Primary biliary cholangitis (PBC)
Concise definition
Primary biliary cholangitis (PBC; formerly primary biliary cirrhosis) is an autoimmune, cholestatic liver disease caused by immune‑mediated destruction of small intrahepatic bile ducts. Progressive duct loss produces cholestasis, portal inflammation and fibrosis, ultimately leading to cirrhosis and its complications if untreated.
Epidemiology and pathogenesis
- Predominantly affects middle‑aged women (≈90% female; typical onset 30-65 years).
- Primary lesion: chronic non‑suppurative destructive cholangitis with loss of interlobular bile ducts (ductopenia).
- Immunological hallmarks: antimitochondrial antibodies (AMA) and increased IgM.
- Pathogenesis involves autoreactive lymphocytes directed against biliary epithelial mitochondrial antigens, causing duct damage.
Typical clinical features
- Many patients are asymptomatic at diagnosis and are detected by routine blood tests.
- Common symptoms:
- Fatigue (very common, often disproportionate to objective findings).
- Cholestatic pruritus (can be severe).
- Jaundice (usually a later feature).
- Signs of advanced disease reflect cirrhosis and portal hypertension: hepatosplenomegaly, ascites, variceal bleeding, hepatic encephalopathy.
- Autoimmune comorbidity (e.g., Sjögren’s syndrome, thyroid disease, systemic sclerosis) is common.