title: The diagnostic utility of anti-melanoma differentiation-associated gene 5 antibody testing for predicting the prognosis of Japanese patients with DM.
abstract: OBJECTIVE
  Interstitial lung disease (ILD), especially rapidly progressive ILD (RPILD), is a major poor prognostic factor in patients with DM. We investigated the association of anti-melanoma differentiation-associated gene 5 (MDA5) antibody (Ab) with clinical characteristics and mortality in Japanese patients with DM.
  
  
  METHODS
  Seventy-nine DM patients, comprising 58 classic DM and 21 clinically amyopathic DM (CADM) patients, were enrolled. Serum Abs were screened by immunoprecipitation assays, and an immunosorbent assay (ELISA) was used for MDA5. The relationships of clinical characteristics and mortality with each Ab were investigated.
  
  
  RESULTS
  Anti-MDA5 Ab was detected in 17 patients. Anti-clinically amyopathic DM 140  kDa polypeptide Abs (anti-CADM-140 Abs) were found in 16 of the 17 anti-MDA5 Ab(+) patients. Skin ulcers, palmar papules, CADM, RPILD and mediastinal emphysema were widely distributed in anti-MDA5 Ab(+) patients. Mortality at 6 months as well as 5 years was also significantly higher in anti-MDA5 Ab(+) patients than in anti-MDA5 Ab(-) patients. In a multivariable Cox regression analysis, mortality was independently associated with anti-MDA5 Ab (relative hazard 6.33; 95% CI 1.43, 28.0). All of the deaths in anti-MDA5 Ab(+) patients were attributed to respiratory failure of RPILD; however, RPILD did not worsen in any of the anti-MDA5 Ab(+) patients who survived the first 6 months.
  
  
  CONCLUSIONS
  The presence of anti-MDA5 Ab identifies the characteristic skin, musculoskeletal, pulmonary and prognostic features in patients with DM. In addition, anti-MDA5 Ab seems to predict a group of patients with CADM-complicated fatal RPILD.
authors.affiliation: Department of Immunology and Rheumatology, Unit of Translational Medicine, Graduate School of Biomedical Sciences, Nagasaki University, Sakamoto 1-7-1, Nagasaki 852-8501, Japan. aiueotipstk0926@gmail.com
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Koga
authors.forename: Keita
authors.initials: K
authors.lastname: Fujikawa
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Horai
authors.forename: Akitomo
authors.initials: A
authors.lastname: Okada
authors.forename: Shin-Ya
authors.initials: SY
authors.lastname: Kawashiri
authors.forename: Naoki
authors.initials: N
authors.lastname: Iwamoto
authors.forename: Takahisa
authors.initials: T
authors.lastname: Suzuki
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Nakashima
authors.forename: Mami
authors.initials: M
authors.lastname: Tamai
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Arima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Yamasaki
authors.forename: Hideki
authors.initials: H
authors.lastname: Nakamura
authors.forename: Tomoki
authors.initials: T
authors.lastname: Origuchi
authors.forename: Yasuhito
authors.initials: Y
authors.lastname: Hamaguchi
authors.forename: Manabu
authors.initials: M
authors.lastname: Fujimoto
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishimatsu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mukae
authors.forename: Masataka
authors.initials: M
authors.lastname: Kuwana
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kohno
authors.forename: Katsumi
authors.initials: K
authors.lastname: Eguchi
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Aoyagi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kawakami
mesh_terms: D000888:Antibodies, Anti-Idiotypic / Q000097:blood / Q000276:immunology*; D001323:Autoantibodies / Q000097:blood / Q000276:immunology*; D053487:DEAD-box RNA Helicases / Q000097:blood / Q000276:immunology*; D003882:Dermatomyositis / Q000150:complications / Q000175:diagnosis* / Q000453:epidemiology; D003937:Diagnosis, Differential; D018450:Disease Progression; D004797:Enzyme-Linked Immunosorbent Assay / Q000706:statistics & numerical data*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D047468:Immunoprecipitation / Q000706:statistics & numerical data*; D015994:Incidence; D000072640:Interferon-Induced Helicase, IFIH1; D007564:Japan / Q000453:epidemiology; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000453:epidemiology / Q000209:etiology; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends
chemical_list: D000888:Antibodies, Anti-Idiotypic; D001323:Autoantibodies; C452815:IFIH1 protein, human; D053487:DEAD-box RNA Helicases; D000072640:Interferon-Induced Helicase, IFIH1