Association between nonspecific bronchial hyperreactivity and superoxide anion production by polymorphonuclear leukocytes in chronic airflow 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 airflow obstruction (CAO). No difference in O2- generation 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). The results suggest that oxygen radicals in a direct or indirect way may modulate BHR. Thus, in nonallergic patients with CAO, BHR and inflammation may be linked in a similar way as in allergic patients with asthma.