Increased Spontaneous Production and Generation of Superoxide Anion by Blood Neutrophils in Patients with Asthma

Abstract

Spontaneous production and PMA- and opsonized zymosan- stimulated generation of superoxide anion by blood cells in asthmatic patients were compared with those in normal volunteers and chronic obstructive pulmonary disease (COPD) patients using a lucigenin-dependent chemiluminescence method. Superoxide anion generation by 100 μl of blood in patients with asthma and/or COPD was significantly greater than that in normal subjects [asthma: 5684 ± 253 chemiluminescence (CI); COPD: 4994 ± 240 CL; normal: 2543 ±213 CL]. This is consistent with the increased superoxide generation per leukocyte (PMN) in these patients (Asthma: 1.56 ± 0.08 CL/PMN; COPD: 1.31 ± 0.08 CL/PMN; normal: 0.83 ± 0.07 CL/PMN. However, spontaneous production of superoxide by individual PMNs was increased only in asthmatic patients, compared with that in normal subjects (Asthma: 0.14 ± 0.02 CL/PMN; COPD: 0.07 ± 0.01 CL/PMN; normal: 0.07 ± 0.01 CL/PMN. These results indicate that the respiratory burst is enhanced in both asthmatic patients and COPD patients, and that superoxide production by resting neutrophils is also increased in asthmatic patients, but not in COPD patients, compared with normal subjects.