Can bacteremia cause elevated Liver Function Tests (LFTs)?

Bacteremia and Elevated Liver Function Tests

Yes, bacteremia can cause elevated liver function tests (LFTs) through various mechanisms including direct inflammatory effects, systemic inflammatory response, and hemodynamic changes. 1

Mechanisms of Liver Injury in Bacteremia

Bacteremia can affect liver function through several pathways:

• Systemic inflammatory response: Bacteremia triggers release of inflammatory cytokines that can cause hepatocellular damage
• Direct toxicity: Bacterial toxins may directly injure hepatocytes
• Hemodynamic changes: Sepsis-induced hypoperfusion can lead to ischemic liver injury
• Cholestasis: Inflammatory mediators can impair bile flow and transport
• Drug-induced liver injury: Antibiotics and other medications used to treat infections may cause hepatotoxicity 2, 1

Patterns of Liver Injury in Bacteremia

Two main patterns of liver injury are observed:

1. Hepatocellular pattern (14-53% of cases):

   • Elevated AST and ALT
   • More common in severe infections 1

2. Cholestatic pattern:

   • Elevated bilirubin and gamma-glutamyl transferase
   • May indicate more severe infection 1

Hypoalbuminemia is also commonly observed and reflects disease severity 1.

Clinical Significance

• Bacterial infections are a major precipitating factor for acute-on-chronic liver failure (ACLF), accounting for 30-57% of cases 2
• In Western countries, bacterial infections are precipitating events in one-third of patients admitted with ACLF 2
• Liver function abnormalities may be the only indication of infection, as classic signs like fever and leukocytosis may be absent in up to 30.2% of cases 3
• Serum levels of gamma-GT, ALP, albumin, total cholesterol, and cholinesterase may alter more rapidly when bacterial infections are accompanied by bacteremia 4

Evaluation of Elevated LFTs in Bacteremia

When elevated LFTs are detected in a patient with suspected or confirmed bacteremia:

1. Determine pattern and severity of LFT elevation 1
2. Rule out pre-existing liver disease:
   • Hepatitis B surface antigen
   • Anti-hepatitis C virus antibody
   • Autoimmune markers if indicated 2, 1
3. Review medications for potential hepatotoxicity:
   • Antibiotics
   • Antipyretics
   • Anti-inflammatory medications 1
4. Evaluate for signs of shock or hypoperfusion 1

Management

1. Treat the underlying infection with appropriate antibiotics 1
2. Regular monitoring of liver function tests during treatment 2
3. Supportive care focusing on hydration and symptom management 1
4. Avoid hepatotoxic medications when possible 2, 1
5. Consider alternative antipyretics if acetaminophen is being used extensively 1

Prognosis

• In most cases, hepatic dysfunction is transient and resolves with effective treatment of the underlying infection 1
• Persistent or worsening LFT abnormalities should prompt further investigation 1
• Hypoalbuminemia at admission reflects disease severity and predicts worse outcomes 1
• Interestingly, development of jaundice in elderly patients with bacterial sepsis has been associated with increased survival in some studies 5

Important Considerations

• Clinical features such as elevated temperature and elevated peripheral white blood cell count may be poor indicators of bacterial infection in patients with liver disease 3
• Bacteremia can precipitate gastrointestinal bleeding, renal failure, or hepatic encephalopathy in patients with underlying liver disease 6
• Early diagnosis and treatment of infection is crucial to prevent development of ACLF and improve outcomes 2