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

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 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 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 (p < .001), Ara h 2 sIgG (p = .01), peanut sIgG/sIgE (p < .001) and Ara h 2 sIgG/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 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.