Kinetics of early peanut allergy development and resolution in the EAT, LEAP, and PAS cohorts.

Abstract

Little is known about the development and resolution of early peanut allergy (PA). We examined the natural history and biomarkers of PA longitudinally in 3 cohorts. PA development was examined in the Enquiring About Tolerance (EAT), Learning Early About Peanut (LEAP), and Peanut Allergy Sensitization (PAS) cohorts. Early PA was defined by skin prick test result of >4 mm by 12 months or oral food challenge at study entry. PA was confirmed by oral food challenge at study end point (36 months for EAT, 60 months for LEAP/PAS). Four groups were defined: early PA development with persistence (EP); early PA development with resolution (ER); late PA development (LA); and never peanut allergic. Clinical characteristics and biomarkers were compared between the groups. A total of 56.3% of peanut-allergic children developed PA by 12 months; 32.1% had early PA resolution by study end point. The rate of early PA resolution was 54.2% in EAT, 41.4% in LEAP, and 18.6% in PAS cohorts. Median skin prick test wheals for EP, ER, and LA were 6, 2, and 0 mm at baseline, and 10, 0, 9 mm at study end point. Median peanut-specific IgE (sIgE) levels for EP, ER, and LA were 5.9, 0.4, and 0.3 kU_A/L (P < .001) at baseline; 4.7, 1.3, and 0.9 kU_A/L (P < .001) at 12 months; and 20.1, 0.2, and 5.1 kU_A/L (P < .001) at study end point. LA had slower component expansion (number of components Ara h 1-sIgE, Ara h 2-sIgE, Ara h 3-sIgE > 0.1 kU_A/L) compared to EP. ER showed component expansion from baseline to 12 months but component retraction by study end point. Absence of eczema and egg allergy, low peanut-sIgE, or skin prick test result were predictive of PA resolution. A significant proportion of PA resolves in early childhood. Different phenotypes of PA display different biomarkers trajectories.