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Pea ( Pisum sativum ) allergy in children: Pis s 1 is an immunodominant major pea allergen and presents IgE binding sites with potential diagnostic value
Author(s) -
Popp Jasmin,
Trendelenburg Valérie,
Niggemann Bodo,
Randow Stefanie,
Völker Elke,
Vogel Lothar,
Reuter Andreas,
Spiric Jelena,
Schiller Dirk,
Beyer Kirsten,
Holzhauser Thomas
Publication year - 2020
Publication title -
clinical and experimental allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.462
H-Index - 154
eISSN - 1365-2222
pISSN - 0954-7894
DOI - 10.1111/cea.13590
Subject(s) - immunoglobulin e , allergy , sativum , pisum , allergen , immunology , sensitization , potency , basophil , medicine , biology , biochemistry , antibody , botany , in vitro
Background Food allergy to pea ( Pisum sativum ) has been rarely studied in children at the clinical and molecular levels. Objective To elucidate the allergenic relevance and diagnostic value of pea 7S globulin Pis s 1, nsLTP, and 2S albumins PA1 and PA2 in children. Methods Children with pea‐specific IgE ≥ 0.35 kU A /L and clinical evidence of pea allergy or tolerance were included in the study. IgE binding against pea total protein extract, recombinant (r) rPis s 1, rPA1, rPA2, and natural nsLTP was analysed using IgE immunoblot/inhibition. Mediator release potency was investigated in passively sensitized rat basophil leukaemia (RBL) 2H3‐cells. IgE binding to synthetic overlapping peptides of Pis s 1 was detected on multipeptide microarrays. Results 19 pea‐sensitized children were included, 14 with doctors’ diagnosed allergy and 5 with tolerance to pea (median age 3.5 and 4.5 years, respectively). 11/14 (78%) pea‐allergic and 1/5 (20%) tolerant children were sensitized to Pis s 1. Under the reducing conditions of immunoblot analysis, IgE binding to rPA1 was negligible, sensitization to rPA2 and nsLTP undetectable. Compared to pea total protein extract, rPis s 1 displayed on average 58% IgE binding capacity and a 20‐fold higher mediator release potency. Selected Pis s 1‐related peptides displayed IgE binding in pea‐allergic but not in pea‐tolerant children. Conclusions and Clinical Relevance In this study group, Pis s 1 is a major immunodominant allergen in pea‐allergic children. Evidence for sensitization to nsLTP and 2S albumins was low but requires further verification with regard to conformational epitopes. Recombinant Pis s 1 and related peptides which were exclusively recognized by pea‐allergic children may improve in vitro diagnosis of pea allergy once verified in prospective studies with larger study groups.