[Increased liver enzymes: what should be done?]

Abstract

The transaminases, alkaline phosphatase (AP) and gamma-glutamyl transferase (G-GT) are most widely used as indicators of hepatobiliary disease. Elevated serum levels of transaminases (AST and ALT) usually indicate hepatocellular damage. ALT elevations, however, can also be of extrahepatic origin (muscle). The ratio of the transaminases in serum (AST/ALT) and the mitochondrial isoenzyme of AST are frequently higher in alcoholic than in non-alcoholic liver diseases. Serum activities of AP and G-GT are elevated in cholestasis: Both enzymes, however, are not liver-specific and G-GT activity is induced by alcohol and certain drugs. A hepatic enzyme pattern (predominant transaminase elevation) should be discriminated from a cholestatic pattern (predominant AP and G-GT elevation). The most frequent diagnoses in asymptomatic patients with accidentally detected, mostly mild to moderate transaminase elevations are: alcoholic liver disease, (mostly chronic) viral hepatitis, and already much less frequently, drug induced liver disease and non-alcoholic steatosis. Solely if the respective investigations are negative or/and the transaminases stay elevated for greater than or equal to 6 months despite strict alcohol abstinence, omission of any potentially hepatotoxic drug or weight reduction are further steps justified.