Assessment of airway inflammation using sputum, BAL, and endobronchial biopsies in current and ex-smokers with established COPD
Wen, Y and Reid, DW and Zhang, D and Ward, C and Wood-Baker, R and Walters, EH, Assessment of airway inflammation using sputum, BAL, and endobronchial biopsies in current and ex-smokers with established COPD, International Journal of Chronic Obstructive Pulmonary Disease, 5 pp. 327-334. ISSN 1178-2005 (2010) [Refereed Article]
Rationale: Smoking effects on physiological and gross pathology in chronic obstructive
disease (COPD) are relatively well described. However, there is little known in
COPD about the detailed interrelationships between lung function and inflammatory profiles
in different airway compartments from the same individual and whether airway inflammation
in these different compartments differs in ex- and current smokers with established COPD.
Objectives: We compared sputum, bronchoalveolar (BAL), and airway wall inflammatory
profiles in current versus ex-smokers and related this to smoking intensity and lung function in
17 current and 17 ex-smokers with mild to moderate COPD.
Results: Current smokers had more sputum mast cells (% differential and absolute numbers),
whereas ex-smokers had increased sputum neutrophils. In BAL, there was a significant increase
in eosinophils in current smokers, but ex-smokers had significantly increased neutrophils,
lymphocytes, and epithelial cells. There were no cell profile differences observed in airway
biopsies between current and ex-smokers and there were no correlations between the individual
inflammatory cell populations in any of the airway compartments. In current smokers only,
smoking intensity was negatively correlated with lung function, and associated with a reduction
in overall cellularity of both sputum and BAL.
Conclusion: Airway inflammation persists in ex-smokers with COPD, but differs from COPD
current smokers. The impact of smoking appears to vary in different airway compartments and
any direct relationships between cellularity and lung function tended to be negative, ie, worse
lung function indicated the presence of fewer cells.
current smokers, ex-smokers, airway cellularity, sputum, BAL, endobronchial biopsies