Supplementary Material for: Cross-Reactivity between Anisakis spp. and Wasp Venom Allergens

Background: Anisakiasis is caused by the consumption of raw or undercooked fish or cephalopods parasitized by live L3 larvae of nematode Anisakis spp. Larvae anchor to stomach mucosa releasing excretion/secretion products which contain the main allergens. It has been described that nematode larvae release venom allergen-like proteins among their excretion/secretion products. We investigated potential cross-reactivity between Anisakis and wasp venom allergens. Methods: Two groups of 25 patients each were studied: wasp venom- and Anisakis-allergic patients. Sera from patients were tested by ImmunoCAP, dot-blotting with recombinant Anisakis allergens and ADVIA-Centaur system with Hymenoptera allergens. Cross-reactivity was assessed by IgE immunoblotting inhibition assays. Role of cross-reactive carbohydrate determinants (CCDs) was studied by inhibition with bromelain and periodate treatment. Results: A total of 40% of wasp venom-allergic patients had specific IgE to Anisakis simplex and 20% detected at least one of the Anisakis recombinant allergens tested. Likewise, 44% of Anisakis-allergic patients had specific IgE to Vespula spp. venom and 16% detected at least one of the Hymenoptera allergens tested. Wasp venom-allergic patients detected CCDs in Anisakis extract and peptide epitopes on Anisakis allergens rAni s 1 and rAni s 9, whereas Anisakis-allergic patients only detected CCDs on nVes v 1 allergen from Vespula spp. venom. The only Anisakis allergen inhibited by Vespula venom was rAni s 9. Conclusions: This is the first time that cross-sensitization between wasp venom and Anisakis is described. CCDs are involved in both cases; however, peptide epitopes are only recognized by wasp venom-allergic patients.