IL-17E but not IL-17A is associated with allergic sensitization: results from the LISA study.

Functional studies have provided evidence for the importance of IL-17A and IL-17E in the regulation of immune responses. IL-17A is involved in inflammation and IL-17E is able to induce Th2 cytokine production and eosinophilia. By now it is not clear whether these cytokines correlate with specific IgE levels. The aim of our investigation was to analyse the relationship of these two cytokines to allergic sensitization in context of an epidemiological study. Within the Life style Immune System Allergy study (LISA), we analysed phytohemagglutinin (PHA)-stimulated blood samples of 6 yr old children for the concentration of IL-17A and IL-17E and sera for levels of specific IgE. In total, data from 293 children were available for blood analysis and for the analysis of confounding factors for the allergic sensitization. Among the investigated children, 29% reacted against inhalant and 13.6% against food allergens, whereas 33.1% of children were sensitized to any allergen.IL-17E was associated with high levels of any specific IgE (adjusted odds ratio (OR) 1.45, 95% confidence interval (CI) 1.11–1.90). Furthermore, children with high IL-17E responses (>208.8 pg/ml) were sensitized to food and inhalant allergens (OR 1.45, 95% CI 1.02–2.07 and OR 1.35, 95% CI 1.03–1.77, respectively) and to Der p 1 (OR 1.55, 95% CI 1.12–2.15). In contrast, IL-17A, in trend, was negatively associated to sensitization to timothy (p for trend=0.013) and rye (p for trend=0.026). Concluding IL-17E production is linked to the amount of specific IgE antibodies in blood samples of 6 yr old children.