title: Association of current smoking with airway inflammation in chronic obstructive pulmonary disease and asymptomatic smokers.
abstract: BACKGROUND
  Inflammation in the airways and lung parenchyma underlies fixed airway obstruction in chronic obstructive pulmonary disease. The exact role of smoking as promoting factor of inflammation in chronic obstructive pulmonary disease is not clear, partly because studies often do not distinguish between current and ex-smokers.
  
  
  METHODS
  We investigated airway inflammation in sputum and bronchial biopsies of 34 smokers with chronic obstructive pulmonary disease (9 Global initiative for Chronic Obstructive Lung Disease stage 0, 9 stage I, 10 stage II and 6 stage III) and 26 asymptomatic smokers, and its relationship with past and present smoking habits and airway obstruction.
  
  
  RESULTS
  Neutrophil percentage, interleukin-8 and eosinophilic-cationic-protein levels in sputum were higher in chronic obstructive pulmonary disease (stage I-III) than asymptomatic smokers. Inflammatory cell numbers in bronchial biopsies were similar in both groups. Current smoking correlated positively with macrophages: in bronchial biopsies in both groups, and in sputum in chronic obstructive pulmonary disease. Pack-years smoking correlated positively with biopsy macrophages only in chronic obstructive pulmonary disease.
  
  
  CONCLUSIONS
  Inflammatory effects of current smoking may mask the underlying ongoing inflammatory process pertinent to chronic obstructive pulmonary disease. This may have implications for future studies, which should avoid including mixed populations of smokers and ex-smokers.
authors.affiliation: Department of Pathology, University Medical Centre Groningen, Groningen, The Netherlands. willemse@path.umcg.nl
authors.forename: Brigitte W M
authors.initials: BW
authors.lastname: Willemse
authors.forename: Nick H T
authors.initials: NH
authors.lastname: ten Hacken
authors.forename: Bea
authors.initials: B
authors.lastname: Rutgers
authors.forename: Dirkje S
authors.initials: DS
authors.lastname: Postma
authors.forename: Wim
authors.initials: W
authors.lastname: Timens
mesh_terms: D000368:Aged; D015897:Comorbidity; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D011014:Pneumonia / Q000453:epidemiology* / Q000473:pathology; D015995:Prevalence; D029424:Pulmonary Disease, Chronic Obstructive / Q000453:epidemiology* / Q000473:pathology; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012907:Smoking / Q000453:epidemiology*; D013223:Statistics as Topic