Oral immunotherapy as a curative treatment for food‐allergic preschool children: Current evidence and potential underlying mechanisms

Abstract

The worldwide rising prevalence of food allergy is a major public health concern. Standard care consists of allergen avoidance and rescue medication upon accidental exposure. Oral immunotherapy (OIT) is increasingly being studied as a treatment option. Although desensitization (an increased reaction threshold) is often achieved during OIT, sustained unresponsiveness (SU; clinical nonreactivity after finishing OIT) is not achieved in most patients. A few studies have investigated the effectiveness of OIT in children younger than 4 years of age (early = e‐OIT) and have shown a much more favorable outcome in terms of SU development. Together with food allergy prevention studies, which have demonstrated high efficacy of early oral allergen exposure, the outcomes of e‐OIT studies indicate an early‐life window of opportunity to achieve SU, allowing unrestricted dietary intake. However, the underlying mechanism of the high effectiveness of e‐OIT is not understood yet. Both cohort and OIT studies indicate early‐life immune plasticity. An immature food‐allergic response in the first years of life seems to be a major driver of this immune plasticity, along with a higher tolerogenic immunological state. Allergy maturation can likely be disrupted effectively by early intervention, preventing the development of persistent food allergy. Upcoming studies will provide important additional data on the safety, feasibility, and effectiveness of e‐OIT. Combined with immune mechanistic studies, this should inform the implementation of e‐OIT.

Editorial comment on “Oral immunotherapy as a curative treatment for food‐allergic preschool children: Current evidence and potential underlying mechanisms”

“…3 Diverse clinical trials confirmed the efficacy of e-OIT in inducing desensitization to peanuts. 3 Furthermore, peanut e-OIT in preschoolers exhibited 4 weeks after stopping e-OIT a sustained unresponsiveness (SU) rate of 91% in a randomized trial involving children under 36 months of age, with 70% being under 24 months of age (DEVIL study). 5 The IMPACT study revealed after 26 weeks of avoidance a SU rate of 21% in the e-OIT group versus 2% in the placebo group.…”

“…Allergic side effects are common but mostly mild and self-limiting. 3 Diverse clinical trials confirmed the efficacy of e-OIT in inducing desensitization to peanuts. 3 Furthermore, peanut e-OIT in preschoolers exhibited 4 weeks after stopping e-OIT a sustained unresponsiveness (SU) rate of 91% in a randomized trial involving children under 36 months of age, with 70% being under 24 months of age (DEVIL study).…”

“…Recently published in Pediatric Allergy and the review presented by Barten et al 3 sheds light on the current state of early OIT (e-OIT) as a curative approach for preschool children with food allergies, exploring both the clinical evidence and the underlying mechanisms guiding its success. Through the examination of the recent literature, the authors highlight that e-OIT represents a window of opportunity to induce long-term clinical and immunological tolerance.…”

“…Through the examination of the recent literature, the authors highlight that e-OIT represents a window of opportunity to induce long-term clinical and immunological tolerance. 3 This may be linked to greater plasticity, either as a characteristic of the immature immune system itself or as a capacity to reverse food allergies in young children before they fully mature. Another hypothesis suggests that our tolerogenic capacity is higher in early life, gradually decreasing over time, making tolerance easier to induce in young children.…”

“…Another hypothesis suggests that our tolerogenic capacity is higher in early life, gradually decreasing over time, making tolerance easier to induce in young children. 3 Barten et al's 3 review reported that e-OIT overall has a good safety profile in preschoolers. Allergic side effects are common but mostly mild and self-limiting.…”