DESCRIPTION

• Primary sclerosing cholangitis (PSC) is a progressive, immune-mediated inflammatory liver disease, leading to fibrosis of intrahepatic and extrahepatic bile ducts.
• PSC is frequently associated with inflammatory bowel disease (IBD), most commonly ulcerative colitis.
• Small duct PSC is a disease variant with normal bile ducts on imaging, but labs and histology are consistent with PSC.
• PSC-autoimmune hepatitis (PSC-AIH) describes an overlap syndrome with clinical, biochemical, and histologic findings, and the characteristic of AIH with cholangiography findings is consistent with PSC.
• PSC may progress to biliary cirrhosis, and patients could develop complications like portal hypertension, liver tumors, and liver failure.

EPIDEMIOLOGY

• Rare in children with a prevalence of 1.5 cases per 100,00 children
• Accounts for 2–3% of pediatric liver transplants

PATHOPHYSIOLOGY

• The pathophysiology of PSC is unknown. However, the etiology is likely multifactorial, implicating the microbiome, genetic, immunologic, and environmental factors.
• Although there are no specific autoantibodies diagnostic of PSC, its association with IBD and the presence of autoantibodies suggest the role of autoimmunity in the development of PSC.
• Leakage of bacteria into the portal circulation and gut microbiome dysregulation may contribute to inflammation of the liver and bile ducts.

COMMONLY ASSOCIATED CONDITIONS

PSC is frequently associated with IBD—most commonly, ulcerative colitis.