There is increasing evidence for the role of basophils in allergic bronchial asthma. We studied the potential role of basophils in the pathogenesis of post-exercise-induced bronchoconstriction by measuring the histamine release from basophils both spontaneously and following ConA, FMLP, anti-IgE and TPA treatment. Two groups of patients with allergic asthma were studied: group I consisted of 8 patients with an exercise-induced fall in FEV1 of 20% or more, and group II had 7 patients with bronchial asthma who had less than a 5% fall in FEV1 following exercise. The mean spontaneous histamine release (SHR%) from basophils for group I was significantly larger than that of group II both before as well as at 5-10 and 60 min following exercise. The SHR% at baseline was 25 ± 10 in group I (mean ± SD) and 15 ± 5 in group II (mean ± SD). At 5-10 min following exercise it was 24 ± 6 in group I and 11 ± 2 in group II, while at 60 min following exercise it was 24 ± 6 in group I and 17 ± 2 in group II. There was no significant difference between the two groups in the effect of ConA, FMLP, anti-IgE or TPA treatment on basophil histamine release. The enhanced bronchoconstriction by exercise did not affect histamine release either spontaneously or following those 4 stimuli. It was concluded that, although patients with exercise-induced asthma have a greater degree of spontaneous histamine release, this is not affected by induced bronchoconstriction, a finding which does not support a role for basophils in exercise-induced asthma.
- Bronchial asthma