Double sensitization to honeybee and wasp venom: Immunotherapy with one orwith both venoms? Value of FEIA inhibition for the identification of the cross-reacting IgE antibodies in double-sensitized patients to honeybee and wasp venom

Background: Double sensitization to honeybee (Apis mellifera) and wasp veno m (Vespula spp.) as determined by skin test and measurement of specific IgE is common in hymenoptera sting allergy. Double-sensitized patients have ei ther distinct antibodies for each venom or crossreacting antibodies that re cognize similar or identical epitopes in both venoms. Unfortunately, patien ts often fail to identify the stinging insect which makes it difficult to d istinguish cross-reactors from non cross-reactors. However, for economic re asons as well as for the benefit of the patients, it would be useful to ide ntify complete cross-reactors. Methods: In this study we investigated 24 do uble-sensitized patients who were candidates for venom immunotherapy. Homol ogous and heterologous FEIA inhibition was carried out with honeybee (Apis mellifera) and wasp venom (Vespula spp.) preparations from two different pr oviders. The inhibitor concentrations were ranging from 0 to 100 mug protei n/ml. Results: Sera of 4 patients were completely cross-reacting for one ve nom (3 honeybee, 1 wasp), 8 patients were partially cross-reacting and 10 p atients were not cross-reacting. Two patients were excluded from the study due to insufficient homologous inhibition. Data from specific IgE measureme nts, skin test, and clinical history were not useful for the identification of cross-reacting patients. Conclusion: FEIA inhibition is easy to perform and useful for the identification of patients with complete crossreactivit y. In these patients immunotherapy might be restricted to one venom which i s beneficial for the patient and cost-effective. Copyright (C) 2000 S. Karg er AG, Basel.