Marker of liver and biliary tract disorders

This is a compound of free bilirubin with glucuronic acid - bilirubin glucuronide. Direct bilirubin is synthesized in the liver, and then part of it enters the small intestine with bile. In case of hyperbilirubinemia, direct bilirubin accumulates in elastic tissue, mucous membranes, and skin. An increase in the level of direct bilirubin is observed in parenchymal and obstructive jaundice due to impaired bile flow. Patients with elevated serum levels of direct (bound) bilirubin have bilirubinuria.