title: [Myositis-specific autoantibodies].
abstract: BACKGROUND
  Myositis-specific antibodies (MSA) are autoantibodies that are almost exclusively detected in idiopathic inflammatory myopathies (IIM). This article provides an overview of these autoantibodies and how they can be used clinically to identify subgroups of IIM.
  
  
  METHODS
  The article is based on a non-systematic literature review and our own experience.
  
  
  RESULTS
  MSA can be detected in up to 50 % of patients with IIM. Patients with anti-synthetase antibodies have a constellation of clinical findings termed "the anti-synthetase syndrome", in which interstitial lung disease dominates the clinical picture. Anti-Mi2 antibodies is another myositis-specific antibody. Patients with anti-Mi2 antibodies often have classical dermatomyositis, while the anti-SRP antibody identifies patients with severe myopathy, poor response to treatment with corticosteroids and histological findings of muscle cell necrosis - often lacking inflammatory infiltrates. The newly detected anti-CADMp140 appears to be associated with amyopathic or hypomyopathic dermatomyositis, previously called dermatomyositis sine myositis. Anti-p155 antibodies are most often found in patients who also have cancer.
  
  
  CONCLUSIONS
  Myositis-specific antibodies may be useful for identification of clinical subgroups of IIM and can thereby affect the choice of medical treatment.
authors.affiliation: Revmatologisk avdeling, Oslo universitetssykehus, Rikshospitalet, 0027 Oslo, Norway. jan.tore.gran@rikshospitalet.no
authors.forename: Jan Tore
authors.initials: JT
authors.lastname: Gran
authors.forename: Øyvind
authors.initials: Ø
authors.lastname: Molberg
authors.forename: Gerd Cecilie
authors.initials: GC
authors.lastname: Dobloug
authors.forename: Helena
authors.initials: H
authors.lastname: Andersson
authors.forename: Eli
authors.initials: E
authors.lastname: Taraldsrud
authors.forename: David
authors.initials: D
authors.lastname: Scheie
mesh_terms: D000604:Amino Acyl-tRNA Synthetases / Q000276:immunology; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001323:Autoantibodies / Q000032:analysis*; D003882:Dermatomyositis / Q000276:immunology; D018450:Disease Progression; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D036341:Intercellular Signaling Peptides and Proteins; D009220:Myositis / Q000145:classification / Q000188:drug therapy / Q000276:immunology*; D009687:Nuclear Proteins / Q000276:immunology; D010455:Peptides / Q000276:immunology; D018271:Signal Recognition Particle / Q000276:immunology
chemical_list: D000893:Anti-Inflammatory Agents; D001323:Autoantibodies; C501597:CADM-140 peptide, human; D007166:Immunosuppressive Agents; D036341:Intercellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D010455:Peptides; D018271:Signal Recognition Particle; D000604:Amino Acyl-tRNA Synthetases