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The cellular content of bronchial lavage was studied in 14 patients with sarcoidosis and 20 normal volunteers. There was no alteration in the total number of cells recovered, except for the expected increase in cellularity in smokers. Nonsmoking patients with sarcoidosis had 19.6 per cent lymphocytes, compared to 8.1 per cent lymphocytes in nonsmoking control subjects. The percentage of alveolar macrophages showing spontaneous adherence of one or more bronchial lymphocytes were, respectively, 10.8 and 8.4 in nonsmoking and smoking patients with sarcoidosis, compared to 1.8 and 2.1, respectively, in nonsmoking and smoking control subjects.

Experiments were performed to evaluate the in vitro effects of Escherichia coli lipopolysaccharide on viability and function of human alveolar macrophages. Alveolar macrophages were obtained by fiberoptic bronchoscopy and saline bronchial lavage from 12 normal, nonsmoking volunteers. Cells were incubated with different concentrations of E. coli endotoxin for 1 and 24 h. Endotoxin (10 microgram/ml and more) was cytotoxic for alveolar macrophages after 24 h of incubation and induced significant inhibition of phagocytosis, adherence, and spreading. The effects of endotoxin on alveolar macrophage viability and function were dose and time dependent and were not influenced by indomethacin. Thus, human alveolar macrophages, like other mononuclear phagocytes, are extremely sensitive to endotoxin effects; these observations may be relevant in conditions in which endotoxin may be in contact with alveolar macrophages in vivo: endobronchial infections with gram-negative organisms, byssinosis, chronic bronchitis of grain handles, and humidifier fever.

Alveolar macrophages were obtained from human volunteers, smokers and nonsmokers, by bronchial lavage through a fiberoptic bronchoscope. Cells were incubated in a chemically defined medium containing [(14)C]sucrose (0.36 mM) and varying concentrations of rabbit serum. Pinocytosis was assessed by the cellular uptake of isotope over 30, 75, and 120-min periods. Pinocytic activity of smokers' cells was dependent on serum concentration but always less than the activity of nonsmokers' cells. The degree of pinocytosis by nonsmokers' cells was independent of serum concentration. It is concluded that the decreased level of pinocytic activity in smokers' alveolar macrophages as indicated by the uptake of sucrose in the presence of rabbit serum may represent a form of reticuloendothelial blockade.