Human immunoglobulin isotype profiles produced in response to antigens recognized by monoclonal antibodies specific to Anisakis simplex

Background Anisakis simplex is a medically important pathogen which not onl y causes anisakiasis but may provoke allergy reactions, ranging from mild u rticaria to anaphylactic shock. Objective To investigate anti-Anisakis isotype profiles in anisakiasis and Anisakis allergy patients. Methods Capture ELISA techniques were used to investigate the isotype profi les of antibodies specific for two defined Anisakis simplex antigens, in se rum from Japanese patients with confirmed anisakiasis and from Spanish pati ents with allergy to Anisakis. The antigens were 'UA2R antigens' (two prote ins with Mw of 48 and 67 kDa, recognized by our monoclonal antibody UA2) an d 'UA3R antigens' (two proteins with Mw of 139 and 154 kDa, recognized by o ur monoclonal antibody UA3), Results Considering Igc, the two most frequent isotypes in the response to the UA2R antigens were IgG1 and IgG2, with IgG4 detected in only one case; in response to the UA3R antigens, by contrast, the two most frequent isotyp es were IgG1 and IgG4 (though IgG2 remained reasonably frequent). As regard s potential utility for serodiagnosis, 95% of the Japanese anisakiasis pati ents and 84% of the allergy patients showed detectable IgG1 antibodies to t he UA3R antigens. Furthermore, all allergy patients showed IgE antibodies t o these antigens. Conclusion Anisakis simplex contains antigens that induce responses which a re differentially regulated. Because of their immunogenicity, immunodominan ce and allergenic nature, we consider that the 139/154-kDa antigens recogni zed by our MoAb UA3 are good candidates for use in tests for the diagnosis of anisakiasis and of the allergy caused by this parasite.