title: Pulmonary function and autoantibodies in a long-term follow-up of juvenile dermatomyositis patients.
abstract: OBJECTIVE
  Pulmonary disease is a rare complication in JDM, described in only a few studies. This long-term follow-up study aimed to (i) describe pulmonary involvement in a national cohort of JDM patients estimated by conventional spirometry, (ii) compare pulmonary impairment with overall JDM outcome, and (iii) identify possible associations between pulmonary impairment and myositis-specific autoantibodies (MSAs).
  
  
  METHODS
  Fifty-one JDM patients performed conventional spirometry in a cross-sectional follow-up study. The scores of the Myositis Damage Index (MDI), Myositis Damage by visual analogue scale (MYODAM-VAS) and physician's global damage assessment were used to estimate JDM outcome. ANAs, MSAs and myositis-associated autoantibodies were analysed in all patients.
  
  
  RESULTS
  Forty-two patients (82%) (mean follow-up time 14.3 years) had normal lung function. Four patients (8%) were diagnosed with JDM-related restrictive interstitial lung disease. No patients reported pulmonary symptoms. Patients with restrictive pulmonary function had increased long-term damage estimated by MDI (P = 0.008), MYODAM-VAS (P = 0.04), global assessment (P = 0.03) and number of organ systems involved (P = 0.009). We found significant correlation between the restrictive pulmonary function test and damage by the MDI (r = 0.43, P = 0.003), MYODAM-VAS (r = 0.44, P = 0.002), and global damage assessment (r = 0.43, P = 0.003). No association was found between the restrictive pulmonary function test and autoantibodies.
  
  
  CONCLUSIONS
  In a long-term follow-up study of JDM patients, the majority of patients demonstrated normal lung function. However, restrictive pulmonary impairment was identified in 8% of patients, indicating a need for repetitive pulmonary follow-up in JDM patients. Restrictive pulmonary involvement was associated with increased long-term JDM damage.
authors: Paediatric Department, Holbaek University Hospital, DK-4300 Holbaek, Denmark. permat@dadlnet.dk.
authors: Pernille R
authors: PR
authors: Mathiesen
authors: Frederik
authors: F
authors: Buchvald
authors: Kim G
authors: KG
authors: Nielsen
authors: Troels
authors: T
authors: Herlin
authors: Tina
authors: T
authors: Friis
authors: Susan
authors: S
authors: Nielsen
mesh_terms: D000293:Adolescent; D000328:Adult; D000974:Antibodies, Antinuclear / Q000276:immunology; D001323:Autoantibodies / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D003882:Dermatomyositis / Q000150:complications / Q000276:immunology* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000209:etiology / Q000276:immunology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D012261:Ribonucleoproteins / Q000276:immunology; D012720:Severity of Illness Index; D013147:Spirometry; D014797:Vital Capacity; D055815:Young Adult; D000099207:SS-A Antigen
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies; D012261:Ribonucleoproteins; D000099207:SS-A Antigen; C046750:Jo-1 antibody; C045760:Mi-2 antibodies
keywords: follow-up; juvenile dermatomyositis; myositis-associated autoantibodies; myositis-specific autoantibodies; pulmonary damage