title: Myositis autoantibodies in Korean patients with inflammatory myositis: anti-140-kDa polypeptide antibody is primarily associated with rapidly progressive interstitial lung disease independent of clinically amyopathic dermatomyositis.
abstract: BACKGROUND
  To investigate the association between myositis autoantibodies and clinical subsets of inflammatory myositis in Korean patients.
  
  
  METHODS
  Immunoprecipitation was performed using the sera of classic polymyositis (PM) (n = 11) and dermatomyositis (DM) (n = 38) patients who met the Bohan and Peter criteria for definite inflammatory myositis. A panel of defined myositis autoantibodies was surveyed to investigate the association between each autoantibody and clinical subsets of inflammatory myositis.
  
  
  RESULTS
  Either MSAs, anti-p140, or anti-p155/140 antibodies were found in 63.3% (31/49) of the study subjects. Anti-140-kDa-polypeptide (anti-p140) (18.4%, 9/49) and anti-155/140-kDa polypeptide (anti-p155/140) (16.3%, 8/49) antibodies were the most common, followed by anti-Mi2 (14.3%, 7/49), anti-ARS (12.2%, 6/49) and anti-SRP (2.0%, 1/49) antibodies. All MSAs and anti-p140 and anti-p155/140 antibodies were mutually exclusive. Anti-p140 (23.7%, 9/38), anti-p155/140 (21.1%, 8/38), and anti-Mi2 (18.4%, 3/38) antibodies were found exclusively in DM patients. Anti-p140 antibody was associated with rapidly progressive interstitial lung disease (ILD) (p = 0.001), with a sensitivity of 100.0% (4/4) and a specificity of 85.3% (29/34) in DM patients. Anti-p155/140 antibody was associated with cancer-associated DM (p = 0.009), with a sensitivity of 55.6% (5/9) and a specificity of 89.7% (26/29). Cancer-associated survival was significantly worse when anti-p155/140 antibody was present (19.2 ± 7.6 vs. 65.0 ± 3.5 months, p = 0.032). Finally, anti-ARS antibodies were associated with stable or slowly progressive ILD in PM and DM patients (p = 0.005).
  
  
  CONCLUSIONS
  Anti-p140 and anti-p155/140 antibodies were commonly found autoantibodies in Korean patients with inflammatory myositis. Despite the lack of clinically amyopathic DM patients in the study subjects, a strong association was observed between anti-p140 antibody and rapidly progressive ILD. Anti-p155/140 antibody was associated with cancer-associated myositis and poor survival.
authors.affiliation: Division of Rheumatology, Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
authors.forename: Eun Ha
authors.initials: EH
authors.lastname: Kang
authors.forename: Ran
authors.initials: R
authors.lastname: Nakashima
authors.forename: Tsuneyo
authors.initials: T
authors.lastname: Mimori
authors.forename: Jinhyun
authors.initials: J
authors.lastname: Kim
authors.forename: Yun Jong
authors.initials: YJ
authors.lastname: Lee
authors.forename: Eun Bong
authors.initials: EB
authors.lastname: Lee
authors.forename: Yeong Wook
authors.initials: YW
authors.lastname: Song
mesh_terms: D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000097:blood*; D003882:Dermatomyositis / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D018450:Disease Progression; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D008970:Molecular Weight; D009220:Myositis / Q000150:complications / Q000276:immunology* / Q000473:pathology*; D010455:Peptides / Q000097:blood; D056910:Republic of Korea / Q000453:epidemiology / Q000208:ethnology
chemical_list: D001323:Autoantibodies; D010455:Peptides