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

Background Little is known about the development and resolution of early peanut allergy (PA). We examined the natural history and biomarkers of PA longitudinally in three cohorts. Methods PA development was examined in the EAT, LEAP and PAS cohorts. Early PA was defined by skin prick test (SPT) >4mm by 12-months or oral food challenge (OFC) at study entry. PA was confirmed by OFC at study endpoint (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); never peanut allergic (NA). Clinical characteristics and biomarkers were compared between the groups. Results 56.3% of peanut allergic children developed PA by 12-months; 32.1% had early PA resolution by study endpoint. The rate of early PA resolution was 54.2% in EAT, 41.4% in LEAP and 18.6% in PAS cohorts. Median SPTs for EP, ER and LA were: 6mm, 2mm, 0mm at baseline and 10mm, 0mm, 9mm at study endpoint. Median peanut-sIgE levels for EP, ER and LA were 5.9kU A /L, 0.4kU A /L, 0.3kU A /L (p<0.001) at baseline; 4.7kU A /l, 1.3kU A /L, 0.9kU A /L (p<0.001) at 12-months; and 20.1kU A /L, 0.2kU A /L, 5.1kU A /L (p<0.001) at study endpoint. LA had slower component expansion (number of components Ara h 1-sIgE, Ara h 2-sIgE, Ara h 3-sIgE >0.1kU A /L) compared to EP. ER showed component expansion from baseline to 12-months but component retraction by study endpoint. Absence of eczema and egg allergy, low peanut-sIgE or SPT were predictive of PA resolution. Conclusion A significant proportion of PA resolves in early childhood. Different phenotypes of PA display different biomarkers trajectories.