title: Clinical relevance of combined anti-mitochondrial M2 detection assays for primary biliary cirrhosis.
abstract: BACKGROUND
  Antimitochondrial antibody (AMA) is a specific serologic marker in primary biliary cirrhosis (PBC). The aim of this study was to evaluate the clinical relevance of combined AMA assays.
  
  
  METHODS
  Sera were obtained from 79 patients with PBC and 108 patients with other liver disease. They were tested by indirect immunofluorescence (IIF) using rat kidney/stomach tissue and HEp2 cells as substrate, 4 AMA-M2 assays, anti-sp100, and anti-gp210 assays.
  
  
  RESULTS
  Using IIF-AMA with cut-off titer of 1:40, the sensitivity and specificity for PBC were 88.6% and 87.0%, respectively. A cut-off titer of 1:80 improved the specificity to 93.5%. The 4 commercial assay kits using AMA-M2 autoantibodies showed sensitivity of 55.7-79.7% and specificity of 91.7-95.4% with moderate to good agreement. AMA-M2 assays using both native and recombinant E2 antigens had higher sensitivity. ANAs on HEp2 cells, anti-sp100, and anti-gp210 were detected in 67.1%, 13.9-15.2%, and 22.8-27.8% of PBC patients, respectively. Additional AMA-M2 specific assays in IIF-AMA negative and low titer positive (1:40) sera increased the sensitivity and specificity to 88.6% and 90.7%, respectively.
  
  
  CONCLUSIONS
  Serological diagnosis for PBC using IIF with high titer cut-off and additional AMA-M2 specific tests by ELISA or LIA in IIF-negative sera should be used.
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Eunhee
authors.initials: E
authors.lastname: Han
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Jo
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Hyeyoung
authors.initials: H
authors.lastname: Lee
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Ae-Ran
authors.initials: AR
authors.lastname: Choi
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Jihyang
authors.initials: J
authors.lastname: Lim
authors.affiliation: Departments of Pathology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Eun-Sun
authors.initials: ES
authors.lastname: Jung
authors.affiliation: Departments of Laboratory Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea. Electronic address: ejoh@catholic.ac.kr.
authors.forename: Eun-Jee
authors.initials: EJ
authors.lastname: Oh
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000818:Animals; D034961:Antigens, Nuclear / Q000276:immunology; D001323:Autoantibodies / Q000097:blood* / Q000276:immunology*; D001324:Autoantigens / Q000276:immunology*; D001774:Blood Chemical Analysis / Q000379:methods*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000379:methods*; D006801:Humans; D008105:Liver Cirrhosis, Biliary / Q000097:blood* / Q000276:immunology; D008297:Male; D008875:Middle Aged; D008928:Mitochondria / Q000276:immunology*; D051381:Rats
chemical_list: D034961:Antigens, Nuclear; D001323:Autoantibodies; D001324:Autoantigens; C066642:SP100 protein, human
keywords: Anti-mitochondrial antibody M2 subtype; Anti-mitochondrial autoantibodies; Combined test; Diagnosis; Primary biliary cirrhosis