Role of immunoblotting for diagnosis of insect venom allergy

The serum of 26 patients with a history of previous systemic allergic react ions caused by a insect sting was investigated by using the immunoblot-syst em AlaSTAT-AlaBLOT for determination of specific IgE to insect venom allerg ens (DPC Biermann GmbH, Bad Nauheim, Germany). Furthermore, prick test and insect venom specific IgE antibodies (Magic Lite SQ, Chirion, Fernwald, Ger many) were investigated. Group I of the patients studied included 5 patient s with yellow jacket venom allergy, group II contained 5 patients with hone ybee venom allergy. In group III 6 patients with double sensitization and 2 patients with partial cross reactivity were investigated. Group IV represe nted 8 patients without detectable specific IgE antibodies to insect venom in serum by using Magic Lire SQ test system. In group I, II and III we obta ined nearly similar results comparing determination of specific IgE antibod ies by Magic Lire SQ and by immunoblot AlaSTAT-AlaBLOT. No specific pattern of predicative value for double sensitization or cross reactivity could be observed. Surprisingly, 5 patients of group IV showed antibody signals to venom allergens by using AlaSTAT-AlaBLOT. Four of these patients had a posi tive skin prick test to insect venom. One patient could not be tested becau se of urticaria factitia, The diagnosis of insect venom allergy was establi shed for these patients and immunotherapy was indicated. In summary and alt hgough the number of investigated patients is quite small the immunoblot sy stem AlaSTAT-AlaBLOT seems to be a valuable supplementing method for diagno sis of IgE mediated insect venom allergy and indication of specific immunot herapy in uncertained situations.