Identification of IgE Binding Components and Allergenic Relationship of the Somatic Antigens of Anisakis simplex

Abstract

Background: Anisakis simplex (A. simplex) is a fish parasite which may be responsible for urticaria and anaphylaxis in case of human infections. Objective: We performed this study to identify IgE binding components and evaluate cross-allergenicity with Toxocara, a common cause of parasite allergy and Dermatophagoides pteronyssinus (D.pt). Method: Nine Anisakis allergic patients and 23 non-atopic healthy controls were enrolled. Serum specific IgE and IgG4 antibodies to A. simplex extracts were measured by ELISA. Allergenic relationships with Toxocara were evaluated by immunoCAP, IgE and IgG4 ELISA inhibition tests. IgE binding components were identified by IgE immunoblot analysis and basophil histamine release induced by A. simplex was performed in a representative case. Results: Four of 9 A. simplex allergy patients showed high serum specific IgG4 as well as IgE antibody. No cross- reactivity between A. simplex and D.pt, or Toxocara were observed. Several IgE binding components ranged from 8 to 80 kDa were identified. A significant histamine release by A. simplex extracts was noted from basophils from the representative case. Conclusions: We confirmed that A. simplex could induce IgE mediated response which leads to urticaria and anaphylaxis in patients sensitized to A. simplex. No cross-allergenicity was observed between A. simplex and Toxocara.