Primary sclerosing cholangitis (PSC)
Overview
Primary sclerosing cholangitis (PSC) is a chronic, progressive cholestatic liver disease caused by inflammation and concentric fibrosis of the biliary tree.
Both intrahepatic and extrahepatic ducts are affected, producing multifocal strictures and segmental dilatations that result in cholestasis, recurrent biliary sepsis, progressive biliary cirrhosis and eventually liver failure.
PSC has a strong association with inflammatory bowel disease (especially ulcerative colitis) and confers an increased lifetime risk of biliary tract and colorectal malignancy.
There is no proven disease‑modifying medical therapy; management focuses on treating complications, endoscopic management of dominant strictures and early specialist hepatology referral including consideration of liver transplantation.
Epidemiology and associations
- Predominantly affects adults and is more common in men.
- Strong association with inflammatory bowel disease (IBD), particularly ulcerative colitis: more than 80% of PSC patients have concomitant ulcerative colitis, although PSC remains uncommon among all UC patients.
- Increased lifetime risks include cholangiocarcinoma and gallbladder carcinoma; colorectal neoplasia risk is elevated when IBD is present.
- Autoimmune overlap syndromes occur (for example, PSC-AIH overlap), seen more often in younger patients.
Pathophysiology and histology
- PSC is considered immune‑mediated in genetically predisposed individuals exposed to environmental triggers.