Gastrointestinal mucosal damage in patients with COVID-19 undergoing endoscopy: an international multicentre study

Association Between SARS-CoV-2 Infection and Acute Ischemic Colitis

Purpose

Ischemic colitis appears to be a rare but serious complication of COVID-19. About 33.3% hospitalized COVID-19 patients who underwent endoscopy showed features resembling ischemic colitis. The aim of this prospective study was to describe the symptoms, treatment, and outcomes of these patients, particularly their colonoscopy and histologic findings.

Patients and methods

We conducted a prospective study on ischemic bowel disease associated with COVID-19 across four centers from December 2022 to January 2023. All cases were identified through a comprehensive search of electronic medical records for procedure-related data. The initial diagnosis of ischemic bowel disease was confirmed using colonoscopy and biopsy findings. After the patients were discharged, a 12-month follow-up was conducted through regular phone interviews to assess their clinical outcomes.

Results

Overall, the study included 3 male patients and 9 female patients (age range, 33-76 years). Abdominal pain and hematochezia always occurred within 2 weeks after COVID-19 infection (average 5.5 days). Gastrointestinal manifestations did not parallel the severity of COVID-19 infection. The descending colon was the most susceptible segment, which was involved in 10 patients (83.33%). Colonoscopy revealed diffuse redness, edema, bleeding, erosion, and ulceration of the intestinal mucosa, similar to the findings of ischemic colitis, and biopsy revealed crypt atrophy, reduction, and interstitial bleeding. All patients were self-limited without converting to chronic changes in the next 12 months.

Conclusion

SARS-CoV-2 infection may induce transient acute colon ischemia within 2 weeks, accompanied by severe clinical symptoms such as acute abdominal pain and hematochezia, which are self-limiting and do not lead to chronic symptoms.

Acute liver failure with a massive upper GI bleed meeting the criteria of MIS-C

Multisystem inflammatory syndrome in children (MIS-C) is a known complication of COVID-19. There is still limited knowledge about this condition. Here, we report the case of a previously healthy toddler boy, who presented with acute liver failure and duodenal lesions resulting in severe haematemesis and haemorrhagic shock, requiring intensive care unit care. The patient had persistent transaminitis, a deranged coagulation profile, inflammatory markers were elevated, and laboratory tests were negative for common infectious hepatitis aetiologies as well as COVID-19 Reverse transcription polymerase chain reaction. His COVID-19 antibody was reactive. Upper gastrointestinal endoscopy revealed a Forrest grade III duodenal ulcer. Looking into the constellation of symptoms and laboratory findings a confirmed diagnosis of acute viral hepatitis caused by MIS-C was made. Hence, he was given intravenous methylprednisolone along with intravenous immunoglobulins, after which he improved clinically and transaminitis resolved. The patient was discharged on clinical improvement and was doing fine on follow-up up to 6 months.

Sintilimab-induced severe erosive hemorrhagic gastritis and pyloric obstruction: a case report and literature review

Immune checkpoint inhibitors could restore immune surveillance to attack tumor through targeting CTLA-4, PD-1 or PD-L1, and have achieved huge success. However, immune-related adverse events (irAEs) have been attracting attention as their application is expanding. Gastritis is relatively rare as a subtype of irAEs, particularly severe gastritis. Guidelines on its clinical management still remain undefined due to limited data. Sintilimab is a PD-1 inhibitor approved in China. Here we offer a case of sintilimab-induced severe erosive hemorrhagic gastritis and pyloric obstruction. Conventional proton pump inhibitors and mucosal protective agents did not take effect, so glucocorticoid was chosen. This severe gastritis was successfully cured finally. Our report describing its clinical performances, endoscopic characteristics and treatments, could assist clinicians to better know this rare irAE.

Incidence of persistent SARS-CoV-2 gut infection in patients with a history of COVID-19: Insights from endoscopic examination

Background and study aims Gut infection is common during acute COVID-19, and persistent SARS-CoV-2 gut infection has been reported months after the initial infection, potentially linked to long-COVID syndrome. This study tested the incidence of persistent gut infection in patients with a history of COVID-19 undergoing endoscopic examination. Patients and methods Endoscopic biopsies were prospectively collected from patients with previous COVID-19 infection undergoing upper or lower gastrointestinal endoscopy (UGE or LGE). Immunohistochemistry was used to detect the presence of persistent SARS-CoV-2 nucleocapsid proteins. Results A total of 166 UGEs and 83 LGE were analyzed. No significant differences were observed between patients with positive and negative immunostaining regarding the number of previous COVID-19 infections, time since the last infection, symptoms, or vaccination status. The incidence of positive immunostaining was significantly higher in UGE biopsies than in LGE biopsies (37.34% vs. 16.87%, P =0.002). Smokers showed a significantly higher incidence of positive immunostaining in the overall cohort and UGE and LGE subgroups ( P <0.001). Diabetic patients exhibited a significantly higher incidence in the overall cohort ( P =0.002) and UGE subgroup ( P =0.022), with a similar trend observed in the LGE subgroup ( P =0.055). Conclusions Gut mucosal tissues can act as a long-term reservoir for SARS-CoV-2, retaining viral particles for months following the primary COVID-19 infection. Smokers and individuals with diabetes may be at an increased risk of persistent viral gut infection. These findings provide insights into the dynamics of SARS-CoV-2 infection in the gut and have implications for further research.

Impact of COVID-19 infection on patients admitted with nonvariceal upper gastrointestinal bleeding: an analysis from the National Inpatient Sample

Background

Nonvariceal upper gastrointestinal bleeding (NVUGIB) is a medical emergency that has significant morbidity and mortality. The available data about the impact of COVID-19 infection on mortality in patients with NVUGIB is limited.

Methods

We identified all hospitalizations with a principal diagnosis of NVUGIB in 2020. The baseline characteristics and clinical outcomes of patients with COVID-19 infection were compared to those without COVID-19 infection.

Results

NVUGIB patients with COVID-19 infection had higher mortality (5% vs 2%, P < 0.0001), a longer mean length of stay (6.85 vs 4.48 days, P < 0.0001), and a lower rate of esophagogastroduodenoscopy utilization (40% vs 51%, P < 0.0001) than those without COVID-19 infection. Multivariate logistic regression analysis showed that COVID-19 infection was associated with a higher mortality rate (odds ratio 2.2, 95% confidence interval, 1.4-3.4).

Conclusions

COVID-19 infection is an independent predictor of mortality in adults hospitalized with NVUGIB.

Gastroprotective Role of Fruit Extracts in Gastric Damage Induced by Non-Steroidal Anti-Inflammatory Drugs: A Systematic Review

The aim of this study was to systematically review the scientific literature, with Preferred Reporting Items of Systematic Reviews and Meta-analyses (PRISMA) guidelines, of the articles found in the past 11 years on the gastroprotective role of fruit extracts in gastric ulcers induced by non-steroidal anti-inflammatory drugs (NSAIDs). Scientific articles published between 2010 and 2020 were included in this systematic review, including in vitro and in vivo models, to define the gastroprotective role of fruit extracts. Studies were selected by Rayyan using PubMed, Web of Science, Scopus, and Science Direct databases. The keywords for the search strategy were: "gastric injury," "gastric ulcer," "fruit," "indomethacin," and "aspirin." Twenty-two articles with animal models of gastric ulcers were included. The NSAIDs used were aspirin and indomethacin. To know the damage caused by these, the ulceration index and biomarkers, such as aggressive/defensive factors involved in the gastric ulceration process, were measured. Most studies have shown that fruit extracts have antiulcer activity, with the most abundant metabolites being flavonoids, followed by terpenes and alkaloids. Possible antiulcer activities such as antioxidant, cytoprotective, gastric acid antisecretory, anti-inflammatory, or angiogenesis stimulant were declared, manifested mainly as a reduction of lipid peroxidation products, an increase in antioxidant enzymes and prostaglandins, and by the formation of a protective film through protein precipitation in the ulcer area. This systematic review demonstrates the importance of fruit extracts as gastric protectors.

COVID-19 severity is associated with the risk of gastrointestinal bleeding

OBJECTIVE

The association between the severity of COVID-19 and gastrointestinal (GI) bleeding is unknown. This study aimed to determine whether the severity of COVID-19 is a risk factor for GI bleeding.

DESIGN

A multicentre, retrospective cohort study was conducted on hospitalised patients with COVID-19 between January 2020 and December 2021. The severity of COVID-19 was classified according to the National Institute of Health severity classification. The primary outcome was the occurrence of GI bleeding during hospitalisation. The main analysis compared the relationship between the severity of COVID-19 and the occurrence of GI bleeding. Multivariable logistic regression analysis was performed to evaluate the association between the severity of COVID-19 and the occurrence of GI bleeding.

RESULTS

12 044 patients were included. 4165 (34.6%) and 1257 (10.4%) patients had severe and critical COVID-19, respectively, and 55 (0.5%) experienced GI bleeding. Multivariable analysis showed that patients with severe COVID-19 had a significantly higher risk of GI bleeding than patients with non-severe COVID-19 (OR: 3.013, 95% CI: 1.222 to 7.427). Patients with critical COVID-19 also had a significantly higher risk of GI bleeding (OR: 15.632, 95% CI: 6.581 to 37.130). Patients with severe COVID-19 had a significantly increased risk of lower GI bleeding (OR: 10.349, 95% CI: 1.253 to 85.463), but the risk of upper GI bleeding was unchanged (OR: 1.875, 95% CI: 0.658 to 5.342).

CONCLUSION

The severity of COVID-19 is associated with GI bleeding, and especially lower GI bleeding was associated with the severity of COVID-19. Patients with severe or critical COVID-19 should be treated with caution as they are at higher risk for GI bleeding.

COVID-19 and Gastrointestinal Tract: From Pathophysiology to Clinical Manifestations

Background: Since its first report in Wuhan, China, in December 2019, COVID-19 has become a pandemic, affecting millions of people worldwide. Although the virus primarily affects the respiratory tract, gastrointestinal symptoms are also common. The aim of this narrative review is to provide an overview of the pathophysiology and clinical manifestations of gastrointestinal COVID-19. Methods: We conducted a systematic electronic search of English literature up to January 2023 using Medline, Scopus, and the Cochrane Library, focusing on papers that analyzed the role of SARS-CoV-2 in the gastrointestinal tract. Results: Our review highlights that SARS-CoV-2 directly infects the gastrointestinal tract and can cause symptoms such as diarrhea, nausea/vomiting, abdominal pain, anorexia, loss of taste, and increased liver enzymes. These symptoms result from mucosal barrier damage, inflammation, and changes in the microbiota composition. The exact mechanism of how the virus overcomes the acid gastric environment and leads to the intestinal damage is still being studied. Conclusions: Although vaccination has increased the prevalence of less severe symptoms, the long-term interaction with SARS-CoV-2 remains a concern. Understanding the interplay between SARS-CoV-2 and the gastrointestinal tract is essential for future management of the virus.

Excess Deaths of Gastrointestinal, Liver, and Pancreatic Diseases During the COVID-19 Pandemic in the United States

Objectives: To evaluate excess deaths of gastrointestinal, liver, and pancreatic diseases in the United States during the COVID-19 pandemic. Methods: We retrieved weekly death counts from National Vital Statistics System and fitted them with a quasi-Poisson regression model. Cause-specific excess deaths were calculated by the difference between observed and expected deaths with adjustment for temporal trend and seasonality. Demographic disparities and temporal-spatial patterns were evaluated for different diseases. Results: From March 2020 to September 2022, the increased mortality (measured by excess risks) for Clostridium difficile colitis, gastrointestinal hemorrhage, and acute pancreatitis were 35.9%; 24.8%; and 20.6% higher than the expected. For alcoholic liver disease, fibrosis/cirrhosis, and hepatic failure, the excess risks were 1.4-2.8 times higher among younger inhabitants than older inhabitants. The excess deaths of selected diseases were persistently observed across multiple epidemic waves with fluctuating trends for gastrointestinal hemorrhage and fibrosis/cirrhosis and an increasing trend for C. difficile colitis. Conclusion: The persistently observed excess deaths of digestive diseases highlights the importance for healthcare authorities to develop sustainable strategies in response to the long-term circulating of SARS-CoV-2 in the community.

Neutrophil Activation and Immune Thrombosis Profiles Persist in Convalescent COVID-19

PURPOSE

Following a severe COVID-19 infection, a proportion of individuals develop prolonged symptoms. We investigated the immunological dysfunction that underlies the persistence of symptoms months after the resolution of acute COVID-19.

METHODS

We analyzed cytokines, cell phenotypes, SARS-CoV-2 spike-specific and neutralizing antibodies, and whole blood gene expression profiles in convalescent severe COVID-19 patients 1, 3, and 6 months following hospital discharge.

RESULTS

We observed persistent abnormalities until month 6 marked by (i) high serum levels of monocyte/macrophage and endothelial activation markers, chemotaxis, and hematopoietic cytokines; (ii) a high frequency of central memory CD4+ and effector CD8+ T cells; (iii) a decrease in anti-SARS-CoV-2 spike and neutralizing antibodies; and (iv) an upregulation of genes related to platelet, neutrophil activation, erythrocytes, myeloid cell differentiation, and RUNX1 signaling. We identified a "core gene signature" associated with a history of thrombotic events, with upregulation of a set of genes involved in neutrophil activation, platelet, hematopoiesis, and blood coagulation.

CONCLUSION

The lack of restoration of gene expression to a normal profile after up to 6 months of follow-up, even in asymptomatic patients who experienced severe COVID-19, signals the need to carefully extend their clinical follow-up and propose preventive measures.

SARS-CoV-2 and gastrointestinal diseases

Background

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is the causative agent of the novel coronavirus disease (COVID-19) pandemic, which has caused serious challenges for public health systems worldwide.

Literature review

SARS-CoV-2 invades not only the respiratory system, but also the digestive system, causing a variety of gastrointestinal diseases.

Significance

Understanding the gastrointestinal diseases caused by SARS-CoV-2, and the damage mechanisms of SARS-CoV-2 to the gastrointestinal tracts and gastrointestinal glands are crucial to treating the gastrointestinal diseases caused by SARS-CoV-2.

Conclusion

This review summarizes the gastrointestinal diseases caused by SARS-CoV-2, including gastrointestinal inflammatory disorders, gastrointestinal ulcer diseases, gastrointestinal bleeding, and gastrointestinal thrombotic diseases, etc. Furthermore, the mechanisms of gastrointestinal injury induced by SARS-COV-2 were analyzed and summarized, and the suggestions for drug prevention and treatment were put forward for the reference of clinical workers.

Gastrointestinal disorders in post-COVID syndrome. Clinical guidelines

Summary Post- COVID syndrome refers to the long-term consequences of a new coronavirus infection COVID-19, which includes a set of symptoms that develop or persist after COVID-19. Symptoms of gastrointestinal disorders in post- COVID syndrome, due to chronic infl ammation, the consequences of organ damage, prolonged hospitalization, social isolation, and other causes, can be persistent and require a multidisciplinary approach. The presented clinical practice guidelines consider the main preventive and therapeutic and diagnostic approaches to the management of patients with gastroenterological manifestations of postCOVID syndrome. The Guidelines were approved by the 17th National Congress of Internal Medicine and the 25th Congress of Gastroenterological Scientifi c Society of Russia.

The Spectrum of Digestive Tract Histopathologic Findings in the Setting of Severe Acute Respiratory Syndrome Coronavirus-2 Infection: What Pathologists Need to Know

Although the novel severe acute respiratory syndrome coronavirus-2 is known primarily to affect the respiratory system, current evidence supports its capability to infect and induce gastrointestinal tract injury. Data describing the histopathologic alterations of the digestive system in patients infected with severe acute respiratory syndrome coronavirus-2 are becoming more detailed, as the number of studies is increasing and the quality of our insight into the infection and the histopathologic findings is improving. This review highlights the range of pathologic findings that could be observed in gastrointestinal specimens from patients infected with coronavirus disease 2019 and the potential underlying pathogenetic mechanisms of this disease.

Intestinal Damage, Inflammation and Microbiota Alteration during COVID-19 Infection

Background: The virus SARS-CoV-2 is responsible for respiratory disorders due to the fact that it mainly infects the respiratory tract using the Angiotensin-converting enzyme 2 (ACE2) receptors. ACE2 receptors are also highly expressed on intestinal cells, representing an important site of entry for the virus in the gut. Literature studies underlined that the virus infects and replicates in the gut epithelial cells, causing gastrointestinal symptoms such as diarrhea, abdominal pain, nausea/vomiting and anorexia. Moreover, the SARS-CoV-2 virus settles into the bloodstream, hyperactivating the platelets and cytokine storms and causing gut–blood barrier damage with an alteration of the gut microbiota, intestinal cell injury, intestinal vessel thrombosis leading to malabsorption, malnutrition, an increasing disease severity and mortality with short and long-period sequelae. Conclusion: This review summarizes the data on how SARS-CoV-2 effects on the gastrointestinal systems, including the mechanisms of inflammation, relationship with the gut microbiota, endoscopic patterns, and the role of fecal calprotectin, confirming the importance of the digestive system in clinical practice for the diagnosis and follow-up of SARS-CoV-2 infection.

Colitis as the Main Presentation of COVID-19: A Case Report

The main symptoms of coronavirus disease (COVID-19) are fever, cough, tiredness, and loss of smell and taste. Gastrointestinal symptoms are less common. A 38-year-old female patient, previously healthy, presented with a history of hematochezia up to 8 times per day, followed by abdominal cramps, urgency, and chills for two days. She did not have any respiratory symptoms and was previously vaccinated for COVID-19. She was afebrile, with normal vital signs. Blood samples showed normal complete blood count and increased C-reactive protein (CRP), fibrinogen, and D-dimer levels (66 mg/L, 4.1 g/L, and 2302 μ/L FEU, respectively). Stool samples for stool culture, C. difficile, and viral examination came back negative. On day 3, she reported a mild cough, fever and loss of smell and taste. Nasopharyngeal swab for SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) PCR test came back positive. On day 6, the patient still had hematochezia accompanied by abdominal cramps, but fever and respiratory symptoms withdrew. CRP, fibrinogen, and D-dimers were still elevated, as well as liver enzyme levels. Sigmoidoscopy was performed with biopsies taken from sigmoid and rectum for histology and PCR SARS-CoV-2 testing. CT angiography showed no signs of thrombosis in mesenteric veins or arteries. PCR test for SARS-CoV-2 virus from rectal biopsy sample was positive. Patient was treated with methylprednisolone iv for two days and peroral prednisone afterwards, with mesalamine, metronidazole and enoxaparin. Sigmoidoscopy was repeated after two weeks showing only mild hyperemia. At that time, the patient had normal stool, normal CRP, liver enzyme, fibrinogen, and D-dimer levels, and normocytic anemia (hemoglobin level of 103 g/L). We wanted to show that severe gastrointestinal symptoms, such as hemorrhagic colitis, can be the main presentation of COVID-19, even in young patients with no prior comorbidities. In such a case, PCR test in biopsy samples can be performed to prove SARS-CoV-2 infection of bowel mucosa.

COVID-19 Patients with Early Gastrointestinal Symptoms Show Persistent Deficits in Specific Attention Subdomains

Previous studies have shown that COVID-19 inpatients exhibited significant attentional deficits on the day of discharge. However, the presence of gastrointestinal symptoms (GIS) has not been evaluated. Here, we aimed to verify: (1) whether COVID-19 patients with GIS exhibited specific attention deficits; (2) which attention subdomain deficits discriminated patients with GIS and without gastrointestinal symptoms (NGIS) from healthy controls. On admission, the presence of GIS was recorded. Seventy-four physically functional COVID-19 inpatients at discharge and sixty-eight controls underwent a Go/No-go computerized visual attentional test (CVAT). A Multivariate Analysis of Covariance (MANCOVA) was performed to examine group differences in attentional performance. To discriminate which attention subdomain deficits discriminated GIS and NGIS COVID-19 patients from healthy controls, a discriminant analysis was applied using the CVAT variables. The MANCOVA showed a significant overall effect of COVID-19 with GIS on attention performance. The discriminant analysis indicated that the GIS group could be differentiated from the controls by variability of reaction time and omissions errors. The NGIS group could be differentiated from controls by reaction time. Late attention deficits in COVID-19 patients with GIS may reflect a primary problem in the sustained and focused attention subsystems, whereas in NGIS patients the attention problems are related to the intrinsic-alertness subsystem.

Pathologic Characteristics of Digestive Tract and Liver in Patients with Coronavirus Disease 2019

With the high prevalence of coronavirus disease-2019 (COVID-19), there has been increasing understanding of the pathologic changes associated with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). This review summarizes the pathologic changes in the digestive system and liver associated with COVID-19, including the injuries induced by SARS-CoV2 infection of GI epithelial cells and the systemic immune responses. The common digestive manifestations associated with COVID-19 include anorexia, nausea, vomiting, and diarrhea; the clearance of the viruses in COVID-19 patients with digestive symptoms is usually delayed. COVID-19-associated gastrointestinal histopathology is characterized by mucosal damage and lymphocytic infiltration. The most common hepatic changes are steatosis, mild lobular and portal inflammation, congestion/sinusoidal dilatation, lobular necrosis, and cholestasis.

The Impact of COVID-19 Infection on Miscellaneous Inflammatory Disorders of the Gastrointestinal Tract

The novel coronavirus pandemic of COVID-19 has emerged as a highly significant recent threat to global health with about 600,000,000 known infections and more than 6,450,000 deaths worldwide since its emergence in late 2019. COVID-19 symptoms are predominantly respiratory, with mortality largely related to pulmonary manifestations, but the virus also potentially infects all parts of the gastrointestinal tract with related symptoms and manifestations that affect patient treatment and outcome. COVID-19 can directly infect the gastrointestinal tract because of the presence of widespread angiotensin-converting enzyme 2 receptors in the stomach and small intestine that can cause local COVID-19 infection and associated inflammation. This work reviews the pathopysiology, clinical manifestations, workup, and treatment of miscellaneous inflammatory disorders of the gastrointestinal tract other than inflammatory bowel disease.

Gastrointestinal Bleeding in COVID-19-Infected Patients

COVID-19 infection is an ongoing catastrophic global pandemic with significant morbidity and mortality that affects most of the world population. Respiratory manifestations predominate and largely determine patient prognosis, but gastrointestinal (GI) manifestations also frequently contribute to patient morbidity and occasionally affect mortality. GI bleeding is usually noted after hospital admission and is often one aspect of this multisystem infectious disease. Although the theoretical risk of contracting COVID-19 from GI endoscopy performed on COVID-19-infected patients remains, the actual risk does not seem to be high. The introduction of PPE and widespread vaccination gradually increased the safety and frequency of performing GI endoscopy in COVID-19-infected patients. Three important aspects of GI bleeding in COVID-19-infected patients are (1) GI bleeding is often from mucosal erosions from mucosal infalammation that causes mild GI bleeding; (2) severe upper GI bleeding is often from PUD or stress gastritis from COVID-19 pneumonia; and (3) lower GI bleeding frequently arises from ischemic colitis associated with thromboses and hypercoagulopathy from COVID-19 infection. The literature concerning GI bleeding in COVID-19 patients is presently reviewed.

Diarrhea and Coronavirus Disease 2019 Infection

The global coronavirus disease-2019 (COVID-19) pandemic has caused significant morbidity and mortality, thoroughly affected daily living, and caused severe economic disruption throughout the world. Pulmonary symptoms predominate and account for most of the associated morbidity and mortality. However, extrapulmonary manifestations are common in COVID-19 infections, including gastrointestinal (GI) symptoms, such as diarrhea. Diarrhea affects approximately 10% to 20% of COVID-19 patients. Diarrhea can occasionally be the presenting and only COVID-19 symptom. Diarrhea in COVID-19 subjects is usually acute but is occasionally chronic. It is typically mild-to-moderate and nonbloody. It is usually much less clinically important than pulmonary or potential thrombotic disorders. Occasionally the diarrhea can be profuse and life-threatening. The entry receptor for COVID-19, angiotensin converting enzyme-2, is found throughout the GI tract, especially in the stomach and small intestine, which provides a pathophysiologic basis for local GI infection. COVID-19 virus has been documented in feces and in GI mucosa. Treatment of COVID-19 infection, especially antibiotic therapy, is a common culprit of the diarrhea, but secondary infections including bacteria, especially Clostridioides difficile, are sometimes implicated. Workup for diarrhea in hospitalized patients usually includes routine chemistries; basic metabolic panel; and a complete hemogram; sometimes stool studies, possibly including calprotectin or lactoferrin; and occasionally abdominal CT scan or colonoscopy. Treatment for the diarrhea is intravenous fluid infusion and electrolyte supplementation as necessary, and symptomatic antidiarrheal therapy, including Loperamide, kaolin-pectin, or possible alternatives. Superinfection with C difficile should be treated expeditiously. Diarrhea is prominent in post-COVID-19 (long COVID-19), and is occasionally noted after COVID-19 vaccination. The spectrum of diarrhea in COVID-19 patients is presently reviewed including the pathophysiology, clinical presentation, evaluation, and treatment.

T Cell Response to SARS-CoV-2 Coinfection and Comorbidities

For the past three years, COVID-19 has become an increasing global health issue. Adaptive immune cells, especially T cells, have been extensively investigated in regard to SARS-CoV-2 infection. However, human health and T cell responses are also impacted by many other pathogens and chronic diseases. We have summarized T cell performance during SARS-CoV-2 coinfection with other viruses, bacteria, and parasites. Furthermore, we distinguished if those altered T cell statuses under coinfection would affect their clinical outcomes, such as symptom severity and hospitalization demand. T cell alteration in diabetes, asthma, and hypertension patients with SARS-CoV-2 infection was also investigated in our study. We have summarized whether changes in T cell response influence the clinical outcome during comorbidities.

COVID-19: gastrointestinal and hepatobiliary manifestations

SARS-CoV-2 is the viral agent of COVID-19, a pandemic that surfaced in 2019. Although predominantly a respiratory ailment, patients with COVID-19 can have gastrointestinal (GI) and hepatobiliary manifestations. These manifestations are often mild and transient, but they can be severe and consequential. In the GI tract, ischemic enterocolitis is the most common and significant consequence of COVID-19. In the liver, the reported pathologic findings may often be related to consequences of severe systemic viral infection, but reports of hepatitis presumed to be due to SARS-CoV-2 suggest that direct viral infection of the liver may be a rare complication of COVID-19. In both the GI tract and liver, lingering symptoms of GI or hepatic injury after resolution of pulmonary infection may be part of the evolving spectrum of long COVID.

Pathogenesis and Mechanisms of SARS-CoV-2 Infection in the Intestine, Liver, and Pancreas

The novel coronavirus, SARS-CoV-2, rapidly spread worldwide, causing an ongoing global pandemic. While the respiratory system is the most common site of infection, a significant number of reported cases indicate gastrointestinal (GI) involvement. GI symptoms include anorexia, abdominal pain, nausea, vomiting, and diarrhea. Although the mechanisms of GI pathogenesis are still being examined, viral components isolated from stool samples of infected patients suggest a potential fecal-oral transmission route. In addition, viral RNA has been detected in blood samples of infected patients, making hematologic dissemination of the virus a proposed route for GI involvement. Angiotensin-converting enzyme 2 (ACE2) receptors serve as the cellular entry mechanism for the virus, and these receptors are particularly abundant throughout the GI tract, making the intestine, liver, and pancreas potential extrapulmonary sites for infection and reservoirs sites for developing mutations and new variants that contribute to the uncontrolled spread of the disease and resistance to treatments. This transmission mechanism and the dysregulation of the immune system play a significant role in the profound inflammatory and coagulative cascades that contribute to the increased severity and risk of death in several COVID-19 patients. This article reviews various potential mechanisms of gastrointestinal, liver, and pancreatic injury.

Gastroduodenal injury and repair: novel targets for therapeutic intervention

PURPOSE OF REVIEW

Although the mucosal barrier serves as a primary interface between the environment and host, little is understood about the repair of acute, superficial lesions or deeper, persistent lesions that if not healed, can be the site of increased permeability to luminal antigens, inflammation and/or neoplasia development.

RECENT FINDINGS

Recent studies have focused on focal adhesion kinase, which regulates controlled matrix adhesion during restitution after superficial injury. Actin polymerization regulates cell migration and the importance of actin-related proteins was also highlighted. Work on SARS-CoV-2 infection lent important new insights on gastroduodenal mucosal injury in patients with Covid-19 infection and work done with organoids and intestine-on-a-chip contributed new understanding about how coronaviruses infect gastrointestinal tissues and its resulting barrier dysfunction. A novel risk stratification paradigm was proposed to assist with decision making about repeat endoscopy for patients with gastric or duodenal ulcers and new therapeutic options were studied for ulcer disease. Lastly, work to support the mechanism of metaplasia development after deep injury and parietal cell loss was provided using novel transgenic mouse models.

SUMMARY

Recent studies highlight novel molecular targets to promote mucosal healing after injury of the gastroduodenal mucosa.

Sensing of SARS-CoV-2 by pDCs and their subsequent production of IFN-I contribute to macrophage-induced cytokine storm during COVID-19

Lung-infiltrating macrophages create a marked inflammatory milieu in a subset of patients with COVID-19 by producing a cytokine storm, which correlates with increased lethality. However, these macrophages are largely not infected by SARS-CoV-2, so the mechanism underlying their activation in the lung is unclear. Type I interferons (IFN-I) contribute to protecting the host against SARS-CoV-2 but may also have some deleterious effect, and the source of IFN-I in the lungs of infected patients is not well defined. Plasmacytoid dendritic cells (pDCs), a key cell type involved in antiviral responses, can produce IFN-I in response to SARS-CoV-2. We observed the infiltration of pDCs in the lungs of SARS-CoV-2-infected patients, which correlated with strong IFN-I signaling in lung macrophages. In patients with severe COVID-19, lung macrophages expressed a robust inflammatory signature, which correlated with persistent IFN-I signaling at the single-cell level. Hence, we observed the uncoupling in the kinetics of the infiltration of pDCs in the lungs and the associated IFN-I signature, with the cytokine storm in macrophages. We observed that pDCs were the dominant IFN-α-producing cells in response to the virus in the blood, whereas macrophages produced IFN-α only when in physical contact with infected epithelial cells. We also showed that IFN-α produced by pDCs, after the sensing of SARS-CoV-2 by TLR7, mediated changes in macrophages at both transcriptional and epigenetic levels, which favored their hyperactivation by environmental stimuli. Together, these data indicate that the priming of macrophages can result from the response by pDCs to SARS-CoV-2, leading to macrophage activation in patients with severe COVID-19.

Upper gastrointestinal bleeding in coronavirus disease 2019 patients

PURPOSE OF REVIEW

Upper gastrointestinal bleeding (UGIB) has significant morbidity and UGIB cases have been described in coronavirus disease 2019 (COVID-19) patients. Management of this condition can be challenging considering both the possible severe COVID-19-related pneumonia as well as the risk of the virus spreading from patients to health operators. The aim of this paper is to review the most recent studies available in the literature in order to evaluate the actual incidence of UGIB, its clinical and endoscopic manifestations and its optimal management.

RECENT FINDINGS

UGIB has an incidence between 0.5% and 1.9% among COVID-19 patients, and it typically presents with melena or hematemesis. Peptic ulcers are the most common endoscopic findings. High Charlson Comorbidity Index (CCI), dialysis, acute kidney injury and advanced oncological disease increase the risk for UGIB. Although anticoagulants are commonly used in COVID-19 patients they are not associated with an increased incidence of UGIB. Conservative management is a common approach that results in similar outcomes compared to upper GI endoscopic treatment. Apparently, UGIB in COVID-19 seems not have a detrimental effect and only one study showed an increased mortality in those who developed UGIB during hospitalization.

SUMMARY

Incidence of UGIB in COVID-19 patients is similar to that of the general population. Despite the widespread use of anticoagulants in these patients, they are not associated with an increased risk of UGIB. Conservative management could be an effective option, especially for patients that are at risk of intubation.

Gastrointestinal Ischemia—Stumbling Stone in COVID-19 Patients

The emergence of the novel SARS-CoV2 virus, proclaimed by the World Health Organization (WHO) as a culpable agent for the pandemic situation, caught the scientific and medical communities off guard. One of the most common complications following pulmonary disease is represented by gastrointestinal (GI) disorders, especially ischemic damage. Inflammation, vasculopathy, immobility, endothelial dysfunction, and a hypercoagulable condition have all been proposed as pathophysiological factors for GI ischemia in these patients. Owing to the COVID-19 effect on a variety of GI conditions, especially ischemic changes, and the high mortality rate, physicians should always keep in mind this complication. They should take a deeper look at clinical and imaging modalities in this cohort of patients so that a proper and time-saving treatment strategy can be applied. Our study aimed to elucidate the thrombogenic mechanism in different GI disorders. Moreover, we analyzed the factors related to necrotic GI changes, by summarizing the already reported data of GI ischemia in COVID-19. To the best of our knowledge, this review is the first to incorporate all GI ischemia cases reported in the literature so far.

Potential importance of early treatment of SARS-CoV-2 infection in intestinal transplant patient: A case report

BACKGROUND

Predispositions for severe coronavirus disease 2019 (COVID-19) are age, immunosuppression, and co-morbidity. High levels of maintenance immunosuppression render intestinal transplant (ITx) patients vulnerable for severe COVID-19. COVID-19 also provokes several gastroenterological pathologies which have not been discussed in ITx, so far.

CASE SUMMARY

During the second European COVID-19 wave in November 2020, an ITx recipient was admitted to the hospital because of electrolyte disturbances due to dehydration. Immunosuppression consisted of tacrolimus, azathioprine, and low-dose corticosteroids. During hospitalization, she tested positive on screening COVID-19 nasopharyngeal polymerase chain reaction swab, while her initial test was negative. She was initially asymptomatic and had normal inflammatory markers. Tacrolimus levels were slightly raised, as Azathioprine was temporarily halted. Due to elevated D-dimers at that time, prophylactic low-molecular weight heparin was started. Seven days after the positive test, dyspnea, anosmia, and C-reactive protein increase (25 mg/L) were noted. Remdesivir was administered during 5 d in total. High stomal output was noted in two consecutive days and several days thereafter. To exclude infection or rejection, an ileoscopy and biopsy were performed and excluded these. Four weeks later, she was discharged from the hospital and remains in good health since then.

CONCLUSION

Early eradication of severe acute respiratory syndrome coronavirus 2 in ITx recipients may be warranted to prevent acute rejection provocation by it.

Clinical and Endoscopic Outcomes in Coronavirus Disease-2019 Patients With Gastrointestinal Bleeding

Background and Aims

Over 404 million people worldwide have been infected with coronavirus disease-2019 (COVID-19), 145 million in the United States (77 million) and Europe (151 million) alone (as of February 10, 2022). This paper aims to analyze data from studies reporting gastrointestinal bleeding (GIB) and/or endoscopic findings in COVID-19 patients in Western countries.

Methods

We conducted a systematic review of articles on confirmed COVID-19 cases with GIB in Western countries published in PubMed and Google Scholar databases from June 20, 2020, to July 10, 2021.

Results

A total of 12 studies reporting GIB and/or endoscopic findings in 808 COVID-19 patients in Western countries were collected and analyzed. Outcomes and comorbidities were compared with 18,179 non-GIB COVID-19 patients from Italy and the United States. As per our study findings, the overall incidence of GIB in COVID-19 patients was found to be 0.06%. When compared to the non-GIB cohort, the death rate was significantly high in COVID-19 patients with GIB (16.4% vs 25.4%, P < .001, respectively). Endoscopic treatment was rarely necessary, and blood transfusion was the most common GIB treatment. The most common presentation in GIB patients is melena (n = 117, 47.5%). Peptic, esophageal, and rectal ulcers were the most common endoscopic findings in upper (48.4%) and lower (36.4%) endoscopies. The GIB cohort had worse outcomes and higher incidence of hypertension (61.1%), liver disease (11.2%), and cancer (13.6%) than the non-GIB cohort. Death was strongly associated with hypertension (P < .001, r = 0.814), hematochezia (P < .001, r = 0.646), and esophagogastroduodenoscopy (P < .001, r = 0.591) in COVID-19 patients with GIB.

Conclusions

Overall, the incidence of GIB in COVID-19 patients is similar to that estimated in the overall population, with melena being the most common presentation. The common endoscopic findings in GIB COVID-19 patients were ulcers, esophagitis, gastritis, and colitis. Patients with GIB were more prone to death than non-GIB COVID-19 patients.

Duodenal tropism of SARS-CoV-2 and clinical findings in critically ill COVID-19 patients

Purpose

Duodenal involvement in COVID-19 is poorly studied. Aim was to describe clinical and histopathological characteristics of critically ill COVID-19 patients suffering from severe duodenitis that causes a significant bleeding and/or gastrointestinal dysmotility.

Methods

In 51 critically ill patients suffering from SARS-CoV-2 pneumonia, severe upper intestinal bleeding and/or gastric feeding intolerance were indications for upper gastrointestinal endoscopy. Duodenitis was diagnosed according to macroscopic signs and mucosal biopsies. Immunohistochemistry was performed to detect viral specific protein and ACE2. In situ hybridization was applied to confirm viral replication.

Results

Nine of 51 critically ill patients (18%) suffering from SARS-CoV-2 pneumonia had developed upper GI bleeding complications and/or high gastric reflux. Five of them presented with minor and four (44%) with severe duodenitis. In two patients, erosions had caused severe gastrointestinal bleeding requiring PRBC transfusions. Immunohistochemical staining for SARS-CoV-2 spike protein was positive inside duodenal enterocytes in three of four patients suffering from severe duodenitis. Viral replication could be confirmed by in situ hybridization.

Conclusion

Our data suggest that about 8% of critically ill COVID-19 patients may develop a severe duodenitis presumably associated with a direct infection of the duodenal enterocytes by SARS-CoV-2. Clinical consequences from severe bleeding and/or upper gastrointestinal dysmotility seem to be underestimated.

Supplementary Information

The online version contains supplementary material available at 10.1007/s15010-022-01769-z.

A case of COVID-19 diarrhea relieved by bile acid sequestrant administration

Patients with coronavirus disease 2019 exhibit various gastrointestinal symptoms. Although diarrhea is reported in many cases, the pathophysiology of diarrhea has not been fully clarified. Herein, we report a case of coronavirus disease 2019 with diarrhea that was successfully relieved by the administration of a bile acid sequestrant. The patient was a 59-year-old man whose pneumonia was treated by the administration of glucocorticoids and mechanical ventilation. However, beginning on the 30th hospital day, he developed severe watery diarrhea (up to 10 times a day). Colonoscopy detected ulcers in the terminal ileum and ascending colon. The oral administration of a bile acid sequestrant, colestimide, improved his diarrhea quickly. Ileal inflammation is reported to suppress expression of the gut epithelial apical sodium-dependent bile acid transporter. It decreases bile acid absorption at the distal ileum and increases colonic delivery of bile acids, resulting in bile acid diarrhea. In summary, the clinical course of the case presented in this report suggests that bile acid diarrhea is a possible mechanism of watery diarrhea observed in patients with coronavirus disease 2019.

MORPHOLOGICAL AND FUNCTIONAL FEATURES OF THE MUCOUS MEMBRANE OF SMALL AND LARGE INTESTINE IN PATIENTS WITH COVID-19 AND IN POST-COVID-19 PERIOD

OBJECTIVE

The aim: To reveal the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 and in post-COVID-19 period.

PATIENTS AND METHODS

Materials and methods: In the present study, the authors used biopsy and autopsy material represented by the fragments of the mucous membrane of small and large intestine. All studied material was divided into 10 groups. Group 1 (comparison group) included autopsy material from the deceased who did not have COVID-19 during their lifetime. Groups 2-4 included autopsy material from the deceased who had COVID-19 of varying severity during their lifetime. Groups 5-7 included biopsy material from patients who had recovered from COVID-19 of varying severity, while the duration of the post-COVID period ranged from 1 to 50 days. Groups 8-10 included biopsy material from patients who had in anamnesis COVID-19 of varying severity (the duration of the post-COVID period lasted from 51 to 100 days). Histological, immunohistochemical, morphometric and statistical research methods were used.

RESULTS

Results: The comparative analysis showed a more expressed deficiency of ACE2 in the mucous membrane of small and large intestine in patients with moderate and severe COVID-19 compared with patients in post-COVID-19 period of different duration. In patients who had moderate and severe COVID-19 in anamnesis, ACE2 deficiency decreases with increasing duration of post-COVID-19 period. In patients recovered from mild COVID-19, the ACE2 content increases with the duration of post-COVID-19 period from 1 to 50 days and corresponds to the norm with the duration of this period from 51 to 100 days.

CONCLUSION

Conclusions: The comprehensive morphological study conducted by the authors made it possible, firstly, to clarify the morphological and functional features of the mucous membrane of small and large intestine in patients with COVID-19 of various degrees of severity; secondly, to obtain new data about the morpho-functional state of the mucous membrane of small and large intestine in patients, taking into account different duration of the post-COVID-19 period and the severity of the infection.

[Severe pseudomembranous colitis in patients with previous coronavirus infection]

OBJECTIVE

To analyze treatment outcomes in patients with severe pseudomembranous colitis and previous coronavirus infection.

MATERIAL AND METHODS

We retrospectively analyzed treatment outcomes, clinical, laboratory and histological data in convalescents of COVID-19 who admitted to the department of coloproctology for moderate-to-severe pseudomembranous colitis confirmed by endoscopic examination between 2020 and 2021.

RESULTS

There were 13 patients with moderate pseudomembranous colitis and 6 ones with severe pseudomembranous colitis. Mean period after recovery from coronavirus infection was 19 days. Endoscopy revealed whitish-yellow or gray raised plaques on colonic mucosa in all cases. Four patients with signs of peritonitis underwent emergency surgery. Three patients had perforation of caecum; one patient had perforation of sigmoid colon and widespread peritonitis. Two patients underwent urgent surgery for progressive toxic megacolon and ineffective therapy. Subtotal colectomy and ileostomy were performed in all cases. Histological examination revealed necrosis of not only superficial layer of colon mucosa typical for clostridial colitis, but also the entire thickness of mucosa, as well as submucosal and partially muscular layers in some cases. Mucosal crypt atrophy, fibrinoid effusion in muscular layer, diffuse polymorphonuclear cell infiltration and necrosis of muscular and submucosal nerve plexuses, as well as necrosis of vascular walls with deposition of hyaline-like structures characterize microcirculatory ischemic processes in the colon wall.

CONCLUSION

Severe pseudomembranous colitis associated with COVID-19 may not be associated with clostridial infection. Further analysis of possible ischemic etiology and pathogenesis of gastrointestinal lesions in COVID-19 is needed for preventive and therapeutic measures.

COVID-19-Associated Ischemic Colitis: A Rare Manifestation of COVID-19 Infection-Case Report and Review

Following the first report of COVID-19 infection in December 2019 as a respiratory illness, it has proven to be a multisystem disease. There are few reported cases of ischemic colitis with COVID-19 infection in the medical literature to date and we have limited understanding of its pathophysiology. We report 2 cases of ischemic colitis as the only manifestation of COVID-19. In addition, we review the current limited literature regarding COVID-19-associated ischemic colitis.

Review of COVID-19, part 1: Abdominal manifestations in adults and multisystem inflammatory syndrome in children

The coronavirus disease 2019 (COVID -19) pandemic caused by the novel severe acute respiratory syndrome coronavirus (SARS-CoV-2) has affected almost every country in the world, resulting in severe morbidity, mortality and economic hardship, and altering the landscape of healthcare forever. Although primarily a pulmonary illness, it can affect multiple organ systems throughout the body, sometimes with devastating complications and long-term sequelae. As we move into the second year of this pandemic, a better understanding of the pathophysiology of the virus and the varied imaging findings of COVID-19 in the involved organs is crucial to better manage this complex multi-organ disease and to help improve overall survival. This manuscript provides a comprehensive overview of the pathophysiology of the virus along with a detailed and systematic imaging review of the extra-thoracic manifestation of COVID-19 with the exception of unique cardiothoracic features associated with multisystem inflammatory syndrome in children (MIS-C). In Part I, extra-thoracic manifestations of COVID-19 in the abdomen in adults and features of MIS-C will be reviewed. In Part II, manifestations of COVID-19 in the musculoskeletal, central nervous and vascular systems will be reviewed.

Gastrointestinal manifestations and SARS-CoV-2 infection

Since COVID-19 occurrence in late 2019, intense research efforts on an unprecedented scale have focused on the study of named severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry mechanisms and clinical presentations. As for other coronaviruses, SARS-CoV-2 presents with extrarespiratory clinical manifestations such as diarrhea, nausea, vomiting, and abdominal pain which highlight that the gastrointestinal (GI) system as another viral target along with the typical presentations of COVID-19 which is characterized primarily by respiratory symptoms. The digestive system is involved in many systemic functions through the gut-brain axis and systemic immunity modulation. Therefore, the GI system plays an important role in the presentation of the disease, pathogenesis, and possibly treatment outcomes. This minireview summarizes recent work to study SARS-CoV-2 infection as it relates to comorbidities, GI symptoms. This will help to strategize the priorities in understanding the impact of the virus on outcomes in various aspects.

SARS-CoV-2 infection and replication in human gastric organoids

COVID-19 typically manifests as a respiratory illness, but several clinical reports have described gastrointestinal symptoms. This is particularly true in children in whom gastrointestinal symptoms are frequent and viral shedding outlasts viral clearance from the respiratory system. These observations raise the question of whether the virus can replicate within the stomach. Here we generate gastric organoids from fetal, pediatric, and adult biopsies as in vitro models of SARS-CoV-2 infection. To facilitate infection, we induce reverse polarity in the gastric organoids. We find that the pediatric and late fetal gastric organoids are susceptible to infection with SARS-CoV-2, while viral replication is significantly lower in undifferentiated organoids of early fetal and adult origin. We demonstrate that adult gastric organoids are more susceptible to infection following differentiation. We perform transcriptomic analysis to reveal a moderate innate antiviral response and a lack of differentially expressed genes belonging to the interferon family. Collectively, we show that the virus can efficiently infect the gastric epithelium, suggesting that the stomach might have an active role in fecal-oral SARS-CoV-2 transmission.

Gastroduodenal ischemia in a patient with severe SARS-CoV-2 infection

A 54-year-old male, with a past medical history of hypertension, dyslipidemia, obesity and diastolic heart failure, was admitted due to COVID-19 pneumonia. Respiratory failure gradually deteriorated and the patient was transferred to the Intensive Care Unit (ICU), where mechanical ventilation and venovenous extracorporeal membrane oxygenation (VV-ECMO) were started. On the second day in ICU, he had a septic shock due to ventilator-associated pneumonia. Five days later, the patient had new-onset melena and laboratory data showed a hemoglobin level of 7.8g/dL.

A Rare Case of COVID-19 Pneumonia Concomitant with Bleeding from Acute Gastric Mucosal Lesions

A 70-year-old man was diagnosed with coronavirus disease 2019 (COVID-19) pneumonia. Twenty-six days after admission, he experienced hematemesis despite improvement in his respiratory symptoms. Contrast-enhanced computed tomography revealed edematous stomach wall thickening with neither ischemic findings in the gastric wall nor obstruction of the gastric artery. Emergent esophagogastroduodenoscopy showed diffuse dark-red mucosa accompanied by multiple easy-bleeding, irregularly shaped ulcers throughout almost the whole stomach without active bleeding or visible vessels. The clinical course, including the endoscopic findings, progressed favorably with conservative treatment. COVID-19 pneumonia can present with acute gastric mucosal lesion, which may be induced by microvascular thrombosis due to COVID-19-related coagulopathy.