Association between nonspecific bronchial hyperreactivity and superoxide anion production by polymorphonuclear leukocytes in chronic air-flow obstruction.

Inflammatory reactions are believed to be important in nonspecific bronchial hyperreactivity (BHR). To investigate the potential role for oxidant-mediated modulation of BHR, we investigated oxidative metabolism of polymorphonuclear leukocytes (PMN) from the peripheral blood in 28 nonallergic patients with chronic air-flow obstruction (CAO). No difference in O2- was found between 14 smokers and 14 ex-smokers with CAO. A significant correlation was found between the degree of BHR and O2(-)-generation of PMN after stimulation with 20 ng/ml phorbol myristate acetate, both in smokers (r = 0.59, p less than 0.01) and in ex-smokers (r = 0.79, p less than 0.01). In the light of other findings in experimental animal studies, the results suggest a direct or indirect role for O2- in the modulation of BHR. Thus, in nonallergic patients with CAO, BHR and inflammation may be linked in a similar way as in allergic patients with asthma.