Marked elevation in which laboratory test is associated with obstructive jaundice?

Marked elevation in alkaline phosphatase is associated with obstructive jaundice. This laboratory test measures the level of alkaline phosphatase, an enzyme found in various tissues throughout the body, particularly the liver and bones. When there is an obstruction in the bile ducts, the flow of bile is impaired, leading to an accumulation of bile salts and bilirubin in the blood. This condition causes a significant increase in alkaline phosphatase levels.

Obstructive jaundice itself results from conditions such as gallstones, tumors, or strictures that block the bile ducts, preventing bile from reaching the intestine and causing bilirubin to be reabsorbed into circulation. While indirect bilirubin may also be elevated in jaundice, particularly in cases of hemolysis, it is the alkaline phosphatase level that specifically points to cholestasis or obstruction in the biliary system.