgery, at least 3 (7.5%) developed sepsis, and 13 (32.5%) died. Other abdominal thrombotic events (such as celiac aortic thrombosis) leading to mesenteric ischemia can also result in severe intestinal necrosis and require intestinal resection (Zamboni et al., 2021).

Mild intestinal ischemia can lead to reduced diet and malabsorption. Severe intestinal ischemia or necrosis leads to the dissemination of gut bacteria, endotoxins, and microbial metabolites into the blood (Figure 2 bottom), aggravating hyperinflammation and the hypercoagulability state. Such patients need emergency excision of the necrotic bowel, which significantly increases mortality.FIGURE 2

Figure 2. Intestinal thrombosis leads to intestinal mucosal necrosis and dissemination of gut bacteria, endotoxins, and microbial metabolites in blood. (Top) Mesenteric vascular endotheliitis (initiated by viremia and accelerated by cytokines), hyperactivated platelets and high levels of phosphatidylserine (PS) promote a high rate of mesenteric thrombus in COVID-19 patients (mesenteric vein is shown in Supplementary Figure 1). (Bottom) Intestinal microthrombi and hypoxemia rapidly lead to intestinal mucosal ischemia and necrosis. The damaged gut–blood barrier leads to dissemination of gut bacteria, endotoxins, and microbial metabolites in blood.

Long-Term Gastrointestinal Sequelae

Long-term GI complications are common in recovering COVID-19 patients. In one systematic review of post-acute COVID-19 manifestations, diarrhea was among the top 10 most common complaints, with a prevalence of 6%. Other long-term GI symptoms include nausea, vomiting, abdominal pain, loss of appetite, and weight loss (Aiyegbusi et al., 2021Huang et al., 2021). The exact mechanisms of the GI sequelae remain unclear. Recently, persistent endotheliopathy, higher levels of thrombin (Fogarty et al., 2021), and residual SARS-CoV-2 viral antigens in the GI tract (Cheung et al., 2022) were described in convalescent COVID-19 patients. These data suggest that prolonged intestinal infection, persistent endothelial injury (abnormal intestinal–blood barrier), and microthrombi could be causes of the persistent GI symptoms.

The Mechanisms of Intestinal Thrombosis

Damaged Endothelial Cells

Resected bowel samples from COVID-19 patients routinely exhibit thrombi and endotheliitis, indicating the important role of EC injury in mesenteric thrombosis (Bhayana et al., 2020Chiu et al., 2020Kaafarani et al., 2020). SARS-CoV-2 infection (Varga et al., 2020) and elevated inflammatory cytokines (He et al., 2016) damage mesenteric vascular ECs. In response, EC cell margins retract, extending phosphatidylserine (PS) positive filopods and releasing endothelial microparticles (MPs; Figure 3BHe et al., 2016). The PS+ filopods and MPs can be co-stained by Xa and Va and support fibrin formation (Figures 3BD). The exposed PS then activates tissue factor on ECs, triggering the extrinsic coagulation pathway (Versteeg et al., 2013). Next, higher levels of FVIII and vWF released from damaged EC contribute to the hypercoagulable state and platelet aggregation, respectively (Goshua et al., 2020). Thrombomodulin is then released from ECs in its soluble form, which has an attenuated capacity to activate Protein C due to a lack of other cofactors on ECs, such as endothelial protein C receptor (Versteeg et al., 2013). Finally, upregulation of endothelial cell adhesion molecules recruits neutrophils and platelets and further contributes to thrombosis (Tong et al., 2020Li L. et al., 2021).FIGURE 3

Figure 3. Phosphatidylserine exposure on activated/apoptotic cells and microparticles (MPs) promotes fibrin formation. (A) Phosphatidylserine is usually confined to the inner leaflet of the cell membrane. This asymmetry is maintained through ATP-dependent inward transport of PS by flippases and outward transport of non-PS by floppases (left). Upon stimulation, calcium transients will inhibit ATP-dependent transport and stimulate the nonselective lipid transporter scramblase (ATP-independent), resulting in PS exposure (right). (B–D) Human umbilical vein ECs were treated with healthy human plasma and TNF-ɑ (our previous study; He et al., 2016). (B) ECs retracts the cell margins, extends PS positive filopods and releases endothelial-MPs. (C) The PS+ filopods and MPs can be co-stained by Xa and Va. (D) ECs (green) were incubated with MPs-depleted plasma (MDP) in the presence of calcium for 30 min and stained with Alexa Fluro 647-anti-fibrin for 30 min. Considerable fibrin stands among cultured ECs along with filopodia. (E) Confocal images showed PS expression on platelets of patients stained with Alexa 488 lactadherin (our previous study; Ma et al., 2017). MPs from the activated platelet (*) had formed at the margin area located between the distinct outlines. (F) MPs from plasma were co-stained by Xa and Va (or lactadherin and annexin V; our previous study; Gao et al., 2015). (G) MPs that were incubated with recalcified MDP for 30 min and stained with Alexa Fluro 647-anti-fibrin for 30 min. Converted fibrin networks were detected around MPs. The inset bars represent 5 μm in (B–D,G) and 2 μm in (E,F).

Hyperactivated Platelets and Phosphatidylserine Storm

Although COVID-19 patients exhibit mild thrombocytopenia, the remaining platelets are hyperactivated (Manne et al., 2020Taus et al., 2020Zaid et al., 2020). Studies have shown that platelets from COVID-19 patients have increased P-selectin and αIIbβ3 expression. P-selectin on activated platelets interacts with integrin αIIb3 on monocytes to form platelet-monocyte complexes, which induce monocyte tissue factor expression (Hottz et al., 2020). The activated platelets can also induce neutrophils to release neutrophil extracellular traps (NETs; Middleton et al., 2020). Furthermore, platelets from COVID-19 patients aggregate and adhere more efficiently to collagen-coated surfaces under flow conditions (Manne et al., 2020Zaid et al., 2020). Meanwhile, activated platelets release α- and dense-granule contents including FV, FXI, fibrinogen and vWF (Zaid et al., 2020). In addition, activated platelets also produce inflammatory cytokines, fueling cytokine storm (Taus et al., 2020Zaid et al., 2020). Most importantly, activated platelets expose higher levels of PS and release higher numbers of PS+ MPs (Figures 3EGZaid et al., 2020Althaus et al., 2021).

Phosphatidylserine is the most abundant negatively charged phospholipid in mammalian cells and is usually confined to the inner leaflet of the cell membrane (Versteeg et al., 2013). This asymmetry is maintained through ATP-dependent inward transport of PS by flippases and outward transport of other phospholipids by floppases (Figure 3A left). Upon stimulation, transiently increased calcium inhibits ATP-dependent transport and stimulates the nonselective lipid transporter scramblase (ATP-independent), resulting in PS exposure on the outer membrane (Figure 3A right). During this process, microvesicles derived from the budding of cellular membranes will be released. These MPs are typically <1 μm and express PS (Burnier et al., 2009). The exposure of PS on the surface of cells and MPs provides a catalytic surface for factor Xa and thrombin formation in vivo (Versteeg et al., 2013). We have previously demonstrated that PS mediates 90% of Xa and thrombin formation and significantly increases thrombosis in vivo (Shi and Gilbert, 2003).

Cytokines and virus infection can activate blood cells and ECs, resulting in higher levels of PS+ cells and MPs. As COVID-19 progresses, the developing cytokine storm activates more blood cells, leading to PS storm. Platelets are highly sensitive to circulating cytokines, releasing large amounts of cytokines and PS exposed MPs into the plasma (Taus et al., 2020Althaus et al., 2021) and thus are a major contributor to PS storm. Previous studies found an unusual elevation of FVa in severe COVID-19 patients (248 IU/dl, higher than any previous disease; Stefely et al., 2020von Meijenfeldt et al., 2021). The degree of FVa elevation in these patients may be the result of PS storm.

Collectively, SARS-CoV-2 infection is the initiating factor for injury of the intestinal vascular ECs, which is then aggravated by systemic cytokines, leading to endotheliitis. Subsequently, the hyperactivated platelets in circulation rapidly accumulate around the damaged ECs, inducing tissue factor expression, NET release, and activating the intrinsic/extrinsic coagulation pathways. Simultaneously, the high levels of PS expression in circulating cells and MPs further promote thrombin and fibrin formation (Figure 2 top).

Early Antithrombotic Treatment

Vaccines and antithrombotic therapy are effective measures to reduce intestinal damage and fight against the COVID-19 pandemic (Baden et al., 2021Chalmers et al., 2021). Vaccines induce adaptive immunity to clear the virus, reducing intestinal infection and intestinal damage. However, the usefulness of vaccines is limited by incomplete vaccine acceptance and viral mutations (Hacisuleyman et al., 2021Wang et al., 2021). Vaccines are also ineffective for already infected patients. Therefore, more attention should be paid to antithrombotic therapy. Studies had shown that thrombotic events mainly occurred within 7 days of COVID-19 diagnosis (both inpatients and outpatients; Mouhat et al., 2020Ho et al., 2021). Meanwhile, two large randomized controlled trials (RCTs) from the same platform showed that therapeutic anticoagulation reduced mortality in moderate cases but not in severe ones, suggesting that delayed anticoagulant therapy may lead to treatment failure (REMAP-CAP Investigators et al., 2021a,b). More importantly, a recent study reported three asymptomatic COVID-19 patients who developed abdominal (or intestinal) thrombosis leading to intestinal necrosis (Zamboni et al., 2021). All these data suggest that antithrombotic therapy should be initiated once COVID-19 is diagnosed (excluding patients with contraindications). Early prophylactic antithrombotic therapy can reduce the activation of vascular ECs and blood cells, preventing intestinal thrombosis, ensuring sufficient intestinal perfusion, maintaining the normal gut–blood barrier, avoiding malabsorption, malnutrition, and intestinal flora entering the bloodstream. Further, attenuated injury and decreased microthrombi in convalescent patients may lower the risk of long-term GI sequelae. Meanwhile, unobstructed systemic circulation can also accelerate the removal of SARS-CoV-2, inflammatory cytokines and damaged blood cells by the mononuclear phagocyte system.

Anticoagulation

Table 1 summarizes the RCTs of anticoagulant therapy in COVID-19 patients. For outpatients, early anticoagulant therapy reduced hospitalization and supplemental oxygen (Gonzalez-Ochoa). While, delayed treatment had no similar effect (ACTIV-4B and Ananworanich). Thus, oral anticoagulant therapy should be initiated in outpatients once COVID-19 is diagnosed. For non-critically ill patients, therapeutic doses of low molecular weight heparin (LMWH) reduced thrombotic events and mortality, and increased organ support-free days (REMAP-CAP, ACTIV-4a, ATTACC; RAPID; HEP-COVID). However, therapeutic doses of rivaroxaban did not improve clinical outcomes and increased bleeding (ACTION). This is potentially because novel oral anticoagulants do not share the anti-inflammatory and antiviral functions of heparin. Intestinal damage might also result in abnormal absorption of oral anticoagulants. Therefore, therapeutic LMWH should be the first choice for non-critically ill patients. For critically ill patients, RCTs showed that moderate and therapeutic doses were not superior to prophylactic ones. Results from several other studies suggest that the overwhelming thrombosis leads to failure of anticoagulant therapy at therapeutic doses (Leentjens et al., 2021Poor, 2021). Faced with this dilemma, an editorial in N Engl J Med argued that profibrinolytic strategies should be considered (Ten Cate, 2021). More studies are needed to explore optimal antithrombotic therapy in critically ill patients.TABLE 1

Table 1. Randomized clinical trials of anticoagulant therapy in COVID-19 patients.

Inhibition of Platelet Activation

As COVID-19 progresses, cytokine storm activates platelets, which not only participate in primary hemostasis, but also are the major components of PS storm. Autopsy results show a high prevalence of platelet-fibrin-rich microthrombi in lung and extrapulmonary organs, including the gastrointestinal tract (Bradley et al., 2020Polak et al., 2020). Early inhibition of platelet activation can reduce platelet activity and prevent PS storm, thus decreasing thrombosis and mortality. Several observational studies have shown that aspirin decreases mechanical ventilation, ICU admission, and mortality (Chow et al., 2020Santoro et al., 2022). The RCTs testing antiplatelet agents were still preliminary. A recent RCT suggested that aspirin was associated with an increase in survival and reduction in thrombotic events (RECOVERY Collaborative Group, 2022). In addition, anti-inflammatory therapy (e.g., dexamethasone, 6 mg once daily; RECOVERY Collaborative Group et al., 2020) inhibits cytokine storm, as well as platelet activation, reducing mortality. Overall, inhibition of platelet activation is also important to reduce mortality through the prevention of thrombosis and organs damage.

Factors Influencing Antithrombotic Treatment

Thrombotic Risk Factors or Co-morbidities

Studies have shown that obesity, hyperglycemia and diabetes are associated with increased thrombotic events (including intestinal thrombosis), COVID-19 severity, and mortality (Drucker, 2021Stefan et al., 2021). Other thrombotic risk factors include previous venous thromboembolism, active cancer, known thrombophilic condition, recent trauma or surgery, age ≥70 years, respiratory/cardiac/renal failure, and inflammatory bowel disease (Susen et al., 2020). These factors or co-morbidities heighten basal inflammatory levels and endothelial damage, leading to premature cytokine and PS storms, ultimately increasing thrombosis and mortality. Thus, more active antithrombotic therapy strategies should be adopted in these patients. For patients with mild COVID-19 with these factors, the French Working Group on Perioperative Hemostasis and the French Study Group on Thrombosis and Hemostasis recommend higher (intermediate) doses of anticoagulant therapy (Susen et al., 2020). For moderately ill patients, therapeutic doses of anticoagulant therapy should be initiated as soon as possible to prevent excessive microthrombus formation. The need for extended thromboprophylaxis in discharged patients remains controversial. However, a recent RCT showed that rivaroxaban (10 mg/day, 35 days) improved clinical outcomes in discharged COVID-19 patients with higher thrombotic risk factors (Ramacciotti et al., 2022), supporting extended thromboprophylaxis in patients with these risk factors or co-morbidities.

Vaccination

Although more than half the world population has received at least one dose of the vaccines, there are relatively little data of antithrombotic therapy in vaccinated patients. Studies of viral dynamics show that the viral loads of vaccinated patients are as high as that of unvaccinated patients, but drop significantly faster (Brown et al., 2021Klompas, 2021). Thus, vaccinated patients have shorter hospital stays, and are less likely to progress to critical illness and death (Tenforde et al., 2021Thompson et al., 2021). Nevertheless, antithrombotic therapy is still beneficial for the vaccinated patients. Firstly, heparin has anti-inflammatory and antiviral functions and can interfere with the binding of SARS-CoV-2 to ACE2 and shorten the duration of virus infection (Kwon et al., 2020Pereyra et al., 2021). Secondly, antithrombotic therapy protects cells from damage, PS exposure, and microthrombi formation, maintains unobstructed blood circulation, and facilitates virus clearance (by vaccine-induced adaptive immunity). Thirdly, thrombosis remains an important factor in disease progression. Antithrombotic therapy further reduces thrombosis and mortality, especially in vaccinated patients with high risk factors or co-morbidities. Lastly, although vaccines reduce the incidence, a subset of vaccinated patients will still develop long-term sequelae or Long Covid (Ledford, 2021Antonelli et al., 2022). Persistent viral infection and microthrombi are the primary causes (Ledford, 2021Xie et al., 2022), and early antithrombotic therapy is still needed to prevent them.

Conclusion and Future Research

During COVID-19 disease progression, SARS-CoV-2 infiltrates the blood stream from the initial respiratory tract infection, causing viremia, hyperactivated platelets and PS storm. The virus settles into the vascular beds of extrapulmonary organs, ultimately causing infection of intestinal epithelial cell. Damaged ECs, combined with hyperactivated platelets and PS storm, promote intestinal thrombosis, resulting in intestinal ischemia or necrosis. The damaged gut–blood barrier leads to malabsorption, malnutrition and intestinal flora entering the bloodstream, which significantly increase disease severity and mortality. Prolonged intestinal infection, persistent endothelial injury and microthrombi contribute to the long-term GI sequelae after discharge. Early prophylactic antithrombotic therapy can prevent microthrombi, ensuring sufficient intestinal perfusion, maintaining the normal intestinal function, and reducing the risk of long-term GI sequelae. More active antithrombotic therapy should be adopted in patients with other thrombotic risk factors or co-morbidities. Even in vaccinated COVID-19 patients, antithrombotic therapy is also important to decrease (intestinal) thrombosis, mortality and the risk of long-term GI sequelae.

With the Omicron pandemic, patients requiring hospitalization and ICU treatment decline rapidly. However, people are increasingly concerned about Long Covid. In terms of long-term GI sequelae, the detailed mechanisms of prolonged intestinal infection and persistent microthrombi remain unclear. And whether anticoagulant therapy can decrease GI symptoms in patients with long-term GI sequelae deserves further study. Finally, the impact of vaccines on long-term GI sequelae remains unclear in previously infected and breakthrough infected patients.

References

Aiyegbusi, O. L., Hughes, S. E., Turner, G., Rivera, S. C., McMullan, C., Chandan, J. S., et al. (2021). Symptoms, complications and management of long COVID: a review. J. R. Soc. Med. 114, 428–442. doi: 10.1177/01410768211032850

PubMed Abstract | CrossRef Full Text | Google Scholar

Althaus, K., Marini, I., Zlamal, J., Pelzl, L., Singh, A., Häberle, H., et al. (2021). Antibody-induced procoagulant platelets in severe COVID-19 infection. Blood 137, 1061–1071. doi: 10.1182/blood.2020008762

PubMed Abstract | CrossRef Full Text | Google Scholar

Ananworanich, J., Mogg, R., Dunne, M. W., Bassyouni, M., David, C. V., Gonzalez, E., et al. (2021). Randomized study of rivaroxaban vs. placebo on disease progression and symptoms resolution in high-risk adults with mild COVID-19. Clin. Infect. Dis. doi: 10.1093/cid/ciab813 [Epub ahead of print].

PubMed Abstract | CrossRef Full Text | Google Scholar

Antonelli, M., Penfold, R. S., Merino, J., Sudre, C. H., Molteni, E., Berry, S., et al. (2022). Risk factors and disease profile of post-vaccination SARS-CoV-2 infection in UK users of the COVID symptom study app: a prospective, community-based, nested, case-control study. Lancet Infect. Dis. 22, 43–55. doi: 10.1016/S1473-3099(21)00460-6

CrossRef Full Text | Google Scholar

Baden, L. R., El Sahly, H. M., Essink, B., Kotloff, K., Frey, S., Novak, R., et al. (2021). Efficacy and safety of the mRNA-1273 SARS-CoV-2 vaccine. N. Engl. J. Med. 384, 403–416. doi: 10.1056/NEJMoa2035389

CrossRef Full Text | Google Scholar

Bhayana, R., Som, A., Li, M. D., Carey, D. E., Anderson, M. A., Blake, M. A., et al. (2020). Abdominal imaging findings in COVID-19: preliminary observations. Radiology 297, E207–E215. doi: 10.1148/radiol.2020201908

PubMed Abstract | CrossRef Full Text | Google Scholar

Bradley, B. T., Maioli, H., Johnston, R., Chaudhry, I., Fink, S. L., Xu, H., et al. (2020). Histopathology and ultrastructural findings of fatal COVID-19 infections in Washington state: a case series. Lancet 396, 320–332. doi: 10.1016/S0140-6736(20)31305-2

PubMed Abstract | CrossRef Full Text | Google Scholar

Brown, C. M., Vostok, J., Johnson, H., Burns, M., Gharpure, R., Sami, S., et al. (2021). Outbreak of SARS-CoV-2 infections, including COVID-19 vaccine breakthrough infections, associated with large public gatherings – Barnstable County, Massachusetts, July 2021. MMWR Morb. Mortal. Wkly Rep. 70, 1059–1062. doi: 10.15585/mmwr.mm7031e2

PubMed Abstract | CrossRef Full Text | Google Scholar

Burnier, L., Fontana, P., Kwak, B. R., and Angelillo-Scherrer, A. (2009). Cell-derived microparticles in haemostasis and vascular medicine. Thromb. Haemost. 101, 439–451. doi: 10.1160/TH08-08-0521

CrossRef Full Text | Google Scholar

Bushman, F. D., McCormick, K., and Sherrill-Mix, S. (2019). Virus structures constrain transmission modes. Nat. Microbiol. 4, 1778–1780. doi: 10.1038/s41564-019-0523-5

PubMed Abstract | CrossRef Full Text | Google Scholar

Caccialanza, R., Formisano, E., Klersy, C., Ferretti, V., Ferrari, A., Demontis, S., et al. (2021). Nutritional parameters associated with prognosis in non-critically ill hospitalized COVID-19 patients: the NUTRI-COVID19 study. Clin. Nutr. doi: 10.1016/j.clnu.2021.06.020 [Epub ahead of print].

CrossRef Full Text | Google Scholar

Chalmers, J. D., Crichton, M. L., Goeminne, P. C., Cao, B., Humbert, M., Shteinberg, M., et al. (2021). Management of hospitalised adults with coronavirus disease 2019 (COVID-19): a European Respiratory Society living guideline. Eur. Respir. J. 57:2100048. doi: 10.1183/13993003.00048-2021

PubMed Abstract | CrossRef Full Text | Google Scholar

Chan, K. H., Sridhar, S., Zhang, R. R., Chu, H., Fung, A. Y., Chan, G., et al. (2020). Factors affecting stability and infectivity of SARS-CoV-2. J. Hosp. Infect. 106, 226–231. doi: 10.1016/j.jhin.2020.07.009

CrossRef Full Text | Google Scholar

Chang, L., Zhao, L., Gong, H., Wang, L., and Wang, L. (2020). Severe acute respiratory syndrome coronavirus 2 RNA detected in blood donations. Emerg. Infect. Dis. 26, 1631–1633. doi: 10.3201/eid2607.200839

PubMed Abstract | CrossRef Full Text | Google Scholar

Cheung, C. C. L., Goh, D., Lim, X., Tien, T. Z., Lim, J. C. T., Lee, J. N., et al. (2022). Residual SARS-CoV-2 viral antigens detected in GI and hepatic tissues from five recovered patients with COVID-19. Gut 71, 226–229. doi: 10.1136/gutjnl-2021-324280

PubMed Abstract | CrossRef Full Text | Google Scholar

Cheung, K. S., Hung, I. F. N., Chan, P. P. Y., Lung, K. C., Tso, E., Liu, R., et al. (2020). Gastrointestinal manifestations of SARS-CoV-2 infection and virus load in faecal samples from a Hong Kong cohort: systematic review and meta-analysis. Gastroenterology 159, 81–95. doi: 10.1053/j.gastro.2020.03.065

CrossRef Full Text | Google Scholar

Chiu, C. Y., Sarwal, A., Mon, A. M., Tan, Y. E., and Shah, V. (2020). Gastrointestinal: COVID-19 related ischemic bowel disease. J. Gastroenterol. Hepatol. 36:850. doi: 10.1111/jgh.15254

PubMed Abstract | CrossRef Full Text | Google Scholar

Chow, J. H., Khanna, A. K., Kethireddy, S., Yamane, D., Levine, A., Jackson, A. M., et al. (2020). Aspirin use is associated with decreased mechanical ventilation, ICU admission, and in-hospital mortality in hospitalized patients with COVID-19. Anesth. Analg. 132, 930–941. doi: 10.1213/ANE.0000000000005292

CrossRef Full Text | Google Scholar

Connors, J. M., Brooks, M. M., Sciurba, F. C., Krishnan, J. A., Bledsoe, J. R., Kindzelski, A., et al. (2021). Effect of antithrombotic therapy on clinical outcomes in outpatients with clinically stable symptomatic COVID-19: the ACTIV-4B randomized clinical trial. JAMA 326, 1703–1712. doi: 10.1001/jama.2021.17272

PubMed Abstract | CrossRef Full Text | Google Scholar

D’Amico, F., Baumgart, D. C., Danese, S., and Peyrin-Biroulet, L. (2020). Diarrhea during COVID-19 infection: pathogenesis, epidemiology, prevention, and management. Clin. Gastroenterol. Hepatol. 18, 1663–1672. doi: 10.1016/j.cgh.2020.04.001

PubMed Abstract | CrossRef Full Text | Google Scholar

Das Adhikari, U., Eng, G., Farcasanu, M., Avena, L. E., Choudhary, M. C., Triant, V. A., et al. (2021). Faecal SARS-CoV-2 RNA is associated with decreased COVID-19 survival. Clin. Infect. Dis. doi: 10.1093/cid/ciab623 Epub ahead of print

PubMed Abstract | CrossRef Full Text | Google Scholar

Deng, W., Bao, L., Gao, H., Xiang, Z., Qu, Y., Song, Z., et al. (2020). Ocular conjunctival inoculation of SARS-CoV-2 can cause mild COVID-19 in rhesus macaques. Nat. Commun. 11:4400. doi: 10.1038/s41467-020-18149-6

CrossRef Full Text | Google Scholar

Di Filippo, L., De Lorenzo, R., D’Amico, M., Sofia, V., Roveri, L., Mele, R., et al. (2021). COVID-19 is associated with clinically significant weight loss and risk of malnutrition, independent of hospitalisation: a post-hoc analysis of a prospective cohort study. Clin. Nutr. 40, 2420–2426. doi: 10.1016/j.clnu.2020.10.043

PubMed Abstract | CrossRef Full Text | Google Scholar

Drucker, D. J. (2021). Diabetes, obesity, metabolism, and SARS-CoV-2 infection: the end of the beginning. Cell Metab. 33, 479–498. doi: 10.1016/j.cmet.2021.01.016

CrossRef Full Text | Google Scholar

El Moheb, M., Naar, L., Christensen, M. A., Kapoen, C., Maurer, L. R., Farhat, M., et al. (2020). Gastrointestinal complications in critically ill patients with and without COVID-19. JAMA 324, 1899–1901. doi: 10.1001/jama.2020.19400

PubMed Abstract | CrossRef Full Text | Google Scholar

Fogarty, H., Townsend, L., Morrin, H., Ahmad, A., Comerford, C., Karampini, E., et al. (2021). Persistent endotheliopathy in the pathogenesis of long COVID syndrome. J. Thromb. Haemost. 19, 2546–2555. doi: 10.1111/jth.15490

CrossRef Full Text | Google Scholar

Gao, C., Xie, R., Yu, C., Ma, R., Dong, W., Meng, H., et al. (2015). Thrombotic role of blood and endothelial cells in uremia through phosphatidylserine exposure and microparticle release. PLoS One 10:e0142835. doi: 10.1371/journal.pone.0142835

PubMed Abstract | CrossRef Full Text | Google Scholar

Gonzalez-Ochoa, A. J., Raffetto, J. D., Hernández, A. G., Zavala, N., Gutiérrez, O., Vargas, A., et al. (2021). Sulodexide in the treatment of patients with early stages of COVID-19: a randomized controlled trial. Thromb. Haemost. 121, 944–954. doi: 10.1055/a-1414-5216

CrossRef Full Text | Google Scholar

Goshua, G., Pine, A. B., Meizlish, M. L., Chang, C. H., Zhang, H., Bahel, P., et al. (2020). Endotheliopathy in COVID-19-associated coagulopathy: evidence from a single-Centre, cross-sectional study. Lancet Haematol. 7, e575–e582. doi: 10.1016/S2352-3026(20)30216-7

CrossRef Full Text | Google Scholar

Guo, M., Tao, W., Flavell, R. A., and Zhu, S. (2021). Potential intestinal infection and faecal-oral transmission of SARS-CoV-2. Nat. Rev. Gastroenterol. Hepatol. 18, 269–283. doi: 10.1038/s41575-021-00416-6

CrossRef Full Text | Google Scholar

Hacisuleyman, E., Hale, C., Saito, Y., Blachere, N. E., Bergh, M., Conlon, E. G., et al. (2021). Vaccine breakthrough infections with SARS-CoV-2 variants. N. Engl. J. Med. 384, 2212–2218. doi: 10.1056/NEJMoa2105000

CrossRef Full Text | Google Scholar

Hasanoglu, I., Korukluoglu, G., Asilturk, D., Cosgun, Y., Kalem, A. K., Altas, A. B., et al. (2021). Higher viral loads in asymptomatic COVID-19 patients might be the invisible part of the iceberg. Infection 49, 117–126. doi: 10.1007/s15010-020-01548-8

PubMed Abstract | CrossRef Full Text | Google Scholar

He, Z., Si, Y., Jiang, T., Ma, R., Zhang, Y., Cao, M., et al. (2016). Phosphotidylserine exposure and neutrophil extracellular traps enhance procoagulant activity in patients with inflammatory bowel disease. Thromb. Haemost. 115, 738–751. doi: 10.1160/TH15-09-0710

CrossRef Full Text | Google Scholar

Ho, F. K., Man, K. K. C., Toshner, M., Church, C., Celis-Morales, C., Wong, I. C. K., et al. (2021). Thromboembolic risk in hospitalized and nonhospitalized COVID-19 patients: a self-controlled case series analysis of a nationwide cohort. Mayo Clin. Proc. 96, 2587–2597. doi: 10.1016/j.mayocp.2021.07.002

PubMed Abstract | CrossRef Full Text | Google Scholar

Hottz, E. D., Azevedo-Quintanilha, I. G., Palhinha, L., Teixeira, L., Barreto, E. A., Pão, C. R. R., et al. (2020). Platelet activation and platelet-monocyte aggregates formation trigger tissue factor expression in severe COVID-19 patients. Blood 136, 1330–1341. doi: 10.1182/blood.2020007252

PubMed Abstract | CrossRef Full Text | Google Scholar

Hu, F., Chen, F., Ou, Z., Fan, Q., Tan, X., Wang, Y., et al. (2020). A compromised specific Humoral immune response against the SARS-CoV-2 receptor-binding domain is related to viral persistence and periodic shedding in the gastrointestinal tract. Cell. Mol. Immunol. 17, 1119–1125. doi: 10.1038/s41423-020-00550-2

CrossRef Full Text | Google Scholar

Huang, N., Pérez, P., Kato, T., Mikami, Y., Okuda, K., Gilmore, R. C., et al. (2021). SARS-CoV-2 infection of the oral cavity and saliva. Nat. Med. 27, 892–903. doi: 10.1038/s41591-021-01296-8

PubMed Abstract | CrossRef Full Text | Google Scholar

INSPIRATION Investigators Sadeghipour, P., Talasaz, A. H., Rashidi, F., Sharif-Kashani, B., Beigmohammadi, M. T., et al. (2021). Effect of intermediate-dose vs. standard-dose prophylactic anticoagulation on thrombotic events, extracorporeal membrane oxygenation treatment, or mortality among patients with COVID-19 admitted to the intensive care unit: the INSPIRATION randomized clinical trial. JAMA 325, 1620–1630. doi: 10.1001/jama.2021.4152

PubMed Abstract | CrossRef Full Text | Google Scholar

Jacobs, J. L., and Mellors, J. W. (2020). Detection of SARS-CoV-2 RNA in blood of patients with COVID-19: what does it mean? Clin. Infect. Dis. doi: 10.1093/cid/ciaa1316 [Epub ahead of print].

CrossRef Full Text | Google Scholar

Kaafarani, H. M. A., El Moheb, M., Hwabejire, J. O., Naar, L., Christensen, M. A., Breen, K., et al. (2020). Gastrointestinal complications in critically ill patients with COVID-19. Ann. Surg. 272, e61–e62. doi: 10.1097/SLA.0000000000004004

CrossRef Full Text | Google Scholar

Klompas, M. (2021). Understanding breakthrough infections following mRNA SARS-CoV-2 vaccination. JAMA 326, 2018–2020. doi: 10.1001/jama.2021.19063

PubMed Abstract | CrossRef Full Text | Google Scholar

Kwon, P. S., Oh, H., Kwon, S. J., Jin, W., Zhang, F., Fraser, K., et al. (2020). Sulfated polysaccharides effectively inhibit SARS-CoV-2 in vitro. Cell Discov. 6:50. doi: 10.1038/s41421-020-00192-8

PubMed Abstract | CrossRef Full Text | Google Scholar

Lan, J., Ge, J., Yu, J., Shan, S., Zhou, H., Fan, S., et al. (2020). Structure of the SARS-CoV-2 spike receptor-binding domain bound to the ACE2 receptor. Nature 581, 215–220. doi: 10.1038/s41586-020-2180-5

CrossRef Full Text | Google Scholar

Ledford, H. (2021). Do vaccines protect against long COVID? What the data say. Nature 599, 546–548. doi: 10.1038/d41586-021-03495-2

CrossRef Full Text | Google Scholar

Leentjens, J., van Haaps, T. F., Wessels, P. F., Schutgens, R. E. G., and Middeldorp, S. (2021). COVID-19-associated coagulopathy and antithrombotic agents-lessons after 1 year. Lancet Haematol. 8, e524–e533. doi: 10.1016/S2352-3026(21)00105-8

PubMed Abstract | CrossRef Full Text | Google Scholar

Lemos, A. C. B., do Espírito Santo, D. A., Salvetti, M. C., Gilio, R. N., Agra, L. B., Pazin-Filho, A., et al. (2020). Therapeutic versus prophylactic anticoagulation for severe COVID-19: a randomized phase II clinical trial (HESACOVID). Thromb. Res. 196, 359–366. doi: 10.1016/j.thromres.2020.09.026

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, L., Huang, M., Shen, J., Wang, Y., Wang, R., Yuan, C., et al. (2021). Serum levels of soluble platelet endothelial cell adhesion molecule 1 in COVID-19 patients are associated with disease severity. J. Infect. Dis. 223, 178–179. doi: 10.1093/infdis/jiaa642

PubMed Abstract | CrossRef Full Text | Google Scholar

Li, Y., Schneider, A. M., Mehta, A., Sade-Feldman, M., Kays, K. R., Gentili, M., et al. (2021). SARS-CoV-2 viremia is associated with distinct proteomic pathways and predicts COVID-19 outcomes. J. Clin. Invest. 131:e148635. doi: 10.1172/JCI148635

CrossRef Full Text | Google Scholar

Livanos, A. E., Jha, D., Cossarini, F., Gonzalez-Reiche, A. S., Tokuyama, M., Aydillo, T., et al. (2021). Intestinal host response to SARS-CoV-2 infection and COVID-19 outcomes in patients with gastrointestinal symptoms. Gastroenterology 16, 2435.e34–2450.e34. doi: 10.1053/j.gastro.2021.02.056

CrossRef Full Text | Google Scholar

Lopes, R. D., de Barros, E., Silva, P. G. M., Furtado, R. H. M., Macedo, A. V. S., Bronhara, B., et al. (2021). Therapeutic versus prophylactic anticoagulation for patients admitted to hospital with COVID-19 and elevated D-dimer concentration (ACTION): an open-label, multicentre, randomised, controlled trial. Lancet 397, 2253–2263. doi: 10.1016/S0140-6736(21)01203-4

CrossRef Full Text | Google Scholar

Luo, Y., Xue, Y., Mao, L., Yuan, X., Lin, Q., Tang, G., et al. (2020). Prealbumin as a predictor of prognosis in patients with coronavirus disease 2019. Front. Med. 7:374. doi: 10.3389/fmed.2020.00374

PubMed Abstract | CrossRef Full Text | Google Scholar

Lv, L., Jiang, H., Chen, Y., Gu, S., Xia, J., Zhang, H., et al. (2021). The faecal metabolome in COVID-19 patients is altered and associated with clinical features and gut microbes. Anal. Chim. Acta 1152:338267. doi: 10.1016/j.aca.2021.338267

PubMed Abstract | CrossRef Full Text | Google Scholar

Ma, R., Xie, R., Yu, C., Si, Y., Wu, X., Zhao, L., et al. (2017). Phosphatidylserine-mediated platelet clearance by endothelium decreases platelet aggregates and procoagulant activity in sepsis. Sci. Rep. 7:4978. doi: 10.1038/s41598-018-24187-4

PubMed Abstract | CrossRef Full Text | Google Scholar

Manne, B. K., Denorme, F., Middleton, E. A., Portier, I., Rowley, J. W., Stubben, C., et al. (2020). Platelet gene expression and function in patients with COVID-19. Blood 136, 1317–1329. doi: 10.1182/blood.2020007214

PubMed Abstract | CrossRef Full Text | Google Scholar

Mao, R., Qiu, Y., He, J. S., Tan, J. Y., Li, X. H., Liang, J., et al. (2020). Manifestations and prognosis of gastrointestinal and liver involvement in patients with COVID-19: a systematic review and meta-analysis. Lancet Gastroenterol. Hepatol. 5, 667–678. doi: 10.1016/S2468-1253(20)30126-6

PubMed Abstract | CrossRef Full Text | Google Scholar

Marcos-Jubilar, M., Carmona-Torre, F., Vidal Laso, R., Ruiz-Artacho, P., Filella, D., Carbonell, C., et al. (2022). Therapeutic versus prophylactic bemiparin in hospitalized patients with non-severe COVID-19 pneumonia (BEMICOP): an open-label, multicenter, randomized trial. Thromb. Haemost. 122, 295–299. doi: 10.1055/a-1667-7534

PubMed Abstract | CrossRef Full Text | Google Scholar

McFadyen, D. J., Stevens, H., and Karlheinz, P. (2020). The emerging threat of (micro)thrombosis in COVID-19 and its therapeutic implications. Circ. Res. 127, 571–587. doi: 10.1161/CIRCRESAHA.120.317447

CrossRef Full Text | Google Scholar

Middleton, E. A., He, X. Y., Denorme, F., Campbell, R. A., Ng, D., Salvatore, S. P., et al. (2020). Neutrophil extracellular traps contribute to immunothrombosis in COVID-19 acute respiratory distress syndrome. Blood 136, 1169–1179. doi: 10.1182/blood.2020007008

CrossRef Full Text | Google Scholar

Moore, J. B., and June, C. H. (2020). Cytokine release syndrome in severe COVID-19. Science 368, 473–474. doi: 10.1126/science.abb8925

CrossRef Full Text | Google Scholar

Mouhat, B., Besutti, M., Bouiller, K., Grillet, F., Monnin, C., Ecarnot, F., et al. (2020). Elevated D-dimers and lack of anticoagulation predict PE in severe COVID-19 patients. Eur. Respir. J. 56:2001811. doi: 10.1183/13993003.01811-2020

PubMed Abstract | CrossRef Full Text | Google Scholar

Norsa, L., Bonaffini, P. A., Indriolo, A., Valle, C., Sonzogni, A., and Sironi, S. (2020). Poor outcome of intestinal ischemic manifestations of COVID-19. Gastroenterology 159, 1595.e1–1597.e1. doi: 10.1053/j.gastro.2020.06.041

PubMed Abstract | CrossRef Full Text | Google Scholar

Perepu, U. S., Chambers, I., Wahab, A., Ten Eyck, P., Wu, C., Dayal, S., et al. (2021). Standard prophylactic versus intermediate dose enoxaparin in adults with severe COVID-19: a multi-center, open-label, randomized controlled trial. J. Thromb. Haemost. 19, 2225–2234. doi: 10.1111/jth.15450

PubMed Abstract | CrossRef Full Text | Google Scholar

Pereyra, D., Heber, S., Schrottmaier, W. C., Santol, J., Pirabe, A., Schmuckenschlager, A., et al. (2021). Low molecular weight heparin use in COVID-19 is associated with curtailed viral persistence: a retrospective multicenter observational study. Cardiovasc. Res. 117, 2807–2820. doi: 10.1093/cvr/cvab308

PubMed Abstract | CrossRef Full Text | Google Scholar

Polak, S. B., Van Gool, I. C., Cohen, D., von der Thüsen, J. H., and van Paassen, J. (2020). A systematic review of pathological findings in COVID-19: a pathophysiological timeline and possible mechanisms of disease progression. Mod. Pathol. 33, 2128–2138. doi: 10.1038/s41379-020-0603-3

CrossRef Full Text | Google Scholar

Poor, H. D. (2021). Pulmonary thrombosis and thromboembolism in COVID-19. Chest 160, 1471–1480. doi: 10.1016/j.chest.2021.06.016

CrossRef Full Text | Google Scholar

Puelles, V. G., Lütgehetmann, M., Lindenmeyer, M. T., Sperhake, J. P., Wong, M. N., Allweiss, L., et al. (2020). Multiorgan and renal tropism of SARS-CoV-2. N. Engl. J. Med. 383, 590–592. doi: 10.1056/NEJMc2011400

PubMed Abstract | CrossRef Full Text | Google Scholar

Ramacciotti, E., Barile Agati, L., Calderaro, D., Aguiar, V. C. R., Spyropoulos, A. C., de Oliveira, C. C. C., et al. (2022). Rivaroxaban versus no anticoagulation for post-discharge thromboprophylaxis after hospitalisation for COVID-19 (MICHELLE): an open-label, multicentre, randomised, controlled trial. Lancet 399, 50–59. doi: 10.1016/S0140-6736(21)02392-8

PubMed Abstract | CrossRef Full Text | Google Scholar

RECOVERY Collaborative Group (2022). Aspirin in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial. Lancet 399, 143–151. doi: 10.1016/S0140-6736(21)01825-0

CrossRef Full Text | Google Scholar

RECOVERY Collaborative Group Horby, P., Lim, W. S., Emberson, J. R., Mafham, M., Bell, J. L., et al. (2020). Dexamethasone in hospitalized patients with Covid-19. N. Engl. J. Med. 384, 693–704. doi: 10.1056/NEJMoa2021436

PubMed Abstract | CrossRef Full Text | Google Scholar

REMAP-CAP Investigators ACTIV-4a Investigators ATTACC Investigators Goligher, E. C., Bradbury, C. A., McVerry, B. J., et al. (2021a). Therapeutic anticoagulation with heparin in critically ill patients with Covid-19. N. Engl. J. Med. 385, 777–789. doi: 10.1056/NEJMoa2103417

PubMed Abstract | CrossRef Full Text | Google Scholar

REMAP-CAP Investigators ACTIV-4a Investigators ATTACC Investigators Lawler, P. R., Goligher, E. C., Berger, J. S., et al. (2021b). Therapeutic anticoagulation with heparin in noncritically ill patients with Covid-19. N. Engl. J. Med. 385, 790–802. doi: 10.1056/NEJMoa2105911

PubMed Abstract | CrossRef Full Text | Google Scholar

Rizvi, A., Patel, Z., Liu, Y., Satapathy, S. K., Sultan, K., and Trindade, A. J. (2021). Gastrointestinal sequelae 3 and 6 months after hospitalization for coronavirus disease 2019. Clin. Gastroenterol. Hepatol. 19, 2438.e1–2440.e1. doi: 10.1016/j.cgh.2021.06.046

CrossRef Full Text | Google Scholar

Santoro, F., Nuñez-Gil, I. J., Vitale, E., Viana-Llamas, M. C., Reche-Martinez, B., Romero-Pareja, R., et al. (2022). Antiplatelet therapy and outcome in COVID-19: the health outcome predictive evaluation registry. Heart 108, 130–136. doi: 10.1136/thoraxjnl-2021-217561

PubMed Abstract | CrossRef Full Text | Google Scholar

Shi, J., and Gilbert, G. E. (2003). Lactadherin inhibits enzyme complexes of blood coagulation by completing for phospholipid binding sites. Blood 101, 2628–2636. doi: 10.1182/blood-2002-07-1951

PubMed Abstract | CrossRef Full Text | Google Scholar

Sholzberg, M., Tang, G. H., Rahhal, H., AlHamzah, M., Kreuziger, L. B., Áinle, F. N., et al. (2021). Effectiveness of therapeutic heparin versus prophylactic heparin on death, mechanical ventilation, or intensive care unit admission in moderately ill patients with covid-19 admitted to hospital: RAPID randomised clinical trial. BMJ 375:n2400. doi: 10.1136/bmj.n2400

CrossRef Full Text | Google Scholar

Spyropoulos, A. C., Goldin, M., Giannis, D., Diab, W., Wang, J., Khanijo, S., et al. (2021). Efficacy and safety of therapeutic-dose heparin vs. standard prophylactic or intermediate-dose heparins for thromboprophylaxis in high-risk hospitalized patients with COVID-19: the HEP-COVID randomized clinical trial. JAMA Intern. Med. 181, 1612–1620. doi: 10.1001/jamainternmed.2021.6203

PubMed Abstract | CrossRef Full Text | Google Scholar

Stefan, N., Birkenfeld, A. L., and Schulze, M. B. (2021). Global pandemics interconnected – obesity, impaired metabolic health and COVID-19. Nat. Rev. Endocrinol. 17, 135–149. doi: 10.1038/s41574-020-00462-1

CrossRef Full Text | Google Scholar

Stefely, J. A., Christensen, B. B., Gogakos, T., Cone Sullivan, J. K., Montgomery, G. G., Barranco, J. P., et al. (2020). Marked factor V activity elevation in severe COVID-19 is associated with venous thromboembolism. Am. J. Hematol. 95, 1522–1530. doi: 10.1002/ajh.25979

PubMed Abstract | CrossRef Full Text | Google Scholar

Suh, Y. J., Hong, H., Ohana, M., Bompard, F., Revel, M. P., Valle, C., et al. (2021). Pulmonary embolism and deep vein thrombosis in COVID-19: a systematic review and meta-analysis. Radiology 298, E70–E80. doi: 10.1148/radiol.2020203557

CrossRef Full Text | Google Scholar

Sultan, S., Altayar, O., Siddique, S. M., Davitkov, P., Feuerstein, J. D., Lim, J. K., et al. (2020). AGA institute rapid review of the gastrointestinal and liver manifestations of COVID-19, meta-analysis of international data, and recommendations for the consultative management of patients with COVID-19. Gastroenterology 159, 320.e27–334.e27. doi: 10.1053/j.gastro.2020.05.001

PubMed Abstract | CrossRef Full Text | Google Scholar

Susen, S., Tacquard, C. A., Godon, A., Mansour, A., Garrigue, D., Nguyen, P., et al. (2020). Prevention of thrombotic risk in hospitalized patients with COVID-19 and hemostasis monitoring. Crit. Care 24:364. doi: 10.1186/s13054-020-03000-7

CrossRef Full Text | Google Scholar

Tan, B. K., Mainbourg, S., Friggeri, A., Bertoletti, L., Douplat, M., Dargaud, Y., et al. (2021). Arterial and venous thromboembolism in COVID-19: a study-level meta-analysis. Thorax 76, 970–979. doi: 10.1136/thoraxjnl-2020-215383

PubMed Abstract | CrossRef Full Text | Google Scholar

Taus, F., Salvagno, G., Canè, S., Fava, C., Mazzaferri, F., Carrara, E., et al. (2020). Platelets promote thromboinflammation in SARS-CoV-2 pneumonia. Arterioscler. Thromb. Vasc. Biol. 40, 2975–2989. doi: 10.1161/ATVBAHA.120.315175

PubMed Abstract | CrossRef Full Text | Google Scholar

Ten Cate, H. (2021). Surviving Covid-19 with heparin? N. Engl. J. Med. 385, 845–846. doi: 10.1056/NEJMe2111151

PubMed Abstract | CrossRef Full Text | Google Scholar

Tenforde, M. W., Self, W. H., Adams, K., Gaglani, M., Ginde, A. A., McNeal, T., et al. (2021). Association between mRNA vaccination and COVID-19 hospitalization and disease severity. JAMA 326, 2043–2054. doi: 10.1001/jama.2021.19499

CrossRef Full Text | Google Scholar

Thompson, M. G., Burgess, J. L., Naleway, A. L., Tyner, H., Yoon, S. K., Meece, J., et al. (2021). Prevention and attenuation of Covid-19 with the BNT162b2 and mRNA-1273 vaccines. N. Engl. J. Med. 385, 320–329. doi: 10.1056/NEJMoa2107058

PubMed Abstract | CrossRef Full Text | Google Scholar

Tong, M., Jiang, Y., Xia, D., Xiong, Y., Zheng, Q., Chen, F., et al. (2020). Elevated expression of serum endothelial cell adhesion molecules in COVID-19 patients. J. Infect. Dis. 222, 894–898. doi: 10.1093/infdis/jiaa349

CrossRef Full Text | Google Scholar

Varga, Z., Flammer, A. J., Steiger, P., Haberecker, M., Andermatt, R., Zinkernagel, A. S., et al. (2020). Endothelial cell infection and endotheliitis in COVID-19. Lancet 395, 1417–1418. doi: 10.1016/S0140-6736(20)30937-5

PubMed Abstract | CrossRef Full Text | Google Scholar

Versteeg, H. H., Heemskerk, J. W., Levi, M., and Reitsma, P. H. (2013). New fundamentals in hemostasis. Physiol. Rev. 93, 327–358. doi: 10.1152/physrev.00016.2011

PubMed Abstract | CrossRef Full Text | Google Scholar

von Meijenfeldt, F. A., Havervall, S., Adelmeijer, J., Lundström, A., Magnusson, M., Mackman, N., et al. (2021). Elevated factor V activity and antigen levels in patients with Covid-19 are related to disease severity and 30-day mortality. Am. J. Hematol. 96, E98–E100. doi: 10.1002/ajh.26085

PubMed Abstract | CrossRef Full Text | Google Scholar

Wang, P., Nair, M. S., Liu, L., Iketani, S., Luo, Y., Guo, Y., et al. (2021). Antibody resistance of SARS-CoV-2 variants B.1.351 and B.1.1.7. Nature 593, 130–135. doi: 10.1038/s41586-021-03398-2

CrossRef Full Text | Google Scholar

Wang, W., Xu, Y., Gao, R., Han, K., Wu, G., and Tan, W. (2020). Detection of SARS-CoV-2 in different types of clinical specimens. JAMA 323, 1843–1844. doi: 10.1001/jama.2020.3786

PubMed Abstract | CrossRef Full Text | Google Scholar

Wölfel, R., Corman, V. M., Guggemos, W., Seilmaier, M., Zange, S., Müller, M. A., et al. (2020). Virological assessment of hospitalized patients with COVID-2019. Nature 581, 465–469. doi: 10.1038/s41586-020-2196-x

CrossRef Full Text | Google Scholar

Xiao, F., Sun, J., Xu, Y., Li, F., Huang, X., Li, H., et al. (2020a). Infectious SARS-CoV-2 in feces of patient with severe COVID-19. Emerg. Infect. Dis. 26, 1920–1922. doi: 10.3201/eid2608.200681

PubMed Abstract | CrossRef Full Text | Google Scholar

Xiao, F., Tang, M., Zheng, X., Liu, Y., Li, X., and Shan, H. (2020b). Evidence for gastrointestinal infection of SARS-CoV-2. Gastroenterology 158, 1831.e3–1833.e3. doi: 10.1053/j.gastro.2020.02.055

PubMed Abstract | CrossRef Full Text | Google Scholar

Xie, Y., Xu, E., Bowe, B., and Al-Aly, Z. (2022). Long-term cardiovascular outcomes of COVID-19. Nat. Med. doi: 10.1038/s41591-022-01689-3 [Epub ahead of print].

CrossRef Full Text | Google Scholar

Zaid, Y., Puhm, F., Allaeys, I., Naya, A., Oudghiri, M., Khalki, L., et al. (2020). Platelets can associate with SARS-CoV-2 RNA and are hyperactivated in COVID-19. Circ. Res. 127, 1404–1418. doi: 10.1161/CIRCRESAHA.120.317703

CrossRef Full Text | Google Scholar

Zamboni, P., Bortolotti, D., Occhionorelli, S., Traina, L., Neri, L. M., Rizzo, R., et al. (2021). Bowel ischemia as onset of COVID-19 in otherwise asymptomatic patients with persistently negative swab. J. Intern. Med. 291, 224–231. doi: 10.1111/joim.13385

CrossRef Full Text | Google Scholar

Zang, R., Gomez Castro, M. F., McCune, B. T., Zeng, Q., Rothlauf, P. W., Sonnek, N. M., et al. (2020). TMPRSS2 and TMPRSS4 promote SARS-CoV-2 infection of human small intestinal enterocytes. Sci. Immunol. 5:eabc3582. doi: 10.1126/sciimmunol.abc3582

CrossRef Full Text | Google Scholar

Zhang, Y., Chen, C., Zhu, S., Shu, C., Wang, D., Song, J., et al. (2020). Isolation of 2019-nCoV from a stool specimen of a laboratory- confirmed case of the coronavirus disease 2019 (COVID-19). China CDC Wkly 2, 123–124. doi: 10.46234/ccdcw2020.033

PubMed Abstract | CrossRef Full Text | Google Scholar

Zhang, P., He, Z., Yu, G., Peng, D., Feng, Y., Ling, J., et al. (2021). The modified NUTRIC score can be used for nutritional risk assessment as well as prognosis prediction in critically ill COVID-19 patients. Clin. Nutr. 40, 534–541. doi: 10.1016/j.clnu.2020.05.051

PubMed Abstract | CrossRef Full Text | Google Scholar

Zhang, H., Shao, B., Dang, Q., Chen, Z., Zhou, Q., Luo, H., et al. (2021). Pathogenesis and mechanism of gastrointestinal infection With COVID-19. Front. Immunol. 12:674074. doi: 10.3389/fimmu.2021.674074

CrossRef Full Text | Google Scholar

Zhao, F., Yang, Y., Wang, Z., Li, L., Liu, L., and Liu, Y. (2020). The time sequences of respiratory and rectal viral shedding in patients with coronavirus disease 2019. Gastroenterology 159, 1158.e2–1160.e2. doi: 10.1053/j.gastro.2020.05.035

CrossRef Full Text | Google Scholar

Zhong, P., Xu, J., Yang, D., Shen, Y., Wang, L., Feng, Y., et al. (2020). COVID-19-associated gastrointestinal and liver injury: clinical features and potential mechanisms. Signal Transduct. Target. Ther. 5:256. doi: 10.1038/s41392-020-00373-7

PubMed Abstract | CrossRef Full Text | Google Scholar

Zhou, J., Li, C., Liu, X., Chiu, M. C., Zhao, X., Wang, D., et al. (2020). Infection of bat and human intestinal organoids by SARS-CoV-2. Nat. Med. 26, 1077–1083. doi: 10.1038/s41591-020-0912-6

Review of Mesenteric Ischemia in COVID-19 Patients

Authors: Amit GuptaOshin SharmaKandhala SrikanthRahul MishraAmoli Tandon & Deepak Rajput  Indian Journal of Surgery (2022) Published: 

Abstract

The new coronavirus (COVID-19) infection, first detected in Wuhan, China in 2019 has become a pandemic that has spread to nearly every country in the world. Through October 11, 2021, more than 23 billion confirmed cases and 4.8 million fatalities were reported globally. The bulk of individuals afflicted in India during the first wave were elderly persons. The second wave, however, resulted in more severe diseases and mortality in even younger age groups due to mutations in the wild virus. Symptoms may range from being asymptomatic to fatal acute respiratory distress syndrome (ARDS). In addition to respiratory symptoms, patients may present with gastrointestinal symptoms such as stomach pain, vomiting, loose stools, or mesenteric vein thrombosis. The frequency of patients presenting with thromboembolic symptoms has recently increased. According to certain studies, the prevalence of venous thromboembolism among hospitalized patients ranges from 9 to 25%. It was also shown that the incidence is significantly greater among critically sick patients, with a prevalence of 21–31%. Although the exact origin of thromboembolism is unknown, it is considered to be produced by several altered pathways that manifest as pulmonary embolism, myocardial infarction, stroke, limb gangrene, and acute mesenteric ischemia. Acute mesenteric ischemia (AMI) is becoming an increasingly prevalent cause of acute surgical abdomen in both intensive care unit (ICU) and emergency room (ER) patients. Mesenteric ischemia should be evaluated in situations with unexplained stomach discomfort. In suspected situations, appropriate imaging techniques and early intervention, either non-surgical or surgical, are necessary to avert mortality. The purpose of this article is to look at the data on acute mesenteric ischemia in people infected with COVID-19.

Introduction

Aside from the respiratory system, the gastrointestinal system is the most common site of SARS-COV-2 infection. This might be because enterocyte and vascular endothelial membranes have large amounts of angiotensin-converting enzyme receptor 2, a membrane integral protein. As a result, the COVID virus induces direct enterocyte invasion as well as indirect endothelial injury-induced thrombosis/intestinal ischemia in the bowel [1]. ICU patients are more prone than non-ICU patients to suffer acute mesenteric ischemia. This might be because, in addition to the direct viral activity on vascular endothelium, ICU patients have extra persistent pro-inflammatory effects. Cases have been observed even among individuals who have recovered from infection [2]. A rising number of cases of acute mesenteric ischemia in COVID-19 patients have been reported in the literature since the outbreak of this pandemic (list of reported cases are summarized in the Table 1). AMI risk was shown to be increased with age, male sex, and comorbidities such as hypertension, obesity, and diabetes mellitus. Because of delayed clinical manifestation, AMI-related mortality is quite significant, with 60–80% [3].Table 1 Summary of the cases reported on mesenteric ischemia in COVID-19 patientsFull size table

Case summary

A 55 years old man with no known comorbidity presented to the emergency department of our institute with severe pain abdomen and multiple episodes of vomiting. He reported the recent recovery from the non-complicated COVID-related illness. He did not report any intake of anticoagulants. On clinical examination, abdomen was unremarkable. X-ray chest, x-ray erect abdomen, and ultrasound abdomen were unremarkable. Mesenteric ischemia was suspected and the patient was subjected to CT angiography abdomen, which revealed thrombus at the origin of the superior mesenteric artery and impending gangrene of the small bowel (Fig. 1). Emergency laparotomy was done and intraoperatively found the gangrenous bowel involving the distal jejunum and almost the entire ileum sparing the terminal ileum (Fig. 2). Resection of the gangrenous small bowel and end jejunostomy was done. Later, he was given ICU care, but unfortunately, the patient succumbed to multi-organ dysfunction syndrome.

figure 1
Fig. 1
figure 2
Fig. 2

Pathophysiology

Although the specific etiology of hypercoagulable state and subsequent mesenteric ischemia in COVID-19 patients is unknown, these thromboembolic events can be related to alterations in all three Virchow triad characteristics (vascular endothelial injury, hypercoagulability, and stasis). A variety of variables complicate the etiology of thrombus development, one of which is vascular endothelial injury. Capillary permeability, hemostasis, and fibrinolysis are all maintained by the vascular endothelium (Fig. 3). Direct invasion causes endothelial cells to be damaged and lysed, resulting in an imbalance between pro and anticoagulant states [4]. Furthermore, vascular endothelial cells displayed morphological changes such as cellular expansion, retraction, and intercellular connection breakage [5]. The elevated levels of pro-inflammatory markers, von Willebrand factor, tissue factor, fibrinogen, and circulating microvesicles in the COVID-19 patients explain their hypercoagulability [6]. Antiphospholipid antibodies are elevated in some situations [7]. Patients who are critically ill, on limited oxygen support, and mechanical breathing are less mobilized, which increases the risk of deep venous thrombosis [3].

figure 3
Fig. 3

These mesenteric vascular thromboses cause acute hypoxia in the intestinal wall, which stimulates the renin-angiotensin system, causing mesenteric vasospasm and an elevated risk of hypoxic injury. SARS-COV binds to ACE 2 receptors in intestinal cells, causing cell lysis [8]. As a result, both hypoxia and direct invasion can trigger intestinal cell death. The loss of this epithelial barrier function in the gut promotes increased contact with enteric bacteria/endotoxins and viral particle penetration into the circulation [5]. The hypoxia continues, resulting in transmural infarction, perforation, and peritonitis. In one example of mesenteric ischemia induced by invasive mucormycosis, the presence of fungal components in the mesenteric microcirculation was documented [2]. See the flow chart summarizing the pathophysiology of mesenteric ischemia in covid-19 infection.

Clinical Presentation

Patients with mesenteric ischemia may exhibit a range of symptoms, from nonspecific complaints to peritonitis-like symptoms. Most of the patients developed symptoms a few days after being discharged successfully with proper symptomatic inpatient care. Although the respiratory symptoms predominate mesenteric ischemia presents with nonspecific abdominal symptoms such as loose stools, abdominal pain, nausea, vomiting, abdominal distension, and bleeding per rectum may occur in addition to the usual clinical presentation with respiratory features [6]. When opposed to arterial thrombosis, venous thrombosis has a delayed onset of symptoms. At first, sudden onset pain in the abdomen may be the sole symptom, and it may develop after 5–14 days. Abdominal clinical examination is nonyielding in the majority of cases. Abdominal signs would not develop unless the bowel gangrene or bowel perforation with peritonitis occurs [9].

Investigations

Blood investigations

Despite extensive study on the subject of acute mesenteric ischemia, the associated biomarkers were shown to be neither sensitive nor selective [10]. Elevated lactic acid levels and fibrin degradation products like D-dimer have low specificity and remain elevated in severe COVID-19 without AMI. However, biomarkers associated with hypercoagulable conditions aid in the initiation of preventive treatment and, to a lesser extent, in the management of COVID-related thrombotic events. Increased biomarkers of inflammation and infection include leukopenia (due to corticosteroid usage) and other signs such as C-reactive protein, procalcitonin, and IL-6. D-dimer, ferritin, prothrombin time, and lactate dehydrogenase are additional significant markers. The severity of increased lactate dehydrogenase and ferritin levels is associated with high mortality[8].

Radiological imaging

In the emergency room, an X-ray of the abdomen and an ultrasound are helpful for early examinations. X-ray of the erect abdomen helps in initial assessment in cases presented with features of obstruction or perforation. Ultrasound in the early phase may show SMA occlusion and bowel spasm or ultrasound findings in the early stages of acute mesenteric ischemia may appear normal [11]. In the intermediate phase, USG is not useful because of the presence of a large amount of gas-filled intestinal loops. In the late phase, USG may reveal fluid-filled lumen, bowel wall thinning, evidence of extra-luminal fluid, decreased or absent peristalsis. Therefore, USG may be helpful in the diagnosis of advanced bowel obstruction, gangrene, and perforation with peritoneal collection [12]. Ultrasonography revealed some other important features with distended and sludge-filled gall bladder with bile stasis. Portal venous gas also can be detected on ultrasonography which can be better characterized with the help of computed tomography [13].

Computed tomography

The gold standard investigation is CT angiography. CT observations commonly encountered in acute mesenteric ischemia secondary to COVID-19 includes thrombus in the aorta/SMA/portal circulation, augmentation of the bowel wall, thickness of the bowel wall with distention(> 3 cm), edema, and stranding of the mesentery, pneumatosis intestinalis or portal venous gas suggesting bowel wall ischemia, and non-enhancing thick bowel wall seen in bowel infarction, bowel perforation secondary to bowel infarction may present discontinuity of bowel wall with localized air collection. One should remember that pneumatosis intestinalis may also occur due to mechanical ventilation. Pneumoperitoneum occurs when there is severe intestinal necrosis and perforation. There were additional reports of nonspecific features such as a dilated gut with a fluid-filled lumen, distended gallbladder with bile stasis, features of solid organ ischemia, and pancreatitis [14]. MRI, despite its accessibility, has drawbacks such as a longer acquisition time and lower resolution than CT angiography [12].

Management

A summary of cases of acute mesenteric ischemia has been tabulated (Table 1). Management of acute mesenteric ischemia in COVID-19 includes the following:

  • Supportive measures: Crystalloid rehydration and empirical antibacterial treatment should begin before angiography or any surgical resection. Comorbidity management, hemodynamic support in unstable patients, and electrolyte balance correction are all critical components of patient care [10].
  • Anticoagulation: There is insufficient data in 19 patients to warrant thromboprophylaxis. According to the Tang et al. study, low-dose heparin prophylaxis decreased thrombotic events and mortality in those with D-dimer levels over 3 mg/ml. Despite the increased risk of bleeding, mesenteric ischemia should be treated with intraoperative and postoperative anticoagulation [15].
  • Revascularisation: Revascularization with catheter-directed thrombolysis and thrombectomy by percutaneous/surgical intervention can be explored in instances where there is no indication of significant intestinal ischemia. Catheter-directed thrombolysis with unfractionated heparin and recombinant tissue plasminogen activators can accomplish this. Because of the increased risk of re-thrombosis, vascular clearance is not indicated in instances of superior mesenteric vein thrombus [15].
  • Resection of the gangrenous bowel: Depending on clinical suspicion, a CT angiography examination of mesenteric vasculature and bowel health can be performed, and an emergency exploration call should be placed. Intraoperatively, if the patient is normotensive, has no sepsis or peritonitis, and the remaining bowel viability is unquestionable, the gangrenous bowel is to be removed, and the remaining bowel can be considered for re-anastomosis. In unfavorable circumstances, a stoma should be created following gangrenous bowel resection [11]. The margin dissection in venous thrombosis should be broader than in arterial thrombosis. To assure the bowel’s survivability, abdominal closure should be temporary, and a relook laparotomy should be done 48 h later. Histopathological examination of the resected intestine may indicate patchy or widespread necrotic changes from mucosa to transmural thickness. In the submucosal vasculature, fibrin-containing microthrombi with perivascular neutrophilic infiltration is observed.
  • Management of short bowel syndrome: The therapy varies depending on the length of colon left after excision of infarcted bowel caused by mesenteric ischemia.
  • Medical- In severe diarrhea, fluid and electrolyte loss must be replaced. TPN for feeding and histamine-2 receptor antagonists or PPIs for stomach acid secretion reduction. Loperamide and diphenoxylate are anti-motility medicines that delay small intestine transit whereas Octreotide reduces the volume of gastrointestinal secretions.
  • Non-transplant surgical therapy- Done to improve the absorption capacity of the remaining intestine by restoring intestinal continuity. Increased nutrient and fluid absorption is the goal. Segmental reversal of the small bowel, fabrication of small intestinal valves, and electrical pacing of the small bowel are all procedures used to delay intestinal transit. Longitudinal intestinal lengthening and tailoring technique (LILT) and serial transverse arthroplasty process are two intestinal lengthening procedures (STEP).
  • Intestinal transplantation- Life-threatening problems such as liver failure, thrombosis of major central veins, frequent episodes of severe dehydration, and catheter-related sepsis are reasons for intestinal transplantation [16].

Prognosis

Acute mesenteric ischemia has a poor prognosis, and life is reliant on prompt diagnosis and treatment. If detected within 24 h, the likelihood of survival is 50%, but it declines to 30% beyond that [17].In operated cases, COVID infection acts as an independent risk factor and is responsible for higher mortality [18].

Conclusion

SARS-COV-2 infection even though initially thought to be respiratory infection; later cases detected presenting with multisystem involvement. The presentation may vary from asymptomatic or mildly symptomatic to severe respiratory distress syndrome or thromboembolic phenomenon requiring ICU care. The exact mechanism of thromboembolism is not established. However, the increasing number of acute mesenteric ischemia is quite alarming. The treating physician should be overcautious in patients presenting with abdominal symptoms either currently affected or recovered from COVID-related illness. In high-risk patients, early start of prophylactic anticoagulation may be beneficial. Earlier intervention is known acute mesenteric ischemia cases with operative or minimally invasive procedures may give higher survival benefits. It mandates more research to determine the causes of thromboembolism, as well as preventive and therapeutic anticoagulation in these individuals.

References

  1. Jin B, Singh R, Ha SE, Zogg H, Park PJ, Ro S (2021) Pathophysiological mechanisms underlying gastrointestinal symptoms in patients with COVID-19. World J Gastroenterol. Baishideng Publishing Group Co 27:2341–52CAS Article Google Scholar 
  2. Jain M, Tyagi R, Tyagi R, Jain G (2021) Post-COVID-19 gastrointestinal invasive mucormycosis. Indian J Surg 22:1–3
  3. Kerawala AA, Das B, Solangi A (2021) Mesenteric ischemia in COVID-19 patients: a review of current literature. World J Clin Cases 9(18):4700–4708Article Google Scholar 
  4. Kichloo A, Dettloff K, Aljadah M, Albosta M, Jamal S, Singh J et al (2020) COVID-19 and hypercoagulability: a review. Clin Appl Thromb 26
  5. Parry AH, Wani AH, Yaseen M (2020) Acute mesenteric ischemia in severe Coronavirus-19 (COVID-19): possible mechanisms and diagnostic pathway. Acad Radiol 27(8):1190Article Google Scholar 
  6. Cheung S, Quiwa JC, Pillai A, Onwu C, Tharayil ZJ, Gupta R (2020) Superior mesenteric artery thrombosis and acute intestinal ischemia as a consequence of COVID-19 infection. Am J Case Rep 21:1–3Google Scholar 
  7. Zhang Y, Xiao M, Zhang S, Xia P, Cao W, Jiang W et al (2020) Coagulopathy and antiphospholipid antibodies in patients with Covid-19. N Engl J Med. 382(17):e38Article Google Scholar 
  8. Al Mahruqi G, Stephen E, Abdelhedy I, Al WK (2021) Our early experience with mesenteric ischemia in COVID-19 positive patients. Ann Vasc Surg 73:129–132Article Google Scholar 
  9. Karna ST, Panda R, Maurya AP, Kumari S (2020) Superior mesenteric artery thrombosis in COVID-19 Pneumonia: an underestimated diagnosis—first case report in Asia. Indian J Surg 82(6):1235–1237Article Google Scholar 
  10. Singh B, Kaur P (2021) COVID-19 and acute mesenteric ischemia: a review of literature. Hematol Transfus Cell Ther 43(1):112–116Article Google Scholar 
  11. Janež J, Klen J (2021) Multidisciplinary diagnostic and therapeutic approach to acute mesenteric ischaemia: a case report with literature review. SAGE Open Med Case Rep 9:2050313X2110048Article Google Scholar 
  12. Mc W (2010) Acute mesenteric ischemia: diagnostic approach and surgical treatment. Semin Vasc Surg 23(1):9–20Article Google Scholar 
  13. Bhayana R, Som A, Li MD, Carey DE, Anderson MA, Blake MA et al (2020) Abdominal imaging findings in COVID-19: Preliminary observations. Radiology 297(1):E207–E215
  14. Keshavarz P, Rafiee F, Kavandi H, Goudarzi S, Heidari F, Gholamrezanezhad A (2021) Ischemic gastrointestinal complications of COVID-19: a systematic review on imaging presentation. Clin Imaging 73:86–95Article Google Scholar 
  15. Bergqvist D, Svensson PJ (2010) Treatment of mesenteric vein thrombosis. Semin Vasc Surg 23(1):65–68Article Google Scholar 
  16. Seetharam P, Rodrigues G (2011) Short bowel syndrome: a review of management options. Saudi J Gastroenterol 17(4):229–235Article Google Scholar 
  17. Krothapalli N, Jacob J (2021) A rare case of acute mesenteric ischemia in the setting of COVID-19 infection. Cureus 13(3):0–4Google Scholar 
  18. Haffner MR, Le HV, Saiz AM, Han G, Fine J, Wolinsky P et al (2021) Postoperative In-hospital morbidity and mortality of patients with COVID-19 infection compared with patients without COVID-19 infection. JAMA Netw Open 4(4):10–13Article Google Scholar 
  19. Ucpinar BA, Sahin C (2020) Superior mesenteric artery thrombosis in a patient with COVID-19: a unique presentation. J Coll Physicians Surg Pak 30(10):S112–S114Google Scholar 
  20. Khesrani LS, Chana k, Sadar FZ, Dahdouh A, Ladjadj Y, Bouguermouh D (2020) Intestinal ischemia secondary to Covid-19. J Pediatr Surg Case Rep 61:101604Article Google Scholar 
  21. Norsa L, Valle C, Morotti D, Bonaffini PA, Indriolo A, Sonzogni A (2020) Intestinal ischemia in the COVID-19 era. Dig Liver Dis 52(10):1090–1091CAS Article Google Scholar 
  22. Rodriguez-Nakamura RM, Gonzalez-Calatayud M, Martinez Martinez AR (2020) Acute mesenteric thrombosis in two patients with COVID-19. Two cases report and literature review. Int J Surg Case Rep 76:409–14Article Google Scholar 
  23. VartanogluAktokmakyan T, Tokocin M, Meric S, Celebi F (2021) Is mesenteric ischemia in COVID-19 patients a surprise? Surg Innov 28(2):236–238Article Google Scholar 
  24. Levolger S, Bokkers RPH, Wille J, Kropman RHJ, de Vries JPPM (2020) Arterial thrombotic complications in COVID-19 patients. J Vasc Surg Cases Innov Tech 6(3):454–459Article Google Scholar 
  25. Thuluva SK, Zhu H, Tan MML, Gupta S, Yeong KY, Wah STC et al (2020) A 29-year-old male construction worker from india who presented with left-sided abdominal pain due to isolated superior mesenteric vein thrombosis associated with SARS-CoV-2 infection. Am J Case Rep 21:1–5Article Google Scholar 
  26. Lari E, Lari A, AlQinai S, Abdulrasoul M, AlSafran S, Ameer A et al (2020) Severe ischemic complications in Covid-19—a case series. Int J Surg Case Rep 75(June):131–135Article Google Scholar 
  27. Singh B, Mechineni A, Kaur P, Ajdir N, Maroules M, Shamoon F et al (2020) Acute intestinal ischemia in a patient with COVID-19 infection. Korean J Gastroenterol 76(3):164–166Article Google Scholar 
  28. De Roquetaillade C, Chousterman BG, Tomasoni D, Zeitouni M, Houdart E (2020) Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID- 19. The COVID-19 resource centre is hosted on Elsevier Connect , the company ’ s public news and information. (January)
  29. Sehhat S, Talebzadeh H, Hakamifard A, Melali H, Shabib S, Rahmati A et al (2020) Acute mesenteric ischemia in a patient with COVID-19: a case report. Arch Iran Med 23(9):639–643Article Google Scholar 
  30. Beccara LA, Pacioni C, Ponton S, Francavilla S, Cuzzoli A (2020) Arterial mesenteric thrombosis as a complication of SARS-CoV-2 infection. Eur J Case Rep Intern Med 7(5).
  31. Ignat M, Philouze G, Aussenac-belle L (2020) Since January 2020 Elsevier has created a COVID-19 resource centre with free information in English and Mandarin on the novel coronavirus COVID- 19 . The COVID-19 resource centre is hosted on Elsevier Connect , the company ’ s public news and information. (Jan)
  32. Farina D, Rondi P, Botturi E, Renzulli M, Borghesi A, Guelfi D et al (2021) Gastrointestinal: bowel ischemia in a suspected coronavirus disease (COVID-19) patient. J Gastroenterol Hepatol 36(1):41CAS Article Google Scholar 
  33. Azouz E, Yang S, Monnier-Cholley L, Arrivé L (2020) Systemic arterial thrombosis and acute mesenteric ischemia in a patient with COVID-19. Intensive Care Med 46(7):1464–1465CAS Article Google Scholar 
  34. Vulliamy P, Jacob S, Davenport RA (2020) Acute aorto-iliac and mesenteric arterial thromboses as presenting features of COVID-19. Br J Haematol 189(6):1053–1054CAS Article Google Scholar 
  35. Bianco F, Ranieri AJ, Paterniti G, Pata F, Gallo G (2020) Acute intestinal ischemia in a patient with COVID-19. Tech Coloproctol 24(11):1217–1218CAS Article Google Scholar 
  36. Filho A do C, Cunha B da S (2020) Case report – inferior mesenteric vein thrombosis and COVID-19. 2020060282
  37. Mitchell JM, Rakheja D, Gopal P (2021) SARS-CoV-2-related hypercoagulable state leading to ischemic enteritis secondary to superior mesenteric artery thrombosis. Clin Gastroenterol Hepatol 19(11):e111CAS Article Google Scholar 
  38. English W, Banerjee S (2020) Coagulopathy and mesenteric ischaemia in severe SARS-CoV-2 infection. ANZ J Surg 90(9):1826Article Google Scholar 
  39. de Barry O, Mekki A, Diffre C, Seror M, El Hajjam M, Carlier RY (2020) Arterial and venous abdominal thrombosis in a 79-year-old woman with COVID-19 pneumonia. Radiol Case Rep 15(7):1054–1057Article Google Scholar 
  40. Kraft M, Pellino G, Jofra M, Sorribas M, Solís-Peña A, Biondo S, Espín-Basany E (2021) Incidence, features, outcome and impact on health system of de-novo abdominal surgical diseases in patients admitted with COVID-19. Surg J R Coll Surg Edinb Irel 19:e53–e58Google Scholar 
  41. Besutti G, Bonacini R, Iotti V, Marini G, Riva N, Dolci G et al (2020) Abdominal visceral infarction in 3 patients with COVID-19. Emerg Infect Dis 26(8):1926–1928CAS Article Google Scholar 
  42. Kielty J, Duggan WP, O’Dwyer M (2020) Extensive pneumatosis intestinalis and portal venous gas mimicking mesenteric ischaemia in a patient with SARS-CoV-2. Ann R Coll Surg Engl 102(6):E145–E147CAS Article Google Scholar 
  43. Pang JHQ, Tang JH, Eugene-Fan B (2021) A peculiar case of small bowel stricture in a coronavirus disease 2019 patient with congenital adhesion band and superior mesenteric vein thrombosis. Ann Vasc Surg 70:286–289Article Google Scholar 
  44. Osilli D, Pavlovica J, Mane R, Ibrahim M, Bouhelal A, Jacob S (2020) Case reports: mild COVID-19 infection and acute arterial thrombosis. J Surg Case Rep (9):1–3

SARS-CoV-2 and acute diverticulitis: The expanding gastrointestinal manifestations of COVID-19 infection

Authors: Simcha Weissman,Anna Belyayeva,Sachit Sharma,Muhammad Aziz, J Transl Int Med. 2021 Mar; 9(1): 59–60.Published online 2021 Mar 31. doi: 10.2478/jtim-2021-0019PMCID: PMC8016353PMID: 3385080

SARS-CoV-2, the novel coronavirus which emerged in late 2019, has spread rapidly and resulted in a global pandemic. Typical presenting symptoms of SARS-CoV-2 infection, that is, COVID-19, include fever, myalgias, fatigue, dry cough, dyspnea, and anosmia, with pneumonia being the most common disease complication. Although less frequent, gastrointestinal symptoms, including nausea, vomiting, abdominal pain, and diarrhea, have been reported and have in fact implicated the gastrointestinal tract as a primary system involved in the clinical expression of COVID-19. We describe the case of a patient who presented with gastrointestinal symptoms, tested COVID-19 positive, and was subsequently found to have pneumonia as well as acute diverticulitis. This report showcases the need to recognize the expanding gastrointestinal manifestations of the COVID-19 infection and remain astute to its subsequent, often nuanced, clinical implications.

A 61-year old female with a history of lupus nephritis status-post renal transplant, chronic pelvic venous thrombosis status-post vascular stenting, hypertension, and diverticulosis presented to the emergency department (ED) with three days of progressive nausea, vomiting, abdominal pain, and diarrhea. Physical examination revealed tachycardia, tachypnea, bilateral rales, and tenderness in the left lower abdomen. Laboratory tests revealed a leukocyte count of 8.3×103/μL, a neutrophil-to-lymphocyte ratio of 6.65, erythrocyte sedimentation rate of 127 mm/h (normal 0–15 mm/h), and d-dimer of 1,251 (normal < 500 ng/mL). SARS-CoV-2 pharyngeal swab rRT-PCR was positive. Chest radiograph revealed bilateral pulmonary opacities and consolidation. As the patient complained of continued abdominal pain, computed tomography (CT) abdomen and pelvis was ordered and revealed sigmoid colonic diverticular wall thickening and adjacent pericolonic fat stranding, consistent with acute diverticulitis. With bowel rest, intravenous antibiotics, analgesics, and supplemental oxygen, the patient improved and was discharged home after four days.

To our knowledge, while recent case reports have described gastrointestinal symptomatology of COVID-19, this represents the first reported case of COVID-19 associated acute diverticulitis. While the pathophysiologic mechanism is unclear, as with many of the manifestations of COVID-19, we hypothesize that viral entry via colonocyte angiotensin-converting enzyme 2 (ACE-2) receptors or a systemic inflammatory reaction may have been responsible.[1] Viral strain may also impact differential manifestations of COVID-19.[1] Interestingly, on a similar note, the etiopathogenesis of acute diverticulitis also remains uncertain, but the role of viral infection in a subset of cases has been postulated.[23] Notably, as the gastrointestinal symptomatology in this case could have been attributed solely to viral illness, imaging to make a diagnosis of acute diverticulitis may never have been pursued, and in fact was initially deferred. Awareness of this manifestation can help prevent overseeing common and acute gastrointestinal pathology of COVID-19. Moreover, gastrointestinal symptomatology are of unique significance in COVID-19 patients, in contrast to other viral illnesses, owning to the fact that they often appear early and worsen during the disease course.[4]

Thus, while COVID-19-induced diverticulitis remains seemingly rare and largely unexplored, clinicians should maintain a broad differential diagnosis in COVID positive patients presenting with gastrointestinal symptoms.[4] Additionally, on this basis, we believe it is vital to institute SARS-CoV-2 precautions in patients who present with either respiratory or gastrointestinal symptoms amidst the current pandemic. Moreover, as many aspects of this disease continue to be appreciated, clinicians should not shy away from ordering abdominal imaging when other/concomitant pathology is suspected in order to help facilitate earlier and potentially impactful real-time diagnosis and treatment.

References

1. Patel KP, Patel PA, Vunnam RR, Hewlett AT, Jain R, Jing R. Gastrointestinal, hepatobiliary, and pancreatic manifestations of COVID-19. J Clin Virol. 2020;128:104386. et al. [PMC free article] [PubMed] [Google Scholar]

2. Schieffer KM, Kline BP, Harris LR, Deiling S, Koltun WA, Youchum GS. A Differential Host Response to Viral Infection Defines a Subset of Earlier-Onset Diverticulitis Patients. J Gastrointestin Liver Dis. 2018;27:249–55. [PMC free article] [PubMed] [Google Scholar]

3. Hollink N, Dzabic M, Wolmer N, Bostrom L, Rahbar A. High Prevalence of an Active Human Cytomegalovirus Infection in Patients with Colonic Diverticulitis. J Clin Virol. 2007;40:116–9. [PubMed] [Google Scholar]

4. Galanopoulos M, Gkeros F, Doukatas A, Karianakis G, Pontas C, Tsoukalas N. COVID-19 pandemic: Pathophysiology and manifestations from the gastrointestinal tract. World J Gastroenterol. 2020;26:4579–4588. et al. [PMC free article] [PubMed] [Google Scholar]

Prevalence of organ impairment in Long COVID patients 6 and 12 months after initial symptoms

Authors:  Pooja Toshniwal PahariaMar 24 2022Reviewed by Danielle Ellis, B.Sc.

In a recent study posted to the medRxiv* preprint server, researchers assessed the prevalence of organ impairment in long coronavirus disease 2019 (COVID-19) six months and a year post-COVID-19 at London and Oxford.

Multi-organ impairment associated with long COVID-19 is a significant health burden. Standardized multi-organ evaluation is deficient, especially in non-hospitalized patients. Although the symptoms of long COVID-19, also known as post-acute sequelae of COVID-19 (PASC), are well-established, the natural history is poorly classified by symptoms, organ impairment, and function.

About the study

In the present prospective study, researchers assessed organ impairment in long COVID-19 patients six months and a year after the onset of early symptoms and correlated them to their clinical presentation.

The participants were recruited based on specialist referral or the response to advertisements in sites such as Mayo Clinic Healthcare, Perspectum, and Oxford from April 2020 to August 2021, based on their COVID-19 history.

The study was conducted on COVID-19 patients who recovered from the acute phase of the infection. Their health status, symptoms, and organ impairment were assessed. The symptoms assessed comprised cardiopulmonary, severe dyspnoea, and cognitive dysfunction. Biochemical and physiological parameters were analyzed at baseline and post-organ impairment. The radiological investigation comprised multi-organ magnetic resonance imaging (MRI) performed in the long COVID-19 patients and healthy controls.

Over a year, the team prospectively investigated the symptoms, organ impairment, and function, especially dyspnea, cognitive dysfunction, and health-related quality of life (HRQoL). They also evaluated the association between organ impairment and clinical symptoms.

Patients with symptoms of active pulmonary infections (body temperature >37.8°C or ≥3 coughing episodes in a day) and hospital discharges in the previous week or >4 months were excluded from the study. Asymptomatic patients and those with MRI contraindications such as defibrillators, pacemakers, devices with metal implants, and claustrophobia were removed.

Participants with impaired organs, as diagnosed by blood investigations, incidental findings, or MRI, were included in the follow-up assessments. Every visit comprised blood investigations, MRI scanning, and online questionnaire surveys, which were to be filled out beforehand. In addition, a sensitivity analysis was performed that excluded patients at risk of metabolic disorders (including body mass index (BMI) ≥30 kg/m2, diabetes, and hypertension)

Results

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Out of 536 participants, the majority were middle-aged (mean age 45 years), female (73%), White (89%), and healthcare workers (32%). About 13% of the COVID-19 patients hospitalized during the acute phase of the infection completed the baseline evaluation. A total of 331 patients (62%) had incidental findings, organ impairment, or reduction in the symptoms from the baseline at both the time points.

Cognitive dysfunction (50% and 38%), poor HRQoL (EuroQOL <0.7 in 55% and 45%), and severe dyspnea (36% and 30%) were observed at six months and one year, respectively. On follow-up, the symptoms were reduced, especially cardiopulmonary and systemic symptoms, whereas fatigue, dyspnea, and cognitive dysfunction were consistently present. The greatest impact on quality of life was related to pain and difficulties performing routine activities. Almost every patient took time off work due to COVID-19. The symptoms were largely associated with obese women, young age, and impairment of a single organ.

At baseline, fibrous inflammation was observed in the pancreas (9%), heart (9%), liver (11%), and kidney (15%). Additionally, increased volumes of the spleen (8%), kidney (9%), and liver (7%) were observed. Moreover, reduced lung capacity (2%), excess adipose deposits in pancreatic tissues (15%) and liver (25%) were observed. High liver fibro-inflammation was associated with cognitive dysfunction at follow-up in 19% and 12% of patients with and without cognitive dysfunction, respectively. Low liver fat was more likely in those without severe dyspnoea at both time points. Increased liver volumes at follow-up were associated with lower HRQoL scores.

The prevalence of multi and single-organ impairment was 23% and 59% at baseline, respectively, and persisted in 27% and 59% of the participants on follow-up assessments. Most of the organ impairments were mild. However, they did not improve substantially between visits. Notably, participants without organ impairment had the lowest symptom burden.

Most biochemical parameters were normal except creatinine kinase (8% and 13%), lactate dehydrogenase (16% and 22%), mean cell hemoglobin concentration (21% and 15%), and cholesterol (46% and 48%), at six months and a year post-COVID-19, respectively. These biochemical markers increased from the baseline on follow-up assessments.

Conclusion

To summarize, organ impairment was detected in 59% of the patients at six months post-COVID-19 and persisted in 59% at one-year follow-up. This has significant implications on the quality of life, symptoms, and long-term health of the patients. These observations highlight the requirement for enhanced preventive measures and integrated patient care to decrease the long COVID-19 burden.

Journal reference:

Different SARS-CoV-2 variants may give rise to different long COVID symptoms, study suggests

Italian study of long-COVID patients suggests those infected with the Alpha variant experienced different neurological and emotional symptoms compared to those who contracted the original form of SARS-CoV-2

Authors: EUROPEAN SOCIETY OF CLINICAL MICROBIOLOGY AND INFECTIOUS DISEASES

24-MAR-2022

New research to be presented at this year’s European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Lisbon, Portugal (23-26 April), suggests that the symptoms connected to long COVID could be different in people who are infected with different variants. The study is by Dr Michele Spinicci and colleagues from the University of Florence and Careggi University Hospital in Italy.

Estimates suggest that over half of survivors of SARS-CoV-2 infection experience post-acute sequelae of COVID-19 (PASC), more commonly known as ‘long COVID’ [1]. The condition can affect anyone—old and young, otherwise healthy, and those with underlying conditions. It has been seen in people who were hospitalised with COVID-19 and those with mild symptoms. But despite an increasing body of literature, long COVID remains poorly understood.

In this study, researchers did a retrospective observational study of 428 patients—254 (59%) men and 174 (41%) women—treated at the Careggi University Hospital’s post-COVID outpatient service between June 2020 and June 2021, when the original form of SARS-CoV-2 and the Alpha variant were circulating in the population. The patients had been hospitalised with COVID-19 and discharged 4-12 weeks before attending a clinical visit at the outpatient service and completing a questionnaire on persistent symptoms (an average [median] of 53 days after hospital discharge). In addition, data on medical history, microbiological and clinical COVID-19 course, and patient demographics were obtained from electronic medical records.

At least three-quarters 325/428 (76%) of patients reported at least one persistent symptom. The most common reported symptoms were shortness of breath (157/428; 37%) and chronic fatigue (156/428; 36%) followed by sleep problems (68/428; 16%), visual problems (55/428; 13%), and brain fog (54/428; 13%).

Analyses suggest that people with more severe forms, who required immunosuppressant drugs such as tocilizumab, were six times as likely to report long COVID symptoms, while those who received high flow oxygen support were 40% more likely to experience ongoing problems. Women were almost twice as likely to report symptoms of long COVID compared with men. However, patients with type 2 diabetes seemed to have a lower risk of developing long COVID symptoms. The authors say that further studies are needed to better understand this unexpected finding.

Researchers performed a more detailed evaluation comparing the symptoms reported by patients infected between March and December 2020 (when the original SARS-COV-2 was dominant) with those reported by patients infected between January and April 2021 (when Alpha was the dominant variant) and discovered a substantial change in the pattern of neurological and cognitive/emotional problems.

They found that when the Alpha variant was the dominant strain, the prevalence of myalgia (muscle aches and pain), insomnia, brain fog and anxiety/depression significantly increased, while anosmia (loss of smell), dysgeusia (difficulty in swallowing), ad impaired hearing were less common (figure 2 in notes to editors).

“Many of the symptoms reported in this study have been measured, but this is the first time they have been linked to different COVID-19 variants”, says Dr Spinicci. “The long duration and broad range of symptoms reminds us that the problem is not going away, and we need to do more to support and protect these patients in the long term. Future research should focus on the potential impacts of variants of concern and vaccination status on ongoing symptoms.”

The authors acknowledge that the study was observational and does not prove cause and effect, and they could not confirm which variant of the virus caused the infection in different patients—which may limit the conclusions that can be drawn.