Which enzyme is primarily affected in biliary tract obstruction?

• A. AST
• B. CK
• C. GGT
• D. LD

Answer: (C)

In cases of biliary tract obstruction, the enzyme that is primarily affected is gamma-glutamyl transferase (GGT). This enzyme is found in high concentrations in the liver and biliary tract, making it particularly sensitive to conditions that involve bile duct obstruction, such as cholestasis or bile duct stones.

When there is obstruction, the liver produces more GGT, leading to elevated levels in the blood. This rise in GGT can serve as a useful indicator of liver and biliary tract issues. In contrast, while other enzymes like AST (aspartate aminotransferase), CK (creatine kinase), and LD (lactate dehydrogenase) can indicate various types of tissue damage, they are not as specific to biliary obstruction as GGT is. Therefore, measuring GGT levels is a valuable diagnostic tool in evaluating liver function and the presence of potential biliary obstruction.