COVID-19 and the liver: a narrative review of the present state of knowledge

Novel corona virus disease (COVID-19) is an ongoing pandemic that has spread across the globe. The virus primarily infects type-2 pneumocytes in alveoli and causes lung disease, with severity ranging from mild pneumonia to acute respiratory distress syndrome. The virus also invades gastrointestinal epithelial cells, hepatocytes, and biliary epithelial cells. Derangement of liver function tests is noted in about one third of patients and appears to correlate with more severe disease. There are multiple mechanisms by which the virus can cause liver injury; immune-mediated inflammation and direct viral cytotoxicity are believed to be the predominant mechanisms. Liver injury appears to be transient, usually recovering with resolution of illness. Limited available studies and experience from prior corona virus pandemics seem to suggest that immunosuppressed patients have similar outcomes compared to non-immunosuppressed patients. Age and comorbid conditions seem to influence outcome, irrespective of immune status. Additionally, patients with preexisting comorbid conditions are more prone to acquire infection and should strictly adhere to travel and social distancing advisories. Telemedicine should be utilized to provide uninterrupted care for patients with liver disease, and clinic or hospital visits should be advised only in sick patients with advanced liver disease. In conclusion, liver dysfunction is not uncommon in COVID-19, it generally improves with resolution of disease, and patients with chronic liver disease (CLD) need continued follow up, uninterrupted by the ongoing pandemic, preferably in virtual clinic settings.