Trial Shows Mechanism of Oral Immunotherapy in Peanut Allergy Desensitization

Findings of research into the mechanism by which oral immunotherapy (OIT) induces a lack of clinical reactivity to peanuts in patients with peanut allergies was presented at the American College of Allergy, Asthma, and Immunology (ACAAI) Annual Scientific Meeting, held in New Orleans, LA, November 4 to 8, 2021.

The phase 2 POISED trial (ClinicalTrials.gov Identifier: NCT02103270) examined peanut OIT in 120 study participants. To obtain the results presented, investigators had isolated peripheral blood mononuclear cells from blood samples of participants in the trial’s placebo- and OIT-treated study arms. The blood samples, which had been collected and frozen at baseline and at week 104, were then stimulated with 200mg/ml peanut solution for 24 hours and probed with a comprehensive metal-conjugated antibody panel, with data collected via mass cytometer.

Investigators found that peanut-reactive CD4⁺ T cells could be identified following the peanut stimulus by upregulation of CD69 and CD40L surface expression. Notably, there was a significant reduction in the median expression of OX40 among peanut-reactive CD4⁺ T cells in the blood of participants receiving OIT compared with placebo, as well as an increase in the frequency of CD27⁺ peanut-reactive CD4⁺ T cells in the OIT group vs the placebo group.

Investigators concluded that “Peanut OIT attenuates the Th2 phenotype of allergen-reactive CD4⁺ cells, thus leading to desensitization to peanut.”

Reference

Do E, Dunham D, Kaushik A, Manohar M, Chinthrajah S, Nadeau K. Mass cytometry analysis reveals dampening of Th2 phenotype among peanut-reactive CD4+ T cells following peanut-OIT. Presented at: American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting; November 4-8, 2021; New Orleans, LA. Abstract A010.