COVID-19 and the liver: A brief and core review

Abstract

Coronavirus disease 2019 has a wide range of clinical spectrum from asymptomatic infection to severe infection resulting in death within a short time. Currently, it is known that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) does not only cause a respiratory tract infection but a more complicated disease that can lead to multiple system involvement including the liver. Herein, we evaluate the epidemiology, the impact of liver injury/ dysfunction on disease prognosis, the pathophysiological mechanisms and management of liver injury. More than one-fourth of the patients have abnormal liver function tests, mostly a mild-to-moderate liver dysfunction. Liver injury is significantly associated with a poor clinical outcome. Direct cytotoxic effect of SARS-CoV-2, the immune response (“cytokine storm”), the complications related to the disease, and drugs used in the treatments are the pathophysiological mechanisms responsible for liver injury. However, the exact mechanism is not yet clearly explained. The binding of SARS-CoV-2 to the angiotensin-converting enzyme 2 receptors and entering the hepatocyte and cholangiocytes can cause cytotoxic effects on the liver. Excessive immune response has an important role in disease progression and causes acute respiratory distress syndrome and multi-organ failures accompanied by liver injury. Treatment drugs, particularly lopinavir/ritonavir, remdesivir and antibiotics are a frequent reason for liver injury. The possible reasons should be meticulously investigated and resolved.

Keywords: COVID-19; SARS-CoV-2; Liver injury; Liver dysfunction; Chronic liver disease; Pathophysiology

Core Tip: The study evaluated the incidence of liver injury in coronavirus disease 2019 (COVID-19) patients and its impact on clinical outcomes and pathophysiological mechanism of liver injury. More than one-fourth of COVID-19 patients had suffered from liver injury, mostly a mild-to-moderate liver dysfunction. Liver involvement is independently associated with adverse clinical outcomes. Direct viral cytotoxic effect, complications of the disease, and drugs used in the treatments are the pathophysiological mechanisms suggested for liver injury. However, the exact mechanism was not clearly explained. The actual cause should be carefully investigated in the presence of abnormal liver function tests, and appropriate treatments provided for possible factors.