title: Activated CD8+ T cells and natural killer T cells in bronchoalveolar lavage fluid in hypersensitivity pneumonitis and sarcoidosis.
abstract: BACKGROUND
  Sarcoidosis and hypersensitivity pneumonitis are diffuse parenchymal lung diseases characterized by formation of non-caseating granulomas with a bronchocentric distribution. Analysis of the white blood cell differential profile in bronchoalveolar lavage fluid can be a useful supplement in the diagnostic work-up.
  
  
  OBJECTIVE
  Diagnostic markers that can improve the discrimination of sarcoidosis and hypersensitivity pneumonitis are wanted.
  
  
  METHODS
  Bronchoalveolar lavage fluid fractions of CD4+ and CD8+ T cells expressing the activation marker HLA-DR and fractions of natural killer T cells determined by flow cytometry were investigated in sarcoidosis (N=83), hypersensitivity pneumonitis (N=10) and healthy control subjects (N=15).
  
  
  RESULTS
  In hypersensitivity pneumonitis, natural killer T cell fractions were over 7-fold greater [median (IQR): 5.5% (3.5-8.1) versus 0.7% (0.5-1.2), p<0.0001], and HLA-DR+ fractions of CD8+ lymphocytes were almost two fold greater [median (IQR): 79% (75-82) versus 43% (34-52), p<0.0001] than in sarcoidosis. In healthy control subjects, natural killer T cell fractions of leucocytes and HLA-DR+ fractions of CD8+ lymphocytes were lower [median (IQR): 0.3% (0.3-0.6) and 30% (26-34), p=0.02 and p=0.01 compared to sarcoidosis]. The combined use of these two markers seems to discriminate the diseases very well.
  
  
  CONCLUSIONS
  This study suggests a role for the bronchoalveolar lavage fluid lymphocyte subsets HLA-DR+ CD8+ T cells and natural killer T cells in the diagnostic work up of sarcoidosis and hypersensitivity pneumonitis.
authors.affiliation: Department of thoracic medicine St.Olavs University Hospital and Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology. anders.tondell@gmail.com.
authors.forename: A
authors.initials: A
authors.lastname: Tøndell
authors.forename: A D
authors.initials: AD
authors.lastname: Rø
authors.forename: M
authors.initials: M
authors.lastname: Børset
authors.forename: T
authors.initials: T
authors.lastname: Moen
authors.forename: M
authors.initials: M
authors.lastname: Sue-Chu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000542:Alveolitis, Extrinsic Allergic / Q000175:diagnosis / Q000276:immunology*; D015415:Biomarkers / Q000032:analysis; D001992:Bronchoalveolar Lavage Fluid / Q000276:immunology*; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D016022:Case-Control Studies; D005260:Female; D005434:Flow Cytometry; D006684:HLA-DR Antigens / Q000032:analysis; D006801:Humans; D018655:Lymphocyte Count; D008297:Male; D008875:Middle Aged; D055611:Natural Killer T-Cells / Q000276:immunology*; D011237:Predictive Value of Tests; D017565:Sarcoidosis, Pulmonary / Q000175:diagnosis / Q000276:immunology*; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006684:HLA-DR Antigens