title: Autoantibodies to a 140-kd polypeptide, CADM-140, in Japanese patients with clinically amyopathic dermatomyositis.
abstract: OBJECTIVE
  To identify novel autoantibodies specific for dermatomyositis (DM), especially those specific for clinically amyopathic DM (C-ADM).
  
  
  METHODS
  Autoantibodies were analyzed by immunoprecipitation in 298 serum samples from patients with various connective tissue diseases (CTDs) or idiopathic pulmonary fibrosis (IPF). Antigen specificity of the sera was further examined by immunoblotting and indirect immunofluorescence (IF). The disease specificity and clinical features associated with the antibody of interest were determined.
  
  
  RESULTS
  Eight sera recognized a polypeptide of approximately 140 kd (CADM-140 autoantigen) by immunoprecipitation and immunoblotting. Immunoreactivity was detected in the cytoplasm, and indirect IF revealed a granular or reticular pattern. Anti-CADM-140 antibodies were detected in 8 of 42 patients with DM, but not in patients with other CTDs or IPF. Interestingly, all 8 patients with anti-CADM-140 antibodies had C-ADM. Among 42 patients with DM, those with anti-CADM-140 autoantibodies had significantly more rapidly progressive interstitial lung disease (ILD) when compared with patients without anti-CADM-140 autoantibodies (50% versus 6%; P = 0.008).
  
  
  CONCLUSIONS
  These results indicate that the presence of anti-CADM-140 autoantibodies may be a novel marker for C-ADM. Further attention should be directed to the detection of rapidly progressive ILD in those patients with anti-CADM-140 autoantibodies.
authors.affiliation: Keio University School of Medicine, Tokyo, Japan. shins@sc.itc.keio.ac.jp
authors.forename: Shinji
authors.initials: S
authors.lastname: Sato
authors.forename: Michito
authors.initials: M
authors.lastname: Hirakata
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
authors.forename: Akira
authors.initials: A
authors.lastname: Suwa
authors.forename: Shinichi
authors.initials: S
authors.lastname: Inada
authors.forename: Tsuneyo
authors.initials: T
authors.lastname: Mimori
authors.forename: Takeji
authors.initials: T
authors.lastname: Nishikawa
authors.forename: Chester V
authors.initials: CV
authors.lastname: Oddis
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Ikeda
mesh_terms: D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D003882:Dermatomyositis / Q000276:immunology*; D005260:Female; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins; D007564:Japan; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D010455:Peptides / Q000097:blood*
chemical_list: D001323:Autoantibodies; C501597:CADM-140 peptide, human; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides