Liver injury in severe COVID-19 infection: current insights and challenges

The outbreak of COVID-19 is a serious health threat worldwide. Different degrees of liver injury or liver dysfunctions have been reported in patients with COVID-19 infection. However, currently, it remains unclear to what extent liver diseases should be considered as significant risk factors for the severity and mortality of COVID-19. Moreover, the mechanisms involved in liver injury in severe COVID-19 infection are not yet well understood.

This review summarizes the current evidence on liver function abnormalities in COVID-19 patients and the effects of preexisting liver disease on the disease severity. This review also illustrates the possible underlying mechanisms linking COVID-19 to liver injury, as well as provides recommendations to prevent liver damage in COVID-19 infection.

The elevated levels of ALT, AST, GGT and bilirubin are common in more severe patients than non-severe or mild COVID-19 patients. Patients with preexisting medical conditions including chronic hepatic diseases are at higher risk for severe illness from COVID-19 infection. The drug's effects, possible viral inclusion in liver cells, systemic inflammation and hypoxia are potential causes of liver injury in severe COVID-19. Nevertheless, further studies are needed focusing on the preexisting hepatic diseases on prevention, treatment and outcome of COVID-19.