Specific IgE determination to Ani s 1, a major allergen from Anisakis simplex, is a useful tool for diagnosis

Background: The most serious limitation of the serodiagnosis of parasitoses is the occurrence of cross-reactions. Objective: The possible use of Anisakis simplex major allergen Ani s 1 for diagnosis. Patients and Methods: Forty-nine non-fish-allergic patients with Anisakis.simplex hypersensitivity, 21 patients without allergic episodes suffering intestinal anisakiasis with obstruction of the intestinal lumen, and 10 unrelated sera as a control were included in this study to determine specific immunoglobulin (Ig)E and I-G to Anisakis simplex major allergen Am s 1 by immunoblotting. Results: Eighty-six percent of patients with Anisakis simplex hypersensitivity showed specific I-E directed to Am s 1. Identical result was obtained for I-G detection in this group. Among patients with intestinal anisakiasis, 86% showed specific IgE, but only 29% had specific IgG (P < 0.001, two-tailed Fisher exact test). One of the 10 control subjects was positive both for 1,E and I-G (P < 0.001). Conclusions: Determination of specific IgE directed to Anisakis simplex major allergen Am s 1 is a useful tool for the diagnosis of hypersensitivity and intestinal anisakiasis. Further, measurement of specific I-G directed to Anisakis.simplex major allergen Am s 1 is only valid for Anisakis simplex allergy.