Evolution of epitope-specific IgE and IgG(4) antibodies in children enrolled in the LEAP trial.

Affiliation

Suarez-Farinas M(1), Suprun M(2), Bahnson HT(3), Raghunathan R(4), Getts R(5), duToit G(6), Lack G(6), Sampson HA(7).
Author information:
(1)Icahn Institute for Genomics and Multiscale Biology, Icahn School of Medicine at Mount Sinai, New York, NY; Center for Biostatistics, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY.
(2)Division of Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY.
(3)Benaroya Research Institute and the Immune Tolerance Network, Seattle, Wash.
(4)Center for Biostatistics, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York, NY.
(5)AllerGenis LLC, Hatfield, Pa.
(6)Department of Pediatrics, St Thomas Hospital and King's College London, London, United Kingdom.
(7)Division of Pediatric Allergy and Immunology, Icahn School of Medicine at Mount Sinai, New York, NY. Electronic address: [Email]

Abstract

BACKGROUND: In the LEAP (Learning Early About Peanut Allergy) trial, early consumption of peanut in high-risk infants was found to decrease the rate of peanut allergy at 5 years of age. Sequential epitope-specific (ses-)IgE is a promising biomarker of clinical peanut reactivity. OBJECTIVE: We sought to compare the evolution of ses-IgE and ses-IgG4 in children who developed (or not) peanut allergy and to evaluate the immunomodulatory effects of early peanut consumption on these antibodies. METHODS: Sera from 341 children (LEAP cohort) were assayed at baseline, 1, 2.5, and 5 years of age, with allergy status determined by oral food challenge at 5 years. A bead-based epitope assay was used to quantitate ses-IgE and ses-IgG4 to 64 sequential epitopes from Ara h 1 to Ara h 3 and was analyzed using linear mixed-effect models. RESULTS: In children avoiding peanut who became peanut allergic, the bulk of peanut ses-IgE did not develop until after 2.5 years. Minimal increases of ses-IgE occurred after 1 year in consumers, but not to the same epitopes as those in children developing peanut allergy. No major changes in ses-IgE were seen in nonallergic or sensitized children. IgE in sensitized consumers was detected against peanut proteins. ses-IgG4 increased over time in most children regardless of consumption or allergy status. CONCLUSIONS: Early peanut consumption in infants at high risk of developing peanut allergy appears to divert the immunologic response to a presumably "protective" effect. In general, consumers tend to generate ses-IgG4 earlier and in greater quantities than nonconsumers do, whereas only avoiders tend to generate significant quantities of ses-IgE.