Proinflammatory or regulatory cytokines released from BALF macrophages of healthy smokers

Background: Chronic smoking influences bronchoalveolar ravage fluid (BALF) cell profiles in healthy subjects, which may alter profiles of inflammatory and regulatory cytokines. Objective: We focused on the evaluation of smoki ng-related changes in the amounts of cytokines released from BALF macrophag es. Methods: We measured the amounts of immunoreactive culture supernatants by using ELISA. Results:The amounts of IL-1 receptor antagonist (IL-1ra) w ere lower in smokers [n = 10, median 22.1 ng/ml, 25th and 75th percentiles (18.7-39.1)] than in nonsmokers [n = 10, 48.6 (39.2-66.1), p = 0.010]. In s mokers, lipopolysaccharide stimulation revealed decreases in the amounts of interleukin-6 (IL-6) [nonsmokers: 2.1 ng/ml (0.68-5.4 vs. smokers: 0.5 (0. 03-0.87), p = 0.049] as well as IL-1ra [nonsmokers: 69.2 ng/ml (48.3-83.8) vs, smokers: 27.3 (17.2-56.7), p = 0.028]. A delay in release from intracel lular storage was not the cause of the reduced amounts of IL-l ra. In addit ion, interleukin-lp (IL-1 beta) was positively correlated with IL-6 and gra nulocyte macrophage colony-stimulating factor in nonsmokers, but not in smo kers. Furthermore, the decreases in IL-1ra and interleukin-8 were correlate d with the increase in the number of BALF macrophages in smokers, but not i n nonsmokers. Conclusions: Chronic smoking caused changes in the profiles o f cytokines released from BALF macrophages in healthy subjects. Decreases i n the amounts of regulatory cytokines, but not prominent changes in the amo unts of inflammatory ones, were characteristic.