Screening the allergenic repertoires of wheat and maize with sera from double‐blind, placebo‐controlled food challenge positive patients

• Published in: Allergy (Copenhagen) Vol. 61; no. 1; pp. 128 - 135
• Main Authors: Weichel, M., Vergoossen, N. J., Bonomi, S., Scibilia, J., Ortolani, C., Ballmer‐Weber, B. K., Pastorello, E. A., Crameri, R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Munksgaard International Publishers 01.01.2006; Blackwell
• Subjects: Adolescent; Adult; Age Distribution; Allergens - immunology; Allergic diseases; Anaphylaxis - immunology; Biological and medical sciences; Blotting, Western; cDNA phage surface display; Child; Double-Blind Method; Female; Food Hypersensitivity - blood; Food Hypersensitivity - diagnosis; Food Hypersensitivity - epidemiology; Fundamental and applied biological sciences. Psychology; Fundamental immunology; Humans; IgE‐binding repertoires; Immunoglobulin E - analysis; Immunoglobulin E - immunology; Immunopathology; Incidence; maize allergy; Male; Mass Screening; Medical sciences; Middle Aged; recombinant allergens; Reference Values; Risk Assessment; Sensitivity and Specificity; Sex Distribution; wheat allergy; Wheat Hypersensitivity - blood; Wheat Hypersensitivity - diagnosis; Zea mays - immunology; Allergy; Monocotyledones; IgE; recombinant allergens; Phage display; Immunology; Gene; Gramineae; maize allergy; Angiospermae; Serum; Immunologic repertoire; Recombinant protein; Human; cDNA phage surface display. IgE-binding repertoires; Immunopathology; Zea mays; Corn; Medical screening; Complementary DNA; wheat allergy; Placebo; Spermatophyta; Wheat; Allergen; Provocation test
• ISSN: 0105-4538; 1398-9995
• DOI: 10.1111/j.1398-9995.2006.00999.x

Background:  Food allergy to wheat and maize is an increasing factor of deterioration of life quality, especially childhood and can, in rare cases, even induce anaphylaxis. Although omega‐5 gliadin from wheat and maize lipid transfer protein have been characterized as major cereal allergens on the molecular level, the list of food allergens is far to be complete. Methods:  To identify the IgE‐binding repertoires of wheat and maize we screened respective cDNA libraries displayed on phage surface with sera from patients with a confirmed food allergy. The study included six patients with a positive double‐blind, placebo‐controlled food challenge (DBPCFC) to wheat, nine patients with a positive DBPCFC to maize, and six patients with anaphylactic reactions after ingestion of wheat. Results:  The enriched sequences encoding IgE‐binding proteins showed heterogeneous repertoires for both, wheat and maize. The selected wheat repertoire yielded 12, the maize repertoire 11 open reading frames. Among these we identified allergens belonging to already characterized allergens families, such as gliadin, profilin and beta‐expansin. Besides, we found novel proteins with high cross‐reactive potential, such as thioredoxins, as well as sequences that had so far not been related to cereal allergy at all. The IgE‐binding capacity of some selected proteins was evaluated in vitro and cross‐reactivity was demonstrated by competition ELISA. Conclusion:  With regard to the heterogeneity of the characterized sequences as well as to the biochemical nature of the new allergens detected we conclude that wheat and maize‐related food allergy is more complex than so far anticipated.