Basophil activation test (BAT) in double-sensitized patients with Hymenoptera venom allergy: additional benefit of component-resolved diagnostics.

Abstract

In Hymenoptera venom allergy serologically double-sensitized patients it is often difficult to identify the culprit insect for venom immunotherapy (VIT). To evaluate if basophil activation tests (BATs) performed not only with venom extracts but additionally with single component-resolved diagnostics could differentiate between sensitized and allergic individuals and how the test results influenced the physicians' decision regarding VIT. BATs were performed with bee and wasp venom extracts and with single components (Api m 1, Api m 10, Ves v 1, Ves v 5) in 31 serologically double-sensitized patients. In 28 finally included individuals 9 BATs were positive and 4 negative for both venoms. 14/28 BATs showed positive results for wasp venom alone. 2/10 BATs positive for bee venom were only positive to Api m 1 and 1/28 BAT only to Api m 10, but not for whole bee venom extract. 5/23 BATs positive for wasp venom were only positive for Ves v 5, but negative for wasp venom extract and Ves v 1. Finally, VIT with both insect venoms was recommended in 4/28 individuals, with wasp venom alone in 21/28 patients and with bee venom alone in 1/28. In 2 cases no VIT was recommended. BATs with Ves v 5, followed by Api m 1 and Api m 10, were helpful for the decision for VIT with the clinically relevant insect in 8/28 (28.6%) patients. A BAT with components should therefore be additionally carried out in cases with equivocal results.