Primary Biliary Cholangitis

Definition

Primary biliary cholangitis (PBC) is a chronic autoimmune cholestatic liver disease characterized by progressive destruction of intrahepatic bile ducts, leading to cholestasis, fibrosis, and eventually cirrhosis.

Epidemiology

• Predominantly affects middle-aged women (female-to-male ratio ~9:1)
• Peak incidence between 40–60 years
• Prevalence higher in Northern Europe and North America
• Rare in children and males
• Often associated with other autoimmune disorders: Sjögren syndrome, thyroid disease, systemic sclerosis

Etiology

• Autoimmune destruction of small intrahepatic bile ducts
• Genetic predisposition: HLA-DR8, HLA-DRB1 alleles
• Environmental triggers suspected: infections, xenobiotics
• Association with other autoimmune diseases
• No known infectious or viral cause

Pathophysiology

• Immune-mediated destruction of small intrahepatic bile ducts
• Cholestasis leads to accumulation of bile acids, causing hepatocyte injury
• Progressive fibrosis develops, leading to cirrhosis and portal hypertension
• Chronic inflammation triggers autoimmune responses (AMA antibodies against PDC-E2 enzyme)
• Eventually leads to liver failure if untreated