Reassessing the role of hyaluronidase in yellow jacket venom allergy
Received 13 February 2009; received in revised form 3 August 2009; accepted 10 August 2009. published online 12 November 2009.
Background
Yellow jacket hyaluronidase (YJ-HYA) is considered a major allergen in yellow jacket allergy. It shows 50% homology with the hyaluronidase from honeybee venom, Api m 2. Recently, IgE binding to YJ-HYA and cross-reactivity with Api m 2 has been shown to be due to cross-reactive carbohydrate determinants (CCDs).
Objective
We sought to quantify the importance of YJ-HYA in yellow jacket allergy and the cross-reactivity with Api m 2 by discriminating between carbohydrate and peptide epitopes.
Methods
IgE binding to Vespula species venom was studied by means of Western blotting in 136 patients with yellow jacket allergy (31 in vitro single positive to yellow jacket venom and 105 in vitro double-positive to yellow jacket-honeybee). Inhibition studies were carried out with MUXF-BSA (isolated bromelain glycopeptides linked to bovine serum albumin) and purified Api m 2.
Results
Among yellow jacket single-positive sera, only 1 of 31 bound with YJ-HYA, whereas this was the case in 87% of 105 double-positive sera. Of 83 patients in whom inhibitions were performed, 65% reacted with hyaluronidase through CCDs alone, 27% reacted with both CCDs and peptide epitopes, and 8% reacted only with the hyaluronidase peptide. The protein-specific reactivity with YJ-HYA was cross-inhibited by Api m 2 in 48% (14/29). Antigen 5 and phospholipase A1 were each recognized by around 90% of sera from both groups, together identifying 97% of patients.
Conclusion
Hyaluronidase is a minor yellow jacket venom allergen, and only 10% to 15% of patients with yellow jacket allergy are estimated to have IgE against the hyaluronidase protein. Peptide-specific cross-reactivity with Api m 2 occurs in half of these sera. Component-resolved diagnosis with antigen 5 and phospholipase would detect virtually all patients with yellow jacket venom allergy.
Disclosure of potential conflict of interest: F. Altmann has received research support from the European Community, the Austrian Science Fund, and Austria Wirtschaftsservice. The rest of the authors have declared that they have no conflict of interest.
ABSTRACT