Bronchial and basophil reaction to polymyxin B in asthmatic patients.

The hypothesis that increased reactivity to polymyxin B in asthmatic patients is not limited to the bronchi but also exists in basophils was investigated in 26 atopic asthmatic subjects. Quantification of basophil degranulation induced by polymyxin B was performed using a flow-cytometric method. Significant degranulation was noted in 17 patients, but in none of 10 healthy controls. There was close relationship between basophil "releasability" to polymyxin B and bronchial reactivity to inhaled polymyxin B. These findings support the hypothesis.