Buckwheat allergy in adults: comparison of specific IgE between homemade ELISA and CAP system, and identification of IgE-binding components

Abstract

Background and objective: Ingestion and inhalation of buckwheat flour can induce IgE mediated bronchoconstriction and anaphylaxis in sensitized individuals, expecially in childhood. The aim of this study was to determine the sensitization rate of buckwheat allergen, measure the level of specific LgE to buckwheat, and identify IgE-binding components in adult patients with various allergic diseases. Methods; 1,738 allergy patients and 40 healthy controls were enrolled. skin prick tests were performed using homemade buckwheat extract. the specific IgE level to homemade buckwheat allergen was measured by ELISA, and results were compard to those of the CAP system. ELISA inhibition tests were done to evaluate allergenic relationships with major food allergens and IgE binding components ere identified using IgE immunoblot analysis. Results: Among 1,738 patients tested, 60 patients (3.5%) showed more than a 2+ response on skin prick tests to buckwheat. The prevalence of serum specific IgE to buckwheat ranged from 24% in patients with a 2+ response to buckwheat skin prick test, to 50% in patients with a 4+ response. The mean absorbance value increased with skin reactivity although it was not statistically significnt. However, CAP results were signficantly correlated with skin reactivity(p<0.05). A significant correlation was noted between (the) results by homemade ELISA and CAP. IgE immunolot demonstrated 20 IgE binding components ranging from 20 to 114 kDa, and 10 components were bound to IgE in more than 50% of the patients tested. Conclusion: Natural buckwheat allergens should be considered as one of the causative food allergens in exposed adults. Specific IgE results by homemade ELISA were comparable with those of CAP system. Twenty IgE binding components and 10 major allergens were noted within natural buckwheat allergen. Further studies will be needed to evaluated the allergenic relationships with other food allergens.