title: Establishment of an ELISA to detect anti-glycyl-tRNA synthetase antibody (anti-EJ), a serological marker of dermatomyositis/polymyositis and interstitial lung disease.
abstract: BACKGROUND
  The aminoacyl transfer RNA synthetases (ARSs) are a group of enzymes that charge amino acids to the cognate transfer RNA during the translation process. Previous reports demonstrated autoantibodies to 8 different ARS. Although anti-glycyl-tRNA synthetase antibodies (anti-EJ) are mainly found in patients with inflammatory myopathy, information on their clinical significances is limited, partly due to a lack of commercially available tests.
  
  
  METHODS
  We developed an ELISA and immunoprecipitation method by using recombinant EJ protein to detect the anti-EJ of 453 patients with various autoimmune connective tissue diseases (ACTDs). We also studied the influence of 3 cytokines-IL-1β, IFN-γ and IFN-α-on the level of EJ mRNA and protein expressed by human fetal lung fibroblasts.
  
  
  RESULTS
  Five patients were positive for anti-EJ. Although 3 of these patients had dermatomyositis/polymyositis, the other 2 patients did not have myositis. The three patients with high levels of anti-EJ antibodies in ELISA were complicated with interstitial lung disease. There was no significant change in the level of EJ protein expressed by human fetal lung fibroblasts stimulated by the cytokines.
  
  
  CONCLUSIONS
  We developed an ELISA to detect anti-EJ by using recombinant protein. This easy-to-use ELISA could help clarify the clinical significance of anti-EJ in ACTDs.
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors: Hiroaki
authors: H
authors: Hane
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Electronic address: ymuro@med.nagoya-u.ac.jp.
authors: Yoshinao
authors: Y
authors: Muro
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors: Kanako
authors: K
authors: Watanabe
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors: Yasushi
authors: Y
authors: Ogawa
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors: Kazumitsu
authors: K
authors: Sugiura
authors: Department of Dermatology, Nagoya University Graduate School of Medicine, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan.
authors: Masashi
authors: M
authors: Akiyama
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001323:Autoantibodies / Q000032:analysis*; D015415:Biomarkers / Q000097:blood; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D016207:Cytokines / Q000097:blood; D003882:Dermatomyositis / Q000097:blood / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006032:Glycine-tRNA Ligase / Q000276:immunology*; D006801:Humans; D047468:Immunoprecipitation; D017563:Lung Diseases, Interstitial / Q000097:blood / Q000175:diagnosis*; D008297:Male; D008875:Middle Aged; D017285:Polymyositis / Q000097:blood / Q000175:diagnosis*; D011994:Recombinant Proteins / Q000276:immunology; D055815:Young Adult
chemical_list: D001323:Autoantibodies; D015415:Biomarkers; D016207:Cytokines; D011994:Recombinant Proteins; D006032:Glycine-tRNA Ligase
keywords: Dermatomyositis; EJ; ELISA; Glycyl-tRNA synthetase; Interstitial lung disease; Polymyositis