title: Specific IgE determination to epitope peptides of omega-5 gliadin and high molecular weight glutenin subunit is a useful tool for diagnosis of wheat-dependent exercise-induced anaphylaxis.
abstract: Wheat omega-5 gliadin and a high m.w. glutenin subunit (HMW-glutenin) have been reported as major allergens in wheat-dependent exercise-induced anaphylaxis. A simultaneous detection of specific IgE to epitope sequences of both proteins is considered to be a reliable method for diagnosis of wheat-dependent exercise-induced anaphylaxis. However, the IgE-binding epitope of HMW-glutenin remains unknown. The aim of this study was to determine the IgE-binding epitopes of HMW-glutenin to establish a useful system of identifying patients with wheat-dependent exercise-induced anaphylaxis. For determination of IgE-binding epitopes of HMW-glutenin overlapping peptides were synthesized and reactivities of IgE Abs in the sera of patients to those peptides were analyzed. Three IgE-binding epitopes, QQPGQ, QQPGQGQQ, and QQSGQGQ, were identified within primary sequence of HMW-glutenin. Epitope peptides, which include IgE-binding sequences of omega-5 gliadin and a HMW-glutenin, were synthesized and peptide-specific IgE Abs were measured by CAP-System fluorescent enzyme immunoassay. Twenty-nine of 30 patients with wheat-dependent exercise-induced anaphylaxis had specific IgE Abs to these epitope peptides. None of the 25 sera from healthy subjects reacted to both epitope peptides. Twenty-five patients with atopic dermatitis who had specific IgE to wheat and/or gluten had very low or nonexistent levels of epitope peptide-specific IgE Abs. These results indicated that measurement of IgE levels specific to epitope peptides of omega-5 gliadin and HMW-glutenin is useful as an in vitro diagnostic method for the assessment of patients with wheat-dependent exercise-induced anaphylaxis.
authors.affiliation: Department of Dermatology, Shimane University School of Medicine, Izumo, Japan. hmatsuo@med.shimane-u.ac.jp
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Matsuo
authors.forename: Kunie
authors.initials: K
authors.lastname: Kohno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Niihara
authors.forename: Eishin
authors.initials: E
authors.lastname: Morita
mesh_terms: D000485:Allergens / Q000276:immunology*; D000595:Amino Acid Sequence; D000707:Anaphylaxis / Q000175:diagnosis* / Q000209:etiology; D000906:Antibodies / Q000032:analysis; D052179:Antigens, Plant; D016022:Case-Control Studies; D003876:Dermatitis, Atopic / Q000175:diagnosis; D018604:Epitope Mapping; D000939:Epitopes; D015444:Exercise; D005903:Gliadin / Q000276:immunology*; D005983:Glutens / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques / Q000592:standards; D007073:Immunoglobulin E / Q000032:analysis* / Q000276:immunology; D021122:Protein Subunits / Q000276:immunology; D021182:Wheat Hypersensitivity / Q000150:complications / Q000175:diagnosis
chemical_list: D000485:Allergens; D000906:Antibodies; D052179:Antigens, Plant; D000939:Epitopes; D021122:Protein Subunits; C475180:omega-5 gliadin, wheat; D007073:Immunoglobulin E; D005983:Glutens; D005903:Gliadin; C037302:glutenin