Remarkable gastrointestinal and liver manifestations of COVID-19: A clinical and radiologic overview

SARS-CoV-2 Spike protein triggers gut impairment since mucosal barrier to innermost layers: From basic science to clinical relevance

Studies have reported the occurrence of gastrointestinal (GI) symptoms, primarily diarrhea, in COVID-19. However, the pathobiology regarding COVID-19 in the GI tract remains limited. This work aimed to evaluate SARS-CoV-2 Spike protein interaction with gut lumen in different experimental approaches. Here, we present a novel experimental model with the inoculation of viral protein in the murine jejunal lumen, in vitro approach with human enterocytes, and molecular docking analysis. Spike protein led to increased intestinal fluid accompanied by Cl- secretion, followed by intestinal edema, leukocyte infiltration, reduced glutathione levels, and increased cytokine levels [interleukin (IL)-6, tumor necrosis factor-α, IL-1β, IL-10], indicating inflammation. Additionally, the viral epitope caused disruption in the mucosal histoarchitecture with impairment in Paneth and goblet cells, including decreased lysozyme and mucin, respectively. Upregulation of toll-like receptor 2 and toll-like receptor 4 gene expression suggested potential activation of local innate immunity. Moreover, this experimental model exhibited reduced contractile responses in jejunal smooth muscle. In barrier function, there was a decrease in transepithelial electrical resistance and alterations in the expression of tight junction proteins in the murine jejunal epithelium. Additionally, paracellular intestinal permeability increased in human enterocytes. Finally, in silico data revealed that the Spike protein interacts with cystic fibrosis transmembrane conductance regulator (CFTR) and calcium-activated chloride conductance (CaCC), inferring its role in the secretory effect. Taken together, all the events observed point to gut impairment, affecting the mucosal barrier to the innermost layers, establishing a successful experimental model for studying COVID-19 in the GI context.

Digestive system infection by SARS‑CoV‑2: Entry mechanism, clinical symptoms and expression of major receptors (Review)

Besides causing severe acute respiratory syndrome (SARS), SARS‑coronavirus 2 (SARS‑CoV‑2) also harms the digestive system. Given the appearance of numerous cases of SARS‑CoV‑2, it has been demonstrated that SARS‑CoV‑2 is able to harm target organs such as the gastrointestinal tract, liver and pancreas, and either worsen the condition of patients with basic digestive illnesses or make their prognosis poor. According to several previously published studies, angiotensin‑converting enzyme II (ACE2) and transmembrane serine protease II (TMPRSS2) are expressed either singly or in combination in the digestive system and in other regions of the human body. In order to change the viral conformation, create a fusion hole and release viral RNA into the host cell for replication and transcription, SARS‑CoV‑2 is capable of binding to these two proteins through the spike protein on its surface. As a result, the body experiences an immune reaction and an inflammatory reaction, which may lead to nausea, diarrhea, abdominal pain and even gastrointestinal bleeding, elevated levels of liver enzymes, acute liver injury, pancreatitis and other serious lesions. In order to provide possible strategies for the clinical diagnosis and treatment of digestive system diseases during the COVID‑19 pandemic, the molecular structure of SARS‑CoV‑2 and the mechanism via which SARS‑CoV‑2 enters the human body through ACE2 and TMPRSS2 were discussed in the present review, and the clinical manifestations of SARS‑CoV‑2 infection in the digestive system were also summarized. Finally, the expression characteristics of ACE2 and TMPRSS2 in the main target organs of the digestive system were described.

Abdominal Imaging Findings in Patients with COVID-19 Part 2: Solid Organs

Since severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) first appeared in China in December 2019, the globe has been dealing with an ever-increasing incidence of coronavirus disease 2019 (COVID-19). In addition to respiratory disorders, 40% of patients present with gastrointestinal (GI) involvement. Abdominal pain is the most common indication for computed tomography (CT) and ultrasonography. After GI tract involvement, solid visceral organ infarction is the most prevalent abdominal abnormality in COVID-19. This review aims to gather the available data in the literature about imaging features of solid abdominal organs in patients with COVID-19. Gallbladder wall thickening and distension, cholelithiasis, hyperdense biliary sludge, acalculous cholecystitis, periportal edema, heterogeneous liver enhancement, and liver hypodensity and infarction are among hepatobiliary imaging findings in CT, particularly in patients admitted to ICU. Pancreatic involvement can develop as a result of direct SARS-CoV2 invasion with signs of acute pancreatitis in abdominal CT, such as edema and inflammation of the pancreas. Infarction was the most prevalent renal and splenic involvement in patients with COVID-19 who underwent abdominal CT presenting with areas of parenchymal hypodensity. In conclusion, although solid abdominal organs are rarely affected by COVID-19, clinicians must be familiar with the manifestations since they are associated with the disease severity and poor outcome.

Case report of restless anal syndrome as restless legs syndrome variant after COVID-19

Background

Coronavirus disease 2019 (COVID-19) has a broad spectrum from respiratory and nasopharyngeal symptoms, cerebrovascular diseases, impaired consciousness, and skeletal muscle injury. Emerging evidence has indicated the neural spread of this novel coronavirus. Restless legs syndrome (RLS) is a common neurological, sensorimotor disorder, but highly under diagnosis disorder. Restless anal syndrome as restless legs syndrome variant associated with COVID-19 has been previously not published. We report a case presenting with restless anal syndrome following COVID-19.

Case presentation

Although a 77-year-old male with COVID-19 improved to normal respiratory function 21 days after admission and treatment of favipiravir 200 mg per day for 14 days and dexamethasone 6.6 mg per day for 5 days, the insomnia and anxiety symptoms remained. Several weeks after discharge, he gradually began to experience restless, deep anal discomfort, approximately 10 cm from the perineal region. The following features were observed in the anal region; urge to move is essential, with worsening with rest, improvement with exercise, and worsening at evening. Colonoscopy revealed internal haemorrhoids without other rectal lesions. Neurological findings including deep tendon reflex, perineum loss of sensory and spinal cord injury, revealed no abnormalities. Diabetes militias, kidney dysfunction and iron deficiency status were not confirmed. Family history of RLS and periodic limb movements were not observed. Clonazepam at 1.5 mg per day resulted in the alleviation restless anal discomfort.

Conclusions

We reported a case presenting with restless anal syndrome following affection of COVID-19 as restless legs syndrome variant. This case fulfilled 4 essential features of RLS, urge to move, worsening with rest, improvement with exercise, and worsening at evening. To date, no case of restless anal syndrome associated with COVID-19 has been previously published. This case report may reflect the associative impacts of COVID-19 on the neuropsychiatric state. The long-term outcomes of neuropsychiatric conditions should continue to be monitored.