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

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, 9.6 years) with anaphylaxis to peanuts were hospitalized for 5 days and then gradually fed increasing amounts of peanut powder up to 133 mg/day. One year later, they underwent an oral food challenge after 2 weeks of peanut avoidance. Those who were asymptomatic after ingesting 795 mg 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 12 months in the OIT group and at 0 and 12 months 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 58.2/38.1 kUa/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 194.0 kUa/L, after 1 month and then significantly decreased to 57.5 kUa/L at 12 months. Meanwhile, the median peanut- and Ara h2-specific IgG and IgG4 levels increased significantly after 1 month.

Low-dose OIT induces immunological changes and has the capability of achieving sustained unresponsiveness in children with peanut anaphylaxis.