title: Asymptomatic primary biliary cirrhosis: clinical features, prognosis, and symptom progression in a large population based cohort.
abstract: BACKGROUND
  Many patients with primary biliary cirrhosis (PBC) are asymptomatic at the time of diagnosis. However, because most studies of asymptomatic PBC have been small and from tertiary centres, asymptomatic PBC remains poorly characterised.
  
  
  OBJECTIVE
  To describe the features and progression of initially asymptomatic PBC patients.
  
  
  METHODS
  Follow up by interview and note review of a large geographically and temporally defined cohort of patients with PBC, collected by multiple methods.
  
  
  RESULTS
  Of a total of 770 patients, 469 (61%) were asymptomatic at diagnosis. These patients had biochemically and histologically less advanced disease than initially symptomatic patients. Median survival was similar in both groups (9.6 v 8.0 years, respectively) possibly due to excess of non-liver related deaths in asymptomatic patients (31% v 57% of deaths related to liver disease). Survival in initially asymptomatic patients was not affected by subsequent symptom development. By the end of follow up, 20% of initially asymptomatic patients had died of liver disease or required liver transplantation. The majority of initially asymptomatic patients developed symptoms of liver disease if they were followed up for long enough (Kaplan-Meier estimate of proportion developing symptoms: 50% after five years, 95% after 20 years). However, 45% of patients remained asymptomatic at the time of death.
  
  
  CONCLUSIONS
  Although asymptomatic PBC is less severe at diagnosis than symptomatic disease, it is not associated with a better prognosis, possibly due to an increase in non-hepatic deaths. The reasons for this are unclear but may reflect confounding by other risk factors or surveillance bias. These findings have important implications for future treatment strategies.
authors.affiliation: Newcastle University Medical School, Newcastle, UK. martin.prince@ncl.ac.uk
authors.forename: M I
authors.initials: MI
authors.lastname: Prince
authors.forename: A
authors.initials: A
authors.lastname: Chetwynd
authors.forename: W L
authors.initials: WL
authors.lastname: Craig
authors.forename: J V
authors.initials: JV
authors.lastname: Metcalf
authors.forename: O F W
authors.initials: OF
authors.lastname: James
mesh_terms: D000368:Aged; D002423:Cause of Death; D016009:Chi-Square Distribution; D015331:Cohort Studies; D018450:Disease Progression; D004739:England / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000175:diagnosis* / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis