rApi m 3 and rApi m 10 improve detection of honey bee sensitization in Hymenoptera venom-allergic patients with double sensitization to honey bee and yellow jacket venom.

Recombinant allergens improve the diagnostic precision in Hymenoptera venom allergy (HVA), in particular in patients with double sensitization to both honey bee (HBV) and yellow jacket venom (YJV). While currently available vespid allergens allow the detection of >95% of YJV-allergic patients, the sensitization frequency to the only available HBV marker allergen rApi m 1 in HBV-allergic patients is lower. Here, we demonstrate that sIgE to additional HBV marker allergens rApi m 3 and rApi m 10 allows the detection of genuine HBV sensitization in 46-65% of Api m 1 negative sera. This is of particular relevance in patients with double sensitization to HBV and YJV that did not identify the culprit insect. Addition of sIgE to rApi m 3 and rApi m 10 provides evidence of HBV sensitization in a large proportion of rApi m 1-negative patients and thus provides a diagnostic marker and rationale for VIT treatment with HBV, which otherwise would have been missing.

Component-resolved evaluation of the content of major allergens in therapeutic extracts for specific immunotherapy of honeybee venom allergy.

Allergen-specific immunotherapy is the only curative treatment of honeybee venom (HBV) allergy, which is able to protect against further anaphylactic sting reactions. Recent analyses on a molecular level have demonstrated that HBV represents a complex allergen source that contains more relevant major allergens than formerly anticipated. Moreover, allergic patients show very diverse sensitization profiles with the different allergens. HBV-specific immunotherapy is conducted with HBV extracts which are derived from pure venom. The allergen content of these therapeutic extracts might differ due to natural variations of the source material or different down-stream processing strategies of the manufacturers. Since variations of the allergen content of therapeutic HBV extracts might be associated with therapeutic failure, we adressed the component-resolved allergen composition of different therapeutic grade HBV extracts which are approved for immunotherapy in numerous countries. The extracts were analyzed for their content of the major allergens Api m 1, Api m 2, Api m 3, Api m 5 and Api m 10. Using allergen-specific antibodies we were able to demonstrate the underrepresentation of relevant major allergens such as Api m 3, Api m 5 and Api m 10 in particular therapeutic extracts. Taken together, standardization of therapeutic extracts by determination of the total allergenic potency might imply the intrinsic pitfall of losing information about particular major allergens. Moreover, the variable allergen composition of different therapeutic HBV extracts might have an impact on therapy outcome and the clinical management of HBV-allergic patients with specific IgE to particular allergens.