Risk Subgroups and Intervention Effects Among Infants at High Risk for Peanut Allergy: A Model for Clinical Decision Making

In a secondary analysis of the Learning Early About Peanut Allergy trial, subgroups of infants were identified with the intervention effects of early peanut introduction.The Learning Early About Peanut Allergy trial included 640 patients (4–11 months old) with severe eczema, egg allergy and peanut skin prick test ≤ 4 mm. They were randomized to consumption of peanut protein (307) or avoidance (314) until 60 months of age.The first stage of data analysis was classification and regression tree analysis modeling to predict risk of peanut allergy at 60 months between the groups. A conditional random forest analysis was used to select variables, including peanut specific IgE, IgG4, and component testing, plus the clinical variable already described.Higher peanut specific IgE and Ara h 2 slgE were identified as predictors of peanut allergy at 60 months. This suggests that participants with peanut IgE < 0.22 kU/L and Ara h 2 sIgE > 0.10 kU/L showed a probability, with both biomarkers being negative, of 6.69% of being allergic at 60 months.Baseline elevation of specific IgE and Ara h 2 sIgE are predictors of allergy to peanut at 60 months. Infants with higher predicted probability of peanut allergy benefit more from early introduction of peanut protein.The use of clinical characteristics and released biomarkers will identify patients who are more or less likely to respond to early introduction of peanut to prevent allergy at 60 months. This information can provide further support for pediatricians' recommendations regarding early introduction of peanuts.