Comparison of in vitro neutrophil elastase release in nonsmokers and smokers

Protease-antiprotease imbalance in the lung is considered a likely pathogenetic mechanism in the development of emphysema. To assess whether differences in enzyme release from stimulated neutrophils could be a factor leading to increased elastase release in the lung, we compared the in vitro release of elastase and a lysosomal enzyme, β-glucosaminidase, from neutrophils of nonsmokers and smokers. Neutrophils were stimulated in vitro by zymosan as a phagocytic stimulus, and the synthetic polypeptide, N-formyl-methionyl-leucyl-phenyl-alanine (FMLP) as chemotactic factor. We studied 54 male subjects, 24 nonsmokers (mean age, 39.5 ± SD 14.4 yr) and 30 smokers (mean age, 45.4 ± SD 8.2 yr). Smokers were divided into 2 groups according to results of their lung function, 17 with normal and 13 with abnormal lung function. Smokers with abnormal lung function were older (59.8 ± SD 11.8 yr) and had smoked more (45.6 ± SD 18.2 pack-years) than smokers with normal lung function (mean age, 39.8 ± SD 11.0 yr; smoking, 22...