Surface morphology and function of human pulmonary alveolar macrophages from smokers and non-smokers

Pulmonary alveolar macrophages were obtained by saline lavage from 23 healthy male volunteers--10 non-smokers and 13 cigarette smokers. Lavage produced three times as many alveolar macrophages in smokers than in non-smokers. When macrophages from smokers and from non-smokers were incubated in vitro, more cells from smokers adhered to glass, spread out, and showed enhanced nitroblue tetrazolium (NBT) reduction. The surface morphology of alveolar macrophages from smokers showed more with a plate like appearance and ridge like membrane surface, while the macrophages from non-smokers were predominantly spherical with ruffles. The proportions of cells which stained highly for beta galactosidase were 55% in smokers and 11% in non-smokers. Thus, in a resting state in vitro, alveolar macrophages from smokers were more active than those from non-smokers. When, however, macrophages from smokers and non-smokers were incubated with immunobeads and with opsonised or non-opsonised BCG, the phagocytic activity and stimulated NBT reduction of alveolar macrophages from smokers were similar to or somewhat less than those of non-smokers.