Immunomodulation by bronchial lavage cells in normal individuals and patients with bronchogenic carcinoma

The ability of bronchoalveolar lavage cells to facilitate lymphoproliferation to mitogen in a system which allows assessment of pulmonary alveolar macrophage accessory cell function was investigated. Bronchoalveolar lavage cells were obtained from healthy non-smokers and smokers and from patients undergoing diagnostic bronchoscopy. Lavaged cells were cultured with monocyte-depleted homologous blood lymphocytes obtained from healthy, young volunteers and stimulated with suboptimal (2 micrograms/ml) or optimal (20 micrograms/ml) concentrations of phytohemagglutinin. Mitogen responses of lymphocytes in all groups were related to the number of lavage cells added, increasing with 1:100 and 1:10 bronchoalveolar lavage cell to lymphocyte ratios and decreasing with 1:2 and 1:1 ratios. Lymphoproliferative responses observed in smoker and nonsmoker cultures were not different. In contrast, maximal proliferative responses of cell cultures from patients with epidermoid and small cell carcinoma were decreased compared with cultures from patients with adenocarcinoma or controls. These data show that pulmonary bronchial lavage cells from smokers and nonsmokers provide similar dose related augmentation and suppression of lymphocyte mitogenic responses. Furthermore, accessory cell function of lavage cell populations is normal in patients with adenocarcinoma, but depressed in patients with epidermoid or small cell carcinoma.