Exercise-induced allergic reactions on desensitization to wheat after rush oral immunotherapy.

BACKGROUND: The effect of oral immunotherapy (OIT) on wheat allergy is promising in terms of the potential to obtain desensitization; however, the frequency of exercise-induced allergic reactions on desensitization (EIARDs) and the associated risk factors remain to be determined. METHODS: Twenty-five patients underwent rush OIT for wheat allergy, and 21 achieved the full-dose intake of wheat products (5 g of wheat protein). Exercise-provocation tests were repeatedly performed after the ingestion of a full-dose wheat product. The time-course of the levels of the specific IgEs (sIgE) to wheat extract, total gliadin, deamidated gliadin, recombinant gliadin components (α/ß-, γ- and ω-5-), and glutenin (high and low molecular weight) components was analyzed using ImmunoCAP® , ELISA, or IgE immunoblotting. RESULTS: Fourteen patients (66.7%) were diagnosed as EIARD+, which remained 5 years after rush OIT in 11 patients (52.4%). There were no differences in the clinical backgrounds of the EIARD+ and EIARD- patients. However, EIARD+ patients showed significantly higher sIgE levels to all gliadin and glutenin components than EIARD- patients before OIT. The sIgE levels to each component decreased equally after 1 and 2 years of OIT. On IgE immunoblotting, sera from all patients reacted to the multiple gluten bands, and some reacted to the water-soluble bands. The intensity of all IgE-reactive bands also became equally lighter after OIT. CONCLUSIONS: EIARDs were frequently observed and remained for a long period after successful OIT for wheat allergy. None of the specific wheat components were found to contribute to EIARDs.

INSOLUBILITY AND ALTERATION OF ALLERGENIC ACTIVITY OF WHEAT PROTEINS IN PROCESSED FOODS.

BACKGROUND: Food processing causes decomposition, denaturation or polymerization of protein, which may alter an allergic reaction. This study aimed to investigate the insolubility and alteration of wheat allergens in processed foods and the reactivity to patient sera. METHODS: We extracted proteins from wheat flour, udon and bread using different extracts and conducted SDS-polyacrylamide gel electrophoresis. IgE-immunoblotting was also conducted using sera from children with wheat allergy. RESULTS: Soluble protein was extracted from wheat flour, and gluten fractions were also extracted by adding SDS. However, no proteins were able to be extracted from udon or bread witout severing the disulfide bonds under reducing condition. Only trace amounts of protein were detected in the water after boiling udon noodles. The reactivity of IgE antibody to the extracted protein did not differ among the different processed food types. CONCLUSIONS: Wheat allergens became strongly insolubilized after gluten formation and heating. However, the reactivity of IgE antibody to each allergen was not affected by food processing. Further studies are needed for the effects on clinical symptoms.