Tolerance Induction Program Effect Explains Variation in Wheal Size, sIgE, and IgG4 in Peanut Allergic Children

Abstract

Background: Tolerance induction oral immunotherapy, unique to our centre and termed the Tolerance Induction Program (TIP), has shown promise as a safe form of treatment in peanut allergic children. Evaluations of emerging treatments for peanut allergy typically report from a population average perspective. Our study sought to compare rate of decline in peanut-skin prick testing wheal size and sIgE following one year of high dose, weekly peanut immunotherapy using the standard population average approach to findings that account for subject variation in intercepts and slopes. Methods: This is a descriptive study in 51 peanut allergic children who underwent TIP at the Translational Pulmonary and Immunology Research Centre in Long Beach, California. Post intervention reductions in peanutwheal size and sIgE were assessed using Wilcoxen signed rank test and mixed effects modelling procedures. Results: The population average approach estimated reduction in wheal size to 29% of baseline value (p<0.001), compared to 41% after adjustment for random intercepts and slopes, p<0.001. Reduction in sIgE to 30% of baseline value using the population average approach (p<0.001), compared to 46% in the random intercepts model (p<0.001), and 44% in the random intercepts and slopes model (p=0.064). Conclusions: Tolerance induction oral immunotherapy significantly reduced peanut-SPT wheal size and sIgE in peanut allergic children. The subject specific approach produced more conservative effect estimates than observed using the standard population average approach.