Conjugated, direct bilirubin (DBil)

Conjugated Bilirubin Test - Liver Function Assessment

Conjugated bilirubin is the fraction of bilirubin that undergoes esterification in liver hepatocytes and is soluble in plasma. The test measures the concentration of conjugated bilirubin, which is excreted into bile. In the intestines, bacterial enzymes convert it into urobilinogen and stercobilin.

When to Perform the Test?

The test is performed to assess liver function and for the diagnosis and differentiation of jaundice.

Disease Entities

In cases of elevated direct bilirubin levels, disease entities include: intrahepatic cholestasis (Dubin-Johnson syndrome, familial hyperbilirubinemia), extrahepatic cholestasis (bile duct obstruction, gallstones, tumors), hepatitis, and liver cirrhosis.

Symptoms

Conjugated bilirubin (DBil) measurement is performed when symptoms such as jaundice (yellowish discoloration of the skin and mucous membranes), especially in newborns, right upper quadrant pain, ascites, and changes in urine and stool color are observed.