Oral immunotherapy with low allergenic hydrolysed egg in egg allergic children

Abstract

Background: A major drawback of oral immunotherapy for food allergy is the possibility of severe side-effects. We assessed both safety and efficacy of a low allergenic hydrolysed egg (HydE) preparation used in a double-blind placebo-controlled randomized study in egg allergic children.

Methods: In a pilot multicentre study, 29 egg allergic patients (aged 1-5.5 years) were administered daily for 6 months 9 g HydE or placebo in a blinded, randomized manner. Safety was verified by oral food challenge to assess tolerance towards HydE at the start and efficacy by an open oral food challenge (OFC, primary outcome) at the end. Additionally, changes in basophil activation and specific IgE and IgG4 were assessed.

Results: All egg allergic patients randomized to HydE (n = 15) tolerated the full dose at day 1 and received the maintenance dose from the start at home. No statistically significant difference was observed on the final OFC (36% and 21% had a negative OFC in the treatment and placebo groups, respectively). Specific IgG4 levels increased, while both CD203c+ and CD63+ basophils decreased significantly more over time in the treatment than in the placebo group.

Conclusions: HydE can be regarded as a safe, low allergenic product to use in children allergic to egg. Although not significant, HydE given for 6 months increased numerically the proportion of patients becoming tolerant to egg. HydE induced a modulation of the immune response towards better tolerance. A longer treatment period and/or a higher dose may improve the clinical outcome and should be evaluated.

Keywords: basophil activation test; egg; food allergy; hydrolysed proteins; oral immunotherapy.