IgE, IgG1 and IgG4 response to specific allergens in sensitized subjects showing different clinical reactivity to Anisakis simplex

Background. Anisakis simplex hypersensitive subjects may be sensitized without clinical allergy, or experience acute symptoms or chronic urticaria induced by raw fish. We studied whether the 3 subgroups differ in IgE, IgG1 or IgG4 reactivity to specific Anisakis simplex allergens. Methods. 28 Anisakis simplex-hypersensitive adults, 11 with acute symptoms, 9 with chronic urticaria, and 8 sensitized were studied. IgE, IgG1 and IgG4 to rAni s 1, 5, 9 and 10 were sought by ELISA. IgE and IgG4 to nAni s 4 were determined by WB. Results. IgE to Ani s 1, 4, 5, 9, and 10 were found in 8, 3, 2, 5, and 9 sera, respectively. Nine sera did not react to any allergen. IgG1 to Ani s 1, 5, 9, and 10 were detected in 5, 16, 14, and 4 sera, respectively. Four sera did not react to any of the 4 allergens. IgG4 to Ani s 1, 4, 5, 9, and 10 were detected in 10, 0, 2, 6 and 1 sera, respectively. Fifteen subjects did not react to any of the 5 allergens. On ELISA sensitized subjects showed lower IgE and IgG1 levels than patients. IgG4 levels were highest in the sensitized group. The prevalence of IgE, IgG1 or IgG4 reactivity to any of the studied allergens did not differ between the 3 subgroups. Conclusion. The clinical expression of Anisakis simplex sensitization does not seem to depend on IgE reactivity to a specific allergen of the parasite, nor on the presence of IgG antibodies possibly related with blocking activity.