Impact of Gastrointestinal Symptoms in COVID-19: a Molecular Approach

Differential Gene Expression Profiles Involved in the Inflammations Due to COVID-19 and Inflammatory Bowel Diseases and the Investigation of Predictive Biomarkers

Gastrointestinal manifestations in COVID-19 were attributed to 74-86% of the hospitalised patients due to severe or prolonged pathogenesis. Though it is a respiratory disease, the impact it elicits on the gastrointestinal tract and brain are intense. Inflammatory bowel disease including Crohn's disease and ulcerative colitis are idiopathic inflammatory disorders of the gastrointestinal tract. The intrinsic mechanisms involved in gut inflammations due to a respiratory viral disease can be deciphered when the gene expression profiles of COVID-19 and IBD are compared. The current study utilises an integrated bioinformatics approach to unravel them. The publicly available gene expression profiles of colon transcriptomes infected with COVID-19, Crohn's disease and Ulcerative colitis were retrieved, integrated and analysed for the identification of differentially expressed genes. The inter-relational analysis along with gene annotation and pathway enrichment detailed the functional and metabolic pathways of the genes during normal and diseased conditions. The protein-protein interactions deduced from the STRING database and the identified hub genes predicted potential biomarker candidates for COVID-19, Crohn's disease and ulcerative colitis. The inflammatory response pathways were upregulated and enrichment of chemokine signalling, altered lipid metabolism, coagulation and complement cascades were seen in all three conditions along with impaired transport mechanisms. CXCL11, MMP10, and CFB are predicted to be overexpressed biomarkers, whilst GUCA2A, SLC13A2, CEACAM, and IGSF9 as downregulated novel biomarker candidates for colon inflammations. The three miRNAs hsa-miR-16-5p, hsa-miR-21-5p, and hsa-miR-27b-5p exhibited significant interactions with the upregulated hub genes and four long non-coding RNAs NEAT1, KCNQ1OT1, and LINC00852 capable of regulating miRNA were also predicted. This study offers significant information on the underlying molecular mechanisms of inflammatory bowel disease with identification of potential biomarkers.

SARS-CoV-2 envelope protein induces necroptosis and mediates inflammatory response in lung and colon cells through receptor interacting protein kinase 1

SARS-CoV-2 Envelope protein (E) is one of the crucial components in virus assembly and pathogenesis. The current study investigated its role in the SARS-CoV-2-mediated cell death and inflammation in lung and gastrointestinal epithelium and its effect on the gastrointestinal-lung axis. We observed that transfection of E protein increases the lysosomal pH and induces inflammation in the cell. The study utilizing Ethidium bromide/Acridine orange and Hoechst/Propidium iodide staining demonstrated necrotic cell death in E protein transfected cells. Our study revealed the role of the necroptotic marker RIPK1 in cell death. Additionally, inhibition of RIPK1 by its specific inhibitor Nec-1s exhibits recovery from cell death and inflammation manifested by reduced phosphorylation of NFκB. The E-transfected cells' conditioned media induced inflammation with differential expression of inflammatory markers compared to direct transfection in the gastrointestinal-lung axis. In conclusion, SARS-CoV-2 E mediates inflammation and necroptosis through RIPK1, and the E-expressing cells' secretion can modulate the gastrointestinal-lung axis. Based on the data of the present study, we believe that during severe COVID-19, necroptosis is an alternate mechanism of cell death besides ferroptosis, especially when the disease is not associated with drastic increase in serum ferritin.

Helicobacter pylori and epithelial mesenchymal transition in human gastric cancers: An update of the literature

Gastric cancer, a multifactorial disease, is considered one of the most common malignancies worldwide. In addition to genetic and environmental risk factors, infectious agents, such as Epstein-Barr virus (EBV) and Helicobacter pylori (H.pylori) contribute to the onset and development of gastric cancer. H. pylori is a type I carcinogen that colonizes the gastric epithelium of approximately 50% of the world's population, thus increasing the risk of gastric cancer development. On the other hand, epithelial mesenchymal transition (EMT) is a fundamental process crucial to embryogenic growth, wound healing, organ fibrosis and cancer progression. Several studies associate gastric pathogen infection of the epithelium with EMT initiation, provoking cancer metastasis in the gastric mucosa through various molecular signaling pathways. Additionally, EMT is implicated in the progression and development of H. pylori-associated gastric cancer. In this review, we recapitulate recent findings elucidating the association between H. pylori infection in EMT promotion leading to gastric cancer progression and metastasis.

Comprehensive insight into altered host cell-signaling cascades upon Helicobacter pylori and Epstein-Barr virus infections in cancer

Cancer is characterized by mutagenic events that lead to disrupted cell signaling and cellular functions. It is one of the leading causes of death worldwide. Literature suggests that pathogens, mainly Helicobacter pylori and Epstein-Barr virus (EBV), have been associated with the etiology of human cancer. Notably, their co-infection may lead to gastric cancer. Pathogen-mediated DNA damage could be the first and crucial step in the carcinogenesis process that modulates numerous cellular signaling pathways. Altogether, it dysregulates the metabolic pathways linked with cell growth, apoptosis, and DNA repair. Modulation in these pathways leads to abnormal growth and proliferation. Several signaling pathways such RTK, RAS/MAPK, PI3K/Akt, NFκB, JAK/STAT, HIF1α, and Wnt/β-catenin are known to be altered in cancer. Therefore, this review focuses on the oncogenic roles of H. pylori, EBV, and its associated signaling cascades in various cancers. Scrutinizing these signaling pathways is crucial and may provide new insights and targets for preventing and treating H. pylori and EBV-associated cancers.

Gastrointestinal Manifestations of SARS-CoV-2: Transmission, Pathogenesis, Immunomodulation, Microflora Dysbiosis, and Clinical Implications

The clinical manifestation of COVID-19, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the respiratory system of humans is widely recognized. There is increasing evidence suggesting that SARS-CoV-2 possesses the capability to invade the gastrointestinal (GI) system, leading to the manifestation of symptoms such as vomiting, diarrhea, abdominal pain, and GI lesions. These symptoms subsequently contribute to the development of gastroenteritis and inflammatory bowel disease (IBD). Nevertheless, the pathophysiological mechanisms linking these GI symptoms to SARS-CoV-2 infection remain unelucidated. During infection, SARS-CoV-2 binds to angiotensin-converting enzyme 2 and other host proteases in the GI tract during the infection, possibly causing GI symptoms by damaging the intestinal barrier and stimulating inflammatory factor production, respectively. The symptoms of COVID-19-induced GI infection and IBD include intestinal inflammation, mucosal hyperpermeability, bacterial overgrowth, dysbiosis, and changes in blood and fecal metabolomics. Deciphering the pathogenesis of COVID-19 and understanding its exacerbation may provide insights into disease prognosis and pave the way for the discovery of potential novel targets for disease prevention or treatment. Besides the usual transmission routes, SARS-CoV-2 can also be transmitted via the feces of an infected person. Hence, it is crucial to implement preventive and control measures in order to mitigate the fecal-to-oral transmission of SARS-CoV-2. Within this context, the identification and diagnosis of GI tract symptoms during these infections assume significance as they facilitate early detection of the disease and the development of targeted therapeutics. The present review discusses the receptors, pathogenesis, and transmission of SARS-CoV-2, with a particular focus on the induction of gut immune responses, the influence of gut microbes, and potential therapeutic targets against COVID-19-induced GI infection and IBD.

Plant derived active compounds as potential anti SARS-CoV-2 agents: an in-silico study

Plants are a valued potential source of drugs for a variety of diseases and are often considered less toxic to humans. We investigated antiviral compounds that may potentially target SARS-CoV-2 antigenic spike (S) and host proteins; angiotensin-converting enzyme2 (ACE2), and transmembrane serine protease2 (TMPRSS2). We scrutinized 36 phytochemicals from 15 Indian medicinal plants known to be effective against RNA viruses via molecular docking. Besides, the TMPRSS2 structure was modeled and validated using the SWISS-MODEL. Docking was performed using Autodock Vina and 4.2 followed by visualization of the docking poses on Pymol version 2.4.0 and Discovery Studio Visualizer. Molecular docking showed that 12 out of 36 active compounds interacted efficiently with S, ACE2, and TMPRSS2 proteins. The ADMET profile generated using the swissADME and pkCSM server revealed that these compounds were possessed druggable properties. The Amber 12 simulation package was used to carry out energy minimizations and molecular dynamics (MD) simulations. The total simulation time for both S protein: WFA and S protein: WND complexes was 300 ns (100 ns per replica). A total of 120 structures were extracted from the last 60 ns of each MD simulation for further analysis. MM-PBSA and MM-GBSA were employed to assess the binding energy of each ligand and the receptor-binding domain of the viral S-protein. The methods suggested that WND and WFA showed thermodynamically favorable binding energies, and the S protein had a higher affinity with WND. Interestingly, Leu455 hotspot residue in the S protein, also predicted to participate in binding with ACE2, was engaged by WND and WFA. HighlightsPlants' natural active compounds may aid in the development of COVID-19 therapeutics.MD simulation study revealed stable binding of withanolide D and withaferin A with spike proteinWithanolide D and withaferin A could be effective against SARS-CoV-2 spike protein.Discovery of druggable agents that have less or lack of binding affinity with ACE2 to avoid the organs associated with comorbidities.According to ADMET selected phytochemicals may be used as druggable compounds.Communicated by Ramaswamy H. Sarma.

SARS-CoV-2 genome variations and evolution patterns in Egypt: a multi-center study

A serious global public health emergency emerged late November 2019 in Wuhan City, China, by a new highly pathogenic virus, SARS-CoV-2. The virus evolution spread has been tracked by three developing databases: GISAID, Nextstrain and PANGO to understand its circulating variants. In this study, 110 diagnosed positive COVID-19 patient's samples, were collected from Kasr Al-Aini Hospital and the Children Cancer Hospital Egypt 57357 between May 2020 and January 2021, with clinical severity ranging from mild to severe. The viral genomes were sequenced by next generation sequencing, and phylogenetic analysis was performed to understand viral transmission dynamics. According to Nextstrain clades, most of our sequenced samples belonged to clades 20A and 20D, which in addition to clade 20B were present from the beginning of sample collection in May 2020. Clades 19A and 19B, on the other hand, appeared in the mid and late 2020 respectively, followed by the disappearance of clade 20B at the end of 2020. We identified a relatively high prevalence of the D614G spike protein variant and novel patterns of mutations associated together and with different clades. We also identified four mutations, spike H49Y, ORF3a H78Y, ORF8 E64stop and nucleocapsid E378V, associated with higher disease severity. Altogether, our study contributes genetic, phylogenetic, and clinical correlation data about the spread of the SARS-CoV-2 pandemic in Egypt.

Robust SARS-CoV-2-specific and heterologous immune responses in vaccine-naïve residents of long-term care facilities who survive natural infection

We studied humoral and cellular immunity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in 152 long-term care facility staff and 124 residents over a prospective 4-month period shortly after the first wave of infection in England. We show that residents of long-term care facilities developed high and stable levels of antibodies against spike protein and receptor-binding domain. Nucleocapsid-specific responses were also elevated but waned over time. Antibodies showed stable and equivalent levels of functional inhibition against spike-angiotensin-converting enzyme 2 binding in all age groups with comparable activity against viral variants of concern. SARS-CoV-2 seropositive donors showed high levels of antibodies to other beta-coronaviruses but serostatus did not impact humoral immunity to influenza or other respiratory syncytial viruses. SARS-CoV-2-specific cellular responses were similar across all ages but virus-specific populations showed elevated levels of activation in older donors. Thus, survivors of SARS-CoV-2 infection show a robust and stable immunity against the virus that does not negatively impact responses to other seasonal viruses.

Plant-derived active compounds as a potential nucleocapsid protein inhibitor of SARS-CoV-2: an in-silico study

The coronavirus disease 2019 (COVID-19) is caused by SARS-CoV-2. This virus has a high mismatch repair proofreading ability due to its unique exonuclease activity, making it knotty to treat. The nucleocapsid protein can serve as a potential antiviral drug target, as this protein is responsible for multiple captious functions during the viral life cycle. Herein, we have investigated the potential to repurpose active antiviral compounds of plant origins for treating the SARS-CoV-2 infection. In the present study, we followed the molecular docking methodology to screen druggable natural plants' active compounds against the nucleocapsid protein of SARS-CoV-2. The virtual screening of all 68 compounds revealed that the top seven active compounds, such as withanolide D, hypericin, silymarin, oxyacanthine, withaferin A, Acetyl aleuritolic acid, and rhein, exhibit good binding affinity with druggable ADME properties, toxicity, and Pass prediction. The stability of the docked complexes was studied by conducting molecular simulations of 100 ns. MM-GBSA calculated the binding free energy uncovered that withanolide D, hypericin, and silymarin result in highly stable binding conformations in three different sites of the nucleocapsid protein. However, further investigation is needed in order to validate the candidacy of these inhibitors for clinical trials. HighlightsNatural plants' active compounds may aid in the inhibition of SARS-CoV-2 replication and COVID-19 therapeutics.Hypericin, silymarin, withanolide D, oxyacanthine, withaferin A, Acetyl aleuritolic acid, and rhein are effective against SARS-CoV-2 N protein.Studied natural plants' active compounds could be useful against COVID-19 and its associated organs comorbidities.ADMET properties of selected compounds favor these compounds as druggable candidates.Communicated by Ramaswamy H. Sarma.

Post-COVID-19 Liver Injury: Comprehensive Imaging With Multiparametric Ultrasound

OBJECTIVES

This study aimed to define patterns of liver injury after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection using multiparametric ultrasound (mpUS) in a variable patient population with differing severities of COVID-19.

METHODS

Ninety patients were enrolled into the study: 56 had SARS-CoV-2 3-9 months prior to enrolment; 34 served as a clinically healthy control group. All patients underwent an mpUS evaluation of the liver (elastography, dispersion and attenuation imaging). Seventy-six patients had abdominal magnetic resonance (MR) and noncontrast enhanced thoracic computed tomography (CT) scans performed at the same day. All patients were screened for biochemical markers of liver injury.

RESULTS

Liver elasticity, viscosity, and steatosis values were significantly altered in patients after COVID-19, with particularly higher fibrosis scores compared to the control group (P < .001). Increased biochemical markers of liver injury correlated with changes in mpUS (P < .05), but not with findings on CT or MR findings. Seventeen of 34 hospitalized patients had a moderate or severe course of the disease course with more pronounced changes in mpUS. Increased body mass index was found to influence liver injury and correlated with more severe forms of COVID-19 (P < .001).

CONCLUSIONS

COVID-19 can cause liver injury observable using mpUS. More severe forms of COVID-19 and patient obesity are related to increased values of liver damage observed. In comparison to MRI and CT, mpUS appears to be more sensitive to involvement of liver parenchyma. Further research is warranted to establish this promising method for evaluating post-COVID-19 liver involvement in the aftermath of the pandemic.

Post COVID-19 Complications, Adjunct Therapy Explored, And Steroidal After Effects

For survivors of the COVID-19 disease, defeating the virus is just the beginning of a long road to recovery. The virus’s inducibility and catastrophic effects are distributed in multiple organs. The induction of cytokine storms in COVID-19 patients is due to the interaction of the SARS-CoV-2 virus and the host receptor, leading to various immunopathological consequences that might eventually lead to death. So far, it has hit tons of people across the world, but there is still no effective treatment. Patients facing the complications of COVID-19 after recovering have shown extensive clinical symptoms similar to previously circulating coronaviruses. Previous knowledge, and literature have opened up ways to treat this disease and manage post-COVID-19 complications, which poses a severe challenge to health system globally and may exacerbate the fragmentation of diseases. The use of steroids, as a treatment, showed various health problems and side-effects in COVID-19 patients. This review substantially discusses various post-COVID-19 complications observed, adjunctive therapies used along with common COVID-19treatment and spotlighted their side effects and consequences. This review provides latest literature on COVID-19 which emphasizes the subsequent complications in various organs, side-effects of drug, and alternative regimes that were used to treat COVID-19.

Frequency and Impact of Preadmission Digestive Symptoms on Outcome in Severe COVID-19: A Prospective Observational Cohort Study

Background

Coronavirus disease-2019 (COVID-19) commonly presents with respiratory symptoms. However, symptoms involving the digestive system may be present, significance of which is not well studied in the Indian scenario.

Methods

This prospective observational cohort study included consecutive patients with severe COVID-19 admitted to intensive care unit of our tertiary care hospital from September 9, 2020, to March 14, 2021. We evaluated the frequency of preadmission digestive symptoms and compared the demographic, clinical, laboratory parameters, and organ failure at admission and during intensive care along with mortality between those with and without digestive symptoms. In the digestive group, we sought to find predictors of mortality.

Results

Digestive symptoms were present in 76/234 (32.4%) with severe COVID-19 infection. In comparison to nondigestive group, digestive patients had higher need for noninvasive ventilation (p 0.028), invasive lines (68%, p 0.003), vasopressors (64%, p 0.01), blood product transfusion (21.1%, p <0.001), and heart failure (55.4%, p 0.041). Confounding factors of alcohol abuse, smoking, sedentary lifestyle as a causative agent for heart failure could not be ruled out. Proportional mortality rate is higher in the digestive group (65.8%, p = 0.015). Mortality is multifactorial with preadmission abdominal pathologies (HR 4.3) or central nervous system (CNS)-related comorbidities (HR 2.829), presentation with multiple digestive symptoms (HR 6.9), higher sequential organ failure assessment score (SOFA) score at admission (HR 1.258) and discharge (HR 1.162), and presence of acute kidney injury (AKI) Grade 3 (HR 2.95) as predictors of mortality. After adjusting for all confounders, need for vasopressor was observed to be associated with 11.58 times higher risk of mortality.

Conclusion

Preadmission digestive symptoms may be associated with a turbulent illness with invasive interventions, heart failure, and greater proportional mortality in severe COVID-19. AKI Grade 3 is identified as a preventable risk factor predicting mortality. CTRI/2021/03/032325.

How to cite this article

Karna ST, Singh P, Revadi G, Khurana A, Shivhare A, Saigal S, et al. Frequency and Impact of Preadmission Digestive Symptoms on Outcome in Severe COVID-19: A Prospective Observational Cohort Study. Indian J Crit Care Med 2021;25(11):1247–1257.

Chromatographic estimation of a novel triple-therapy combination targeting Helicobacter pylori eradication in different matrices

Aim: Helicobacter pylori infection is a prevalent global bacterial infection that can potentially exaggerate symptoms of other serious infections like SARS-CoV-2 (COVID-19). Methodology: Herein, an efficient, accurate and cost-effective high-performance liquid chromatography-diode array detector method was developed and validated for determination of the novel triple therapy combination of tinidazole (TD), clarithromycin (CLR) and lansoprazole (LAN) in different analytical matrices (pharmaceutical formulation, dissolution media and spiked human plasma). Results: Successful chromatographic separation was achieved using Agilent Microsorb-MV 100-5 CN column (250 × 4.6 mm, 5 μm) and a mobile phase consisted of acetonitrile and 10.0 mM phosphate buffer, pH 7.5 ± 0.1 at flow rate of 1 ml/min via gradient elution. UV-detection was accomplished at 210.0 nm for CLR and 290.0 nm for TD and LAN. Conclusion: The developed method clearly provides a reliable, beneficial and cost-effective tool for quality control, dissolution testing and biological applications of the mentioned drugs.

Helicobacter pylori infection and hypochlorhydria in Zambian adults and children: A secondary data analysis

Background

Hypochlorhydria (gastric pH >4) increases susceptibility to diarrhoea, iron deficiency, and gastric cancer. We sought to clarify the prevalence of this condition and its predisposing factors in Zambia by pooling data from previous studies conducted in hospital and community settings.

Methods

Gastric pH was measured in participants from five separate studies by collecting gastric aspirate from fasted adults and children under 3 years of age undergoing gastroscopy. Gastric pH was correlated with serological testing for Human Immunodeficiency Virus (HIV) and Helicobacter pylori (H. pylori) infections.

Results

We studied 597 individuals (487 adults and 110 children). Hypochlorhydria was present in 53% of adults and 31% of children. HIV infection was detected in 41% of adults and 11% of children. H. pylori serology was available for 366 individuals: 93% of adults and 6% of children were seropositive. In univariate analysis, hypochlorhydria was significantly associated with HIV seropositivity (OR 1.7; 95% CI 1.2–2.4; p = 0.004) and H. pylori antibody seropositivity (OR 4.9; 95% CI 2.8–8.6; p<0.0001), and with advancing age in HIV negative individuals (p = 0.0001). In multivariable analysis, only H. pylori was associated with hypochlorhydria (OR 4.0; 95% CI 2.2–7.2; p<0.0001) while excluding possible exposure to proton pump inhibitors.

Conclusions

Hypochlorhydria is common in our population, with H. pylori being the dominant factor. Only young HIV seronegative individuals had a low prevalence of hypochlorhydria. This may have implications for the risk of other health conditions including gastric cancer.

Gastroenterology and liver disease during COVID-19 and in anticipation of post-COVID-19 era: Current practice and future directions

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has emerged as a major threat to global public health. The virus causes the clinical syndrome known as coronavirus disease 2019 (COVID-19), in which multiple organs can get affected. Apart from manifestations of the respiratory system, which predominate, its clinical presentation is frequently accompanied by symptoms of the gastro-intestinal (GI) tract and liver abnormalities. The correlation of symptoms and abnormalities with disease severity is discussed, leading to ambiguous results from international literature. Moreover, the disease infects patients with co-existing liver and GI disorders affecting both their health status and the availability of healthcare services provided to them. The risk of transmission of the disease during aerosol-generating procedures has changed the diagnostic approach and follow-up algorithms for liver and GI diseases. For the safety of both doctors and patients, telemedicine and distant evaluation have become everyday practice, whereas several routines and emergency visits at outpatient and emergency departments have been postponed or delayed. Vaccination against SARS-CoV-2 is underway, providing hope to humanity and the expectation that the post-COVID-19 era is near. This review aims to update knowledge about the manifestations of COVID-19 related to liver and GI diseases and the effect of the pandemic on the diagnostic and therapeutic procedures for these diseases with a special focus on how current practices have changed and what changes will possibly remain in the future.

An Update on Antiviral Therapy Against SARS-CoV-2: How Far Have We Come?

COVID-19 pandemic has spread worldwide at an exponential rate affecting millions of people instantaneously. Currently, various drugs are under investigation to treat an enormously increasing number of COVID-19 patients. This dreadful situation clearly demands an efficient strategy to quickly identify drugs for the successful treatment of COVID-19. Hence, drug repurposing is an effective approach for the rapid discovery of frontline arsenals to fight against COVID-19. Successful application of this approach has resulted in the repurposing of some clinically approved drugs as potential anti-SARS-CoV-2 candidates. Several of these drugs are either antimalarials, antivirals, antibiotics or corticosteroids and they have been repurposed based on their potential to negate virus or reduce lung inflammation. Large numbers of clinical trials have been registered to evaluate the effectiveness and clinical safety of these drugs. Till date, a few clinical studies are complete and the results are primary. WHO also conducted an international, multi-country, open-label, randomized trials-a solidarity trial for four antiviral drugs. However, solidarity trials have few limitations like no placebos were used, additionally any drug may show effectiveness for a particular population in a region which may get neglected in solidarity trial analysis. The ongoing randomized clinical trials can provide reliable long-term follow-up results that will establish both clinical safety and clinical efficacy of these drugs with respect to different regions, populations and may aid up to worldwide COVID-19 treatment research. This review presents a comprehensive update on majorly repurposed drugs namely chloroquine, hydroxychloroquine, remdesivir, lopinavir-ritonavir, favipiravir, ribavirin, azithromycin, umifenovir, oseltamivir as well as convalescent plasma therapy used against SARS-CoV-2. The review also summarizes the data recorded on the mechanism of anti-SARS-CoV-2 activity of these repurposed drugs along with the preclinical and clinical findings, therapeutic regimens, pharmacokinetics, and drug-drug interactions.

Implications of SARS-CoV-2 infection for neurogastroenterology

BACKGROUND

Coronavirus disease 2019 (COVID-19) is associated with gastrointestinal and hepatic manifestation in up to one fifth of patients. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the etiologic agent of COVID-19, infects gastrointestinal epithelial cells expressing angiotensin-converting enzyme 2 (ACE2) receptors triggering a cascade of events leading to mucosal and systemic inflammation. Symptomatic patients display changes in gut microbiota composition and function which may contribute to intestinal barrier dysfunction and immune activation. Evidence suggests that SARS-CoV-2 infection and related mucosal inflammation impact on the function of the enteric nervous system and the activation of sensory fibers conveying information to the central nervous system, which, may at least in part, contribute symptom generation such as vomiting and diarrhea described in COVID-19. Liver and pancreas dysfunctions have also been described as non-respiratory complications of COVID-19 and add further emphasis to the common view of SARS-CoV-2 infection as a systemic disease with multiorgan involvement.

PURPOSE

The aim of this review was to highlight the current knowledge on the pathophysiology of gastrointestinal SARS-CoV-2 infection, including the crosstalk with the gut microbiota, the fecal-oral route of virus transmission, and the potential interaction of the virus with the enteric nervous system. We also review the current available data on gastrointestinal and liver manifestations, management, and outcomes of patients with COVID-19.

Mutational analysis of structural proteins of SARS-CoV-2

SARS-CoV-2 transmissibility is higher than that of other human coronaviruses; therefore, it poses a threat to the populated communities. We investigated mutations among envelope (E), membrane (M), and spike (S) proteins from different isolates of SARS-CoV-2 and plausible signaling influenced by mutated virus in a host. We procured updated protein sequences from the NCBI virus database. Mutations were analyzed in the retrieved sequences of the viral proteins through multiple sequence alignment. Additionally, the data was subjected to ScanPROSITE to analyse if the mutations generated a relevant sequence for host signaling. Unique mutations in E, M, and S proteins resulted in modification sites like PKC phosphorylation and N-myristoylation sites. Based on structural analysis, our study revealed that the D614G mutation in the S protein diminished the interaction with T859 and K854 of adjacent chains. Moreover, the S protein of SARS-CoV-2 consists of an Arg-Gly-Asp (RGD) tripeptide sequence, which could potentially interact with various members of integrin family receptors. RGD sequence in S protein might aid in the initial virus attachment. We speculated crucial host pathways which the mutated isolates of SARS-CoV-2 may alter like PKC, Src, and integrin mediated signaling pathways. PKC signaling is known to influence the caveosome/raft pathway which is critical for virus entry. Additionally, the myristoylated proteins might activate NF-κB, a master molecule of inflammation. Thus the mutations may contribute to the disease pathogenesis and distinct lung pathophysiological changes. Further the frequently occurring mutations in the protein can be studied for possible therapeutic interventions.

Diarrhea Is Associated with Increased Severity of Disease in COVID-19: Systemic Review and Metaanalysis

COVID-19 has become a pandemic since its emergence in Wuhan, China. The disease process was initially defined by presence of respiratory symptoms; however, it is now well studied and shown in evidence that this is a multisystem process. Involvement of gastrointestinal (GI) system has been identified, and GI symptoms can be the only presenting symptoms in some patients. Hence, it is important to identify and understand the GI symptoms associated with COVID-19 for appropriate care of patient. We conducted a systematic review and metaanalysis to identify the GI symptoms of COVID-19 and identify association of diarrhea with severity of COVID-19. We performed extensive search of Medline and Embase from December 2019 to May 2020 to identify articles reporting GI symptoms in COVID-19 patients. The primary outcome was prevalence of GI symptoms in COVID-19 patients, and secondary outcome was the association of diarrhea with disease severity. A total of 38 studies with 8407 patients were included. Of the total patients, 15.47% patients had at least one GI symptom. The pooled prevalence of nausea/vomiting was 7.53% and diarrhea was 11.52%. On metaanalysis, patients with diarrhea as one of the presenting symptoms were more likely to have severe disease (OR 1.63, 95% CI: 1.11–3.38, p = 0.01). Our systematic review and metaanalysis demonstrated that GI symptoms are common in COVID-19. Presence of diarrhea as a presenting symptom is associated with increased disease severity and likely worse prognosis. Early recognition of patients is needed for prompt management of this at-risk population.