Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (685 page)

   Use

   Most sensitive tests for acute hepatocellular injury (e.g., viral, drug); precedes increase in serum bilirubin by approximately 1 week

   Interpretation

Increased In

   Hepatocellular damage, liver cell necrosis, or injury of any cause.

   Alcoholic hepatitis (AST > ALT).

   Viral and chronic hepatitis (ALT > AST).

   Early acute hepatitis: AST is usually higher initially, but by 48 hours, ALT is usually higher.

   AST levels of 500 U/L suggest acute hepatocellular injury; seldom >500 U/L in obstructive jaundice, cirrhosis, viral hepatitis, AIDS, alcoholic liver disease.

   Acute fulminant viral hepatitis: Abrupt AST rise may be seen (rarely >4,000 IU/L) and declines more slowly; positive serologic tests and acute chemical injury.

   Congestive heart failure, arrhythmia, sepsis, and GI hemorrhage AST levels reach to a peak of 1,000–9,000 U/L, declining by 50% within 3 days and to <100 U/L within a week, suggesting shock liver with centrolobular necrosis. Serum bilirubin and ALP reflect underlying disease.

   Trauma to skeletal or heart muscle.

   Acute heart failure (AST > ALT).

   Severe exercise, burns, heat stroke.