title: The natural history of small-duct primary sclerosing cholangitis.
abstract: OBJECTIVE
  The long-term prognosis of patients with small-duct primary sclerosing cholangitis (PSC) remains incompletely characterized. We aimed at determining the natural history and long-term outcomes of a large number of patients with small-duct PSC.
  
  
  METHODS
  Data from 83 patients with well-characterized small-duct PSC from several medical institutions in Europe and the United States were combined. Each patient with small-duct PSC was randomly matched to 2 patients with large-duct PSC by age, gender, calendar year of diagnosis, and institution.
  
  
  RESULTS
  The median age at diagnosis in both groups was 38 years (61% males). Nineteen (22.9%) of the 83 patients with small-duct PSC progressed to large-duct PSC in a median of 7.4 (interquartile range [IQR], 5.1-14) years. One patient with small-duct PSC who progressed to large-duct PSC was diagnosed with cholangiocarcinoma but after progression to large-duct PSC; 20 patients with large-duct PSC developed cholangiocarcinoma. Patients with small-duct PSC had a significantly longer transplantation-free survival compared with large-duct PSC patients (13 years [IQR, 10-17] vs 10 years [IQR, 6-14], respectively; hazard ratio, 3.04; 95% confidence interval: 1.82-5.06; P < .0001). Two patients with small-duct PSC who underwent liver transplantation had recurrence of small-duct PSC in the graft 9 and 13 years, respectively, after transplantation.
  
  
  CONCLUSIONS
  Small-duct PSC is a disease of progressive potential but associated with a better long-term prognosis as compared with large-duct PSC. Small-duct PSC may recur after liver transplantation. Cholangiocarcinoma does not seem to occur in patients with small-duct PSC, unless the disease has progressed to large-duct PSC.
authors.affiliation: Department of Internal Medicine, Section of Gastroenterology and Hepatology, Sahlgrenska University Hospital, Gothenburg, Sweden. einar.bjornsson@medic.gu.se
authors.forename: Einar
authors.initials: E
authors.lastname: Björnsson
authors.forename: Rolf
authors.initials: R
authors.lastname: Olsson
authors.forename: Annika
authors.initials: A
authors.lastname: Bergquist
authors.forename: Stefan
authors.initials: S
authors.lastname: Lindgren
authors.forename: Barbara
authors.initials: B
authors.lastname: Braden
authors.forename: Roger W
authors.initials: RW
authors.lastname: Chapman
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Boberg
authors.forename: Paul
authors.initials: P
authors.lastname: Angulo
mesh_terms: D000328:Adult; D002423:Cause of Death / Q000639:trends; D002760:Cholangiopancreatography, Endoscopic Retrograde; D049448:Cholangiopancreatography, Magnetic Resonance; D015209:Cholangitis, Sclerosing / Q000175:diagnosis* / Q000209:etiology* / Q000401:mortality; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate / Q000639:trends; D013548:Sweden / Q000453:epidemiology; D013997:Time Factors; D006113:United Kingdom / Q000453:epidemiology; D014481:United States / Q000453:epidemiology