title: Lung-dominant connective tissue disease among patients with interstitial lung disease: prevalence, functional stability, and common extrathoracic features.
abstract: OBJECTIVE
  To describe the characteristics of a cohort of patients with lung-dominant connective tissue disease (LD-CTD).
  
  
  METHODS
  This was a retrospective study of patients with interstitial lung disease (ILD), positive antinuclear antibody (ANA) results (≥ 1/320), with or without specific autoantibodies, and at least one clinical feature suggestive of connective tissue disease (CTD).
  
  
  RESULTS
  Of the 1,998 patients screened, 52 initially met the criteria for a diagnosis of LD-CTD: 37% were male; the mean age at diagnosis was 56 years; and the median follow-up period was 48 months. During follow-up, 8 patients met the criteria for a definitive diagnosis of a CTD. The remaining 44 patients comprised the LD-CTD group, in which the most prevalent extrathoracic features were arthralgia, gastroesophageal reflux disease, and Raynaud's phenomenon. The most prevalent autoantibodies in this group were ANA (89%) and anti-SSA (anti-Ro, 27%). The mean baseline and final FVC was 69.5% and 74.0% of the predicted values, respectively (p > 0.05). Nonspecific interstitial pneumonia and usual interstitial pneumonia patterns were found in 45% and 9% of HRCT scans, respectively; 36% of the scans were unclassifiable. A similar prevalence was noted in histological samples. Diffuse esophageal dilatation was identified in 52% of HRCT scans. Nailfold capillaroscopy was performed in 22 patients; 17 showed a scleroderma pattern.
  
  
  CONCLUSIONS
  In our LD-CTD group, there was predominance of females and the patients showed mild spirometric abnormalities at diagnosis, with differing underlying ILD patterns that were mostly unclassifiable on HRCT and by histology. We found functional stability on follow-up. Esophageal dilatation on HRCT and scleroderma pattern on nailfold capillaroscopy were frequent findings and might come to serve as diagnostic criteria.
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Daniel Antunes Silva
authors.initials: DA
authors.lastname: Pereira
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Olívia Meira
authors.initials: OM
authors.lastname: Dias
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Guilherme Eler de
authors.initials: GE
authors.lastname: Almeida
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Mariana Sponholz
authors.initials: MS
authors.lastname: Araujo
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Letícia Barbosa
authors.initials: LB
authors.lastname: Kawano-Dourado
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Bruno Guedes
authors.initials: BG
authors.lastname: Baldi
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Ronaldo Adib
authors.initials: RA
authors.lastname: Kairalla
authors.affiliation: University of São Paulo, School of Medicine, Hospital das Clínicas, São Paulo, Brazil, Department of Cardiorespiratory Diseases, University of São Paulo School of Medicine, São Paulo, Brazil; and Director. Department of Pulmonology, Instituto do Coração - InCor, Heart Institute - University of São Paulo School of Medicine Hospital das Clínicas, São Paulo, Brazil.
authors.forename: Carlos Roberto Ribeiro
authors.initials: CR
authors.lastname: Carvalho
mesh_terms: D000974:Antibodies, Antinuclear / Q000032:analysis; D001323:Autoantibodies / Q000032:analysis*; D001938:Brazil / Q000453:epidemiology; D003240:Connective Tissue Diseases / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D005260:Female; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D013147:Spirometry; D014057:Tomography, X-Ray Computed
chemical_list: D000974:Antibodies, Antinuclear; D001323:Autoantibodies
keywords: Autoantibodies; Autoimmunity; Connective tissue diseases; Idiopathic interstitial pneumonias