Riccardo Asero1, Emanuele Bellotto2, Alessandra Ghiani2, Roberta Aina2, Danilo Villalta3, Sandra Citterio4. 1. Ambulatorio di Allergologia, Clinica San Carlo, Paderno Dugnano, Milan, Italy. 2. Dipartimento di Science Ambientali, Università di Milano-Bicocca, Milan, Italy. 3. Allergologia e Immunologia Clinica, Azienda Ospedaliera, S Maria degli Angeli, Pordenone, Italy. 4. Dipartimento di Science Ambientali, Università di Milano-Bicocca, Milan, Italy. Electronic address: sandra.citterio@unimib.it.
Abstract
BACKGROUND: In many areas of Europe, double sensitization to ragweed and mugwort is common, and because of the overlapping flowering periods of the 2 plants, it is not possible to diagnose the primary sensitizing allergen source and hence to determine the proper immunotherapy. OBJECTIVES: To elucidate whether double-sensitized patients are cosensitized or cross-sensitized and, in the latter case, to define the primary sensitizer. METHODS: Serum samples from 34 patients with late summer respiratory allergy underwent skin prick testing with whole ragweed, and mugwort extracts were analyzed for their reactivity to recombinant Art v 1 and Amb a 1 by ImmunoCAP and then to Amb a 1, Art v 6, and Art v 1 isoforms by a proteomic approach. In double reactors, the primary sensitizing sources were detected by inhibition experiments. RESULTS: Serum samples from patients monosensitized to ragweed contained IgE to epitopes specific of all Amb a 1 isoforms. In contrast, serum samples from double reactors found to be primarily sensitized to mugwort reacted to Art v 1 and Art v 6 and cross-reacted to a few Amb a 1 isoforms. Finally, serum samples from double reactors found to be primarily sensitized to ragweed contained IgE reacting to all Amb a 1 isoforms, part of which cross-reacted to Art v 6. We did not find cosensitized patients. CONCLUSION: This study found that Art v 6 plays an important role in mugwort allergy and that the cross-reactivity between Art v 6 and Amb a 1 is frequent, bidirectional, and clinically relevant in the area of Milan.
BACKGROUND: In many areas of Europe, double sensitization to ragweed and mugwort is common, and because of the overlapping flowering periods of the 2 plants, it is not possible to diagnose the primary sensitizing allergen source and hence to determine the proper immunotherapy. OBJECTIVES: To elucidate whether double-sensitized patients are cosensitized or cross-sensitized and, in the latter case, to define the primary sensitizer. METHODS: Serum samples from 34 patients with late summer respiratory allergy underwent skin prick testing with whole ragweed, and mugwort extracts were analyzed for their reactivity to recombinant Art v 1 and Amb a 1 by ImmunoCAP and then to Amb a 1, Art v 6, and Art v 1 isoforms by a proteomic approach. In double reactors, the primary sensitizing sources were detected by inhibition experiments. RESULTS: Serum samples from patients monosensitized to ragweed contained IgE to epitopes specific of all Amb a 1 isoforms. In contrast, serum samples from double reactors found to be primarily sensitized to mugwort reacted to Art v 1 and Art v 6 and cross-reacted to a few Amb a 1 isoforms. Finally, serum samples from double reactors found to be primarily sensitized to ragweed contained IgE reacting to all Amb a 1 isoforms, part of which cross-reacted to Art v 6. We did not find cosensitized patients. CONCLUSION: This study found that Art v 6 plays an important role in mugwortallergy and that the cross-reactivity between Art v 6 and Amb a 1 is frequent, bidirectional, and clinically relevant in the area of Milan.
Authors: J Pham; C Oseroff; D Hinz; J Sidney; S Paul; J Greenbaum; R Vita; E Phillips; S Mallal; B Peters; A Sette Journal: Clin Exp Allergy Date: 2016-07-26 Impact factor: 5.018