Liver Injury in COVID-19 Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) preferentially infects cells in the respiratory tract, but several studies have also demonstrated low levels of SARS-CoV-2 copies in the liver. The hypothesis that patients with COVID-19 may develop liver dysfunction is supported by findings showing abnormal liver test results in such patients, but the exact mechanisms by which SARS-CoV-2 induces liver damage remain unclear. Liver injury in COVID-19 patients has probably a multifactorial etiology including the rapid onset of a systemic pro-inflammatory state due to viral infection, the use of potentially hepatotoxic drugs, pneumonia-associated hypoxia, and the eventual direct injury of the liver by SARS-CoV-2. This chapter will discuss the potential pathophysiological mechanisms for SARS-CoV-2 hepatic tropism and an overview about the main biochemical and histopathological findings observed in liver from COVID-19 patients. Finally, the effects that this infection can produce in patients with chronic liver disease will be also discussed.

Liver Chemistries in Patients with Severe or Non-severe COVID-19: A Meta-Analysis

ABSTRACTBackground and AimsCumulating observations have indicated that patients with coronavirus disease (COVID-19) undergo different patterns of liver impairment. We performed a meta-analysis of published liver manifestations and described the liver damage in COVID-19.MethodsWe searched PubMed, Google Scholar, Embase, Cochrane Library, medRxiv, bioRxiv, and three Chinese electronic databases through April 18, 2020, in accordance with the Preferred Reporting Items for Meta-Analyses. We analyzed pooled data on liver chemistries stratified by COVID-19 severity using a fixed or random-effects model.ResultsIn the meta-analysis of 37 studies, which included a total of 6,235 patients, the pooled mean alanine aminotransferase (ALT) was 36.4 IU/L in the severe COVID-19 cases and 27.8 IU/L in the non-severe cases (95% confidence interval [CI]: − 9.4 to − 5.1, p < 0.0001). The pooled mean aspartate aminotransferase (AST) was 46.8 IU/L in the severe cases and 30.4 IU/L in the non-severe cases (95% CI: − 15.1 to − 10.4, p < 0.0001). Furthermore, regardless of disease severity, the AST level is often higher than the ALT level. Compared with the non-severe cases, the severe cases tended to have higher γ-glutamyltransferase levels but lower albumin levels.ConclusionsIn this meta-analysis, we comprehensively described three patterns of liver impairment related to COVID-19, namely hepatocellular injury, cholestasis, and hepatocellular disfunction, according to COVID-19 severity. Patients with abnormal liver test results are at higher risk of progression to severe disease. Close monitoring of liver chemistries provides an early warning against disease progression.Lay SummaryData on abnormal liver chemistries related to coronavirus disease (COVID-19) are cumulating but are potentially confusing. We performed a meta-analysis of 37 studies that included a total of 6,235 patients with COVID-19. We noted that patients with abnormal liver test results are at higher risk of progression to severe disease and close monitoring of liver chemistries provides early warning against disease progression.

Hepatic Disorders

The evaluation of patients who have abnormal liver test results includes many clinical factors: the patient’s symptoms, age, risk factors for liver disease, personal or family history of liver disease, medications, and physical examination findings. A standard algorithm can aid in evaluating abnormal liver test results in an efficient, cost-effective manner.

Hepatology

The evaluation of patients who have abnormal liver test results includes many clinical factors: the chief complaints of the patient, patient age, risk factors for liver disease, personal or family history of liver disease, medications, and physical examination findings. Because of these many factors, designing a standard algorithm for the evaluation of abnormal liver test results is difficult and often inefficient. Nevertheless, with basic information, abnormalities can be evaluated in an efficient, cost-effective manner. Diseases that predominantly affect the biliary system are called cholestatic diseases. They can affect the microscopic ducts (eg, primary biliary cirrhosis) or the large bile ducts (eg, pancreatic cancer causing obstruction of the common bile duct), or both (eg, primary sclerosing cholangitis).