Sensitization to the fish parasite Anisakis simplex: clinical and laboratory aspects.
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.
Moneo
Ignacio
I
Immunology, Hospital Carlos III, Sinesio Delgado 10, Madrid, 28029, Spain. imoneog@hotmail.com
Caballero
Maria-Luisa
ML
Rodriguez-Perez
Rosa
R
Rodriguez-Mahillo
Ana-I
AI
Gonzalez-Muñoz
Miguel
M
D000485:Allergens / Q000009:adverse effects / Q000737:chemistry / Q000276:immunology*; D000818:Animals; D017163:Anisakis / Q000276:immunology*; D000947:Antigens, Helminth / Q000737:chemistry / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D005399:Fishes / Q000276:immunology / Q000469:parasitology*; D005512:Food Hypersensitivity / Q000209:etiology / Q000276:immunology; D006801:Humans; D006969:Hypersensitivity, Immediate / Q000209:etiology*; D015151:Immunoblotting; D007073:Immunoglobulin E / Q000097:blood; D012680:Sensitivity and Specificity
D000485:Allergens; D000947:Antigens, Helminth; D007073:Immunoglobulin E