Clinical efficacy and immunological changes subjacent to egg oral immunotherapy

[Background]: Evidence of the efficacy of food oral immunotherapy (OIT) is not robust enough to change clinical practice from current standard management. Furthermore, the immunologic changes underlying food desensitization are unknown. [Objective]: To establish the immunologic basal status and differences between an egg-allergic group of children and a population of nonallergic children and to investigate the safety and efficacy of a specific egg OIT protocol to induce clinical desensitization and the associated immune responses. [Methods]: Children with or without egg allergy were recruited. Allergic subjects underwent an OIT protocol based on weekly doses of egg protein and a maintenance phase. Immune profile and changes in all subjects were investigated by measuring T-helper cells types 1 and 2 (TH1 and TH2) and T-regulatory cytokines and transcription factors and egg-specific IgE and IgG4 levels. [Results]: At baseline, a significantly lower production of ovalbumin-specific interleukin (IL)-10 and tumor necrosis factor-α and a trend toward higher IL-5 and IL-13 were found in allergic children. The egg OIT protocol enabled 60% of them to ingest 32 mL of egg white. Significant increases in egg-specific IgG4 levels and IL-10 production, with a trend toward lower IL-5 and IL-13 and higher tumor necrosis factor-α and interferon-γ levels, and significant decreases in egg-specific IgE concentration were observed. Conclusion Egg-allergic individuals display a bias toward TH2 type cytokine production and decreased TH1 and IL-10 responses compared with nonallergic individuals. The OIT protocol was safe and effective in inducing egg desensitization, leading to a shift in the immune profile of allergic individuals toward a nonallergic phenotype.Ms Perezábad, Dr López-Fandiño, Dr Molina, and Dr López-Expósito are participants in the COST-Action ImpARAS FA1402. Ms Perezábad received an Formación de Personal Universitario grant from the Ministerio de Educación, Cultura y Deporte (Spain). Instituto de Estudios del Huevo.Peer Reviewe