title: Epidemiology and the initial presentation of autoimmune hepatitis in Sweden: a nationwide study.
abstract: OBJECTIVE
  Autoimmune hepatitis (AIH) is a chronic liver disease, which if untreated can lead to cirrhosis and hepatic failure. The aim of the study was to investigate the incidence, prevalence, diagnostic tradition and clinical initial presentation of AIH.
  
  
  METHODS
  Analyses were performed in 473 patients identified as having probable or definite AIH.
  
  
  RESULTS
  The incidence of AIH was 0.85/100,000 (95% CI 0.69-1.01) inhabitants, which is somewhat lower than reported previously. The point prevalence amounted to 10.7/100,000 (95% CI 8.8-13.1), and 76% of the cases were females. The age-related incidence curve was bimodal but men were found to have only one incidence peak in the late teens, whereas women had a peak after menopause. AIH was presented as a spectrum of clinical settings from detected "en passant" to acute liver failure. Almost 30% of patients already had liver cirrhosis at diagnosis. Autoantibodies indicative of AIH type 1 were found in 79% of cases. Other concomitant autoimmune diseases were frequently found (49%).
  
  
  CONCLUSIONS
  The incidence and prevalence figures confirm that AIH is a fairly uncommon disease in the Swedish population. Symptoms at presentation were unspecific, but almost half of the patients were jaundiced, with around 30% having liver cirrhosis. The majority of Swedish AIH patients had AIH type 1.
authors.affiliation: Department of Medicine, Umeå University Hospital, Umeå, Sweden. marten.werner@vll.se
authors.forename: Mårten
authors.initials: M
authors.lastname: Werner
authors.forename: Hanne
authors.initials: H
authors.lastname: Prytz
authors.forename: Bodil
authors.initials: B
authors.lastname: Ohlsson
authors.forename: Sven
authors.initials: S
authors.lastname: Almer
authors.forename: Einar
authors.initials: E
authors.lastname: Björnsson
authors.forename: Annika
authors.initials: A
authors.lastname: Bergquist
authors.forename: Sven
authors.initials: S
authors.lastname: Wallerstedt
authors.forename: Hanna
authors.initials: H
authors.lastname: Sandberg-Gertzén
authors.forename: Rolf
authors.initials: R
authors.lastname: Hultcrantz
authors.forename: Per
authors.initials: P
authors.lastname: Sangfelt
authors.forename: Ola
authors.initials: O
authors.lastname: Weiland
authors.forename: Ake
authors.initials: A
authors.lastname: Danielsson
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D005260:Female; D019693:Hepatitis, Autoimmune / Q000175:diagnosis* / Q000453:epidemiology*; D006801:Humans; D015994:Incidence; D008297:Male; D015995:Prevalence; D012189:Retrospective Studies; D013548:Sweden / Q000453:epidemiology