Low-dose oral immunotherapy for children with anaphylactic peanut allergy in Japan.

Abstract

Oral immunotherapy (OIT) is a promising treatment for persons with allergy; however, it can also cause adverse allergic reactions. In this study, we investigated the efficacy of low-dose OIT for anaphylactic peanut allergy. Twenty-four children (median age, 9.6years) with anaphylaxis to peanuts were hospitalized for 5days and then gradually fed increasing amounts of peanut powder up to 133mg/day. One year later, they underwent an oral food challenge after 2weeks of peanut avoidance. Those who were asymptomatic after ingesting 795mg of peanut protein were defined as having achieved sustained unresponsiveness. We measured peanut- and Ara h2-specific immunoglobulin (Ig) E, IgG, and IgG4 levels at 0, 1, 3, 6, and 12months in the OIT group and at 0 and 12months in the control group. At baseline, all children in the OIT group and 8 in the control group had a history of anaphylaxis. The median peanut-/Ara h2-specific IgE levels in the OIT and control groups were 55.4/48.6 and 58.2/38.1kUa/L, respectively. One year later, 8 (33.3%) children in the OIT group exhibited sustained unresponsiveness, while none in the control group did. In the OIT group, the median peanut-specific IgE levels significantly increased to 194.0kUa/L, after 1month and then significantly decreased to 57.5kUa/L at 12months. Meanwhile, the median peanut- and Ara h2-specific IgG and IgG4 levels increased significantly after 1month. Low-dose OIT induces immunological changes and has the capability of achieving sustained unresponsiveness in children with peanut anaphylaxis.