COVID-19 and gastroenteric manifestations

Coronavirus disease 2019 (COVID-19), caused by the infection of a novel coronavirus [severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)], has become a pandemic. The infection has resulted in about one hundred million COVID-19 cases and millions of deaths. Although SARS-CoV-2 mainly spreads through the air and impairs the function of the respiratory system, it also attacks the gastrointestinal epithelial cells through the same receptor, angiotensin converting enzyme 2 receptor, which results in gastroenteric symptoms and potential fecal-oral transmission. Besides the infection of SARS-CoV-2, the treatments of COVID-19 also contribute to the gastroenteric manifestations due to the adverse drug reactions of anti-COVID-19 drugs. In this review, we update the clinical features, basic studies, and clinical practices of COVID-19-associated gastroenteric manifestations.     

Liver dysfunction-related COVID-19: A narrative review

The coronavirus 2019 disease (COVID-19) is caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2. This disease was designated by the World Health Organization as a pandemic on March 11, 2020, which is not seen before. There are no classical features among the cases of the disease owing to the involvement of nearly all body tissues by the virus. Hepatic involvement is one of the characteristics of the COVID-19 course. There are six possible mechanisms of such involvement: Direct virus injury, drug-induced effect, inflammatory cytokine storm, hypoxia-ischemic destruction, abnormalities in liver function tests, and pre-existing chronic liver diseases. Liver abnormalities are seen commonly in the severe or critical stage of COVID-19. Therefore, these abnormalities determine the COVID-19 severity and carry a high rate of morbidity and mortality. The elderly and patients with comorbidities like diabetes mellitus and hypertension are more vulnerable to liver involvement. Another issue that needs to be disclosed is the liver manifestations following the COVID-19 vaccination, such as autoimmune hepatitis. Of note, complete vaccination with third and fourth booster doses is necessary for patients with previous chronic liver diseases or those who have been subjected to liver transplantation. This review aims to explore the various aspects of liver dysfunction during the COVID-19 course regarding the epidemiological features, predisposing factors, pathophysiological mechanisms, hepatic manifestations due to COVID-19 or following vaccination, role of liver function tests in the assessment of COVID-19 severity, adverse effects of the therapeutic agents for the disease, and prognosis.     

Implications of COVID-19 for inflammatory bowel disease: Opportunities and challenges amidst the pandemic

Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic various measures have been taken to mitigate the effects of the global health crisis in this unprecedented time. According to the World Health Organization, more than 5 million people have been infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) and with more than 300000 deaths attributed to COVID-19 worldwide. There is emerging evidence that SARS-CoV-2 utilizes angiotensin-converting enzyme 2 receptors to enter human cells which are found in abundance in the alveoli and intestines. In addition, the infection is noted to be more severe in patients with co-morbid conditions, those who are malnourished, immunosuppressed and immunocompromised. Inflammatory bowel disease (IBD) which includes ulcerative colitis and Crohn’s disease is chronic remitting and relapsing disorders with intestinal and extraintestinal manifestation. IBD patients are often malnourished and on immunosuppressive medications and there is a hypothetical concern that IBD patients are at substantial risk of COVID-19 infection. The management of IBD patients is often complex and poses unique challenges for gastroenterologists during the pandemic. The purpose of this review article is to summarize the growing level of evidence and understanding of the management of IBD during the COVID-19 pandemic, in the light of international and national gastroenterology society guidelines. We performed a thorough literature search on IBD, SARS-CoV-2 and COVID-19 on PubMed, EMBASE, OVID Medline and Google Scholar and pertaining literature was critically examined and summarized. Per national and international society guidelines and recommendations, IBD is not a risk factor for SARS-CoV-2 infection. IBD patients should continue with their medications and they should follow universal precautions i.e. masks, hand and respiratory hygiene and avoidance of health care facilities and public toilets as general population. Among IBD patients older age, having active disease, and co-morbid conditions are risk factors for a severe SARS-CoV-2 infection. Furthermore, elective endoscopic and surgical procedures can be delayed or deferred until discussing the risks and benefits with patients.     

COVID-19 infection and liver injury: Clinical features,biomarkers, potential mechanisms,treatment, and management challenges

It is hypothesized that liver impairment caused by coronavirus disease 2019 (COVID-19) infection might play a central role in severe clinical presentations. Liver injury is closely associated with severe disease and, even with antiviral drugs, have a poor prognosis in COVID-19 patients. In addition to the common hepatobiliary disorders caused by COVID-19, patients with pre-existing liver diseases demand special considerations during the current pandemic. Thus, it is vital that upon clinical presentation, patients with concurrent pre-existing liver disease associated with metabolic dysfunction and COVID-19 be managed properly to prevent liver failure. Careful monitoring and early detection of liver damage through biomarkers after hospitalization for COVID-19 is underscored in all cases, particularly in those with pre-existing metabolic liver injury. The purpose of this study was to determine most recent evidence regarding causality, potential risk factors, and challenges, therapeutic options, and management of COVID-19 infection in vulnerable patients with pre-existing liver injury. This review aims to highlight the current frontier of COVID-19 infection and liver injury and the direction of liver injury in these patients.     

Prevention,diagnostic evaluation,management and prognostic implications of liver disease in critically ill patients with COVID-19

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, broke out in December 2019 in Wuhan city of China and spread rapidly worldwide. Therefore, by March 2020, the World Health Organization declared the disease a global pandemic. Apart from the respiratory system, various other organs of the human body are also seriously affected by the virus. Liver injury in patients with a severe form of COVID-19 is estimated to be 14.8%-53.0%. Elevated levels of total bilirubin, aspartate aminotransferase and alanine aminotransferase and low levels of serum albumin and prealbumin are the main laboratory findings. Patients with pre-existing chronic liver disease and cirrhosis are much more prone to develop severe liver injury. This literature review presented the recent scientific findings regarding the pathophysiological mechanisms responsible for liver injury in critically ill patients with COVID-19, the various interactions between drugs used to treat the disease and the function of the liver and the specific tests providing the possibility of early diagnosis of severe liver injury in these patients. Moreover, it highlighted the burden that COVID-19 put on health systems worldwide and its effect on transplant programs and the care provided to critically ill patients in general and particularly to those with chronic liver disease.     

Living with liver disease in the era of COVID-19-the impact of the epidemic and the threat to high-risk populations

The cardinal symptoms of severe acute respiratory syndrome coronavirus 2 infection as the pandemic began in 2020 were cough, fever, and dyspnea, thus characterizing the virus as a predominantly pulmonary disease. While it is apparent that many patients presenting acutely to the hospital with coronavirus disease 2019 (COVID-19) infection have complaints of respiratory symptoms, other vital organs and systems are also being affected. In fact, almost half of COVID-19 hospitalized patients were found to have evidence of some degree of liver injury. Incidence and severity of liver injury in patients with underlying liver disease were even greater. According to the Centers of Disease Control and Prevention, from August 1, 2020 to May 31, 2022 there have been a total of 4745738 COVID-19 hospital admissions. Considering the gravity of the COVID-19 pandemic and the incidence of liver injury in COVID-19 patients, it is imperative that we as clinicians understand the effects of the virus on the liver and conversely, the effect of underlying hepatobiliary conditions on the severity of the viral course itself. In this article, we review the spectrum of novel studies regarding COVID-19 induced liver injury, compiling data on the effects of the virus in various age and high-risk groups, especially those with preexisting liver disease, in order to obtain a comprehensive understanding of this disease process. We also provide an update of the impact of the new Omicron variant and the changing nature of COVID-19 pathogenesis.     

Gastrointestinal and hepatic manifestations of COVID-19 infection: Lessons for practitioners

Originating from Wuhan in China, coronavirus disease 2019 (COVID-19) spread globally within months and was declared a pandemic by World Health Organization in March 2020, making it one of the biggest healthcare calamities of our time. As more data on COVID-19 infection became available, what was initially thought to be a simple respiratory illness was found to be more complex. Many extra-pulmonary manifestations are now frequently reported for COVID-19 in available literature, most commonly gastrointestinal and hepatopancreato-biliary manifestations. Due to early scarcity of data, extra pulmonary manifestations were initially overlooked and may have contributed to nosocomial spread of the infection. Practitioners, especially gastroenterologists, who frequently encounter patients with these symptoms, need to be aware of them. This can not only help minimize the nosocomial spread, ensure safety of provider but also help conserve already stretched-thin healthcare resources. A tremendous amount of COVID-19 related literature is getting added to the growing pool every day, making it difficult for providers to follow. The aim of our review is to summarize the available evidence for gastrointestinal and hepatopancreatobiliary manifestations of COVID-19. We here briefly discussed the possible pathophysiologic mechanism for these manifestations and summarized the recommendations put forward by multiple gastrointestinal societies regarding safe and effective clinical practice during the ongoing pandemic.     

COVID-19 and liver diseases,what we know so far

Coronavirus disease 2019 (COVID-19) pneumonia outbreak started in December 2019. On March 12, 2020, the World Health Organization (WHO) declared that the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) constitutes a pandemic, and as of May 2021, SARS-CoV-2 has infected over 167.3 million patients, including 3.4 million deaths, reported to WHO. In this review, we will focus on the relationship between SARS-CoV-2 infection and the liver. We will discuss how chronic liver diseases affect the COVID-19 disease course and outcomes. We will also discuss the SARS-CoV-2 effects on the liver, mechanisms of acute liver injury, and potential management plans.     

Surgical treatment of hepatocellular carcinoma in the era of COVID-19 pandemic: A comprehensive review of current recommendations

The new coronavirus disease 2019 (COVID-19) pandemic has resulted in a global health emergency that has also caused profound changes in the treatment of cancer. The management of hepatocellular carcinoma (HCC) across the world has been modified according to the scarcity of care resources that have been diverted mostly to face the surge of hospitalized COVID-19 patients. Oncological and hepatobiliary societies have drafted recommendations regarding the adaptation of guidelines for the management of HCC to the current healthcare situation. This review focuses on specific recommendations for the surgical treatment of HCC (i.e., hepatic resection and liver transplantation), which still represents the best chance of cure for patients with very early and early HCC. While surgery should be pursued for very selected patients in institutions where standards of care are maintained, alternative or bridging methods, mostly thermoablation and transarterial therapies, can be used until surgery can be performed. The prognosis of patients with HCC largely depends on both the characteristics of the tumour and the stage of underlying liver disease. Risk stratification plays a pivotal role in determining the most appropriate treatment for each case and needs to balance the chance of cure and the risk of COVID-19 infection during hospitalization. Current recommendations have been critically reviewed to provide a reference for best practices in the clinical setting, with adaptation based on pandemic trends and categorization according to COVID-19 prevalence.     

Nonalcoholic fatty liver disease and COVID-19: An epidemic that begets pandemic

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global pandemic, affecting all the individuals across the planet. COVID-19 has gained significant attention due to its high prevalence among individuals with diabetes, nonalcoholic fatty liver disease (NAFLD), and metabolic syndrome. NAFLD is the hepatic manifestation of metabolic syndrome and can be associated with a high risk of developing type 2 diabetes. The association of COVID-19 and NAFLD has also gained more attention because NAFLD is highly associated with the epidemic of obesity. NAFLD is a potential risk factor for SARS-CoV-2 infection and severe COVID-19, independent of metabolic syndrome. Importantly, it is not yet clear whether the epidemics of obesity and NAFLD have perpetuated the current pandemic of COVID-19. Further research is urgently needed to assess the following: (1) Whether NAFLD is a high risk factor for SARS-CoV-2 infection; (2) Whether NAFLD is associated with the severe form of COVID-19; and (3) Whether the presence of NAFLD can explain the racial variation in the morbidity and mortality associated with COVID-19. This review summarizes the interactions between COVID-19 and NAFLD, mechanism of liver injury by COVID-19, and effect of lockdown due to COVID- 19 on patients with NAFLD.     

Manifestations and risk factors of COVID-19 and mucormycosis: A mini-review

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 has become a pandemic disease. It also increases the risk of co-infections. Mucormycosis is a severe fungal infectious disease and its causative agent, mucormycetes, belongs to an opportunist fungus Mucoraceae family. Mucormycosis in COVID-19 patients with mucormycosis presents an additional challenge worldwide. Mucormycosis shares certain risk factors and signs and symptoms with COVID-19. In this review, we summarize manifestations and risk factors of mucormycosis and COVID-19.     

Liver manifestations in COVID-19 patients: A review article

The coronavirus disease 2019 (COVID-19) initially presented as a disease that affected the lungs. Then, studies revealed that it intricately affected disparate organs in the human body, with the liver being one of the most affected organs. This review aimed to assess the association between COVID-19 and liver function, shedding light on its clinical implication. However, its exact pathophysiology remains unclear, involving many factors, such as active viral replication in the liver cells, direct cytotoxic effects of the virus on the liver or adverse reactions to viral antigens. Liver symptoms are mild-to-moderate transaminase elevation. In some patients, with underlying liver disease, more serious outcomes are observed. Thus, liver function should be meticulously considered in patients with COVID-19.     

Practical points that gastrointestinal fellows should know in management of COVID-19

Pandemics obligate providers to transform their clinical practice. An extensive effort has been put to find out feasible approaches for gastrointestinal diseases and also to manage coronavirus disease 2019 (COVID-19) related gastrointestinal conditions. Diarrhea, hepatitis, and pancreatitis can be seen in the COVID-19 course. Endoscopic procedures increase the risk of contamination for medical staff and patients despite precautions, therefore indications should be tailored to balance risks vs benefits. Furthermore, whether the immunosupression in inflammatory bowel diseases, liver transplantation, and autoimmune liver diseases increases COVID-19 related risks and how to modify immunosupression are topics of ongoing debate. This review aims to provide most up to date practical approaches that a gastrointestinal fellow should be aware on the problems and management of gastrointestinal and hepatobiliary diseases during the COVID-19 pandemic.     

Non-pulmonary involvement in COVID-19: A systemic disease rather than a pure respiratory infection

During the early phase of the coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), diagnosis was difficult due to the diversity in symptoms and imaging findings and the variability of disease presentation. Pulmonary manifestations are reportedly the main clinical presentations of COVID-19 patients. Scientists are working hard on a myriad of clinical, epidemiological, and biological aspects to better understand SARS-CoV-2 infection, aiming to mitigate the ongoing disaster. Many reports have documented the involvement of various body systems and organs apart from the respiratory tract including the gastrointestinal, liver, immune system, renal, and neurological systems. Such involvement will result in diverse presentations related to effects on these systems. Other presentations such as coagulation defects and cutaneous manifestation may also occur. Patients with specific comorbidities including obesity, diabetes, and hypertension have increased morbidity and mortality risks with COVID-19.     

Patients with cirrhosis during the COVID-19 pandemic: Current evidence and future perspectives

The outbreak of coronavirus disease-2019 (COVID-19) has resulted in a global public health emergency. Patients with cirrhosis were deemed more susceptible to viral infection because of their dysregulated immune response. Similar to the general population, cirrhotic patients exhibit various degrees of COVID-19-related liver injury, which could be attributed to direct virus cytotoxicity, systemic immune system activation, drug-related liver injury, reactivation of pre-existing liver disease, and hypoxic hepatitis. The clinical symptoms in patients with cirrhosis and COVID-19 were similar to those in the general population with COVID-19, with a lower proportion of patients with gastrointestinal symptoms. Although respiratory failure is the predominant cause of mortality in cirrhotic patients with COVID-19, a significant proportion of them lack initial respiratory symptoms. Most evidence has shown that cirrhotic patients have relatively higher rates of morbidity and mortality associated with COVID-19. Advanced cirrhosis was also proposed as an independent factor affecting a poor prognosis and the need to consider COVID-19 palliative care. General measures implemented to prevent the transmission of the virus are also essential for cirrhotic patients, and they should also receive standard cirrhosis care with minimal interruptions. The efficacy of the available COVID-19 vaccines in cirrhotic patients still needs investigation.     

Pharmaconutrition strategy to resolve SARS-CoV-2-induced inflammatory cytokine storm in non-alcoholic fatty liver disease: Omega-3 long-chain polyunsaturated fatty acids

Inflammation is one of the primary factors associated with the causation and/or progression of several lifestyle disorders, including obesity, type 2 diabetes and non-alcoholic fatty liver disease (NAFLD). NAFLD is a spectrum of disorders, and starts with simple steatosis, progresses to non-alcoholic steatohepatitis, and then advances to fibrosis, cirrhosis and finally, hepatocellular carcinoma, due to perpetual cycles of insults caused by inflammation and other cellular stress. Emerging evidence has documented that patients with NAFLD have severe coronavirus disease 2019 (COVID-19), and patients with COVID-19 have a higher liver injury and mortality. Although the exact cause or mechanism is not known, inflammatory cytokine storm is a characteristic feature of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and is known to be associated with higher mortality among COVID-19 patients. Therefore, the COVID-19 pandemic seems to be a major concern in NAFLD patients, who have contracted SARS-CoV-2 infection and develop COVID-19. This is evident in patients at any stage of the NAFLD spectrum, as the inflammatory cytokine storm may cause and/or aggravate the progression or severity of NAFLD. Thus, there is a need for resolution of the inflammatory cytokine storm in these patients. A large body of evidence has demonstrated the efficacy of omega-3 long-chain polyunsaturated fatty acids (ω-3 LCPUFA) in NAFLD conditions, due to their anti-inflammatory, immunomodulatory and anti-viral properties. Therefore, intervention with ω-3 LCPUFA, an effective pharmaconutrient along with the standard treatment for COVID-19 may be useful in the management of the NAFLD spectrum in COVID-19 patients with pre-existing NAFLD conditions by resolving the inflammatory cytokine storm and thereby attenuating its progression. Although there are challenges in implementation, optimistically they can be circumvented and the pharmaconutrition strategy may be potentially helpful in tackling both the pandemics; NAFLD and COVID-19 at least in this subset of patients.     

Hypertransaminasemia in the course of infection with SARS-CoV-2: Incidence and pathogenetic hypothesis

In patients infected with severe acute respiratory syndrome coronavirus 2, the respiratory symptoms, such as fever, cough and dyspnea, are the most frequent clinical manifestations. These patients may also present with less well-defined symptoms like diarrhea, nausea, vomiting and/or abdominal discomfort both at the time of diagnosis and during the clinical course. In a few cases, these symptoms may also present before the appearance of respiratory symptoms. To penetrate the body, Severe acute respiratory syndrome coronavirus 2 uses ACE2 receptors, which are present not only in respiratory epithelium but also in gastrointestinal mucosa and liver cholangiocytes. In several cases, viral RNA is detectable in the stool of patients with coronavirus disease 2019 (COVID-19). The liver damage seems to show a multifactorial origin. About 2%-11% of patients with COVID-19 have known underlying hepatic pathologies. In 14%-53% of COVID-19 cases, there is an alteration of the indices of liver cytolysis and is more frequently observed in severe forms of COVID-19, especially during hospitalization.     

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.     

Is positivity for hepatitis C virus antibody predictive of lower risk of death in COVID-19 patients with cirrhosis?

Liver injury has been reported in coronavirus disease 2019 (COVID-19) cases but the impact of pre-existing liver damage and related etiology have not been completely elucidated. Our research interests include the potential reciprocal influence of COVID-19 and pre-existing liver damage related to hepatitis C virus (HCV) infection, in particular. To this end, we have evaluated three cohorts of patients admitted at three Italian hospitals during the coronavirus pandemic; these included 332 patients with COVID-19 and 1527 patients with HCV who were from established real-world antiviral treatment study cohorts (sofosbuvir/velpatasvir), with either liver disease (various severities; n = 1319) or cirrhosis (n = 208). Among the COVID-19 patients, 10 had cirrhosis (3%), including 7 of metabolic origin and 3 of viral origin. Mortality among the COVID-19 patients was 27.1%, with 70% of those with cirrhosis of metabolic etiology having died. Cirrhosis, older age, low white blood cell count and lymphocyte count being identified as risk predictors of death [odds ratio (OR) = 13.7, 95% confidence interval (CI): 2.59-83.01, P = 0.006; OR = 1.05, 95%CI: 1.03-1.08, P = 0.0001; OR = 1.09, 95%CI: 1.36-1.16, P = 0.001; OR = 0.61, 95%CI: 0.39-0.93, P = 0.023, respectively]. In the two cohorts of HCV patients, COVID-19 diagnosis was made in 0.07% of those with liver disease and 1% of those with cirrhosis. Thus, the prevalence of HCV antibodies among COVID-19-infected patients was comparable to that currently reported for the general population in Italy. Amongst the COVID-19 patients, pre-existing metabolic cirrhosis appears to be associated with higher mortality, while HCV antibodies may be suggestive of “protection” against COVID-19.     

Clinical features and potential mechanism of coronavirus disease 2019-associated liver injury

Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2, has posed a serious threat to global public health security. With the increase in the number of confirmed cases globally, the World Health Organization has declared the outbreak of COVID-19 an international public health emergency. Despite atypical pneumonia as the primary symptom, liver dysfunction has also been observed in many clinical cases and is associated with the mortality risk in patients with COVID-19, like severe acute respiratory syndrome and Middle East respiratory syndrome. Here we will provide a schematic overview of the clinical characteristics and the possible mechanisms of liver injury caused by severe acute respiratory syndrome coronavirus 2 infection, which may provide help for optimizing the management of liver injury and reducing mortality in COVID-19 patients.