Which enzyme pattern is associated with hepatobiliary (cholestatic) injury?

• A. AST and ALT (cellular enzymes increased)
• B. GGT and 5'NT (cholestatic enzymes increased)
• C. Ammonia and TPAG (synthetic function affected)
• D. Enzymes remain normal in hepatobiliary injury

Answer: (B)

When bile flow is disrupted, the pattern of enzyme elevations shifts toward those tied to bile formation and canalicular membranes. Gamma-glutamyl transferase (GGT) and 5'-nucleotidase rise prominently in this cholestatic/ hepatobiliary pattern, signaling injury to the biliary system or impaired bile flow. This contrasts with hepatocellular injury, where the cellular enzymes AST and ALT dominate due to direct hepatocyte damage. Markers of synthetic function, like ammonia or total protein/albumin, reflect the liver’s overall metabolic capacity rather than a specific cholestatic enzyme signature. So the combination of elevated GGT and 5'-nucleotidase best indicates cholestatic injury.