Sensitization to the fish parasite Anisakis simplex: clinical and laboratory aspects

• Published in: Parasitology research (1987) 2007-09, Vol.101 (4), p.1051-1055
• Main Authors: Moneo, Ignacio, Caballero, Maria-Luisa, Rodriguez-Perez, Rosa, Rodriguez-Mahillo, Ana-I, Gonzalez-Muñoz, Miguel
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Allergens - adverse effects; Allergens - chemistry; Allergens - immunology; Animals; Anisakis - immunology; Antigens, Helminth - chemistry; Antigens, Helminth - immunology; Biological and medical sciences; Electrophoresis, Polyacrylamide Gel; Fishes - immunology; Fishes - parasitology; Food Hypersensitivity - etiology; Food Hypersensitivity - immunology; Fundamental and applied biological sciences. Psychology; General aspects; General aspects and techniques. Study of several systematic groups. Models; Humans; Hypersensitivity, Immediate - etiology; Immunoblotting; Immunoglobulin E - blood; Invertebrates; Sensitivity and Specificity; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-007-0587-7

Hypersensitivity to Anisakis simplex is a worldwide medical problem. The parasite larvae die after freezing or cooking, but the tolerance of sensitized subjects to eating frozen fish remains a matter of controversy with contradictory findings. The aim of this study was to test if intolerance to properly cooked/frozen fish was due to the recognition of a particular allergen. Sixty-four patients with Anisakis simplex sensitization were studied by an IgE multiblot using simultaneously five different antigenic extracts. The antigens tested were a crude extract, excretory/secretory allergens, a heated extract, and two gradient ethanol precipitates of the crude extract. Intolerance was reported by 20% of the patients and was not related to the detection of any special allergen, nor to total or specific IgE levels. Intolerant patients only reported a higher frequency of digestive symptoms than the patients who tolerated fish ingestion. The most sensitive immunoblot antigen source was the 50-66% ethanol fraction of a crude extract (10x concentrated) that was found to be positive in 100% of the samples. Interestingly, 95% sensitivity in the IgE-immunoblot assay could be achieved using only two allergens, Ani s 1 and Ani s 4. Allergens from the dead larvae remain a problem for 20% of the sensitized subjects. The use of a fractionated and concentrated crude extract improved the sensitivity of the immunoblot assay.