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.

Food allergy is linked to season of birth, sun exposure, and vitamin D deficiency.

The season of birth and ultraviolet B exposure have been related to the occurrence of food allergy. The levels of vitamin D produced from skin by ultraviolet B exposure might reflect this relationship. Vitamin D is known to induce antimicrobial peptides, protect intestinal flora, enhance the gut epithelial barrier, suppress mast cell activation and IgE synthesis from B cells, and increase the number of tolerogenic dendritic cells and IL-10-producing regulatory T cells. Vitamin D deficiency has been shown to exacerbate sensitization and allergic symptoms in a murine model of food allergy. However, in clinical situations, contradictory observations have been reported regarding the relationship between food allergy and vitamin D deficiency/supplementation. In this review, we have explored the links between food allergy and vitamin D levels. One explanation for the discrepant findings is confounding factors such as race, age, residency, skin color, and epigenetic changes that contribute to vitamin D levels. In addition, the season of birth influences the development of atopic dermatitis, which could lead to food sensitization. Finally, ultraviolet radiation could lead to regulatory T cell expansion and immunosuppression, irrespective of vitamin D status. Based on our current understanding, we believe that correction of vitamin D deficiency by supplementation, appropriate skin care, and sufficient ultraviolet radiation exposure could alter the prognosis of food allergy. To identify potential treatment strategies for food allergy, it is essential to gain a better understanding of the appropriate levels of vitamin D and ultraviolet radiation exposure.

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.

Sun exposure inversely related to food sensitization during infancy.

BACKGROUND: Autumn and winter birth (AWB) has been reported to be a risk factor for the development of food allergies. However, the association between seasonal factors and allergic sensitization during early infancy remains unclear. METHODS: We collected data from 732 patients regarding the total and specific immunoglobulin E (tIgE, sIgE) levels in infants younger than 6 months old from November 2001 to October 2012 from the institutional clinical database system. We then analyzed the relationship between the birth month and the value of each parameter. Furthermore, we identified any correlations between the number of sensitized patients and the monthly climatological parameters. RESULTS: The number of tIgE samples obtained from AWB patients (n = 482) was 2.1 times higher than that from patients born in the spring and summer (SSB, n = 225). The number of sIgE samples to egg white, cow's milk, and wheat, the sensitized ratio and the median sIgE titer were also all higher in AWB. The number of sensitized AWB patients to these allergens was 2.75, 3.05, and 3.97 times higher, respectively. A periodic change in the number of sensitized patients was observed annually (highest in October-November and lowest in May). Among the climatological parameters examined, the average solar radiation during the 3-month period after birth showed the strongest negative correlation with the number of sensitized patients (egg white: r = -0.976, cow's milk: r = -0.969, wheat: r = -0.975). CONCLUSIONS: The amount of solar radiation immediately after birth had a strong negative correlation with allergen sensitization before 6 months of age.

The relationship between the season of birth and early-onset food allergies in children.

BACKGROUND: This study examined the relationship between the season of birth (SoB) and other factors with the development of FA. METHODS: A multicenter, cross-sectional pilot study recruited 1197 patients with FA. The main study recruited 440 incident cases (FA group) definitively diagnosed as FA at 0-1 year of age. In both studies, the frequency of autumn-winter births (AWBs) in FA patients was compared to the regional control population. In the main study, we analyzed the differences in the SoB and other factors between patients in the FA group and those in the non-FA group (n = 332) in allergy clinics. RESULTS: The pilot study showed that the frequency of AWB (57.6%) in the FA patients was significantly higher than that of the regional control population (50.4%, OR, 1.34; p < 0.001). The main study also showed the dominance of AWB (62.7%) in the FA group in comparison with that in the regional control population (50.2%, OR, 1.70; p < 0.001). Preterm birth (OR, 0.43; p = 0.027) and the presence of two or more elder siblings (OR, 0.27; p = 0.012) were significantly associated with a lower frequency of FA than those of non-FA. AWB (RR, 1.21; p = 0.020) and preterm birth (RR, 0.55; p = 0.017) were significantly associated with a number of trigger foods. The SoB effect was observed in FA patients irrespective of the presence of infantile eczema. CONCLUSIONS: AWB was predominant in the patients with newly diagnosed food allergies.