Background: Intestinal barrier dysfunction may lead to a break in tolerance and development of food allergy (FA). There is contradictory evidence on whether intestinal permeability (IP) is altered in IgE-mediated FA. Thus, we sought to determine whether IP differed between children with eczema who did (FA group) or did not (atopic controls, ACs) develop FA and whether peanut sensitization, allergy and early introduction impacted IP using serum biomarkers zonulin, soluble CD14, and Intestinal Fatty Acid Binding Protein among randomly selected participants enrolled in the Learning Early About Peanut allergy trial. Methods: FA group was defined as having at least one FA at either baseline (4-11 months) or 60 months of age (V60). ACs had eczema at baseline and no FA at either visit. Serum IP markers (sIPMs) were measured by ELISA at baseline and V60 and their relationship with clinical characteristics of participants were analyzed using parametric tests and linear regression models. Results: We evaluated 237 FA subjects and 76 ACs. sIPM levels were similar in FA subjects and ACs at baseline and V60. Age when the child first developed any FA (<1 year vs >1 year), eczema severity, peanut sensitization, peanut allergy, and early peanut introduction were not statistically significantly associated with sIPM levels. Total IgE and eosinophil levels, peanut-specific IgE, IgG4 and IgG4/IgE ratio were not correlated with sIPM levels. Conclusion: No differences in sIPMs were detected to support altered IP in infants with FA compared to ACs or following early peanut introduction among peanut sensitized children.

BACKGROUND: Characterization of allergic responses to cockroach (CR), a common aeroallergen associated with asthma, has focused mainly on IgE reactivity, but little is known about T cell responses, particularly in children. We conducted a functional evaluation of CR allergen-specific T cell reactivity in a cohort of CR allergic children with asthma. METHODS: Peripheral blood mononuclear cells (PBMCs) were obtained from 71 children, with mild-to-moderate asthma who were enrolled in a CR immunotherapy (IT) clinical trial, prior to treatment initiation. PBMC were stimulated with peptide pools derived from 11 CR allergens, and CD4+ T cell responses assessed by intracellular cytokine staining. RESULTS: Highly heterogeneous responses in T cell reactivity were observed among participants, both in terms of the magnitude of cytokine response and allergen immunodominance. Reactivity against Bla g 9 and Bla g 5 was most frequent. The phenotype of the T cell response was dominated by IL-4 production and a Th2 polarized profile in 54.9% of participants, but IFN production and Th1 polarization was observed in 25.3% of the participants. The numbers of regulatory CD4+ T cells were also highly variable and the magnitude of effector responses and Th2 polarization were positively correlated with serum IgE levels specific to a clinical CR extract. CONCLUSIONS: Our results demonstrate that in children with mild-to-moderate asthma, CR-specific T cell responses display a wide range of magnitude, allergen dominance, and polarization. These results will enable examination of whether any of the variables measured are affected by IT and/or are predictive of clinical outcomes.