BRONCHOALVEOLAR LAVAGE NEUTROPHILIA IN ASTHMATIC AND HEALTHY-VOLUNTEERS AFTER CONTROLLED EXPOSURE TO OZONE AND FILTERED PURIFIED AIR

Study objective: To characterize the pulmonary response of asthmatic a nd healthy nonsmoking adult men to 0.20 ppm ozone by controlled chambe r exposure. Design: A prospective, crossover study of five atopic asth matic and five normal subjects randomly exposed to ozone and filtered purified air (FPA) for 6 h, consisting of 30-min alternating periods o f rest and moderate exercise. The two exposures were separated by at l east 30 days. Setting: A controlled exposure in a stainless steel cham ber. Patients: Five atopic asthmatic and five normal subjects between 18 and 45 years of age. Treatment with medications was withheld from a sthmatics prior to the exposures. Ail subjects were nonsmokers. Interv entions: Symptoms were assessed throughout the exposures. Pulmonary fu nction was measured at baseline, hourly throughout an exposure, and af ter an exposure. Bronchoalveolar lavage (BAL) was performed 18 h after the completion of an exposure. The BAL fluid (BALF) was analyzed for cell count and differential; the cell-free supernatant was analyzed fo r albumin, tumor necrosis factor (TNF), interleukin 1 (IL-1), interleu kin 6 (IL-6), and interleukin 8 (IL-8). Results: There were statistica lly significant increases in IL-8 levels, as well as percent polymorph onuclear neutrophils (PMNs) and PMNs per milliliter of lavage in asthm atics exposed to ozone as compared with the same asthmatics exposed to FPA and the same normal subjects exposed to ozone and FPA, Interleuki n 6 was also significantly increased in asthmatics exposed to ozone. T he BALF albumin, TNF, and IL-1 levels were not significantly different among the four groups. There were no differences between asthmatics a nd healthy controls exposed to ozone or FPA in baseline to postexposur e FEV(1), FVC, FEV(1)/FVC, and sRaw. Conclusions: We conclude that ast hmatics exposed to ozone develop a significant BALF neutrophilia and i ncreased levels of the cytokines, IL-8 and IL-6. These BALF findings o ccur even though the level of ozone exposure was not significant enoug h to reduce pulmonary function.