Positive associations between infections of Toxoplasma gondii and seropositivity with Anisakis simplex in human patients suffering from chronic urticaria

Association between anti-Anisakis simplex antibodies and interleukin-7 levels

IL-7 is a crucial factor for the development of lymphocytes, and it is absolutely necessary for γδ T cells. Mice deficient in L-7 have a deficit of B and αβ T lymphocytes, and an absence of mature γδ TCR cells. IL-7 is essential for the survival, development and maturation of Schistosoma sp., although its production is associated with protection against intestinal helminths. The presence of anti-Anisakis simplex antibodies, especially IgA, is related to a lower frequency in CD3 + CD56 + αβ + lymphocytes and all subpopulations of γδ T cells. In this work, the relationship of IL-7 with humoral and cellular responses against A. simplex in 100 healthy subjects was studied. We have found significantly higher IL-7 levels in anti-A. simplex IgA-positive subjects (p < 0.001). The positivity of anti-A. simplex IgA was associated with a significant reduction in the frequency of CD3 + αβ+ (p < 0.01), CD3 + CD4 + αβ+, CD3 + CD8 + αβ+, CD3 + CD56 + αβ+, CD3 + γδ+, CD3 + CD4-CD8-γδ+ and CD3 + CD56 + γδ+ (p < 0.05) cells. In the case of NKT cells, this same phenomenon was also associated with IgE positivity. There was a weak inverse correlation (Spearman) of IL-7 levels with the frequencies of CD3 + CD4 + αβ+ (-0.125, p = 0.047), CD3 + CD8 + αβ+ (-0.204, p = 0.032), CD3 + CD56 + αβ+ (-0.247, p = 0.007), CD3 + γδ+ (-0.267, p = 0.007), CD3 + CD4-CD8-γδ+ (-0.266, p = 0.003), and CD3 + CD8 + γδ + (-0.302, p = 0.002) cells. The role of NKT cells in the anti-A. simplex response was confirmed and an association between IL and 7 levels and specific antibodies, especially IgA, was demonstrated. The higher production of IL-7 would represent a compensatory mechanism in response to the reduction in lymphocyte populations associated with the response against this parasite.

New Perspectives on the Diagnosis of Allergy to Anisakis spp

PURPOSE OF REVIEW

To compare the prevalence of sensitization in different countries based on specific IgE values and to evaluate the use of isolated native or recombinant allergens for diagnosis.

RECENT FINDINGS

Isolated allergens help in the diagnosis of truly sensitized patients avoiding false positives due to cross-reactions. Their use is therefore highly recommended, especially when used as a combination of several relevant allergens. The use of purified allergens allows an accurate diagnosis and this has led to three important findings: (1) in addition to the digestive route of sensitization, occupational and non-digestive exposure seems to be clinically relevant. (2) The parasite appears as an important agent for chronic urticaria. And (3) in endemic countries, the amount of highly sensitized subjects in the general population could be as high as 7%. Adequate information to asymptomatic patients on fish consumption habits would avoid new contacts with parasite allergens and decrease their specific IgE levels and consequently the appearance of acute or chronic episodes induced by the parasite.