Baseline epitope-specific IgE profiles are predictive of sustained unresponsiveness or high threshold 1-year post oral immunotherapy in the POISED trial.

Background: Results from the POISED trial suggest that discontinuation of peanut oral immunotherapy can increase the risk of regaining clinical reactivity to peanut.

Objective: We sought to determine whether patients who achieved sustained unresponsiveness (SU) or sustained high threshold (SHT) have different baseline sequential epitope-specific IgE profiles than patients who achieved transient desensitization.

Methods: Subjects in the POISED trial (NCT02103270) were randomized to peanut (n = 95) or placebo (n = 25) for 24 months. Oral immunotherapy-desensitized subjects were then assigned to no peanut (PN-0) (n = 51) or 300 mg peanut (PN-300) (n = 30) for 12 months. SU and SHT were determined by subjects in PN-0 and PN-300, respectively, passing 4000-mg peanut oral challenge. Specific IgE and IgG₄ levels to peanut; Ara h 1, Ara h 2, and Ara h 3 proteins; and 64 allergenic epitopes were measured. We developed machine learning models with bootstrap simulations using baseline data to predict SU/SHT.

Results: Of 80 (84%) subjects who were desensitized to peanut, 13% (n = 8) and 37% (n = 13) achieved SU/SHT in PN-0 and PN-300 groups. Decreases in epitope-and protein-specific IgE levels and increases in IgG₄ levels were observed during 2 years of oral immunotherapy. At baseline, patients with SU in PN-0, but not PN-300, group had lower epitope-specific IgE and protein-specific IgE levels compared with the transient desensitization group. A machine learning model with 12 baseline epitope-specific IgEs and age could predict SU/SHT with accuracy of 94%, area under the curve 0.97, sensitivity 1.00, and specificity 0.91.

Conclusions: Subjects who achieved SU/SHT had different baseline protein- and epitope-specific IgE profiles than subjects with transient desensitization. These profiles may help identify patients with an increased likelihood of achieving SU/SHT.