SARS-CoV-2 has been reported to share 82% genome sequence similarity to SARS-CoV and 50% with Middle East respiratory syndrome coronavirus (MERS-CoV). Liver impairment has been noted in around 60% of patients with SARS. Liver injury has also been reported in patients with MERS-CoV.

According to the reports available on the clinical features of patients with COVID-19, 2-11% of patients with COVID-19 have been shown to have liver comorbidities and 14-53% cases had abnormal alanine aminotransferase and aspartate aminotransferase (AST) levels during disease progression. Patients with severe COVID-19 appear to have a higher likelihood of liver dysfunction.

Liver damage in patients with coronavirus infections could possibly occur as a result of the viral infection of liver cells. A preliminary study has proposed that SARS-CoV-2 might directly bind to ACE2-positive cholangiocytes and lead to a dysregulation of liver function. Pathological analysis of liver tissue from a patient who died from COVID-19; however, did not show viral inclusions in the liver.

Liver impairment could also occur as a result of drug hepatotoxicity. The immune-mediated inflammation, such as cytokine storm and pneumonia-associated hypoxia, might also have a role in liver injury or even lead to liver failure in critically ill COVID-19 patients.

Chronic liver disease also poses a major burden globally. Therefore, it becomes important to understand how varied underlying liver conditions influence liver injury in patients with COVID-19. In patients with COVID-19 with autoimmune hepatitis, the impact of glucocorticoids on disease prognosis is not clearly understood. Provided the expression of the ACE2 receptor in cholangiocytes, It is important to assess if infection with SARS-CoV-2 exacerbates cholestasis in patients with primary biliary cholangitis, or leads to an increase in alkaline phosphatase and GGT. Patients with COVID-19 with liver cirrhosis or liver cancer might also be more prone to SARS-CoV-2 infection due to an immunocompromised status.

A more intensive surveillance system or an individualized therapeutic approach is required for severe patients with COVID-19 with pre-existing conditions such as advanced liver disease.

Source: Zhang C, Shi L, Wang F-S. Liver injury in COVID-19: management and challenges. Lancet Gastroenterology and Hepatology March 4, 2020.