Laboratory diagnosis of hypersensitivity to Anisakis simplex:: a review

Patients suffering anaphylactic reactions after parasitized fish consumption have been reported in Spain in recent years. This reaction is different from the well-known acute or chronic anisakiasis and causes intolerance to parasitized fish ingestion, even after appropriate cooking. High specific IgE values are usually found in these subjects. IgE immunoblotting is now needed to confirm the presence of specific IgE directed to several parasite antigens in order to exclude cross-reactions. Positive specific IgG4 by immunoblotting was found in 60% of the patients, as well as in patients with anisakiasis, and probably reflected recent contact with the parasite proteins. The most specific response of IgE antibodies was directed to low-molecular-mass antigens of the parasite. Therefore, recombinant or purified antigens for in vivo and in vitro use will in future overcome some of the problems found in the diagnosis of sensitized patients.