AIRWAYS OBSTRUCTION, CHRONIC EXPECTORATION, AND RAPID DECLINE OF FEV(1) IN SMOKERS ARE ASSOCIATED WITH INCREASED LEVELS OF SPUTUM NEUTROPHILS

Background - Smoking may cause inflammation of the airways and impairm ent of lung function. To determine the relationship between the type a nd degree of airways inflammation and the decline in lung function, le ucocytes in the sputum of smokers and ex-smokers were examined. Method s - Forty six smokers and exsmokers of median age 64 years (25%; 75% p ercentiles 62; 66) with a smoking history of 40.1 (31.7; 53) pack year s were studied with lung function tests and a questionnaire at the end of a 15 year follow up period. Sputum was induced by inhalation of hy pertonic saline and differential leucocyte counts were performed on cy tospin preparations. Results - Adequate sputum samples were obtained i n 38 subjects (78%). The ratio of forced expiratory volume in one seco nd (FEV(1)) to vital capacity (VC) was 67.1 (60; 72)% and the annual d ecline in FEV(1) was 19.4 (12; 30) ml/year. Subjects with airways obst ruction (FEV(1)/VC <63%) had more neutrophils (77 (50; 86)%) than thos e without airways obstruction (60 (43; 73)%). The percentage of neutro phils was also significantly greater (77 (62; 85)%) in those with chro nic expectoration than in those without expectoration (57 (45; 75)%. I ncreased levels of neutrophils in the sputum were correlated with a ra pid decline in FEV(1) over the 15 year follow up period. Conclusions - Airways obstruction and chronic expectoration, as well as accelerated decline in lung function, are associated with increased numbers of ne utrophils in the sputum of smokers and ex-smokers which suggests that neutrophilic inflammation of the airways may be involved in the pathog enesis of chronic obstructive pulmonary disease.