Abnormal Liver Tests

Tests of hepatocellular injury or cholestasis (J Clin Transl Hepatol 2017;5:394)

  • Aminotransferases (AST, ALT): intracellular enzymes released 2° necrosis/inflammation
    • ALT more specific for liver than is AST (heart, skeletal muscle, kidney, brain, RBC/WBC)
    • ↑ levels seen w/ most types of hepatocellular injury; skeletal musc. injury, MI (AST > ALT)
  • Alkaline phosphatase (Aϕ): enzyme bound in hepatic canalicular membrane ↑ levels seen w/ biliary obstrxn or intrahepatic cholestasis also found in bone, intestines, kidney, placenta; confirm from liver w/: ↑ GGT (or ↑ 5′-NT)
  • Bilirubin: product of heme metab (unconjugated, “indirect”) njugation (“direct”) to make soluble, then excreted into bile.