Can AlaBLOT Predict Efficacy of Bee and Wasp Venom Immunotherapy?

An abstract by Dr. Markus Ollert, et al. (Department of Dermatology and Allergy, Biederstein, Technical University of Munich, Germany) presented at the annual meeting of the American Academy of Allergy, Asthma and Immunology, held in March in San Diego, reported that AlaBLOT* testing accurately predicted whether a bee- or wasp-allergic individual would react to a sting challenge.

In the study, AlaBLOT testing was performed on reactive individuals before and during immunotherapy for wasp and/or bee venom. (DPC’s AlaBLOT tests detect human immunoglobulin binding to allergen immunoblots.) Initially, sera from 29 individuals receiving venom immunotherapy were tested for IgE, IgG and IgG4 to bee and wasp venom. AlaBLOT patterns for venom-specific IgE, IgG and IgG4 reactivity were compared to sting challenge reactivity for these patients. Based on retrospective analysis, a pattern of reactivity was selected to use for predicting sting challenge. A positive sting challenge reaction was predicted by a deficiency in IgG4 production during immunotherapy to at least one allergenic venom component. An additional 19 patients were selected for prospective testing. Each patient was allergic to venom (8 honey bee, 11 wasp) and received immunotherapy. In the second year of immunotherapy, the preimmune and most recent postimmune sera were tested together with AlaBLOT for IgE and IgG4 to either honeybee or wasp venom. Sting challenge reactions were predicted based on the established criteria. Of the 19 patients, 13 were predicted to be nonreactive and 6 reactive to sting challenge. When challenged, 3 proved reactive of the 6 expected to be reactive.

This preliminary study indicates that AlaBLOT testing may be a useful tool for following venom immunotherapy, and could help identify patients whose immunotherapy may need adjustment. Based on the results of this study, a multicenter study following venom immunotherapy is underway to confirm the first findings.

Hundreds of different AlaBLOT allergen strips and development reagents for IgG, IgG4, IgE, and IgA are available from DPC.* For further information, please contact your local DPC representative.

Vespula sp. AlaBLOT with serum from patient who did not react to a sting challenge. Testing for IgE and IgG4 antibodies was performed with sera before the start of immunotherapy (Before) and during immunotherapy at the time of sting challenge (After Negative Sting Challenge). Preimmune IgE bands were qualitatively and quantitatively matched with reactive IgG4 bands at the time of sting challenge.

Vespula sp. AlaBLOT with serum from patient who reacted to a sting challenge. Testing for IgE and IgG4 antibodies was performed with sera before the start of immunotherapy (Before) and during immunotherapy at the time of sting challenge (After Positive Sting Challenge). Preimmune IgE bands were qualitatively and quantitatively not well matched with reactive IgG4 bands at the time of sting challenge.

* Sold as analyte-specific reagents in the US