title: High levels of interleukin-6 in the exhaled breath condensate of patients with COPD.
abstract: BACKGROUND
  Chronic obstructive pulmonary disease (COPD) is characterised by chronic inflammation of the respiratory tract.
  
  
  METHODS
  We investigated the presence of interleukin-6 (IL-6: a cytokine secreted by monocytes/macrophages, T cells, B cells, fibroblasts, bone marrow stromal cells, keratinocytes and endothelial cells) in the exhaled breath condensate of 16 exsmokers with moderate COPD, 12 healthy non-smokers. IL-6 was measured by means of a specific enzyme immunoassay.
  
  
  RESULTS
  IL-6 levels were detectable in all of the subjects, but were higher in the COPD patients (8.0 +/- 0.1 pg/ml; P < 0.0001) than in the healthy non-smokers (4.9 +/- 0.2 pg/ml) with a correlation in this group between age and IL-6 levels (r = 0.597; P < 0.05).
  
  
  CONCLUSIONS
  The increased IL-6 levels in exhaled breath condensate may reflect airway inflammation in patients with COPD.
authors.affiliation: Institute of Respiratory Diseases, University of Milan, Ospedale Maggiore IRCCS, Via F. Sforza, 35, Milano 20125, Italy. e.bucchioni@ic.ac.uk
authors.forename: Enrica
authors.initials: E
authors.lastname: Bucchioni
authors.forename: Sergei A
authors.initials: SA
authors.lastname: Kharitonov
authors.forename: Luigi
authors.initials: L
authors.lastname: Allegra
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Barnes
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods; D005260:Female; D006801:Humans; D007124:Immunoenzyme Techniques / Q000379:methods / Q000592:standards; D015850:Interleukin-6 / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000378:metabolism*; D015203:Reproducibility of Results; D012907:Smoking / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015850:Interleukin-6