title: Exhaled breath condensate 8-isoprostane, clinical parameters, radiological indices and airway inflammation in COPD.
abstract: BACKGROUND
  Exhaled breath condensate (EBC) 8-isoprostane levels were found increased in chronic obstructive pulmonary disease. However, the relation between EBC 8-isoprostane and parameters which have a known predictive value in COPD, remains vastly unknown, and so does subsequently its clinical value.
  
  
  OBJECTIVE
  To investigate the relationship between 8-isoprostane level in EBC and clinical parameters, radiological indices and airway inflammation in COPD patients.
  
  
  METHODS
  We studied 18 COPD patients (all ex-smokers) and 12 healthy controls (5 ex-smokers and 7 never-smokers). All patients underwent clinical evaluation, sputum induction, high-resolution computed tomography (HRCT) of the thorax and EBC 8-isoprostane measurement. 8-Isoprostane levels were correlated with markers that reflect disease severity, such as dyspnea severity, FEV(1) (%pred), emphysema changes and bronchiectasis in HRCT. Emphysema was quantified as the percentage of lung area with attenuation values < -950 Hounsfield units.
  
  
  RESULTS
  8-Isoprostane levels were significantly elevated in EBC of patients with COPD [mean (SE) 18.1 (2) vs. 5.6 (0.7) pg/ml, p = 0.0001], irrespective of lung function impairment. 8-Isoprostane levels were correlated with emphysema score in HRCT (r(2) = 0.43, p = 0.001) as well as with Medical Research Council dyspnea scale score (rho = 0.61, p = 0.005).
  
  
  CONCLUSIONS
  Our findings suggest that EBC 8-isoprostane levels may reflect the extension of lung emphysema in COPD patients. In this respect, further investigation is required in order to evaluate the possible role of EBC 8-isoprostane in assessing disease progress in COPD patients.
authors.affiliation: Department of Thoracic Medicine, Medical School, University of Crete, Heraklion, Greece. appollon7@hotmail.com
authors.forename: Demosthenes
authors.initials: D
authors.lastname: Makris
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Paraskakis
authors.forename: Panos
authors.initials: P
authors.lastname: Korakas
authors.forename: Emmanouil
authors.initials: E
authors.lastname: Karagiannakis
authors.forename: Giorgos
authors.initials: G
authors.lastname: Sourvinos
authors.forename: Nikolaos M
authors.initials: NM
authors.lastname: Siafakas
authors.forename: Nikos
authors.initials: N
authors.lastname: Tzanakis
mesh_terms: D000368:Aged; D001944:Breath Tests; D029481:Bronchitis, Chronic / Q000000981:diagnostic imaging / Q000378:metabolism*; D016022:Case-Control Studies; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000378:metabolism; D004417:Dyspnea / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011656:Pulmonary Emphysema / Q000000981:diagnostic imaging / Q000378:metabolism*; D011859:Radiography; D012720:Severity of Illness Index; D013183:Sputum / Q000166:cytology
chemical_list: C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost