Desensitization of Human Mast Cells: Mechanisms and Potential Utility for Preventing Anaphylaxis

This is an open-label, single-center study of whether oral penicillin desensitization of
healthy sensitive subjects results in allergen cross-desensitization of mast cells by skin
testing and desensitization of peripheral blood basophils. The primary endpoint(s) will be
PC3 prick skin test values to penicillin, aeroallergen(s) and codeine. Secondary endpoints
will be levels of Syk in purified basophils determined by flow cytometry (mean fluorescence
intensity) and basophil degranulation (% tryptase release) to anti-FcåRI and to calcium
ionophore.