Which two markers together are most indicative of biliary obstruction?

Which two markers together are most indicative of biliary obstruction?

• A. GGTP and ALT
• B. GGTP and ALP
• C. ALT and ALP
• D. AST and LDH

Answer: (B)

When bile flow is blocked, cholestasis drives elevations in enzymes produced by the bile ducts. Alkaline phosphatase rises with bile duct injury and is a classic cholestatic marker. Gamma-glutamyl transferase also increases in biliary obstruction and hepatobiliary disease, and it helps confirm that the rise is of hepatobiliary origin rather than from bone. So using both markers together provides the strongest evidence of biliary obstruction: ALP signals cholestasis, and GGTP confirms the hepatic/biliary source of that elevation. The other pairings are less specific for obstruction. ALT can rise with liver injury but isn’t as specifically tied to cholestasis as ALP, and ALT with ALP doesn’t provide the confirmatory aspect that GGTP adds. AST and LDH are more nonspecific indicators of tissue injury and don’t pinpoint biliary blockage.

When bile flow is blocked, cholestasis drives elevations in enzymes produced by the bile ducts. Alkaline phosphatase rises with bile duct injury and is a classic cholestatic marker. Gamma-glutamyl transferase also increases in biliary obstruction and hepatobiliary disease, and it helps confirm that the rise is of hepatobiliary origin rather than from bone. So using both markers together provides the strongest evidence of biliary obstruction: ALP signals cholestasis, and GGTP confirms the hepatic/biliary source of that elevation.

The other pairings are less specific for obstruction. ALT can rise with liver injury but isn’t as specifically tied to cholestasis as ALP, and ALT with ALP doesn’t provide the confirmatory aspect that GGTP adds. AST and LDH are more nonspecific indicators of tissue injury and don’t pinpoint biliary blockage.