Diagnosis of stinging insect allergy : utility of cellular in-vitro tests

PURPOSE OF REVIEW: Diagnosis of stinging insect allergy is based on a detailed history, venom skin tests, and detection of venom-specific IgE. As an additional diagnostic tool, basophil responsiveness to venom allergens has been shown to be helpful in selected patients. This review summarizes the current diagnostic procedures for stinging insect allergy and discusses the latest developments in cellular in-vitro tests. RECENT FINDINGS: Cellular assays have been evaluated in patients with Hymenoptera venom allergy. The diagnostic performance of the cellular mediator release test is similar to that of the flow cytometric basophil activation test (BAT), but the BAT has been the most intensively studied. BAT offers the possibility to assess basophil reactivity to allergens in their natural environment and to simultaneously analyze surface marker expression and intracellular signaling. It has been demonstrated that BAT represents a valuable additional diagnostic tool in selected patients when used in combination with other well established tests. A major limitation is the current lack of unified, standardized protocols. Flow cytometry offers huge possibilities to enhance knowledge of basophil functions. SUMMARY: The BAT may be used as an additional test to confirm the diagnosis of stinging insect allergy in selected patients, provided that it is performed by an experienced laboratory using a validated assay. Test results have to be interpreted by clinicians familiar with the methodological aspects. The utility of the BAT to confirm allergy diagnosis and to predict the risk of subsequent systemic reactions may be improved by combined analysis of multiple surface markers and intracellular signaling pathways.