Multi-sensitization to hymenoptera venoms: diagnostic and clinical features

Background

Double sensitization to both honeybee (Apis mellifera) and Yellow Jacket (Vespula ssp.) venom is common in up to 59% of Northern European Hymenoptera venom allergic patients and this rate is more than 50% in the United States. In Brazil yellow jacket is not a common wasp, but Polistes sp. and Polybia paulista poses the major risk for Brazilian patients. Reports about double sensitization involving honey bee and fire ant (Solenopsis invicta) are rare and there is nothing described about multi-sensitization to insects. Cross-reacting carbohydrate determinants (CCDs) are not present in Polistes sp. venom and are not yet described for Polybia paulista neither Solenopsis invicta. Component-resolved analysis with recombinant species-specific major allergens may help to distinguish true double sensitization from cross-reactivity, except for Polybia paulistaallergens for which these commercial tests are not yet available. Although there is no international consensus on whether immunotherapy regimens should generally include all venoms in multi-sensitized patients the recommendation is that immunotherapy (IT) should be extended to all venoms for which test results are positive and patients might potentially react to.

Methods

We selected a group of ten patients with clinical manifestations of anaphylaxis presenting symptoms that included urticaria, angioedema, diarrhea, respiratory symptoms and loss of consciousness that are sensitized to honeybee, wasps (Polistes and Polybia) and fire ant. They were tested by ImmunoCap, Skin prick test (SPT), Dot Blot and Western Blotting (WB) with Apis mellifera, Polistes sp. and Solenopsis invicta extracts commercially available and also Polybia paulista venom extract produced in our laboratory.

Results

Patients are positive to four venoms tested in Dot blot, WB and SPT. Five patients presented ImmunoCAP <0.35 for one or two venoms tested. WB revealed that patients are recognizing different bands in gel when comparing different venoms suggesting there is no cross-reactivity. Some bands recognized by specific IgEs would be new allergens, since they present distinct molecular weights from allergens already described. Cross-reactivity due to CCD recognition remains to be confirmed.

Conclusions

This is the first report of multisensitization to honeybee, Solenopsis, Polybia and Polistes and considering clinical history, SPT and laboratory results patients presented here should be submitted to IT to all venoms tested. It is important to remark that Polybia paulista venom is not commercially available for treatment and IT to Solenopsis is still not well established. Next steps are to check the presence of CCD in Solenopsis and Polybia venoms and also to identify new IgE reacting molecules.