THE IN-VIVO EFFECT OF ISOCYANATE-INDUCED ASTHMA ON BASOPHIL HISTAMINE-RELEASE

In vitro studies have suggested that basophils are involved in the ast hmatic response to isocyanate. Classified by the type of airway respon se, three groups of patients exposed to isocyanate were studied: 1) no nreactive (n=3), 2) immediate responders (n=4), and 3) late responders (n=4). Basophil histamine release to concanavalin A (conA), FMLP, and anti-IgE was evaluated before and during the airway response. Histami ne release significantly (P=0.009 for conA and 0.03 for anti-IgE) incr eased after exposure to isocyanate only in the group which had late br onchial response. Additionally, good correlation was found between bas eline FEV1/FVC% and degree of histamine release of basophils stimulate d with conA. These findings support a role for basophils in the late a sthmatic response to isocyanate.