Which finding supports obstructive jaundice over hepatocellular injury?

Which finding supports obstructive jaundice over hepatocellular injury?

• A. ALP increased
• B. ALT increased
• C. AST decreased
• D. Bilirubin decreased

Answer: (A)

Obstructive jaundice (cholestasis) shows a cholestatic pattern on labs, where alkaline phosphatase rises prominently because the bile ducts and canalicular membranes respond to blocked bile flow by increasing enzyme production and release. This makes ALP a sensitive indicator of biliary obstruction. In contrast, hepatocellular injury primarily raises transaminases (ALT and AST) due to hepatocyte damage, while ALP is not as markedly elevated. Bilirubin tends to rise in both types of jaundice, but obstruction more often elevates conjugated (direct) bilirubin as excretion into the bile is impaired. Therefore, a finding of increased alkaline phosphatase best supports obstructive jaundice over hepatocellular injury.

Obstructive jaundice (cholestasis) shows a cholestatic pattern on labs, where alkaline phosphatase rises prominently because the bile ducts and canalicular membranes respond to blocked bile flow by increasing enzyme production and release. This makes ALP a sensitive indicator of biliary obstruction. In contrast, hepatocellular injury primarily raises transaminases (ALT and AST) due to hepatocyte damage, while ALP is not as markedly elevated. Bilirubin tends to rise in both types of jaundice, but obstruction more often elevates conjugated (direct) bilirubin as excretion into the bile is impaired. Therefore, a finding of increased alkaline phosphatase best supports obstructive jaundice over hepatocellular injury.