title: Clinical and serologic correlates of anti-PM/Scl antibodies in systemic sclerosis: a multicenter study of 763 patients.
abstract: OBJECTIVE
  Anti-PM/Scl autoantibodies are found in polymyositis, dermatomyositis, systemic sclerosis (SSc), and systemic autoimmune disease overlap syndromes. PM-1α is a major epitope of the PM/Scl complex, and antibodies against PM-1α can be detected using a validated enzyme-linked immunosorbent assay (ELISA). This study was undertaken to determine the prevalence and identify the clinical correlates of anti-PM-1α antibodies in a large cohort of patients with SSc.
  
  
  METHODS
  Serum samples were obtained from 763 patients with SSc enrolled in a multicenter Canadian cohort. The sera were analyzed by ELISA for the presence of antibodies against PM-1α. Associations between the presence of anti-PM-1α antibodies and demographic, clinical, and other serologic manifestations of SSc were investigated.
  
  
  RESULTS
  Anti-PM-1α antibodies were present in 55 patients with SSc (7.2%), of whom almost 50% (26 of 55; 3.4% of the overall cohort) had no other SSc-specific antibodies, namely anticentromere, anti-topoisomerase I, and anti-RNA polymerase III. Features positively associated with the presence of anti-PM-1α antibodies included younger age at disease onset, skeletal muscle involvement, calcinosis, inflammatory arthritis, and overlap disease. Interstitial lung disease was less frequent and there were fewer gastrointestinal symptoms present in patients with anti-PM-1α antibodies compared to patients without these antibodies.
  
  
  CONCLUSIONS
  Anti-PM-1α antibodies are relatively common in SSc and are associated with a distinct clinical phenotype, consistent with that described in association with other anti-PM/Scl autoantibodies. Although anti-PM-1α antibodies are not exclusive of other SSc-specific antibodies, they can be present in the absence thereof. Thus, anti-PM-1α antibodies may have considerable diagnostic and prognostic relevance in SSc.
authors.affiliation: McGill University, Montreal, Quebec, Canada.
authors.forename: Julie
authors.initials: J
authors.lastname: D'Aoust
authors.forename: Marie
authors.initials: M
authors.lastname: Hudson
authors.forename: Solène
authors.initials: S
authors.lastname: Tatibouet
authors.forename: James
authors.initials: J
authors.lastname: Wick
authors.forename: Michael
authors.initials: M
authors.lastname: Mahler
authors.forename: Murray
authors.initials: M
authors.lastname: Baron
authors.forename: Marvin J
authors.initials: MJ
authors.lastname: Fritzler
mesh_terms: D000328:Adult; D000368:Aged; D000888:Antibodies, Anti-Idiotypic / Q000097:blood*; D000974:Antibodies, Antinuclear / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D004264:DNA Topoisomerases, Type I / Q000276:immunology; D000939:Epitopes / Q000097:blood / Q000276:immunology; D005095:Exoribonucleases / Q000276:immunology*; D063326:Exosome Multienzyme Ribonuclease Complex / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012320:RNA Polymerase III / Q000276:immunology; D012189:Retrospective Studies; D012595:Scleroderma, Systemic / Q000097:blood* / Q000453:epidemiology / Q000276:immunology*
chemical_list: D000888:Antibodies, Anti-Idiotypic; D000974:Antibodies, Antinuclear; D015415:Biomarkers; D000939:Epitopes; C538950:anticentromere antibody; D012320:RNA Polymerase III; D005095:Exoribonucleases; D063326:Exosome Multienzyme Ribonuclease Complex; C077044:EXOSC10 protein, human; D004264:DNA Topoisomerases, Type I