Production of interleukin-10 by alveolar macrophages from lung cancer patients

Interleukin (IL)-10 is known to be an autoregulatory factor of functions of monocyte macrophages. The purpose of this study was to determine whether I L-10 production by alveolar macrophages (AMs) is altered in patients with l ung cancer. AMs were obtained by bronchoalveolar lavage from 25 patients wi th lung cancer and 14 control patients. The production of IL-10 by AMs was quantitated by enzyme immunoassay with or without stimulation with lipopoly saccharide (LPS). No significant difference in spontaneous and LPS-stimulat ed IL-IO production by AMs was observed between lung cancer patients and co ntrol patients (mean +/- SEM; 288.0 +/- 56.7 vs. 249.6 +/- 58.4 pg ml(-1)). IL-10 production of LPS-stimulated AMs was not impaired even in lung cance r patients with systemic metastasis. IL-4 failed to suppress LPS-induced pr oduction of IL-10 by AMs both in control patients and in lung cancer patien ts. In eight patients with lung cancer, IL-10 production by AMs was estimat ed before and after systemic chemotherapy and IL-10 production by LPS-stimu lated AMs tended to increase after systemic chemotherapy from 152.3 +/- 51. 9 to 278.0 +/- 112.8 pg ml(-1). As IL-10 is a potent inhibitor of tumour an giogenesis, an important process of tumour progression, these results sugge st that, even in advanced cancer patients, macrophages can produce potent a ngiogenesis inhibitor and systemic chemotherapy may augment this inhibitory activity in the lung. (C) 1999 HARCOURT PUBLISHERS LTD.