Hepatology. 2020 Dec 17. doi: 10.1002/hep.31684. Online ahead of print.
Infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a novel coronavirus that emerged in late 2019 is posing an unprecedented challenge to global health. COVID-19, the clinical disease caused by SARS-CoV-2 has a variable presentation ranging from asymptomatic infection to life-threatening acute respiratory distress syndrome and multi-organ failure. Liver involvement is common during COVID-19 and exhibits a spectrum of clinical manifestations from asymptomatic elevations of liver function tests to hepatic decompensation. The presence of abnormal liver tests has been associated with a more severe presentation of COVID-19 disease and overall mortality. Although SARS-CoV-2 RNA has been detected in the liver of COVID-19 patients, it remains unclear whether SARS-CoV-2 productively infects and replicates in liver cells and has a direct liver-pathogenic effect. The cause of liver injury in COVID-19 can be attributed to multiple factors including virus-induced systemic inflammation, hypoxia, hepatic congestion and drug induced liver disease. Among patients with cirrhosis, COVID-19 has been associated with hepatic decompensation and liver-related mortality. Additionally, COVID-19's impact on healthcare resources can adversely affect delivery of care and outcomes of patients with chronic liver disease. Understanding the underlying mechanisms of liver injury during COVID-19 will be important in the management of COVID-19 patients, especially those with advanced liver disease. This review summarizes our current knowledge of SARS-CoV-2 virus-host interactions in the liver as well the clinical impact of liver disease in COVID-19.