Effect of a serum factor on IgE-mediated histamine release from whole blood.

IgE-mediated histamine release from whole blood was analyzed in 44 patients with bronchial asthma by observing maximum present release and dose-response curves of histamine release induced by anti-IgE and house dust extract. The maximum histamine release from whole blood induced by anti-IgE correlated with total serum IgE levels. There was a close correlation between allergen-induced release from whole blood and the serum levels of specific IgE antibodies. In the maximum histamine release from whole blood induced by both anti-IgE and allergen, the interaction with a serum factor was not clearly recognized. Effect of a serum factor was shown in the dose-response curves of anti-IgE-induced histamine release, but not in those of allergen-induced histamine release. The dose-response curves caused by anti-IgE showed that basophils from cases with a high serum IgE level require much more anti-IgE to produce maximum histamine release than basophils from cases with a low serum IgE level. The results showed that IgE molecules contained in the serum participate in anti-IgE-induced histamine release from whole blood.