A. Peripheral basophil activation testing to Ara h 2 to identify degranulation as percentage of CD63hi basophils by flow cytometry. B. Basophil sensitivity (ED50) and AUC (AUC, filled green) in representative SU (left, blue) and TD (right, red) subjects. C, D. Longitudinal basophil sensitivity and AUC using a generalized additive mixed model (with smoothing by Laplace approximate) to Ara h 2 (C) and peanut (D) in SU (blue) or TD (dashed, red). The y-axis is logarithmically scaled for basophil AUC, the peanut avoidance period is shaded in grey, and the black arrow marks 3 months of OIT. Labeled visits on the x-axis include pre-OIT (Bl), build-up visits (B), maintenance (M), post-OIT oral food challenge (O), post-avoidance double blinded food challenge (D), and the follow-up visits (F). Lines indicate means and shaded regions indicate standard deviation. X-axis lettered labels refer to visits, PreOIT (P), Build-up (B), Maintainance (M), Post-OIT OFC (O), Post-avoidance DBFC (D), Follow-up (F). E. The proportion of the variance in Ara h 2 ED50 change from baseline to post-avoidance explained by quantitative measurements of serum Ara h 2 specific immunoglobulins.