title: Chest abnormalities in juvenile-onset mixed connective tissue disease: assessment with high-resolution computed tomography and pulmonary function tests.
abstract: BACKGROUND
  Mixed connective tissue disease (MCTD) is associated with several chest manifestations. Only a few studies have focused on chest manifestations in juvenile-onset MCTD (jMCTD), and the true prevalence of pulmonary abnormalities on high-resolution computed tomography (HRCT) in these patients is unknown.
  
  
  OBJECTIVE
  To investigate the occurrence of pulmonary abnormalities in jMCTD with particular reference to interstitial lung disease (ILD), and to evaluate a possible association between pulmonary findings and disease-related variables.
  
  
  METHODS
  Twenty-four childhood-onset MCTD patients with median disease duration of 10.5 years (range 1-21 years) were investigated in a cross-sectional study by means of HRCT, pulmonary function tests (PFT), and clinical assessment.
  
  
  RESULTS
  Discrete ILD was identified in six patients (25%). Median extent of ILD was 2.0%, and all except one of the patients had very mild disease in which 5% or less of the parenchyma was affected. The CT features of fibrosis were mainly microcystic and fine intralobular. The most frequently abnormal PFT was carbon monoxide uptake from the lung, which was abnormal in 33% of the patients. PFT and disease duration were not significantly associated with HRCT findings of ILD.
  
  
  CONCLUSIONS
  The prevalence of ILD in childhood-onset MCTD patients was lower than previously believed. In most of the patients with ILD, the findings were subtle and without clinical correlation. The results suggest a low extent of ILD in childhood-onset MCTD, even after long-term disease duration.
authors.affiliation: Department of Radiology, Rikshospitalet University Hospital, Oslo, Norway. trond.mogens.aalokken@rikshospitalet.no
authors.forename: T M
authors.initials: TM
authors.lastname: Aaløkken
authors.forename: V
authors.initials: V
authors.lastname: Lilleby
authors.forename: V
authors.initials: V
authors.lastname: Søyseth
authors.forename: G
authors.initials: G
authors.lastname: Mynarek
authors.forename: A H
authors.initials: AH
authors.lastname: Pripp
authors.forename: B
authors.initials: B
authors.lastname: Johansen
authors.forename: O
authors.initials: O
authors.lastname: Førre
authors.forename: A
authors.initials: A
authors.lastname: Kolbenstvedt
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging; D017563:Lung Diseases, Interstitial / Q000150:complications / Q000175:diagnosis* / Q000000981:diagnostic imaging; D008297:Male; D008947:Mixed Connective Tissue Disease / Q000150:complications* / Q000000981:diagnostic imaging; D012129:Respiratory Function Tests; D014057:Tomography, X-Ray Computed; D014797:Vital Capacity; D055815:Young Adult