Which enzyme is the most sensitive indicator of obstructive jaundice?

Alkaline phosphatase is recognized as the most sensitive enzyme indicator of obstructive jaundice. This is because, during bile duct obstruction or cholestasis, the production of alkaline phosphatase increases significantly. The enzyme is present in high concentrations not only in the liver but also in the bile ducts and bones, making it particularly responsive to conditions that affect bile flow.

In obstructive jaundice, there is a blockage in the bile ducts that leads to an accumulation of bile acids, which subsequently increases the synthesis and release of alkaline phosphatase from the liver. Elevated levels of this enzyme in the serum serve as a clear biochemical marker for such conditions, helping in the diagnosis of liver diseases associated with bile flow obstruction.

Other enzymes, such as alanine aminotransferase, gamma-glutamyltransferase, and lactate dehydrogenase, can also indicate liver function issues or damage but are not as specific or sensitive to obstructive jaundice as alkaline phosphatase. Alanine aminotransferase is more commonly elevated in conditions involving hepatocellular damage, while gamma-glutamyltransferase can be elevated in various liver conditions, and lactate dehydrogenase is more nonspecific to liver diseases. Thus