In vitro impact of anti-immunoglobulin E monoclonal antibodies, including omalizumab on whole blood basophil histamine release: Assessment of direct induction of basophil histamine release and evaluation of modulation of allergen-induced basophil histamine release.

Abstract

The aim of this study was to evaluate the potential of anti-immunoglobulin E (IgE) and/or anti-IgE-IgE immune complexes to release histamine from peripheral blood basophils. In addition, a potential modulating effect of anti-IgE-IgE complexes on allergen-induced peripheral blood basophil histamine release was evaluated. Whole blood basophil histamine release (WBB-HR) tests done by using glass-fiber-based microtiter plates were performed in 62 patients with allergic rhinitis and/or asthma sensitized to perennial allergens. Evaluation of the direct effects of monoclonal anti-IgEs, including E25, E27, and QGE031, on WBB-HR, and the indirect effects of anti-IgE-serum IgE complexes on spontaneous and allergen-induced WBB-HR were conducted. The tests were performed with and without pretreatment of the basophils with interleukin 3, and the results were expressed as the fraction of total histamine content released. There was no difference between WBB-HR induced by any of the studied anti-IgE antibodies and that induced by isotype antibodies for all blood samples assessed, which, for each patient, was significantly less than that induced by positive anti-IgE control antibodies. Similarly, no effect of any of the studied anti-IgE-IgE complexes on spontaneous or allergen-induced WBB-HR could be demonstrated. There was no evidence that humanized, monoclonal anti-IgE antibodies E25 (omalizumab), E27, or QGE031 directly or indirectly induced histamine release from peripheral blood basophils.