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. Coronavirus disease 2019 (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 multiorgan 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 patients with COVID-19, 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 health care 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 patients with COVID-19, 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. (Hepatology 2021;74:1088-1100).
Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was officially declared a pandemic by the World Health Organization in March 2020. COVID-19 has a variable presentation ranging from an asymptomatic illness to severe pneumonia with acute respiratory distress syndrome, accompanied by multiorgan failure, shock, and severe thromboembolic events. The most common clinical features reported among patients who were symptomatic include fever, dry cough, shortness of breath, anosmia and ageusia, and diarrhea.Coronaviruses are enveloped, positive-sense, singlestranded RNA viruses belonging to the Coronaviridae family, responsible for mild upper respiratory and gastrointestinal tract infections in humans. Two emerging members of the Coronaviridae family were previously demonstrated to pose a major public health threat, namely the severe acute respiratory syndrome coronavirus (SARS-CoV) and the Middle Eastern respiratory syndrome coronavirus (MERS)-CoV. In December 2019, the first cases of viral pneumonia caused by a novel coronavirus (SARS-CoV-2) was reported. Over the ensuing months, the virus has rapidly spread globally, resulting in over 50 million infected persons and one million deaths, exceeding other major infectious causes of death worldwide.