Urinalysis and Body Fluids 6th Edition by Majorie DiLorenzo, Susan Strasinger

Exercise 69

An elevated urine bilirubin with a normal urobilinogen is indicative of:

A. Cirrhosis of the liver

B. Hemolytic disease

C. Hepatitis

D. Biliary obstruction

Step 1 of 3

Bilirubin:

Bilirubin is the yellow pigment formed by degradation of hemoglobin into iron, protein and protoporphyrin.

• Iron, and protein are utilized by the body and protoporphyrin is transformed into bilirubin by reticuloendothelial system.

Cycle of bilirubin:

• Bilirubin is discharged into blood circulation and binds with albumin.

• It is then transported to liver. At this condition, bilirubin is insoluble in water and cannot be excreted in urine.

• Conjugation of bilirubin with glucuronic acid in liver by glucuronyl transferase to provide bilirubin diglucuronide (water soluble bilirubin). This is conjugated bilirubin.

• This conjugated bilirubin from liver enters bile duct and next to intestine where bacteria present in intestine forms urobilinogen by reducing action of bilirubin.

• Bilirubin oxidized and sent out in feces as urobilin and stercobilinogen.

Causes of bilirubin:

• When degradation cycle of hemoglobin disrupted by biliary obstruction which is post hepatic jaundice.

• When liver gets damaged (hepatic jaundice).

• Here urobilinogen remains normal in urine and urine bilirubin increases when there is obstruction of bile.