SARS-CoV-2 infection in patients with a normal or abnormal liver.

Severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a novel coronavirus causing coronavirus disease 19 (COVID-19), with an estimated 22 million people infected worldwide so far although involving primarily the respiratory tract, has a remarkable tropism for the liver and the biliary tract. Patients with SARS-CoV-2 infection and no antecedent liver disease may display evidence of cytolytic liver damage, proportional to the severity of COVID-19 but rarely of clinical significance. The mechanism of hepatocellular injury is unclear and possibly multifactorial. The clinical impact of SARS-CoV-2 infection in patients with underlying chronic liver disease, a cohort whose global size is difficult to estimate, has been assessed appropriately only recently and data are still evolving. Patients with cirrhosis are at higher risk of developing severe COVID-19 and worse liver-related outcomes as compared to those with non-cirrhotic liver disease. OLT patients have an intermediate risk. Specific interventions in order to reduce the risk of transmission of infection among this high-risk population have been outlined by international societies, together with recommendations for modified treatment and follow-up regimens during the COVID-19 pandemic. When a vaccine against SARS-CoV-2 becomes available, patients with fibrotic liver disease and those with OLT should be considered as prime targets for prophylaxis of COVID-19, as all other highly susceptible subjects.