Which test value would indicate cholestasis when elevated?

Which test value would indicate cholestasis when elevated?

• A. GGT
• B. ALT
• C. AST
• D. ALKP

Answer: (A)

Cholestasis is a problem with bile flow, so enzymes linked to the biliary system rise when bile can't drain properly. Gamma-glutamyl transferase is concentrated in the bile duct epithelium and becomes elevated with biliary obstruction or cholestatic injury, making it a sensitive indicator of cholestasis. ALT and AST reflect hepatocellular injury (the liver cells themselves) rather than specifically biliary flow issues, so they can go up in many liver conditions, not just cholestasis. Alkaline phosphatase can also rise with cholestasis, but it has non-hepatic sources (like bone, especially in growing animals), which can make interpretation less specific. So, a rise in this enzyme points most directly to cholestasis.

Cholestasis is a problem with bile flow, so enzymes linked to the biliary system rise when bile can't drain properly. Gamma-glutamyl transferase is concentrated in the bile duct epithelium and becomes elevated with biliary obstruction or cholestatic injury, making it a sensitive indicator of cholestasis.

ALT and AST reflect hepatocellular injury (the liver cells themselves) rather than specifically biliary flow issues, so they can go up in many liver conditions, not just cholestasis. Alkaline phosphatase can also rise with cholestasis, but it has non-hepatic sources (like bone, especially in growing animals), which can make interpretation less specific.

So, a rise in this enzyme points most directly to cholestasis.