Diagnostic enzymes

 

Common Diagnostic Enzymes

Enzyme Clinical Significance
ALT/AST Liver injury (viral hepatitis, alcoholic liver disease). AST/ALT > 2 suggests alcoholic etiology.
Alkaline Phosphatase Biliary obstruction (cholestasis), bone disease (Paget disease).
Amylase / Lipase Acute pancreatitis (Lipase is more specific).
CK-MB Myocardial infarction (historically important, now largely replaced by Troponins).
LDH Nonspecific marker; elevated in hemolysis, tissue infarction, and certain malignancies.
High-Yield Clinical Note:

Remember that enzyme levels in serum reflect damage to cellular integrity (leaking of intracellular enzymes into the blood), rather than a change in the enzyme’s catalytic function.