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: Hiroaki Matsuo, Kunie Kohno, Hiroyuki Niihara, Eishin Morita
• Journal: Journal of immunology (Baltimore, Md. : 1950) (J Immunol) Vol. 175 Issue 12 Pg. 8116-22 (Dec 15 2005) ISSN: 0022-1767 [Print] United States
• PMID: 16339549 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Validation Study)

Chemical References

• Allergens
• Antibodies
• Antigens, Plant
• Epitopes
• Protein Subunits
• omega-5 gliadin, wheat
• Immunoglobulin E
• Glutens
• Gliadin
• glutenin

Topics

• Allergens (immunology)
• Amino Acid Sequence
• Anaphylaxis (diagnosis, etiology)
• Antibodies (analysis)
• Antigens, Plant
• Case-Control Studies
• Dermatitis, Atopic (diagnosis)
• Epitope Mapping
• Epitopes
• Exercise
• Gliadin (immunology)
• Glutens (immunology)
• Humans
• Immunoenzyme Techniques (standards)
• Immunoglobulin E (analysis, immunology)
• Protein Subunits (immunology)
• Wheat Hypersensitivity (complications, diagnosis)