BACKGROUND AND PURPOSE:

• SARS and MERS are both associated with liver impairment
• Zhang et al. (The Lancet, 2020) reviewed COVID-19’s impact on the liver

METHODS:

• Review of case studies and data
• Setting
  • The Fifth Medical Center of PLS General Hospital, Beijing, China
• Data sources
  • Authors analyzed 7 published studies plus their own unpublished data that included patients with COVID-19

RESULTS:

• Liver comorbidities: Patients with pre-existing liver conditions ranged from 2 to 11%
• Abnormal levels of ALT and AST: Ranged from 14 to 53%
• Patients with severe COVID-19 tend to have higher rates of liver dysfunction
  • In one review, elevated AST was observed in
    • ICU patients: 62%
    • Non-ICU patients: 25%
  • Fewer cases of abnormal AST levels were identified in the subclinical phase (before symptom onset) vs after symptom onset

Suggested Underlying Mechanism Resulting in Liver Injury

• Liver damage may be caused by viral infection of liver cells
  • 2 to 10% of patients with COVID-19 present with diarrhea
  • SARS-CoV-2 RNA has been detected in stool and blood samples
  • Gamma-glutamyl transferase (GGT), a diagnostic biomarker for cholangiocyte injury, hasn’t yet been reported on in COVID-19 patients
    • The authors report that 54% of hospitalized patients in their center (30 of 56 patients) had elevated GGT levels
    • They also report that 1 patient In their series (1.8%) had elevated alkaline phosphatase levels
  • However, in one pathological study of a patient who died of COVID-19, the virus was not detected in the liver
• Other possible mechanisms
  • Drug hepatotoxicity
  • Immune-mediated inflammation

CONCLUSION:

• There is some evidence that the liver is affected by COVID-19, but the extent and risk factors are still unknown
• Liver damage in mild cases of COVID-19 is often transient and can return to normal with no special treatment | However, liver damage biomarkers are associated with poorer prognosis
• The authors suggest that pre-existing liver and other conditions may also affect the liver damage caused by COVID-19, and should be further investigated
  • Effect of glucocorticoids for patients with autoimmune hepatitis is uncertain
  • Patients with primary biliary cholangitis may also be aggravated by COVID-19
  • Patients with COVID-19 with liver cirrhosis or liver cancer might be more susceptible to SARS-CoV-2 infection

Learn More – Primary Sources:

Liver injury in COVID-19: management and challenges

Related ObG Topics: