SARS-CoV-2 Induced Liver Injury: Incidence, Risk Factors, Impact on COVID-19 Severity and Prognosis in Different Population Groups

A comprehensive review published in the World Journal of Gastroenterology provides insights into the incidence, mechanisms, and implications of liver injury (LI) in COVID-19 patients. The study emphasizes that while the liver is not the primary organ driving COVID-19 mortality, liver function test (LFT) abnormalities are commonly observed, especially in moderate and severe cases.

Key Findings:

  1. Prevalence of Abnormal LFTs: The prevalence of abnormal LFTs in COVID-19 patients ranges from 2.5% to 96.8% globally. The study notes geographical variability in underlying diseases as a determinant for the discrepancies observed between different regions.
  2. Mechanisms of Liver Injury:
    • Direct Liver Injury: There is evidence of SARS-CoV-2’s hepatotropism, with the virus directly impairing liver function. This includes the presence of SARS-CoV-2 within hepatocytes and sinusoidal endothelial cells, and the identification of viral RNA and proteins within hepatocytes.
    • Hypoxia and Cytokine Storm Syndrome: Hypoxia and cytokine storm syndrome are risk factors for LFT abnormalities, leading to hypoxic hepatitis, tissue damage, and liver inflammation.
    • Endotheliopathy and Immuno-thromboinflammation: COVID-19 affects the endothelium, leading to thrombus formation, tissue edema, and organ ischemia, contributing to liver injury.
  3. Clinical Implications:
    • Liver Injury Indicators: Increased levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), total bilirubin, and inflammatory markers are indicators of COVID-19 severity and mortality.
    • Risk Factors for Adverse Outcomes: Age, male gender, chronic liver disease, cirrhosis, obesity, diabetes, and non-alcoholic fatty liver disease are identified as independent prognostic factors for unfavorable COVID-19 outcomes.
  4. COVID-19-Induced Liver Injury Characteristics:
    • The liver injury is mostly secondary, mild, transitory, and self-limiting, not impacting the majority of COVID-19 patients.
    • Severe liver injury and acute liver failure are rare but associated with severe pneumonia and multiple organ dysfunction syndrome.
  5. Potential Long-term Sequelae: There is a suggestion of potential long-term sequelae for the liver, indicating a post-COVID-19 persistent liver injury.

This study underscores the importance of considering liver health in COVID-19 management and highlights the need for further research to understand the long-term impacts of COVID-19 on liver function​​​​.

Read More: https://www.wjgnet.com/1007-9327/full/v29/i16/2397.htm

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