COVID 19 and liver: An A-Z literature review

COVID-19, Possible Hepatic Pathways and Alcohol Abuse-What Do We Know up to 2023?

The pandemic period due to coronavirus disease 2019 (COVID-19) revolutionized all possible areas of global health. Significant consequences were also related to diverse extrapulmonary manifestations of this pathology. The liver was found to be a relatively common organ, beyond the respiratory tract, affected by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Multiple studies revealed the essential role of chronic liver disease (CLD) in the general outcome of coronavirus infection. Present concerns in this field are related to the direct hepatic consequences caused by COVID-19 and pre-existing liver disorders as risk factors for the severe course of the infection. Which mechanism has a key role in this phenomenon-previously existing hepatic disorder or acute liver failure due to SARS-CoV-2-is still not fully clarified. Alcoholic liver disease (ALD) constitutes another not fully elucidated context of coronavirus infection. Should the toxic effects of ethanol or already developed liver cirrhosis and its consequences be perceived as a causative or triggering factor of hepatic impairment in COVID-19 patients? In the face of these discrepancies, we decided to summarize the role of the liver in the whole picture of coronavirus infection, paying special attention to ALD and focusing on the pathological pathways related to COVID-19, ethanol toxicity and liver cirrhosis.

Hepatobiliary long-term consequences of COVID-19: dramatically increased rate of secondary sclerosing cholangitis in critically ill COVID-19 patients

BACKGROUND

Increasing evidence suggests that secondary sclerosing cholangitis (SSC), which can lead to cirrhosis or liver failure, may be a hepatobiliary long-term complication of COVID-19. The aim of this study was to estimate the frequency and outcome of this COVID-19 sequela and to identify possible risk factors.

METHODS

This observational study, conducted at University Hospital Charité Berlin and Unfallkrankenhaus Berlin, Germany, involved hospitalized patients with COVID-19 pneumonia, including 1082 ventilated COVID-19 patients. We compared COVID-19 patients who developed SSC with a COVID-19 control group by univariate and multivariate analyses.

RESULTS

SSC occurrence after COVID-19 was observed exclusively in critically ill patients with invasive ventilation, albeit with extreme clustering among them. One in every 43 invasively ventilated COVID-19 patients developed this complication. Risk factors preceding the development of secondary sclerosing cholangitis in critically ill COVID-19 patients (SSC-CIP) were signs of systemic reduced blood oxygen supply (e.g., low PaO2/FiO2, ischemic organ infarctions), multi-organ failure (high SOFA score) at admission, high fibrinogen levels and intravenous ketamine use. Multivariate analysis confirmed fibrinogen and increased plasma lactate dehydrogenase as independent risk factors associated with cholangiopathy onset. The 1-year transplant-free survival rate of COVID-19-associated SSC-CIP was 40%.

CONCLUSIONS

COVID-19 causes SSC-CIP in a substantial proportion of critically ill patients. SSC-CIP most likely develops due to severe tissue hypoxia and fibrinogen-associated circulatory disturbances. A significant increase of patients with SSC-CIP is to be expected in the post-COVID era.

Meta-analysis of liver injury in patients with COVID-19

BACKGROUND

The coronavirus disease 2019 (COVID-19) is a major public health problem threatening human health. It can lead to multiple system complications, among which liver damage is also a common complication of COVID-19. The pathogenesis of liver injury is complex and involves the interaction of multiple factors. This study aims to investigate the incidence and risk factors of liver injury in COVID-19 patients and analyze the impact of liver injury on clinical prognosis of patients, so as to provide corresponding basis for clinical diagnosis and treatment.

METHODS

PubMed and Cochrane Library were searched in computer to collect original studies on liver injury cases, laboratory indicators and clinical outcomes in COVID-19 patients. Articles were screened according to inclusion and exclusion criteria, and data were meta-analyzed using Stata12.0 software.

RESULTS

A total of 49 studies, including 23,611 patients with COVID-19, had a prevalence of liver injury of 39.63%. Subgroup analysis found that patients in the Americas had the highest incidence of liver injury at 43.7% and lowest in Africa (25.99%). The vast majority of liver injury is manifested by aminotransferase or bilirubin levels greater than 1 times the upper limit of normal (49.16%). The older the age, the male, the associated chronic liver disease, and the higher the levels of white blood cells, neutrophils, and C-reactive protein, the higher the risk of liver injury. The use of hormones, hydroxychloroquine, and tocilizumab increases the risk of liver injury. Patients with concurrent liver injury have longer hospital stays, are more likely to progress to severe cases, and have a higher risk of death than patients without liver injury.

CONCLUSION

The incidence of liver injury in COVID-19 patients was high, affected by age, gender, chronic liver disease, inflammatory state and medication, and patients with liver injury were hospitalized longer and were more likely to have a poor prognosis. Therefore, clinical attention should be paid to early intervention.

Gastrointestinal Imaging Findings in the Era of COVID-19: A Pictorial Review

The potentially fatal COVID-19 pandemic has been associated with a largespectrum of clinical presentations. Beyond the classical pulmonary manifestations, gastrointestinal tract-related symptoms suchas nausea, diarrhea, abdominal distention and pain have been observed in patients, as a consequence of the binding of SARS-CoV-19 to Angiotensin-converting Enzyme 2 (ACE2) receptors in the gastrointestinal (GI) tract. The early recognition ofspecific imaging features, including hepatobiliary involvement, pancreatic involvement, development of solid organ infarcts, ischemic bowel changes and vascular occlusion, plays a key role through the course of the disease. Also, suspicious symptoms, especially in critically ill patients with clinical and biochemical markers of hypovolemia, necessitate timely imaging for bleeding complications. The aim of this pictorial review is to illustrate the spectrum of the GIimaging findings in patients with COVID-19. Awareness of diagnostic imaging hallmarks is crucial to optimize the management of these patients.

Impact of COVID-19 in individuals with and without pre-existent digestive disorders with a particular focus on elderly patients

Coronavirus disease 2019 (COVID-19) has several extrapulmonary symptoms. Gastrointestinal (GI) symptoms are among the most frequent clinical manifestations of COVID-19, with severe consequences reported in elderly patients. Furthermore, the impact of COVID-19 on patients with pre-existing digestive diseases still needs to be fully elucidated, particularly in the older population. This review aimed to investigate the impact of COVID-19 on the GI tract, liver, and pancreas in individuals with and without previous digestive diseases, with a particular focus on the elderly, highlighting the distinctive characteristics observed in this population. Finally, the effectiveness and adverse events of the anti-COVID-19 vaccination in patients with digestive disorders and the peculiarities found in the elderly are discussed.

SARS-CoV-2 induced liver injury: Incidence, risk factors, impact on COVID-19 severity and prognosis in different population groups

Liver is unlikely the key organ driving mortality in coronavirus disease 2019 (COVID-19) however, liver function tests (LFTs) abnormalities are widely observed mostly in moderate and severe cases. According to this review, the overall prevalence of abnormal LFTs in COVID-19 patients ranges from 2.5% to 96.8% worldwide. The geographical variability in the prevalence of underlying diseases is the determinant for the observed discrepancies between East and West. Multifactorial mechanisms are implicated in COVID-19-induced liver injury. Among them, hypercytokinemia with "bystander hepatitis", cytokine storm syndrome with subsequent oxidative stress and endotheliopathy, hypercoagulable state and immuno-thromboinflammation are the most determinant mechanisms leading to tissue injury. Liver hypoxia may also contribute under specific conditions, while direct hepatocyte injury is an emerging mechanism. Except for initially observed severe acute respiratory distress syndrome corona virus-2 (SARS-CoV-2) tropism for cholangiocytes, more recent cumulative data show SARS-CoV-2 virions within hepatocytes and sinusoidal endothelial cells using electron microscopy (EM). The best evidence for hepatocellular invasion by the virus is the identification of replicating SARS-CoV-2 RNA, S protein RNA and viral nucleocapsid protein within hepatocytes using in-situ hybridization and immunostaining with observed intrahepatic presence of SARS-CoV-2 by EM and by in-situ hybridization. New data mostly derived from imaging findings indicate possible long-term sequelae for the liver months after recovery, suggesting a post-COVID-19 persistent live injury.

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.

Liver Damage and COVID-19: At Least a “Two-Hit” Story in Systematic Review

COVID-19 pandemic waves have hit on our lives with pulmonary and, also, gastrointestinal symptoms. The latter also includes acute liver damage linked to direct SARS-CoV-2 action and/or drug-induced (DILI) in the frame of pre-existing chronic liver disease. We aimed to review literature data regarding liver damage during COVID-19. We conducted a systematic search on the main medical databases for original articles, reviews, meta-analyses, randomized clinical trials and case series using the following keywords and acronyms and their associations: liver disease, COVID-19, acute liver damage, drug-induced liver injury, antivirals. Acute liver damage due to SARS-CoV-2 infection is common among COVID-19 patients and is generally self-limiting. However, chronic hepatic diseases, such as metabolic-associated fatty liver disease (MAFLD), are associated with a less favorable prognosis, especially when alkaline phosphatases show a significant rise. Pathophysiology of COVID-19 liver damage is multifaceted and helps understand differences in liver derangement among patients. Thus, early recognition, monitoring and treatment of liver damage are crucial in these patients. In the frame of a not-ending pandemic sustained by SARS-CoV-2, it is crucial to recognize acute hepatic decompensation due to the virus and/or drugs used for COVID-19 treatment.

Clinical prediction rules for adverse evolution in patients with COVID-19 by the Omicron variant

OBJECTIVE

We identify factors related to SARS-CoV-2 infection linked to hospitalization, ICU admission, and mortality and develop clinical prediction rules.

METHODS

Retrospective cohort study of 380,081 patients with SARS-CoV-2 infection from March 1, 2020 to January 9, 2022, including a subsample of 46,402 patients who attended Emergency Departments (EDs) having data on vital signs. For derivation and external validation of the prediction rule, two different periods were considered: before and after emergence of the Omicron variant, respectively. Data collected included sociodemographic data, COVID-19 vaccination status, baseline comorbidities and treatments, other background data and vital signs at triage at EDs. The predictive models for the EDs and the whole samples were developed using multivariate logistic regression models using Lasso penalization.

RESULTS

In the multivariable models, common predictive factors of death among EDs patients were greater age; being male; having no vaccination, dementia; heart failure; liver and kidney disease; hemiplegia or paraplegia; coagulopathy; interstitial pulmonary disease; malignant tumors; use chronic systemic use of steroids, higher temperature, low O2 saturation and altered blood pressure-heart rate. The predictors of an adverse evolution were the same, with the exception of liver disease and the inclusion of cystic fibrosis. Similar predictors were found to be related to hospital admission, including liver disease, arterial hypertension, and basal prescription of immunosuppressants. Similarly, models for the whole sample, without vital signs, are presented.

CONCLUSIONS

We propose risk scales, based on basic information, easily-calculable, high-predictive that also function with the current Omicron variant and may help manage such patients in primary, emergency, and hospital care.

Liver Injury Associated with COVID-19 Infection: Pathogenesis, Histopathology, Prognosis, and Treatment

Liver injury occurs frequently as a consequence of SARS-CoV-2 infection. Direct infection of the liver leads to hepatic impairment with elevated transaminases. In addition, severe COVID-19 is characterized by cytokine release syndrome, which may initiate or exacerbate liver injury. In patients with cirrhosis, SARS-CoV-2 infection is associated with acute-on-chronic liver failure. The Middle East and North Africa (MENA) region is one of the world's regions characterized by a high prevalence of chronic liver diseases. Both parenchymal and vascular types of injury contribute to liver failure in COVID-19, with a myriad of pro-inflammatory cytokines playing a major role in perpetuating liver injury. Additionally, hypoxia and coagulopathy complicate such a condition. This review discusses the risk factors, and the underlying causes of impaired liver functions in COVID-19, with a focus on key players in the pathogenesis of liver injury. It also highlights the histopathological changes encountered in postmortem liver tissues as well as potential predictors and prognostic factors of such injury, in addition to the management strategies to ameliorate liver damage.

COVID-19 and liver injury in individuals with obesity

Coronavirus disease 2019 is an infectious disease caused by the severe acute respiratory syndrome coronavirus 2 that manifests as a variety of clinical manifestations, including liver damage commonly detected by a hepatocellular pattern from liver function tests. Liver injury is associated with a worse prognosis overall. Conditions associated with the severity of the disease include obesity and cardiometabolic comorbidities, which are also associated with nonalcoholic fatty liver disease (NAFLD). The presence of NAFLD, similarly to obesity, is associated with an unfavourable impact on the coronavirus disease 2019 outcome. Individuals with these conditions could present with liver damage and elevated liver function tests due to direct viral cytotoxicity, systemic inflammation, ischemic or hypoxic liver damage or drug side effects. However, liver damage in the setting of NAFLD could also be attributed to a pre-existing chronic low-grade inflammation associated with surplus and dysfunctional adipose tissue in these individuals. Here we investigate the hypothesis that a pre-existing inflammatory status is exacerbated after severe acute respiratory syndrome coronavirus 2 infection, which embodies a second hit to the underestimated liver damage.

Acute-on-chronic liver failure in patients with severe acute respiratory syndrome coronavirus 2 infection

The coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a significant impact on the lives of millions of people, especially those with other concomitant diseases, such as chronic liver diseases. To date, seven coronaviruses have been identified to infect humans. The main site of pathological action of these viruses is lung tissue. However, a substantial number of studies have proven that SARS-CoV-2 shows affinity towards several organs, including the gastrointestinal tract and the liver. The current state of evidence points to several proposed mechanisms of liver injury in patients with COVID-19 and their combination. Liver impairment is considered to be the result of the direct effect of the virus on the hepatic tissue cells, a systemic reaction consisting of inflammation, hypoxia and cytokine storm, drug-induced liver injury, with the possible contribution of a perturbed gut-liver axis. Reactivation of chronic hepatic disease could be another factor for liver impairment in patients with SARS-CoV-2 infection. Acute-on-chronic liver failure (ACLF) is a relatively new syndrome that occurs in 10%–30% of all hospitalized patients with chronic liver disease. It is crucial to recognize high-risk patients due to the increased morbidity and mortality in these cases. Several published studies have reported virus infection as a trigger factor for ACLF. However, to date, there are few relevant studies describing the presence of ACLF in patients with acute SARS-CoV-2 infection. In this minireview we summarize the current state of knowledge regarding the relation between ACLF and acute SARS-CoV-2 infection.

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.

Liver Injury in Patients with COVID-19: A Retrospective Study

Objectives: The objective of this study is to explore the incidence, characteristics, risk factors, and prognosis of liver injury in patients with COVID-19. Methods: We collected clinical data of 384 cases of COVID-19 and retrospectively analyzed the incidence, characteristics, and risk factors of liver injury of the patients. In addition, we followed the patient two months after discharge. Results: A total of 23.7% of the patients with COVID-19 had liver injury, with higher serum AST (P < 0.001), ALT (P < 0.001), ALP (P = 0.004), GGT (P < 0.001), total bilirubin (P = 0.002), indirect bilirubin (P = 0.025) and direct bilirubin (P < 0.001) than the control group. The median serum AST and ALT of COVID-19 patients with liver injury were mildly elevated. Risk factors of liver injury in COVID-19 patients were age (P = 0.001), history of liver diseases (P = 0.002), alcoholic abuse (P = 0.036), body mass index (P = 0.037), severity of COVID-19 (P < 0.001), C-reactive protein (P < 0.001), erythrocyte sedimentation rate (P < 0.001), Qing-Fei-Pai-Du-Tang treatment (P = 0.032), mechanical ventilation (P < 0.001), and ICU admission (P < 0.001). Most of the patients (92.3%) with liver injury were treated with hepatoprotective drugs. 95.6% of the patients returned to normal liver function tests at 2 months after discharge. Conclusions: Liver injury was commen in COVID-19 patients with risk factors, most of them have mild elevations in transaminases, and conservative treatment has a good short-term prognosis.

SARS-CoV-2-mediated liver injury: pathophysiology and mechanisms of disease

BACKGROUND

SARS-CoV-2-induced severe inflammatory response can be associated with severe medical consequences leading to multi-organ failure, including the liver. The main mechanism behind this assault is the aggressive cytokine storm that induces cytotoxicity in various organs. Of interest, hepatic stellate cells (HSC) respond acutely to liver injury through several molecular mechanisms, hence furthering the perpetuation of the cytokine storm and its resultant tissue damage. In addition, hepatocytes undergo apoptosis or necrosis resulting in the release of pro-inflammatory and pro-fibrogenic mediators that lead to chronic liver inflammation.

AIMS

The aim of this review is to summarize available data on SARS-CoV-2-induced liver inflammation in addition to evaluate the potential effect of anti-inflammatory drugs in attenuating SARS-CoV-2-induced liver inflammation.

METHODS

Thorough PubMed search was done to gather and summarize published data on SARS-CoV-2-induced liver inflammation. Additionally, various anti-inflammatory potential treatments were also documented.

RESULTS

Published data documented SARS-CoV-2 infection of liver tissues and is prominent in most liver cells. Also, histological analysis showed various features of tissues damage, e.g., hepatocellular necrosis, mitosis, cellular infiltration, and fatty degeneration in addition to microvesicular steatosis and inflammation. Finally, the efficacy of the different drugs used to treat SARS-CoV-2-induced liver injury, in particular the anti-inflammatory remedies, are likely to have some beneficial effect to treat liver injury in COVID-19.

CONCLUSION

SARS-CoV-2-induced liver inflammation is a serious condition, and drugs with potent anti-inflammatory effect can play a major role in preventing irreversible liver damage in COVID-19.

The ChoCO-W prospective observational global study: Does COVID-19 increase gangrenous cholecystitis?

BACKGROUND

The incidence of the highly morbid and potentially lethal gangrenous cholecystitis was reportedly increased during the COVID-19 pandemic. The aim of the ChoCO-W study was to compare the clinical findings and outcomes of acute cholecystitis in patients who had COVID-19 disease with those who did not.

METHODS

Data were prospectively collected over 6 months (October 1, 2020, to April 30, 2021) with 1-month follow-up. In October 2020, Delta variant of SARS CoV-2 was isolated for the first time. Demographic and clinical data were analyzed and reported according to the STROBE guidelines. Baseline characteristics and clinical outcomes of patients who had COVID-19 were compared with those who did not.

RESULTS

A total of 2893 patients, from 42 countries, 218 centers, involved, with a median age of 61.3 (SD: 17.39) years were prospectively enrolled in this study; 1481 (51%) patients were males. One hundred and eighty (6.9%) patients were COVID-19 positive, while 2412 (93.1%) were negative. Concomitant preexisting diseases including cardiovascular diseases (p < 0.0001), diabetes (p < 0.0001), and severe chronic obstructive airway disease (p = 0.005) were significantly more frequent in the COVID-19 group. Markers of sepsis severity including ARDS (p < 0.0001), PIPAS score (p < 0.0001), WSES sepsis score (p < 0.0001), qSOFA (p < 0.0001), and Tokyo classification of severity of acute cholecystitis (p < 0.0001) were significantly higher in the COVID-19 group. The COVID-19 group had significantly higher postoperative complications (32.2% compared with 11.7%, p < 0.0001), longer mean hospital stay (13.21 compared with 6.51 days, p < 0.0001), and mortality rate (13.4% compared with 1.7%, p < 0.0001). The incidence of gangrenous cholecystitis was doubled in the COVID-19 group (40.7% compared with 22.3%). The mean wall thickness of the gallbladder was significantly higher in the COVID-19 group [6.32 (SD: 2.44) mm compared with 5.4 (SD: 3.45) mm; p < 0.0001].

CONCLUSIONS

The incidence of gangrenous cholecystitis is higher in COVID patients compared with non-COVID patients admitted to the emergency department with acute cholecystitis. Gangrenous cholecystitis in COVID patients is associated with high-grade Clavien-Dindo postoperative complications, longer hospital stay and higher mortality rate. The open cholecystectomy rate is higher in COVID compared with non -COVID patients. It is recommended to delay the surgical treatment in COVID patients, when it is possible, to decrease morbidity and mortality rates. COVID-19 infection and gangrenous cholecystistis are not absolute contraindications to perform laparoscopic cholecystectomy, in a case by case evaluation, in expert hands.

Understanding the Changing Landscape of Health Disparities in Chronic Liver Diseases and Liver Cancer

Liver disease and liver cancer disparities in the U.S. are reflective of complex multiple determinants of health. This review describes the disproportionate burden of liver disease and liver cancer among racial, ethnic, sexual, and gender minority, rural, low socioeconomic status (SES) populations, and place-based contexts. The contributions of traditional and lifestyle-related risk factors (e.g., alcohol consumption, evitable toxin exposure, nutrition quality) and comorbid conditions (e.g., viral hepatitis, obesity, type II diabetes) to disparities is also explored. Biopsychosocial mechanisms defining the physiological consequences of inequities underlying these health disparities, including inflammation, allostatic load, genetics, epigenetics, and social epigenomics are described. Guided by the National Institute on Minority Health and Health Disparities (NIMHD) framework, integrative research of unexplored social and biological mechanisms of health disparities, appropriate methods and measures for early screening, diagnosis, assessment, and strategies for timely treatment and maintaining multidisciplinary care should be actively pursued. We review emerging research on adverse social determinants of liver health, such as structural racism, discrimination, stigma, SES, rising care-related costs, food insecurity, healthcare access, health literacy, and environmental exposures to pollutants. Limited research on protective factors of liver health is also described. Research from effective, multilevel, community-based interventions indicate a need for further intervention efforts that target both risk and protective factors to address health disparities. Policy-level impacts are also needed to reduce disparities. These insights are important, as the social contexts and inequities that influence determinants of liver disease/cancer have been worsened by the coronavirus disease-2019 pandemic and are forecasted to amplify disparities.

Hepatic Disorders and COVID-19: From Pathophysiology to Treatment Strategy

Following the SARS-CoV-2 outbreak and the subsequent development of the COVID-19 pandemic, organs such as the lungs, kidneys, liver, heart, and brain have been identified as priority organs. Liver diseases are considered a risk factor for high mortality from the COVID-19 pandemic. Besides, liver damage has been demonstrated in a substantial proportion of patients with COVID-19, especially those with severe clinical symptoms. Furthermore, antiviral medications, immunosuppressive drugs after liver transplantation, pre-existing hepatic diseases, and chronic liver diseases such as cirrhosis have also been implicated in SARS-CoV-2-induced liver injury. As a result, some precautions have been taken to prevent, monitor the virus, and avoid immunocompromised and susceptible individuals, such as liver and kidney transplant recipients, from being infected with SARS-CoV-2, thereby avoiding an increase in mortality. The purpose of this review was to examine the impairment caused by SARS-CoV-2 infection and the impact of drugs used during the pandemic on the mortality range and therefore the possibility of preventive measures in patients with liver disease.

Liver injury induced by COVID 19 treatment - what do we know?

The severity of coronavirus disease 2019 (COVID-19) may be correlated with the risk of liver injury development. An increasing number of studies indicate that degrees of hepatotoxicity have been associated with using some medications in the management of COVID-19 patients. However, limited studies have systematically investigated the evidence of drug-induced liver injury (DILI) in COVID-19 patients. An increasing number of studies indicate that degrees of hepatotoxicity have been associated with using some of these medications in the management of COVID-19 patients. Significantly, it was relieved after the cessation of these agents. However, to our knowledge, no studies have systematically investigated the evidence of DILI in COVID-19 patients. In this review, we discussed the association between hepatotoxicity in COVID-19 patients and the drugs used in these patients and possible mechanisms of hepatotoxicity. The currently available evidence on the association of different therapeutic agents with hepatotoxicity in COVID-19 patient was systematically reviewed.

Molecular and cellular mechanisms involved in tissue-specific metabolic modulation by SARS-CoV-2

Coronavirus disease 2019 (COVID-19) is triggered by the SARS-CoV-2, which is able to infect and cause dysfunction not only in lungs, but also in multiple organs, including central nervous system, skeletal muscle, kidneys, heart, liver, and intestine. Several metabolic disturbances are associated with cell damage or tissue injury, but the mechanisms involved are not yet fully elucidated. Some potential mechanisms involved in the COVID-19-induced tissue dysfunction are proposed, such as: (a) High expression and levels of proinflammatory cytokines, including TNF-α IL-6, IL-1β, INF-α and INF-β, increasing the systemic and tissue inflammatory state; (b) Induction of oxidative stress due to redox imbalance, resulting in cell injury or death induced by elevated production of reactive oxygen species; and (c) Deregulation of the renin-angiotensin-aldosterone system, exacerbating the inflammatory and oxidative stress responses. In this review, we discuss the main metabolic disturbances observed in different target tissues of SARS-CoV-2 and the potential mechanisms involved in these changes associated with the tissue dysfunction.

Efficacy and safety of glycyrrhizic acid preparation treating comorbid liver injury in COVID-19: A systematic review

Background: No specific drug for COVID-19 has been found, and many studies have found that different degrees of liver injury often occurred after infection with COVID-19. Glycyrrhizic acid preparation (GAP) has been frequently used clinically, often combined with conventional treatments such as antiviral therapy, to improve the prognosis of COVID-19 and patients' liver function. Aims: To critically review and analyze clinical evidence on the efficacy and safety of GAP in the treatment of COVID-19 alone and COVID-19 with comorbid liver injury. Methods: A systematic literature review was performed following a sensitive searching strategy that examines all articles published in "WHO COVID-19 Research Database," "Cochrane Library," "VIP," "CNKI," "Wanfang," and "CBM" from 2020 to July 2022. Articles were evaluated by peer reviewers and used Joanna Briggs Institute (JBI) critical appraisal tools to complete the assessment of the risk of bias. Results: Ten clinical studies were finally included, involving 598 patients with COVID-19, of whom 189 were confirmed to be with comorbid liver injury. The main GAPs used are diammonium glycyrrhizinate and magnesium isoglycyrrhizinate, which have shown efficacy in improving liver function, inhibiting inflammation, and enhancing immunity. We are still seeking more related research. Conclusion: Glycyrrhizic acid preparations (mainly diammonium glycyrrhizinate and magnesium isoglycyrrhizinate) have a considerable clinical effect on improving liver function in patients with COVID-19 alone or with comorbid liver injury. Further studies on the use of GAP in the treatment of COVID-19 with comorbid liver injury and its mechanism are still needed. Systematic Review Registration: [www.crd.york.ac.uk/prospero], identifier [CRD42021234647].

Exosome-Based Theranostics for Liver Diseases

Exosomes are small extracellular vesicles that can be secreted by any type of cell, released into almost all biological fluids, and extracted from anybody fluid such as blood, urine, saliva, and amniotic fluid. The theranostic role of exosome in liver diseases has been widely studied in recent years. In this review, we briefly introduce the biological characteristics of exosomes and then focus on the theranostics of exosomes in liver diseases, specifically gene delivery associated with liver diseases.

Evaluation of Drug-Induced Liver Injury in Hospitalized Patients with SARS-CoV-2 Infection

Elevated liver enzymes are frequently reported in SARS-CoV-2-infected patients. Several mechanisms of liver injury have been proposed, but no clear conclusions were drawn. We aimed to evaluate hepatocellular and cholestatic injury in relation to the administration of potentially hepatotoxic drugs included in the current COVID-19 therapeutic guidelines in a retrospective cohort of 396 hospitalized COVID-19 patients. The main findings of our study are: (1) Significant increase in aminotransferases level was observed during hospitalization, suggesting drug-related hepatotoxicity. (2) Tocilizumab was correlated with hepatocellular injury, including ALT values greater than five times the upper limit of normal. (3) Anakinra was correlated with ALT values greater than three times the upper limit of normal. (4) Younger patients receiving tocilizumab or anakinra had a higher risk of hepatocellular injury. (5) The combination of favipiravir with tocilizumab was associated with AST values greater than three times the upper limit of normal and with an increase in direct bilirubin. (6) The administration of at least three potentially hepatotoxic drugs was correlated with hepatocellular injury, including ALT values greater than five times the upper limit of normal, and with the increase in indirect bilirubin. (7) Remdesivir and favipiravir by themselves did not correlate with hepatocellular or cholestatic injury in our study cohort.

Humoral Immunogenicity to SARS-CoV-2 Vaccination in Liver Transplant Recipients: A Systematic Review and Meta-Analysis

Solid organ transplant recipients generally show reduced immunogenicity to various vaccines. We aimed to assess the immunogenicity of the immune response among orthotopic liver transplant (OLT) recipients after the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. A systematic search was performed to evaluate immunogenicity or adverse events reported after SARS-CoV-2 vaccination. The pooled analysis of 20 studies showed a humoral immune response rate of 0.70 (95% confidence interval [CI], 0.63-0.77) after SARS-CoV-2 vaccination among OLT recipients. The immunogenicity among OLT recipients was significantly lower compared to the overall population and healthy controls, with odds ratios (ORs) of 0.80 and 0.69. However, it was significantly higher than that of patients receiving other organ transplants, especially kidneys, with an OR of 1.50. Male sex, old age, chronic kidney disease, obesity, and multiple or high immunosuppressant doses significantly increased the risk of unresponsiveness in patients with OLT. The overall incidence of any adverse event after vaccination was 0.68 (95% CI, 0.55-0.81), similar to that of control. OLT recipients had an overall humoral immune response rate of 70% after SARS-CoV-2 vaccination, which is lower than that of healthy controls but favourable compared to those of other solid organ transplant recipients.

Potential histopathological and immunological effects of SARS-CoV-2 on the liver

The coronavirus disease outbreak of 2019 (COVID-19) poses a serious threat to public health worldwide. Lung injury is the most common complication of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection. However, other organs, including the liver, can also be affected. Currently, there is limited evidence that liver impairment is associated with severe SARS-CoV-2 infection. Clinicians will need to determine whether liver injury is caused by an underlying liver condition, COVID-19 therapy, the virus directly, or immune-mediated inflammation or represents a complicated disease course in the context of COVID-19. To address the scarcity of data on histopathological changes and immunological effects on the liver with COVID-19 positivity, we analyze and summarize recent findings. We searched PubMed, Medline, Google Scholar, Science Direct, Scopus, and Web of Science databases up to December 1, 2021, identifying published studies with the search terms "Histopathology in COVID-19," "COVID-19," "Pathological changes in liver in COVID-19," "Liver pathology in COVID-19," "immunological effects in liver in COVID-19," and "SARS-CoV-2." This concise review will aid clinicians and researchers in better understanding the tissue histopathology and immunological consequences of SARS-CoV-2 on the liver, enabling improved care planning and avoiding future dangers.

Abdominal pain patterns during COVID-19: an observational study

Abdominal pain and liver injury have been frequently reported during coronavirus disease-2019 (COVID-19). Our aim was to investigate characteristics of abdominal pain in COVID-19 patients and their association with disease severity and liver injury.Data of all COVID-19 patients hospitalized during the first wave in one hospital were retrieved. Patients admitted exclusively for other pathologies and/or recovered from COVID-19, as well as pregnant women were excluded. Patients whose abdominal pain was related to alternative diagnosis were also excluded.Among the 1026 included patients, 200 (19.5%) exhibited spontaneous abdominal pain and 165 (16.2%) after abdomen palpation. Spontaneous pain was most frequently localized in the epigastric (42.7%) and right upper quadrant (25.5%) regions. Tenderness in the right upper region was associated with severe COVID-19 (hospital mortality and/or admission to intensive/intermediate care unit) with an adjusted odds ratio of 2.81 (95% CI 1.27-6.21, p = 0.010). Patients with history of lower abdomen pain experimented less frequently dyspnea compared to patients with history of upper abdominal pain (25.8 versus 63.0%, p < 0.001). Baseline transaminases elevation was associated with history of pain in epigastric and right upper region and AST elevation was strongly associated with severe COVID-19 with an odds ratio of 16.03 (95% CI 1.95-131.63 p = 0.010).More than one fifth of patients admitted for COVID-19 presented abdominal pain. Those with pain located in the upper abdomen were more at risk of dyspnea, demonstrated more altered transaminases, and presented a higher risk of adverse outcomes.

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.

COVID-19: Gastrointestinal manifestations, liver injury and recommendations

Coronavirus disease 2019 (COVID-19) has caused a pandemic that affected all countries with nearly 270 million patients and 5 million deaths, as of as of December, 2021. The severe acute respiratory syndrome coronavirus 2 virus targets the receptor, angiotensin-converting enzyme 2, which is frequently found in human intestinal epithelial cells, bile duct epithelial cells, and liver cells, and all gastrointestinal system organs are affected by COVID-19 infection. The aim of this study is to review the gastrointestinal manifestations and liver damage of COVID-19 infection and investigate the severe COVID-19 infection risk in patients that have chronic gastrointestinal disease, along with current treatment guidelines. A literature search was conducted on electronic databases of PubMed, Scopus, and Cochran Library, consisting of COVID-19, liver injury, gastrointestinal system findings, and treatment. Liver and intestinal involvements are the most common manifestations. Diarrhea, anorexia, nausea/vomiting, abdominal pain are the most frequent symptoms seen in intestinal involvement. Mild hepatitis occurs with elevated levels of transaminases. Gastrointestinal involvement is associated with long hospital stay, severity of the disease, and intensive care unit necessity. Treatments and follow-up of patients with inflammatory bowel diseases, cirrhosis, hepatocellular carcinoma, or liver transplant have been negatively affected during the pandemic. Patients with cirrhosis, hepatocellular carcinoma, auto-immune diseases, or liver transplantation may have a greater risk for severe COVID-19. Diagnostic or therapeutic procedures should be restricted with specific conditions. Telemedicine should be used in non-urgent periodic patient follow up. COVID-19 treatment should not be delayed in patients at the risk group. COVID-19 vaccination should be prioritized in this group.

Meta-Analysis of APP Expression Modulated by SARS-CoV-2 Infection via the ACE2 Receptor

Alzheimer's disease (AD) is characterized by the deposition of amyloid-beta (Aβ) plaques from improper amyloid-beta precursor protein (APP) cleavage. Following studies of inflammation caused by coronavirus-2019 (COVID-19) infection, this study investigated the impact of COVID-19 on APP expression. A meta-analysis was conducted utilizing QIAGEN Ingenuity Pathway Analysis (IPA) to examine the link between severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) and the modulation of APP expression upon virus binding the Angiotensin-converting enzyme-2 (ACE2) receptor. A Core Analysis was run on the infection by severe acute respiratory syndrome (SARS) coronavirus node, which included molecules affected by SARS-CoV-2, revealing its upstream regulators. Intermediary molecules were found between the upstream regulators and ACE2 and between ACE2 and APP. Activation of the upstream regulators downregulated the expression of ACE2 with a Z-score of -1.719 (p-value = 0.086) and upregulated APP with a Z-score of 1.898 (p-value = 0.058), showing a less than 10% chance of the results occurring by chance and pointing to an inverse relationship between ACE2 and APP expression. The neuroinflammation signaling pathway was the fifth top canonical pathway involved in APP upregulation. The study results suggest that ACE2 could be downregulated by SARS-CoV-2, resulting in APP upregulation, and potentially exacerbating the onset and progression of AD.

Efficacy and safety of acetylcysteine for the prevention of liver injury in COVID-19 intensive care unit patients under treatment with remdesivir

AIM

The present double-blinded placebo-controlled randomized clinical trial evaluated prophylactic use of acetylcysteine for the prevention of liver injury in patients with severe COVID-19 pneumonia under treatment with remdesivir.

BACKGROUND

Liver injury is reportedly common in patients with severe COVID-19 pneumonia and can occur not only as a result of disease progression, but as an iatrogenic reaction to remdesivir.

METHODS

A total of 83 adult patients with severe COVID-19 pneumonia were randomly assigned in parallel groups to receive either acetylcysteine or placebo. All the patients received standard care according to institutional protocols, including remdesivir for a total of five days. One gram acetylcysteine was administered intravenously every 12 hours for 42 patients, and 41 patients received the same volume of 0.9% sodium chloride as placebo (Trial Registration: www.irct.ir identifier, IRCT20210726051995N1).

RESULTS

After 5 days, median aspartate transaminase (AST) and alanine transaminase (ALT) levels were significantly lower in the acetylcysteine than in the placebo group. Of those who received the placebo, 30 (73.2%), 4 (9.7%), and 3 (7.3%) patients had serum AST levels elevated between 1-2.5, 2.5-5, and over 5 times the upper limit of normal (ULN), respectively; while in the acetylcysteine group, 33 (78.6%) and 0 patients had AST levels between 1-2.5 and over 2.5 times ULN, respectively (p-value=0.037). In the acetylcysteine group, 23 (54.8%), 1 (2.4%), and 1 (2.4%) patient had serum ALT levels elevated between 1-2.5, 2.5-5, and over 5 times ULN, respectively; in the placebo group, however, 24 (58.5%), 7 (17.1%), and 1 (2.4%) patient had serum ALT levels between 1-2.5, 2.5-5, and over 5 times ULN, respectively (p-value=0.073).

CONCLUSION

Intravenous administration of acetylcysteine significantly prevents liver transaminases elevation and liver injury in seriously ill COVID-19 patients treated with remdesivir.

COVID-19 and the liver: A brief and core review

Coronavirus disease 2019 has a wide range of clinical spectrum from asymptomatic infection to severe infection resulting in death within a short time. Currently, it is known that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not only cause a respiratory tract infection but a more complicated disease that can lead to multiple system involvement including the liver. Herein, we evaluate the epidemiology, the impact of liver injury/ dysfunction on disease prognosis, the pathophysiological mechanisms and management of liver injury. More than one-fourth of the patients have abnormal liver function tests, mostly a mild-to-moderate liver dysfunction. Liver injury is significantly associated with a poor clinical outcome. Direct cytotoxic effect of SARS-CoV-2, the immune response (“cytokine storm”), the complications related to the disease, and drugs used in the treatments are the pathophysiological mechanisms responsible for liver injury. However, the exact mechanism is not yet clearly explained. The binding of SARS-CoV-2 to the angiotensin-converting enzyme 2 receptors and entering the hepatocyte and cholangiocytes can cause cytotoxic effects on the liver. Excessive immune response has an important role in disease progression and causes acute respiratory distress syndrome and multi-organ failures accompanied by liver injury. Treatment drugs, particularly lopinavir/ritonavir, remdesivir and antibiotics are a frequent reason for liver injury. The possible reasons should be meticulously investigated and resolved.

Liver and COVID-19: From care of patients with liver diseases to liver injury

The global pandemic of coronavirus disease 2019 (COVID-19) changed dramatically all priorities on medical society and created several challenges for clinicians caring for patients with liver diseases. We performed a comprehensive review about how COVID-19 can affect the liver, the influence of liver diseases on the risk of developing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 severity and also some strategies to overcome all the challenges clinicians have to face in the management of patients with liver diseases in a period of time when all the focus turned on COVID-19. We analyze the relationship between COVID-19 and non-alcoholic fatty liver disease, alcoholic liver disease, viral hepatitis, autoimmune liver disease, cirrhosis, hepatocellular carcinoma and liver transplantation, as well as the approach to SARS-CoV-2 vaccination.

Metabolic dysfunction associated fatty liver disease and coronavirus disease 2019: clinical relationship and current management

The coronavirus disease 2019 (COVID-19) is caused by the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). At present, the COVID-19 has been prevalent worldwide for more than a year and caused more than four million deaths. Liver injury was frequently observed in patients with COVID-19. Recently, a new definition of metabolic dysfunction associated fatty liver disease (MAFLD) was proposed by a panel of international experts, and the relationship between MAFLD and COVID-19 has been actively investigated. Several previous studies indicated that the patients with MAFLD had a higher prevalence of COVID-19 and a tendency to develop severe type of respiratory infection, and others indicated that liver injury would be exacerbated in the patients with MAFLD once infected with COVID-19. The mechanism underlying the relationship between MAFLD and COVID-19 infection has not been thoroughly investigated, and recent studies indicated that multifactorial mechanisms, such as altered host angiotensin converting enzyme 2 (ACE2) receptor expression, direct viral attack, disruption of cholangiocyte function, systemic inflammatory reaction, drug-induced liver injury, hepatic ischemic and hypoxic injury, and MAFLD-related glucose and lipid metabolic disorders, might jointly contribute to both of the adverse hepatic and respiratory outcomes. In this review, we discussed the relationship between MAFLD and COVID-19 based on current available literature, and summarized the recommendations for clinical management of MAFLD patients during the pandemic of COVID-19.

Drug-induced liver injury and COVID-19: A review for clinical practice

Coronavirus disease 2019 (COVID-19) consists of a systemic disease that can present many complications. The infection presents broad clinical symptoms and a high rate of transmissibility. In addition to severe acute respiratory syndrome, the patients manifest complications beyond the respiratory system. The frequency of liver damage in COVID-19 patients ranges from 14.8% to 53% of patients. One should pay attention to drug-induced liver injury (DILI) in patients with COVID-19, especially considering the off-label use of drugs in prophylactic and therapeutic regimens applied on large scales. This review aims to present relevant information on the medication used so far in COVID-19 patients and its possible hepatotoxicity. We reviewed liver damage in patients with COVID-19 on PubMed and Virtual Health Library to investigate DILI cases. Four studies were selected, involving the medicines remdesivir, tocilizumab and a pharmacovigilance analysis study. The hepatotoxicity profile of drugs presented in the literature considers use in accordance to usual posology standards for treatment. However, drugs currently used in the management of COVID-19 follow different dosages and posology than those tested by the pharmaceutical industry. The deficiency of uniformity and standardization in the assessment of hepatotoxicity cases hinders the publication of information and the possibility of comparing information among healthcare professionals. It is suggested that severe liver injury in COVID-19 patients should be reported in pharmacovigilance institutions, and physicians should pay attention to any considerable abnormal liver test elevation as it can demonstrate unknown drug hepatotoxicity. Liver disorders in COVID-19 patients and the use of several concomitant off-label medications — with a potential risk of further damaging the liver - should at least be a warning sign for rapid identification and early intervention, thus preventing liver damage from contributing to severe impairment in patients.

Drug-Induced Liver Injury in COVID-19 Patients: A Systematic Review

Introduction: The severity of COVID-19 may be correlated with the risk of liver injury development. An increasing number of studies indicate that degrees of hepatotoxicity has been associated with using some medications in the management of COVID-19 patients. However, limited studies had systematically investigated the evidence of drug-induced liver injury (DILI) in COVID-19 patients. Thus, this study aimed to examine DILI in COVID-19 patients. Methods: A systematic search was carried out in PubMed/Medline, EMBASE, and Web of Science up to December 30, 2020. Search items included "SARS-CoV-2", "Coronavirus," COVID-19, and liver injury. Results: We included 22 related articles. Among included studies, there was five case report, five case series, four randomizes control trial (RCT), seven cohort studies, and one cross-sectional study. The drugs included in this systematic review were remdesivir, favipiravir, tocilizumab, hydroxychloroquine, and lopinavir/ritonavir. Among included studies, some studies revealed a direct role of drugs, while others couldn't certainly confirm that the liver injury was due to SARS-CoV-2 itself or administration of medications. However, a significant number of studies reported that liver injury could be attributable to drug administration. Discussion: Liver injury in COVID-19 patients could be caused by the virus itself or the administration of some types of drug. Intensive liver function monitoring should be considered for patients, especially patients who are treated with drugs such as remdesivir, lopinavir/ritonavir, and tocilizumab.

Liver stiffness is associated with disease severity and worse clinical scenarios in coronavirus disease 2019: A prospective transient elastography study

BACKGROUND

Pre-existing chronic liver disease is currently considered a poor prognostic factor for coronavirus disease 2019 (COVID-19). The present study aimed to investigate the association of liver stiffness measurement (LSM) with disease severity and clinical course of COVID-19.

METHODS

We prospectively recruited consecutive hospitalised adult patients with COVID-19 in a 3-month period. Demographic, laboratory, clinical and vibration-controlled transient elastography (VCTE) features were recorded at entry, and all patients were prospectively followed-up. Severe liver fibrosis was defined as an LSM value higher than 9.6 kPA. Multivariate logistic regression analysis was performed to reveal factors associated with disease severity and outcomes.

RESULTS

Out of 98 eligible patients with COVID-19, 12 (12.2%) had severe liver fibrosis. Patients with severe liver fibrosis had higher baseline disease severity (P = .022), more commonly required oxygen treatment at entry (P = .010), and had intensive-care unit (ICU) requirements during the 6 (1-39)-day median follow-up time (P = .017). The presence of severe liver fibrosis was independently associated with disease severity (odds ratio (OR): 7.685, 95% confidence interval (CI): 1.435-41.162, P = .017) and ICU requirement (OR: 46.656, 95% CI: 2.144-1015.090, P = .014). LSM was correlated with alanine aminotransferase levels (P = .005, r: 0.283), but not with other markers of acute hepatic injury or inflammation.

CONCLUSION

Initial VCTE application might help physicians identify patients who are more likely to have severe illness or worse clinical outcomes, in addition to other well-established clinical and laboratory factors. Further multicentre prospective studies are warranted to validate our results.

Critically Ill COVID-19 Patient with Chronic Liver Disease - Insights into a Comprehensive Liver Intensive Care

The novel coronavirus-related coronavirus disease 2019 (COVID-19) pandemic has been relentless in disrupting and overwhelming healthcare the world over. Clinical outcomes of COVID-19 in patients with chronic comorbidities, especially in those with metabolic syndrome, are well documented. Chronic liver disease and cirrhosis patients are a special sub-group, among whom the management of COVID-19 is challenging. Understanding the pathophysiology of COVID-19 in patients with cirrhosis and portal hypertension improves our identification of at-risk patients for disease progression that will further help compartmentalize generalized and specialized treatment options in this special patient group. In this exhaustive review, we critically review the impact of COVID-19 on the liver and in chronic liver disease and cirrhosis patients. We further discuss common features associated with the pathophysiology of COVID-19 and cirrhosis, based on the renin-angiotensin system and deliberate current literature on guidelines for the treatment of COVID-19 and extrapolate the same to the cirrhosis population to provide a concise and stepwise, evidence-based management for cirrhosis patients with severe and critical COVID-19. There are no specific management guidelines for cirrhosis patients with COVID-19 and current recommendations for treatment are as per guidelines for general population. Nevertheless, specific issues like avoiding corticosteroids in decompensated patients with variceal bleeding, suspected sepsis, high grade hepatic encephalopathy and acute kidney injury, use of early mechanical ventilation strategies in those with severe ascites and hepatopulmonary syndrome, avoidance of remdesivir in advanced liver disease, and application of liver-specific severity scores for prognostication and identification of futility need to be highlighted.

Liver dysfunction and SARS-CoV-2 infection

Severe acute respiratory syndrome coronavirus 2 infection is the cause of coronavirus disease 2019 (COVID-19), which predominantly affects the respiratory system; it also causes systemic and multi-organic disease. Liver damage is among the main extrapulmonary manifestations. COVID-19-associated liver injury is defined as any liver damage occurring during the disease course and treatment of COVID-19 in patients with or without pre-existing liver disease, and occurs in approximately one in five patients. Abnormal liver test results have been associated with a more severe course of COVID-19 and other complications, including death. Mechanisms linking COVID-19 to liver injury are diverse. Particular consideration should be made for patients with pre-existing liver disease, such as metabolic dysfunction-associated fatty liver disease, chronic liver disease due to viral or autoimmune disease, liver transplant carriers, or cirrhosis, given the risk for more severe outcomes. This manuscript summarizes the current lines of evidence on COVID-19-associated liver injury regarding pathophysiology, clinical significance, and management in both patients with or without pre-existing liver disease, to facilitate clinicians' access to updated information and patient care. Finally, we mention the ideas and recommendations to be considered for future research.

Abnormal Liver Biochemistry Tests and Acute Liver Injury in COVID-19 Patients: Current Evidence and Potential Pathogenesis

Globally, millions of persons have contracted the coronavirus disease 2019 (COVID-19) over the past several months, resulting in significant mortality. Health care systems are negatively impacted including the care of individuals with cancers and other chronic diseases such as chronic active hepatitis, cirrhosis and hepatocellular carcinoma. There are various probable pathogenic mechanisms that have been presented to account for liver injury in COVID-19 patients such as hepatotoxicity cause by therapeutic drugs, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection of the bile duct cells and hepatocytes, hypoxia and systemic inflammatory response. Liver biochemistry tests such as aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyl transferase (GGT) and alkaline phosphatase (ALP) are deranged in COVID-19 patients with liver injury. Hepatocellular damage results in the elevation of serum AST and ALT levels in early onset disease while a cholestatic pattern that develops as the disease progress causes higher levels of ALP, GGT, direct and total bilirubin. These liver biochemistry tests are prognostic markers of disease severity and should be carefully monitored in COVID-19 patients. We conducted a systematic review of abnormal liver biochemistry tests in COVID-19 and the possible pathogenesis involved. Significant findings regarding the severity, hepatocellular pattern, incidence and related clinical outcomes in COVID-19 patients are highlighted.

COVID-19 in gastroenterology and hepatology: Lessons learned and questions to be answered

BACKGROUND

Although coronavirus disease 2019 (COVID-19) presents primarily as a lower respiratory tract infection, increasing data suggests multiorgan, including the gastrointestinal (GI) tract and liver, involvement in patients who are infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).

AIM

To provide a comprehensive overview of COVID-19 in gastroenterology and hepatology.

METHODS

Relevant studies on COVID-19 related to the study aim were undertaken through a literature search to synthesize the extracted data.

RESULTS

We found that digestive symptoms and liver injury are not uncommon in patients with COVID-19 and varies in different individuals. The most common GI symptoms reported are diarrhea, nausea, vomiting, and abdominal discomfort. Other atypical GI symptoms, such as loss of smell and taste and GI bleeding, have also been reported along with the evolvement of COVID-19. Liver chemistry abnormalities mainly include elevation of aspartate transferase, alanine transferase, and total bilirubin. It is postulated to be related to the binding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus to the angiotensin converting enzyme-2 receptor located on several different human cells.

CONCLUSION

Standardized criteria should be established for diagnosis and grading of the severity of GI symptoms in COVID-19 patients. Gastroenterology and hepatology in special populations, such as children and elderly, should be the focus of further research. Future long-term data regarding GI symptoms should not be overlooked.

COVID-19 impact on the liver

The coronavirus disease 2019 (COVID-19) pandemic imposed arestructuring of global health systems by rethinking spaces used for the care of these patients and the additions of intensive care, infectious diseases and pneumology departments. This paper provides evidence on the presence of severe acute respiratory syndrome coronavirus 2 in hepatocytes and its direct cytopathic activity, as well as the degree of liver damage due to drug toxicity, inflammation and hypoxia in COVID-19. A review of clinical trials has quantified liver damage through both pathology and biochemistry studies. Additionally, we briefly present the results of a study conducted in our clinic on 849 patients admitted for COVID-19 treatment, of which 31 patients had pre-existing chronic liver disease and 388 patients had values above the normal limit for alanine aminotransferase, aspartate aminotransferase, and total bilirubin. It was observed that patients with abnormal liver tests were significantly statistically older, had more comorbidities and had a higher percentage of unfavourable evolution (death or transfer to intensive care). The conclusion of this paper is that the main causes of liver damage are direct viral aggression, coagulation dysfunction and endothelial damage, and patients with impaired liver function develop more severe forms of COVID-19 which requires special care by a multidisciplinary team that includes a hepatologist.

COVID-19 and the liver: What do we know so far?

The coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on public health and healthcare. The pandemic surge and resultant lockdown have affected the standard-of-care of many medical conditions and diseases. The initial uncertainty and fear of cross transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have changed the routine management of patients with pre-existing liver diseases, hepatocellular carcinoma, and patients either listed for or received a liver transplant. COVID-19 is best described as a multisystem disease caused by SARS-CoV-2, and it can cause acute liver injury or decompensation of the pre-existing liver disease. There has been considerable research on the pathophysiology, infection transmission, and treatment of COVID-19 in the last few months. The pathogenesis of liver involvement in COVID-19 includes viral cytotoxicity, the secondary effect of immune dysregulation, hypoxia resulting from respiratory failure, ischemic damage caused by vascular endotheliitis, congestion because of right heart failure, or drug-induced liver injury. Patients with chronic liver diseases, cirrhosis, and hepatocellular carcinoma are at high risk for severe COVID-19 and mortality. The phase III trials of recently approved vaccines for SARS-CoV-2 did not include enough patients with pre-existing liver diseases and excluded immunocompromised patients or those on immunomodulators. This article reviews the currently published research on the effect of COVID-19 on the liver and the management of patients with pre-existing liver disease, including SARS-CoV-2 vaccines.

COVID-19 and the liver: What do we know so far?

The coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on public health and healthcare. The pandemic surge and resultant lockdown have affected the standard-of-care of many medical conditions and diseases. The initial uncertainty and fear of cross transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have changed the routine management of patients with pre-existing liver diseases, hepatocellular carcinoma, and patients either listed for or received a liver transplant. COVID-19 is best described as a multisystem disease caused by SARS-CoV-2, and it can cause acute liver injury or decompensation of the pre-existing liver disease. There has been considerable research on the pathophysiology, infection transmission, and treatment of COVID-19 in the last few months. The pathogenesis of liver involvement in COVID-19 includes viral cytotoxicity, the secondary effect of immune dysregulation, hypoxia resulting from respiratory failure, ischemic damage caused by vascular endotheliitis, congestion because of right heart failure, or drug-induced liver injury. Patients with chronic liver diseases, cirrhosis, and hepatocellular carcinoma are at high risk for severe COVID-19 and mortality. The phase III trials of recently approved vaccines for SARS-CoV-2 did not include enough patients with pre-existing liver diseases and excluded immunocompromised patients or those on immunomodulators. This article reviews the currently published research on the effect of COVID-19 on the liver and the management of patients with pre-existing liver disease, including SARS-CoV-2 vaccines.