IgE Sensitization and Identification of IgE Binding Components of Soybean Allergen in Adult Allergy Patients

Abstract

Background: Soybean is a common food in Korea. Although there has been several studies to report a sensitization rate in childhood patients, there have been no published data to observe IgE-sensitization rate in adult allergy patients in Korea. Objective: The aim of this study was to evaluate the clinical significance of soybean as a food allergen in adult patients. Method: The 1,716 allergy patients and 40 healthy controls were enrolled. The skin prick tests were performed with soybean extracts. Serum specific IgE level to soybean extracts was measured by ELISA and its binding specificity was evaluated using ELISA inhibition test. IgE binding components within soybean extracts were identified using SDS-PAGE ollowed by IgE-immunoblot. Results: Sixty-five patients (3.8%) showed positive responses on the skin prick test to soybean. Serum specific IgE was detectable in 16~29% among the positive reactors. ELISA inhibition test showed significant inhibitions with addition of soybean extracts in a dose dependent manner. IgE-immunoblot analysis demonstrated 21 IgE binding components in which 32 kDa was the most frequently bound one (50%). Conclusion: The sensitization rate to soybean extracts was 3.8% in adult allergy patients and one major allergen (32 kDa) was identified. Soybean should be considered as one of the causative food allergens in this country.