Phagocytic activity of alveolar macrophages in patients with bronchogenic carcinoma.

Human bronchoalveolar cells were obtained by lavage during diagnostic fiberoptic bronchoscopy of 21 patients suspected of having lung malignancies. Of these patients 11 were diagnosed as having primary lung cancer (Group I) and included individuals with squamous cell carcinoma, adenocarcinoma, undifferentiated large and oat cell carcinoma at varying locations and TNM stages, 4 patients demonstrated nonprimary metastatic carcinoma (Group II), and 6 patients did not reveal detectable tumors by bronchoscopy or follow-up (Group III) and were included as study controls. We examined the ability of pulmonary alveolar macrophages (PAMs) lavaged from patients in each of the three study groups to phagocytose opsonized sheep red blood cells. Phagocytic activity varied among patients in the same and different study groups; however, no significant differences were observed in the phagocytic or tumoristatic activities of PAMs recovered from tumor-bearing and nontumor-bearing lung regions of the same patient. Moreover, lavage fluids collected from tumor-bearing regions did not suppress the phagocytic activity of PAMs collected from control lungs nor lung regions contralateral to the tumor-bearing lung. The data do not support the view that bronchial neoplasms or their secreted products suppress phagocytic functions of alveolar macrophages.