Elastase release from human alveolar macrophages: comparison between smokers and nonsmokers.

Alveolar macrophages from smokers, in contrast to those of non-smokers, release elastase into serum-free culture medium. Since enzymes that digest elastin produce pulmonary emphysema in experimental animals, release of elastase by alveolar macrophages from smokers suggests that these cells are important in the pathogenesis of emphysema of smokers.