HYPERBILIRUBINEMIAS

Depending on the nature of the bilirubin elevated, the condition may be grouped into:-

–> conjugated or Unconjugated  hyperbilirubinemia.

A–>  Congenital  Hyperbilirubinemias

They result from abnormal uptake, conjugation or excretion of bilirubin due to inherited defects such as

Crigler-Najjar Syndrome

• The defect is due to conjugation, there is severe deficiency of UDP glucuronyl  transferase. The disease is often fatal and the children die before the age of 2.
• Unconjugated bilirubin level increases to more than 20mg/dl, and hence kernicterus results.
• Bilirubin level  in blood exceeds 20 mg/dl in Crigler-Najjar syndrome Type 1 and does not exceed 20 mg/dl in Crigler-Najjar syndrome Type 2.

Gilbert’s Disease:

• It is inherited as an autosomal dominant trait.
• The defect is in the uptake of bilirubin by the liver.
• Bilirubin level is usually around 3 mg/dl, and patient is asymptomatic, except for the presence of mild jaundice.

Dubin-Johnson Syndrome:

• It is an autosomal recessive trait leading to defective excretion of conjugated bilirubin.
• The disease results from the defective ATP-dependent organic anion transportin bile canaliculi.
• There is a mutation in the MRP-2 protein which is responsible for transport of  conjugated bilirubin into bile.
• The bilirubin gets deposited in the liver and the liver appears black. The condition is referred to as Black liver jaundice.

Rotor Syndrome

• exact defect is not identified. Bilirubin excretion is defective, but there is no staining of the liver. It is an autosomal recessive condition.

B–>Acquired Hyperbilirubinemias:

Physiological Jaundice:

• Called as neonatal hyperbilirubinemia.
• Transient  hyperbilirubinemia  is due to an accelerated rate of destruction of RBCs and also because of the immature hepatic system of conjugation of bilirubin.

Breast milk jaundice

• In some breast-fed infants, prolongation of the  jaundice has been attributed to high level of an estrogen derivative in maternal blood, which is excreted through the milk.

Conjugated Hyperbilirubinemias
A. Dubin Johnson’s syndrome
B. Rotor syndrome
c.Benign Recurrent intrahepatic Cholestatsis (BRIC)
d.Progressive Familial intrahepatic Cholestatsis (FIC)