Primary sclerosing cholangitis (PSC)

(NEJM 2016;375:1161; Clin Liver Dis 2020;15:125)

• Diffuse inflammation of intrahepatic and extrahepatic bile ducts leading to fibrosis & stricturing of biliary system. A/w HLA-B8 and -DR3 or -DR4, frequent ⊕ autoantibodies.

• Epi:

  • ♂ >♀ (20-50 y) ~70% Pts w/ PSC have IBD (usually UC);
  • only 1-4% w/ UC have PSC. ⊕ prognostic factors: ♂, absence of IBD, small duct PSC (Gastro 2017;152:1829).

• Symptoms:

  • fatigue,
  • pruritus,
  • jaundice,
  • fevers,
  • RUQ pain,
  • Diarrhea → ❓ IBD: 🔎 Diagnosis: check colonoscope
  • 50% of Pts asymptomatic

• Ddx:

  • 👉 Extrahepatic cholestasis
  • PBC
  • overlap w/ AIH,
  • IgG4 autoimmune cholangitis,

• Dx:

  • cholangiography (MRCP ± ERCP) → multifocal beaded bile duct strictures
  • exclude 2° cause
  • 一種自身抗體，即核週抗中性粒細胞胞漿抗體 (pANCA)，在約 65% 的 PSC 患者中呈陽性。
  • 60% 至 80% 的 PSC 有潰瘍性結腸炎 (UC)；因此，建議在診斷時進行結腸鏡檢查。
  • may miss dx if confined to small intrahepatic ducts (“small duct PSC”).
  • Liver bx if unclear: onion-skin fibrosis around bile ducts + some findings similar to PBC.

• Treatment-Primary sclerosing cholangitis (PSC)