title: Prevalence of antimitochondrial antibody in Japanese corporate workers in Kanagawa prefecture.
abstract: BACKGROUND
  The prevalence of antimitochondrial antibody (AMA) in humans and its relationship to the development of primary biliary cirrhosis (PBC) are not well known. We have estimated the frequency of AMA in the general population, and studied its association with PBC.
  
  
  METHODS
  We studies 1714 corporate workers (median age, 48 years; range, 30 to 59 years) who had an annual health check from 1998 to 1999 at Kawasaki Social Insurance Hospital in Japan. We used an indirect immunofluorescence method for screening serum AMA. We applied the prevalence of AMA-positive people in the study group to the general population in Japan. Then the inferred AMA-positive population was compared to the actual number of patients with PBC in statistics published by the Japanese Government.
  
  
  RESULTS
  AMA was detected in 11 of 1714 people (0.64%; 95% confidence interval, 0.26% to 1.02%). All these 11 sera reacted with 2-oxoacid-dehydrogenase complex by immunoblotting. Of these 11 individuals, none had subjective symptoms, all had normal serum bilirubin levels, and 6 had abnormal liver function test results. Using published statistics for the Japanese population, we inferred that there were approximately 336,472 AMA-positive people in Japan from age 30 to 59 years. The number of patients with symptomatic PBC recorded by the nationwide epidemiological survey of the Japanese Government was 2459. Thus, we inferred the rate of symptomatic PBC among AMA-positive persons to be about 0.73% (2459/336,472).
  
  
  CONCLUSIONS
  AMA is not a rare antibody in the general population, but few people develop recognizable PBC even if they have AMA.
authors.affiliation: Department of Gastroenterology, Kanto Medical Center, NTT EC (Nippon Telegraph and Telephone East Corporation), Tokyo, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Shibata
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Onozuka
authors.forename: Toshio
authors.initials: T
authors.lastname: Morizane
authors.forename: Hideko
authors.initials: H
authors.lastname: Koizumi
authors.forename: Naomi
authors.initials: N
authors.lastname: Kawaguchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Miyakawa
authors.forename: Makoto
authors.initials: M
authors.lastname: Kako
authors.forename: Keiji
authors.initials: K
authors.lastname: Mitamura
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008105:Liver Cirrhosis, Biliary / Q000175:diagnosis* / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000276:immunology*; D016036:Seroepidemiologic Studies
chemical_list: D001323:Autoantibodies