Specific IgE determination to shrimp (Metapenaeus joyneri) and identification of its allergen

Abstract

Background: Shrimp is one of the major causative crustacean food allergen. An investigation has been reported that tropomyosin belonged to muscle protein is a major allergen within shrimp. But there have been a few investigations on shrimp allergen in Korea. The aim of this study is to evaluate skin reactivity and specific IgE sensitization to Metapenaeus joyneri which is one of the major shrimp in this country, and to identitify IgE binding components and evaluate allergenic relationship with other species. Methods: We performed skin prick test with M. joyneri extract in 1,738 patients. ELISA was performed for detection of serum specific IgE antibody. To evaluate the cross allergenecity between M. joyneri and other crustaceans (crab, lobster, crayfish), Dermatophagoides pteronyssinus (Dpt), triton shell, abalone and buckwheat. ELISA inhibition tests were performed with each four patient's sera showing high specific IgE antibody. To identify IgE binding components, SDS-PAGE followed by IgE-Immunoblot were applied. Results: 211 patients (12.2%) showed positive responses (A/H ≥2+) on skin prick test. Serum specific IgE antibodies were detected in 61 patients (37.2%) of 164 sensitzed patients. ELISA inhibition test using four patient's sera showed significant inhibitions by M. joyneri. and other crustaceans including lobster, crab and crayfish, partial inhibitions were noted by Dpt, triton shell, buckwheat and abalone. SDS-PAGE and IgE-imunoblot with patients' individual sera sensitized to M. joyneri showed 12 IgE binding components (31, 32, 38-44, 57, 70, 81 kDa) and two (31, 32 kDa) were bound to IgE in more than 50% of sera tested. Five (43, 44, 57, 70 and 81 kDa) were bound to IgE in more than 25% of sera tested. Conclusion: Specific IgE was detected in 37.2% of allergy patients sensitized to M. joyneri. Twelve IgE binding components and two (31, 32 kDa) major allergens were indentified. Cross allergenecity was noted with other crustaceans.