Oral Immunotherapy for Children With a High-Threshold Peanut Allergy

To evaluate the safety, efficacy, and feasibility of a simplified peanut protein (PP) oral immunotherapy (OIT) protocol in children with high-tolerance peanut allergy (HTPA).

The study included 104 participants aged 1 to 18 years. Inclusion criteria included an oral food challenge (OFC) confirmed peanut allergy (PA) and tolerance of <100 mg of PP. Twenty-eight children qualified for the 40-week OIT protocol.

The study was a single center, cross-sectional, prospective trial. Participants were classified into low-tolerance peanut allergy (LTPA) (tolerating <100 mg PP), HTPA (tolerating between 100 mg and 300 mg PP), or very HTPA (tolerating ≥300 mg PP) based on initial peanut OFC. The HTPA group received 100 mg PP daily for 20 weeks followed by an OFC to 300 mg PP. If the OFC was passed, the PP dosage was increased to 300 mg daily for 20 weeks. The very HTPA group received 300mg PP daily for 40 weeks. Repeat OFC to 2 g of PP was performed for all participants at the conclusion of the protocol. If the OFC was passed, both groups consumed 2 g of PP 3 times per week. At 6 months, a final OFC of up to 15 g of PP was performed. Skin prick tests, peanut serum and component IgE, and peanut serum and component IgG4 were compared between children classified as HTPA and LTPA.

Of 104 participants, 76 had LTPA and 28 had HTPA (9 had very HTPA). Twenty three of 28 (82%) HTPA and very HTPA children completed the study, and all who completed the study (23 of 23) incorporated ≥2 g of PP 3 times per week into their diet at 6 month follow up. Of the 5 children who discontinued the protocol, 1 participant had an anaphylactic reaction requiring epinephrine, and 2 participants had mild allergic reactions requiring antihistamines. Compared with those with LTPA, children with HTPA had significantly smaller skin prick test sizes (9.2 mm vs 11.6 mm, P = .03), lower peanut sIgE levels (6.4 IU/mL vs 26.7 IU/mL, P = .03), and lower Ara h2 sIgE (5.1 IU/mL vs 22.3 IU/mL, P = .03).

This study showed that a simplified 40-week PP OIT protocol is safe, efficacious, and feasible in treating PA in children with HTPA and very HTPA.

As only 20% of children are expected to outgrow their PA, OIT is used in this group to improve tolerance to PP through daily exposure. This is one of the first studies to evaluate OIT use in participants specifically with HTPA. It supports the safety and efficacy of OIT in this group. Interestingly, all participants completing the protocol successfully incorporated peanut into their diet at 6 month follow up. Currently OIT is used as a PA treatment and is not considered curative. Although these results could be attributed to the OIT protocol, they could also be secondary to the process of natural resolution of PA in these children with already high tolerance. Further studies are needed to evaluate these results.