Liver injury in COVID-19: A minireview

Abstract

Coronavirus disease 2019 (COVID-19), caused by infection with the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), has escalated into a global tragedy afflicting human health, life, and social governance. Through the increasing depth of research and a better understanding of this disease, it has been ascertained that, in addition to the lungs, SARS-CoV-2 can also induce injuries to other organs including the liver. Liver injury is a common clinical manifestation of COVID-19, particularly in severe cases, and is often associated with a poorer prognosis and higher severity of COVID-19. This review focuses on the general existing information on liver injury caused by COVID-19, including risk factors and subpopulations of liver injury in COVID-19, the association between preexisting liver diseases and the severity of COVID-19, and the potential mechanisms by which SARS-CoV-2 affects the liver. This review may provide some useful information for the development of therapeutic and preventive strategies for COVID-19-associated liver injury.

Keywords: Angiotensin-converting enzyme 2; Chronic liver disease; Liver; SARS-CoV-2; Transmembrane serine protease 2.

Figure 1

Mechanisms of liver injury caused by SARS-CoV-2. The mechanisms include direct hepatoxicity (severe acute respiratory syndrome coronavirus 2 affects cholangiocytes or hepatocytes) or indirect hepatic injury (drug-induced liver injury, excessive systemic inflammation and cytokine storm, and deterioration of pre-existing liver disease). SARS-CoV-2: Severe acute respiratory syndrome coronavirus 2; ACE2: Angiotensin-converting enzyme 2; TMPRSS2: Transmembrane serine protease 2.

Figure 2

Possible pathways of SARS-CoV-2 entering into the liver. A: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infects host cells through angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) receptors by its S protein. Direct SARS-CoV-2 infection targeted to hepatocytes or billiary epithelial cells results in hepatocyte injury or bile duct injury; B and C: CD147 (B) and L-SIGN (C) may be alternative receptors for SARS-CoV-2 entry into the liver; D: Antibody dependent enhancement is a pathway which can enhance interaction of virus-based antibody and the CR and/or FC receptor complements further making virus easily entry and infection. ACE2: Angiotensin-converting enzyme 2; TMPRSS2: Transmembrane serine protease 2; LSECs: Liver sinusoidal endothelial cells; BECs: Biliary epithelial cells.