Major and minor allergen Ige reactivity of purple mud crab (Scylla tranquebarica) against a cross-reactive allergen in crustacean and molluscs in patients with a seafood allergy

Abstract

Background: Crabs have been reported as a high exporter of protein and contains great nutritional value. Objective: It is necessary to identify the allergens and the cross-reactivity concerning the mud crab Scylla tranquebarica, shellfish, and mollusks for control of food safety and to facilitate in the identification and treatment of symptoms related to allergy. Methods: IgE extracted of serum from five patients who suffered from anaphylaxis due to crab and five healthy patients. It was taken for analysis via immunoblotting against 11 different crustaceans and molluscs. Results: Based on the analysis, the sera from the patients had responded specifically to a 38-kDa protein in all the crustaceans and molluscs, and it is known as tropomyosin. In certain absorption studies, the 38-kDa protein had exhibited to be the immunodominant epitopes among all crustaceans and molluscs. Sera from all five subjects with Scylla tranquebarica allergy showed IgE reactivates against crabs, prawns, and molluscs, but not to the chicken or murine muscle. Conclusions: Therefore, it can be concluded that the allergic epitopes on tropomyosin are preserved not only in shellfish but also in insects. Thus, a further examination should be done onto the patient with shrimp allergy to determine the potential cross-reactivity inhalant or sensitivity to ingested insects.