The correlation between increased reactivity of the bronchi and of mediator releasing cells in asthma.

The hypothesis that increased reactivity in asthma is not always limited to the bronchi but also exists in the mediator releasing system was investigated in forty-five asthmatic children, approximately half of whom had exercise-induced bronchoconstriction (EIB). The bronchial threshold to histamine was measured as an indicator of the reactivity of the bronchi and the histamine release from leucocytes without adding allergen (spontaneous histamine release) was considered as an indicator of the reactivity of the basophil leucocytes. There was a significant correlation between the histamine threshold and spontaneous histamine release and between these and EIB. These findings support the hypothesis.