title: Identification of clinical features and autoantibodies associated with calcinosis in dermatomyositis.
abstract: OBJECTIVE
  Prior studies have estimated that up to 20% of adults with dermatomyositis (DM) have calcinosis, which can lead to significant morbidity. Identification of risk factors may provide a better understanding of the pathogenesis and ultimately therapy for this difficult clinical problem. Risk factors for calcinosis in adults with DM have not been extensively studied.
  
  
  OBJECTIVE
  To determine the prevalence of calcinosis and to identify associated clinical features in a cohort of extensively phenotyped adults with DM.
  
  
  METHODS
  A cross-sectional study of 126 patients diagnosed as having DM from January 1, 2006, through January 1, 2013, was performed. Patients were adults (≥18 years of age) attending the Stanford University Medical Center clinic.
  
  
  METHODS
  Calcinosis, defined as the presence of calcium deposition in the skin and subcutaneous tissues on physical examination.
  
  
  RESULTS
  Fourteen patients (11.1%) had calcinosis, with the extremities most commonly involved. Patients with vs those without calcinosis had a longer disease duration (median, 6.9 years; range, 2.4-18.1; vs median, 3.9 years; range, 0.2-19.2 years; P = .003) and more fingertip ulcers (50.0% vs 9.3%, P < .001). An association between calcinosis and both interstitial lung disease and anti-MDA-5 autoantibodies was identified, but this association did not persist in multivariate models that adjusted for fingertip ulcers. Fingertip ulcers and disease duration were strongly associated with calcinosis in all multivariate models, independent of the underlying autoantibody present. Autoantibodies to NXP-2 were associated with calcinosis (odds ratio, 15.52; 95% CI, 2.01-119.90), whereas anti-transcriptional intermediary factor 1-γ antibodies were protective (odds ratio, 0.2; 95% CI, 0.01-0.99) in multivariate analyses that adjusted for fingertip ulcers and other covariates.
  
  
  CONCLUSIONS
  Calcinosis was a relatively uncommon clinical feature in our cohort of adults with DM. Our data suggest that calcinosis is positively associated with longer disease duration, fingertip ulcers, and NXP-2 autoantibodies and negatively associated with transcriptional intermediary factor 1-γ antibodies. A common vascular mechanism may underlie the development of both calcinosis and fingertip ulcers in patients with DM.
authors.affiliation: Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California.
authors.forename: Antonia
authors.initials: A
authors.lastname: Valenzuela
authors.affiliation: Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California2Department of Dermatology, Stanford University School of Medicine, Stanford, California.
authors.forename: Lorinda
authors.initials: L
authors.lastname: Chung
authors.affiliation: Division of Rheumatology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Livia
authors.initials: L
authors.lastname: Casciola-Rosen
authors.affiliation: Division of Immunology and Rheumatology, Stanford University School of Medicine, Stanford, California2Department of Dermatology, Stanford University School of Medicine, Stanford, California.
authors.forename: David
authors.initials: D
authors.lastname: Fiorentino
mesh_terms: D000251:Adenosine Triphosphatases / Q000276:immunology; D000328:Adult; D001323:Autoantibodies / Q000097:blood*; D002114:Calcinosis / Q000097:blood* / Q000276:immunology; D003430:Cross-Sectional Studies; D053487:DEAD-box RNA Helicases / Q000276:immunology; D004268:DNA-Binding Proteins / Q000276:immunology; D003882:Dermatomyositis / Q000097:blood* / Q000150:complications; D005260:Female; D005385:Fingers; D006801:Humans; D000072640:Interferon-Induced Helicase, IFIH1; D017563:Lung Diseases, Interstitial / Q000276:immunology; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D012261:Ribonucleoproteins / Q000276:immunology; D012883:Skin Ulcer / Q000276:immunology; D013997:Time Factors; D014157:Transcription Factors / Q000276:immunology; D000099207:SS-A Antigen
chemical_list: D000251:Adenosine Triphosphatases; D001323:Autoantibodies; D053487:DEAD-box RNA Helicases; D004268:DNA-Binding Proteins; D000072640:Interferon-Induced Helicase, IFIH1; D012261:Ribonucleoproteins; D014157:Transcription Factors; D000099207:SS-A Antigen; C511956:TRIM33 protein, human; C452815:IFIH1 protein, human; C551732:MORC3 protein, human