Longitudinal peanut and Ara h 2 specific‐IgE, ‐IgG4, and ‐IgG4/‐IgE ratios are associated with the natural resolution of peanut allergy in childhood

Abstract Background There are no studies of longitudinal immunoglobulin measurements in a population‐based cohort alongside challenge‐confirmed peanut allergy outcomes. Little is known about biomarkers for identifying naturally resolving peanut allergy during childhood. Objectives To measure longitudinal trends in whole peanut and component Ara h 2 sIgE and sIgG 4 in the first 10 years of life, in a population cohort of children with challenge‐confirmed peanut allergy, and to determine whether peanut‐specific immunoglobulin levels or trends are associated with peanut allergy persistence or resolution by 10 years of age. Methods One‐year‐old infants with challenge‐confirmed peanut allergy ( n = 156) from the HealthNuts study ( n = 5276) were prospectively followed at ages 4, 6, and 10 years with questionnaires, skin prick tests, oral food challenges, and plasma total‐IgE, sIgE and sIgG 4 to peanut and Ara h 2. Results Peanut allergy resolved in 33.9% (95% CI = 25.3%, 43.3%) of children by 10 years old with most resolving (97.4%, 95% CI = 86.5%, 99.9%) by 6 years old. Decreasing Ara h 2 sIgE ( p = .01) and increasing peanut sIgG 4 ( p < .001), Ara h 2 sIgG 4 ( p = .01), peanut sIgG 4 /sIgE ( p < .001) and Ara h 2 sIgG 4 /sIgE ( p < .001) from 1 to 10 years of age were associated with peanut allergy resolution. Peanut sIgE measured at 1 year old had the greatest prognostic value (AUC = 0.75 [95% CI = 0.66, 0.82]); however, no single threshold produced both high sensitivity and specificity. Conclusion One third of infant peanut allergy resolved by 10 years of age. Decreasing sIgE and sIgG 4 to peanut and Ara h 2 over time were associated with natural resolution of peanut allergy. However, biomarker levels at diagnosis were not strongly associated with the natural history of peanut allergy.