COVID-19 and the liver: overview.

On 12 March 2020, the WHO declared that the coronavirus disease 2019 (COVID-19) constitutes a pandemic. Cases of liver damage or dysfunction (mainly characterized by moderately elevated serum aspartate aminotransferase levels) have been reported among patients with COVID-19. However, it is currently uncertain whether the COVID-19 related liver damage/dysfunction is due mainly to the viral infection by itself or other coexisting conditions, such as the use of potentially hepatotoxic medications and the coexistence of systemic inflammatory response, respiratory distress syndrome-induced hypoxia, and multiple organ dysfunction. Individuals at high risk for severe COVID-19 are typical of older age and/or present with comorbid conditions such as diabetes, cardiovascular disease, and hypertension. This is also the same profile for those at increased risk for unrecognized underlying liver disease, especially nonalcoholic fatty liver disease. This could make them more susceptible to liver injury from the virus, medications used in supportive management, or hypoxia. So the aim of this review was to illustrate the clinical implications of COVID-19 on the liver in healthy and diseased states as well as the implications of common liver disorders on the outcome of COVID-19.

Antibody Responses after SARS-CoV-2 Vaccination in Patients with Liver Diseases.

The novel mRNA-based vaccines against SARS-CoV-2 display encouraging safety and efficacy profiles. However, there is a paucity of data regarding their immunogenicity and safety in patients with liver diseases (PWLD), especially in those with cirrhosis. We prospectively assessed anti-SARS-CoV-2 S-spike IgG antibodies and neutralizing activity in fully vaccinated PWLD (n = 87) and controls (n = 40). Seroconversion rates were 97.4% (37/38) in cirrhotic PWLD, 87.8% (43/49) in non-cirrhotic PWLD and 100% (40/40) in controls. Adequate neutralizing activity was detected in 92.1% (35/38), 87.8% (43/49) and 100% (40/40) of cirrhotics, non-cirrhotics and controls, respectively. On multivariable analysis, immunosuppressive treatment was negatively correlated with anti-SARS-CoV-2 antibody titers (coefficient (SE): -2.716 (0.634), p < 0.001) and neutralizing activity (coefficient (SE): -24.379 (4.582), p < 0.001), while age was negatively correlated only with neutralizing activity (coefficient (SE): -0.31(0.14), p = 0.028). A total of 52 responder PWLD were reassessed approximately 3 months post-vaccination and no differences were detected in humoral responses between cirrhotic and non-cirrhotic PWLD. No significant side effects were noted post vaccination, while no symptomatic breakthrough infections were reported during a 6-month follow up. Overall, our study shows that m-RNA-based SARS-CoV-2 vaccines are safe and efficacious in PWLD. However, PWLD under immunosuppressive treatment and those of advanced age should probably be more closely monitored after vaccination.

Recent Evidence and Possible Therapy against COVID-19-Mediated Hepatic Dysfunction.

Over the years, a novel RNA coronavirus has emerged with mutational episodes. This virus was confirmed to cause severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and coronavirus infectious disease-2019 (COVID-19). This particular emphasis has raised the risk signal at the global level. Hepatic injury has been known to be a major impairment with varying factors. In recent years, the mechanistic event of hepatic injury is now more controversial and has a lack of justifiable set. Nevertheless, it has been investigated for the prominence of inflammatory signals, viral load in hepatocytes, followed by an intensive care therapeutic defense, and/or drug toxicity. Limited reports are available on infection-mediated hepatic injury, and its associated mechanism is still poorly understood. In the context of COVID-19 infections, the initial episode is pulmonary disorder with a systemic infection in multiple organs, including the liver. The majority of the reported cases reveal hepatic damage or dysfunction among COVID-19-infected patients. Prevalence of altered biochemistry of liver enzymes was also observed in the COVID-19 infected population. Our review focuses on the probable mechanisms and therapeutic options of COVID-19 and its associated hepatic dysfunction. We also discuss the available prescribed medications against COVID-19 infections, such as remdesiver, oseltamivir, lopina-vir/ritonavir, ribavirin, anticoagulant, anti-inflammatory, and immune-based therapies.

Covid-19 and Liver Injury: Role of Inflammatory Endotheliopathy, Platelet Dysfunction, and Thrombosis.

Liver injury, characterized predominantly by elevated aspartate aminotransferase and alanine aminotransferase, is a common feature of coronavirus disease 2019 (COVID-19) symptoms caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). Additionally, SARS-CoV-2 infection is associated with acute-on-chronic liver failure in patients with cirrhosis and has a notably elevated mortality in patients with alcohol-related liver disease compared to other etiologies. Direct viral infection of the liver with SARS-CoV-2 remains controversial, and alternative pathophysiologic explanations for its hepatic effects are an area of active investigation. In this review, we discuss the effects of SARS-CoV-2 and the inflammatory environment it creates on endothelial cells and platelets more generally and then with a hepatic focus. In doing this, we present vascular inflammation and thrombosis as a potential mechanism of liver injury and liver-related complications in COVID-19.

The Impact of COVID-19 on Liver Injury.

The current coronavirus disease outbreak of 2019 (COVID-19) has led to a global pandemic. The principal cause of mortality in COVID-19 is represented lung injury with the development of acute respiratory distress syndrome (ARDS). In patients with COVID-19 infection, liver injury or liver dysfunction has been reported. It may be associated with the general severity of the disease and serve as a prognostic factor for ARDS development. In COVID-19, the spectrum of liver damage may range from direct SARS-CoV-2 viral proteins, inflammatory processes, hypoxemia, the antiviral drugs induced hepatic injury and the presence of the preexisting liver disease. We highlight in this review important topics such as the epidemiological features, potential causes of liver injury, and the strategies for management and prevention of hepatic injury in COVID-19 patients.

The Interrelationship between Liver Function Test and the Coronavirus Disease 2019: A Systematic Review and Meta-Analysis.

Background: The outbreak of the coronavirus disease-2019 (COVID-19) has become a global public health challenge. Assessing the effect of COVID-19 on liver injury is of great importance. A systematic review and meta-analysis were conducted to establish the characteristics of liver function tests in COVID-19 patients. Methods: A systematic search of publications from December 2019 up to April 2020 in Web of Science, Scopus, and Medline (via PubMed) databases was performed. Both cross-sectional and case series studies reporting an association between liver injury and COVID-19 infection were included. The data were analyzed using the STATA software (version 11.0) and the random-effects model for I2>50% was used to pool the results. Results: In this meta-analysis, 42 articles comprising a total of 6,557 COVID-19 patients were studied. The prevalence of increase in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels was 30% and 21% in non-severe patients and 38% and 48% in severe patients, respectively. Patients with severe COVID-19 infection were 4.22, 4.96, and 4.13 times more likely to have elevated AST, ALT, and lactate dehydrogenase (LDH) levels, respectively. Conclusion: Elevation in liver function tests was higher in patients with severe than non-severe COVID-19 infection. Given the widespread use of drugs that increases the risk of hepatotoxicity, healthcare providers should be aware of changes in liver enzymes in COVID-19 patients. The inclusion of other studies from outside China could confirm the pattern of elevation in liver function tests in COVID-19 patients across the globe. Preprint of this article is available on medRxiv, https://www.medrxiv.org/content/10.1101/2020.05.20.20108357v1.

Correlation Between Clinical and Pathological Findings of Liver Injury in 27 Patients With Lethal COVID-19 Infections in Brazil.

Liver test abnormalities are frequently observed in patients with coronavirus disease 2019 (COVID-19) and are associated with worse prognosis. However, information is limited about pathological changes in the liver in this infection, so the mechanism of liver injury is unclear. Here we describe liver histopathology and clinical correlates of 27 patients who died of COVID-19 in Manaus, Brazil. There was a high prevalence of liver injury (elevated alanine aminotransferase and aspartate aminotransferase in 44% and 48% of patients, respectively) in these patients. Histological analysis showed sinusoidal congestion and ischemic necrosis in more than 85% of the cases, but these appeared to be secondary to systemic rather than intrahepatic thrombotic events, as only 14% and 22% of samples were positive for CD61 (marker of platelet activation) and C4d (activated complement factor), respectively. Furthermore, the extent of these vascular findings did not correlate with the extent of transaminase elevations. Steatosis was present in 63% of patients, and portal inflammation was present in 52%. In most cases, hepatocytes expressed angiotensin-converting enzyme 2 (ACE2), which is responsible for binding and entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), even though this ectoenzyme was minimally expressed on hepatocytes in normal controls. However, SARS-CoV-2 staining was not observed. Most hepatocytes also expressed inositol 1,4,5-triphosphate receptor 3 (ITPR3), a calcium channel that becomes expressed in acute liver injury. Conclusion: The hepatocellular injury that commonly occurs in patients with severe COVID-19 is not due to the vascular events that contribute to pulmonary or cardiac damage. However, new expression of ACE2 and ITPR3 with concomitant inflammation and steatosis suggests that liver injury may result from inflammation, metabolic abnormalities, and perhaps direct viral injury.

COVID-19 and liver dysfunction: Epidemiology, association and potential mechanisms.

Currently, there have been more than one hundred million confirmed cases of coronavirus disease 2019 (COVID-19), with two million deaths worldwide. This has caused a huge medical burden. Severe COVID-19 patients can experience multi-organ damage, including cardiac injury, kidney injury, and liver injury. About 2.0%-4.9% of COVID-19 cases involve patients with preexisting liver diseases. Additionally, preexisting liver diseases were reported and associated with severity (odds ratio (OR) or risk ratio (RR) = 1.48-1.70) and mortality (OR or RR = 1.08-2.65) among COVID-19 patients. Furthermore, the prevalence of liver injury was 16%-29% in COVID-19 patients. Higher prevalence of liver injury may worsen prognosis in patients (severity: OR or RR = 1.9-2.6; mortality: OR or RR = 1.1-4.0). The mechanisms of this association between liver injury and severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection are complex, including direct cholangiocyte damage induced by SARS-COV-2, cytokine storm, and drug-induced liver injury. In particular, drug-induced liver injury may be the most important reason. This review discusses the epidemiology of COVID-19 and liver dysfunction as well as potential mechanisms underlying the association between COVID-19 and liver dysfunction or other preexisting liver diseases. However, the association between preexisting liver diseases and COVID-19 prognosis and potential mechanisms underlying these associations require further prospective studies.

Pathophysiology and molecular mechanisms of liver injury in severe forms of COVID-19: An integrative review.

BACKGROUND AND AIMS: SARS-CoV-2 has primary pulmonary impairment, but other organs such as the liver can also be affected. This implies a worsening of patient's prognosis and an increase in morbidity and mortality. The metabolic pathways and molecular factors involved in the genesis of this injury are still unknown. Therefore, we aimed to carry out an integrative review about the pathophysiology and possible molecular mechanisms of liver injury by COVID-19. METHODS: We carried out an integrative literature review in the following databases: PubMed, Scopus, and Embase from December 2020 to March 2021 using the following descriptors: # 1 "COVID-19" (MeSH) AND / OR # 2 "Liver injury" (MeSH) AND / OR # 3 "Pathophysiology" (MesH). RESULTS: The data were extracted and divided into two main themes, for heuristic purposes: "Hepatotropism and SARS-CoV-2", and "Pathophysiological hypotheses for liver injury associated with SARS-CoV-2". CONCLUSIONS: The virus seems to promote liver damage through five mechanisms: direct injury, humoral and cellular inflammatory response, hypoxemia caused by a decrease in the effective circulating volume, reinfection through the portal system, and use of drugs in the treatment. The literature also points out that the expression of the angiotensin-converting enzyme II and transmembrane serine protease 2 receptors is expressive in cholangiocyte and is present in hepatocytes, which is a risk factor for the virus to enter these cells. Finally, patients with previous liver disease appear to be more susceptible to liver injury by COVID-19.

Longitudinal progression of clinical variables associated with graded liver injury in COVID-19 patients.

BACKGROUND: Hospital-acquired liver injury is associated with worse outcomes in COVID-19. This study investigated the temporal progression of clinical variables of in-hospital liver injury in COVID-19 patients. METHODS: COVID-19 patients (n = 1361) were divided into no, mild and severe liver injury (nLI, mLI and sLI) groups. Time courses of laboratory variables were time-locked to liver-injury onset defined by alanine aminotransferase level. Predictors of liver injury were identified using logistic regression. RESULTS: The prevalence of mLI was 39.4% and sLI was 9.2%. Patients with escalated care had higher prevalence of sLI (23.2% vs. 5.0%, p < 0.05). sLI developed 9.4 days after hospitalization. sLI group used more invasive ventilation, anticoagulants, steroids, and dialysis (p < 0.05). sLI, but not mLI, had higher adjusted mortality odds ratio (= 1.37 [95% CI 1.10, 1.70], p = 0.005). Time courses of the clinical variables of the sLI group differed from those of the nLI and mLI group. In the sLI group, alanine aminotransferase, procalcitonin, ferritin, and lactate dehydrogenase showed similar temporal profiles, whereas white-blood-cell count, D-dimer, C-reactive protein, respiration and heart rate were elevated early on, and lymphocyte and SpO2 were lower early on. The top predictors of sLI were alanine aminotransferase, lactate dehydrogenase, respiration rate, ferritin, and lymphocyte, yielding an AUC of 0.98, 0.92, 0.88 and 0.84 at 0, - 1, - 2 and - 3 days prior to onset, respectively. CONCLUSIONS: This study identified key clinical variables predictive of liver injury in COVID-19, which may prove useful for management of liver injury. Late onset of sLI and more aggressive care are suggestive of treatment-related hepatotoxicity.

[Update 2021: COVID-19 from the perspective of gastroenterology]. / Update 2021: COVID-19 aus Sicht der Gastroenterologie.

During COVID 19 pandemic patients typically present with respiratory symptoms. However, in a significant number of patients the gastrointestinal tract is also involved in the disease. Up to 20 % of patients suffering from gastrointestinal symptoms. New insights in pathophysiological aspects might open new therapeutic concepts. This up-date includes current data regarding epidemiology of gastrointestinal symptoms in COVID 19, its role for prognosis and specific risks in relation to immunosuppressive therapies and underlying diseases.

The impact of the COVID-19 epidemic on hospital admissions for alcohol-related liver disease and pancreatitis in Japan.

During the coronavirus disease 2019 (COVID-19) pandemic, there have been health concerns related to alcohol use and misuse. We aimed to examine the population-level change in cases of alcohol-related liver disease and pancreatitis that required admission during the COVID-19 epidemic by interrupted time series (ITS) analysis using claims data. We defined the period from April 2020, when the Japanese government declared a state of emergency, as the beginning of the COVID-19 epidemic. This ITS analysis included 3,026,389 overall admissions and 10,242 admissions for alcohol-related liver disease or pancreatitis from 257 hospitals between July 2018 and June 2020. The rate of admissions per 1000 admissions during the COVID-19 epidemic period (April 2020-June 2020) was 1.2 times (rate ratio: 1.22, 95% confidence interval: 1.12-1.33) compared to the pre-epidemic period. Analyses stratified by sex revealed that the increases in admission rates of alcohol-related liver disease or pancreatitis for females were higher than for males during the COVID-19 epidemic period. The COVID-19 epidemic in Japan might associates an increase in hospital admissions for alcohol-related liver disease and pancreatitis. Our study could support the concern of alcohol consumption and health problems during the COVID-19 pandemic.

Liver injury in COVID-19: Detection, pathogenesis, and treatment.

In the early December 2019, a novel coronavirus named severe acute respiratory syndrome coronavirus 2 was first reported in Wuhan, China, followed by an outbreak that spread around the world. Numerous studies have shown that liver injury is common in patients with coronavirus disease 2019 (COVID-19), and may aggravate the severity of the disease. However, the exact cause and specific mechanism of COVID-associated liver injury needs to be elucidated further. In this review, we present an analysis of the clinical features, potential mechanisms, and treatment strategies for liver injury associated with COVID-19. We hope that this review would benefit clinicians in devising better strategies for management of such patients.

Interplay between nuclear factor erythroid 2-related factor 2 and inflammatory mediators in COVID-19-related liver injury.

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 is a global pandemic and poses a major threat to human health worldwide. In addition to respiratory symptoms, COVID-19 is usually accompanied by systemic inflammation and liver damage in moderate and severe cases. Nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor that regulates the expression of antioxidant proteins, participating in COVID-19-mediated inflammation and liver injury. Here, we show the novel reciprocal regulation between NRF2 and inflammatory mediators associated with COVID-19-related liver injury. Additionally, we describe some mechanisms and treatment strategies.

A giant spontaneous subcapsular hematoma of the liver revealing a COVID-19 infection, a coincidence? (A case report).

Hemorrhagic manifestations during COVID-19 infections are increasingly described in the literature. We report the first case of spontaneous subcapsular hematoma of the liver revealing a COVID-19 infection in a 44-year-old woman with no underlying health condition history, a computerized tomography evaluation showed an aspect of lung ground-glass opacities, with moderate impairment estimated at about 20%. Reverse transcription-polymerase chain reaction confirmed the diagnosis of COVID-19 infection. During the COVID-19 pandemic, non-traumatic bleeding such as spontaneous hematomas in patients with no coagulation disorder could be a manifestation of COVID-19 infection.

Effect of COVID-19 on liver abnormalities: a systematic review and meta-analysis.

Emerging evidence suggest association of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with the development of many liver abnormalities. The overarching aim of this study was therefore to assess the available evidence on the clinical effects of SARS-CoV-2 on the profiles of liver chemistries and coagulation in COVID-19 diagnosed patients. We considered all study designs including epidemiological and observational that reported liver function test abnormalities in patients confirmed with SARS-CoV-2 infection. Medline, Embase databases and Google Scholar as well as relevant reviews were searched to identify appropriate studies from inception to 31st of August 2020. We calculated the pooled mean with 95% confidence intervals (95% CI) through a random-effect model meta-analysis. A total of 35 studies with 10,692 participants were considered for the review from which 23 studies with sufficient quantitative data were included in the meta-analysis. The pooled mean for liver enzymes and coagulation parameters did not significantly change in patients diagnosed with COVID-19 and remained within normal range. Notwithstanding potential bias from confounding factors in interpretation of data in this review, findings from the observational studies and case reports suggest that COVID-19 does not appear to have a significant impact on the transaminases or total bilirubin levels of patients with confirmed SARS-CoV-2 infection. Further controlled studies and larger sample size observational studies are needed with adequate reporting of other liver function parameters are warranted.

Critical appraisal of the mechanisms of gastrointestinal and hepatobiliary infection by COVID-19.

COVID-19 represents a novel infectious disease induced by SARS-CoV-2. It has to date affected 24,240,000 individuals and killed 2,735,805 people worldwide. The highly infectious virus attacks mainly the lung, causing fever, cough, and fatigue in symptomatic patients, but also pneumonia in severe cases. However, growing evidence highlights SARS-CoV-2-mediated extrarespiratory manifestations, namely, gastrointestinal (GI) and hepatic complications. The detection of 1) the virus in the GI system (duodenum, colon, rectum, anal region, and feces); 2) the high expression of additional candidate coreceptors/auxiliary proteins to facilitate the virus entry; 3) the abundant viral angiotensin-converting enzyme 2 receptor; 4) the substantial expression of host transmembrane serine protease 2, necessary to induce virus-cell fusion; 5) the viral replication in the intestinal epithelial cells; and 6) the primarily GI disorders in the absence of respiratory symptoms lead to increased awareness of the risk of disease transmission via the fecal-oral route. The objectives of this review are to provide a brief update of COVID-19 pathogenesis and prevalence, present a critical overview of its GI and liver complications that affect clinical COVID-19 outcomes, clarify associated mechanisms (notably microbiota-related), define whether gut/liver disorders occur more frequently among critically ill patients with COVID-19, determine the impact of COVID-19 on preexisting gut/liver complications and vice versa, and discuss the available strategies for prevention and treatment to improve prognosis of the patients. The novel SARS-CoV-2 can cause gastrointestinal and hepatobiliary manifestations. Metagenomics studies of virobiota in response to SARS-CoV-2 infection are necessary to highlight the contribution of bacterial microflora to COVID-19 phenotype, which is crucial for developing biomarkers and therapeutics.

Prevalence of liver injury in 445 patients with Corona Virus Disease-19-Single-centre experience from southern India.

BACKGROUND: Abnormal liver function tests (LFT) are common in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and vary from 15% to 53%. There are scanty data  from India on the prevalence of liver injury in corona virus disease 2019 (COVID-19) patients. METHODS: We did this retrospective study in a tertiary care hospital, Chennai, India. Patients aged >18 years admitted with COVID-19 from May 1, 2020, to May 31, 2020, were included. We noted the demographic details, symptoms at presentation, history of pre-existing illnesses, and laboratory tests. We also recorded the patient's clinical course and outcome. RESULTS: We took 445 patients for final analysis. Aspartate transaminase (AST) was borderline elevated in 47.5%, mildly elevated in 11.2%, moderately elevated in 2% and severely in 0.7%. Alanine transaminase (ALT) was borderline elevated in 28.7%, mildly elevated in 11.4%, and moderately elevated in 1.3%. Bilirubin and alkaline phosphatase were abnormal in only 19 (4.2%) and 15 (3.3%) patients, respectively. Patients with abnormal LFT were more likely to be symptomatic (90.3% vs. 80.6%, p 0.002). Respiratory symptoms (43.5% vs. 29.7%) and loose stools (11.4% vs. 3.4%) were also more common among them. Patients with abnormal LFT were more likely to have severe disease (25.2% vs. 13.6%, p value 0.003) and mortality (8.8% vs. 0.7%). CONCLUSION: Liver test abnormalities were widespread in patients with COVID-19. Most of the patients had borderline or mild transaminase elevation. Despite only mild changes, patients with abnormal LFT were more likely to be symptomatic and had more severe disease and mortality.

Liver histopathology in COVID-19 patients: A mono-Institutional series of liver biopsies and autopsy specimens.

Few studies have focused on COVID-19 patients' hepatic histopathological features. Many of the described morphological landscapes are non-specific and possibly due to other comorbidities or to Sars-CoV-2-related therapies. We describe the hepatic histopathological findings of 3 liver biopsies obtained from living COVID-19 patients in which active SARS-CoV-2 infection was molecularly confirmed and biopsied because of significant alterations of liver function tests and 25 livers analyzed during COVID-19-related autopsies. Main histopathological findings were (i) the absence of significant biliary tree or vascular damages, (ii) mild/absent lymphocytic hepatitis; (iii) activation of (pigmented) Kupffer cells, (iv) hepatocellular regenerative changes, (v) the presence of steatosis, (vi) sinusoidal ectasia, micro-thrombosis and acinar atrophy in autopsy specimens No viral particle actively infecting the hepatic or endothelial cells was detected at in situ hybridization. The morphological features observed within the hepatic parenchyma are not specific and should be considered as the result of an indirect insult resulting from the viral infection or the adopted therapeutic protocols.