COVID‐19 complications on the digestive system and liver: A current clinical and pathophysiological approach

Abstract

AbstractThe coronavirus disease‐2019 (COVID‐19) pandemic is a public health threat impacting people all over the world. Although severe acute respiratory coronavirus syndrome (SARS‐CoV‐2) was identified as a virus for the respiratory system, it might be responsible for the digestive symptoms associated with COVID‐19. Common gastrointestinal symptoms in COVID‐19 patients are anorexia, vomiting, nausea, abdominal pain, and diarrhea, in addition to abnormal levels of liver enzymes. While the diagnosis of SARS‐CoV‐2 based essentially on respiratory samples, fecal SARS‐CoV‐2 RNA‐analysis can be used as a diagnostic test. In the current COVID‐19 pandemic, 10% to 50% of patients reported hepatic‐gastrointestinal manifestations, especially those with severe illness. Although the gastrointestinal infection is not completely understood, the tissue injury may be due to the direct cytopathic effect of SARS‐CoV‐2, which can invade through the angiotensin conversion enzyme‐2 (ACE2) receptor. Notably, ACE2 receptor expression has been identified in the gastrointestinal tract and cholangiocytes of the liver. Also, COVID‐19 gastrointestinal influence may be multifactorial and related to the cytokine storm, drug‐induced liver injury, and ischemic hypoxic reperfusion that cause multi‐organ injury. This brief review summarizes the available data on the liver and gastrointestinal complications induced by SARS‐CoV‐2 infection, focusing mainly on the mechanisms of pathogenicity.