Etiology and Pathogenesis of Jaundice

Biochemical and Molecular Basis of Bilirubin Metabolism

Jaundice, a common clinical condition, is primarily caused by abnormal metabolism or excretion of bilirubin. Understanding the biochemical pathways governing bilirubin metabolism is crucial in determining its underlying pathology.

Overview of Bilirubin Metabolism

Bilirubin is a yellow pigment derived from the breakdown of hemoglobin in aged red blood cells. It undergoes a complex metabolic process involving the liver, where it is conjugated with glucuronic acid before excretion through bile.

Etiology of Jaundice

Pre-hepatic Jaundice: Caused by excessive hemolysis leading to increased production of unconjugated bilirubin.
Hepatic Jaundice: Resulting from liver dysfunction affecting bilirubin conjugation and transport.
Post-hepatic Jaundice: Due to obstruction in bile ducts causing accumulation of conjugated bilirubin.

Pathogenesis

The progression of jaundice involves disruption in bilirubin metabolism at different stages, leading to clinical manifestations such as yellowing of the skin and sclera. Genetic mutations, liver infections, and gallstone obstruction are common contributing factors.

Clinical Symptoms

Yellow discoloration of skin and eyes
Dark urine and pale stools
Fatigue and abdominal pain

Diagnostic Approaches

Diagnosis includes biochemical assays measuring serum bilirubin levels, liver function tests, and imaging studies like ultrasound and MRI.

Management and Treatment

Therapeutic strategies depend on the underlying etiology, ranging from phototherapy in neonatal jaundice to surgical intervention in obstructive jaundice.