title: Brief report: Association of HLA-DRB1*0101/*0405 with susceptibility to anti-melanoma differentiation-associated gene 5 antibody-positive dermatomyositis in the Japanese population.
abstract: OBJECTIVE
  The complication of interstitial lung disease (ILD) in polymyositis/dermatomyositis (PM/DM) is associated with anti-aminoacyl-transfer RNA synthetase (anti-aaRS) antibody or anti-melanoma differentiation-associated gene 5 (anti-MDA-5) antibody positivity. Anti-MDA-5 antibody is associated with clinically amyopathic DM and fatal outcome due to rapidly progressive ILD in Asian populations. The association between genetic factors and anti-MDA-5 antibody-positive DM is unclear. This study was undertaken to investigate the HLA-DRB1 genotype in patients with anti-MDA-5 antibody-positive DM.
  
  
  METHODS
  We examined genetic differences among 17 patients with anti-MDA-5 antibody-positive DM, 33 patients with anti-aaRS antibody-positive PM/DM, 33 patients with PM/DM without anti-aaRS antibody or ILD, and 265 healthy controls.
  
  
  RESULTS
  The frequencies of HLA-DRB1*0101 and DRB1*0405 were 29% and 71%, respectively, in patients with anti-MDA-5 antibody-positive DM, which were higher than the frequencies in healthy controls (10% and 25%, respectively). Among the 17 patients with anti-MDA-5 antibody-positive DM, 16 (94%) harbored either the DRB1*0101 or DRB1*0405 allele. The combined frequency of the DRB1*0101 allele and the DRB1*0405 allele was significantly higher in patients with anti-MDA-5 antibody-positive DM than in patients with PM/DM without anti-aaRS antibody or ILD, with an odds ratio (OR) of 42.7 (95% confidence interval [95% CI] 4.9-370.2) (P = 1.1 × 10(-5)), or in patients with anti-aaRS antibody-positive PM/DM (OR 13.3 [95% CI 1.6-112.6], P = 4.5 × 10(-3)).
  
  
  CONCLUSIONS
  Our findings indicate that HLA-DRB1*0101/*0405 is associated with susceptibility to anti-MDA-5 antibody-positive DM in the Japanese population.
authors.affiliation: Institute of Rheumatology, Tokyo Women's Medical University, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Gono
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kawaguchi
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
authors.forename: Tomoko
authors.initials: T
authors.lastname: Sugiura
authors.forename: Takefumi
authors.initials: T
authors.lastname: Furuya
authors.forename: Kae
authors.initials: K
authors.lastname: Takagi
authors.forename: Hisae
authors.initials: H
authors.lastname: Ichida
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Katsumata
authors.forename: Masanori
authors.initials: M
authors.lastname: Hanaoka
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ota
authors.forename: Hisashi
authors.initials: H
authors.lastname: Yamanaka
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D044466:Asian People / Q000235:genetics* / Q000706:statistics & numerical data; D001323:Autoantibodies / Q000276:immunology; D053487:DEAD-box RNA Helicases / Q000235:genetics* / Q000276:immunology; D003882:Dermatomyositis / Q000208:ethnology / Q000235:genetics* / Q000276:immunology; D005260:Female; D020022:Genetic Predisposition to Disease / Q000208:ethnology / Q000235:genetics; D005838:Genotype; D059811:HLA-DRB1 Chains / Q000235:genetics*; D006801:Humans; D000072640:Interferon-Induced Helicase, IFIH1; D008297:Male; D008875:Middle Aged
chemical_list: D001323:Autoantibodies; D059811:HLA-DRB1 Chains; C487961:HLA-DRB1*01:01 antigen; C452815:IFIH1 protein, human; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1