Clinical Chemistry - Aspartate Aminotransferase (AST)

AST is a marker of hepatocellular injury, predominantly alcohol-related liver injury (chronic hepatitis C) and cirrhosis (chronic hepatitis B). In alcoholic liver disease, P-5-P becomes deficient, which is greater on ALT activity compared to AST activity. Consequently, ALT activity is reduced, whereas AST activity is increased. The hallmark finding for alcohol liver disease is the AST to ALT ratio of at least 2:1. The marked laboratory findings for ischaemic hepatitis is an elevated bilirubin level, however, AST levels are > 10 times the upper reference range limit. Acute viral hepatitis, drug or toxin induced liver disease and ischaemic liver injury are characterised by extremely elevated aminotransferase levels