THE EFFECT OF EXERCISE ON BASOPHIL HISTAMINE-RELEASE IN PATIENTS WITHBRONCHIAL-ASTHMA

There is increasing evidence for the role of basophils in allergic bro nchial asthma. We studied the potential role of basophils in the patho genesis 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 allerg ic asthma were studied: group I consisted of 8 patients with an exerci se-induced fall in FEV(1) of 20% or more, and group II had 7 patients with bronchial asthma who had less than a 5% fall in FEV(1) following exercise. The mean spontaneous histamine release (SHR%) from basophils for group I was significantly larger than that of group II both befor e as well as at 5-10 and 60 min following exercise. The SHR% at baseli ne was 25 +/- 10 in group I (mean +/- SD) and 15 +/- 5 in group II (me an +/- 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 d ifference between the two groups in the effect of ConA, FMLP, anti-IgE or TPA treatment on basophil histamine release. The enhanced bronchoc onstriction by exercise did not affect histamine release either sponta neously or following those 4 stimuli. It was concluded that, although patients with exercise-induced asthma have a greater degree of spontan eous histamine release, this is not affected by induced bronchoconstri ction, a finding which does not support a role for basophils in exerci se-induced asthma.