The following is a summary of “Kinetics of basophil hyporesponsiveness during short-course peanut oral immunotherapy,” published in the November 2022 issue of Allergy and clinical immunology by Kulis, et al.

Oral immunotherapy (OIT) alters the adaptive immune response while suppressing mast cell and basophil degranulation. For a study, researchers sought to ascertain the rate at which these effects manifest during OIT and, more generally, the kinetics of basophil and mast cell suppression during the duration of treatment.

Twenty individuals, ranging in age from 4 to 12 years, were recruited in a peanut OIT experiment, and after 9 months of treatment, they were evaluated for desensitization and maintained unresponsiveness. Blood was taken on occasion throughout the first month to measure immunoglobulins and monitor basophil activation by CD63, CD203c, and phosphorylated SYK (pSYK).

Twelve of the 16 trial participants who successfully completed the study were desensitized following OIT, and 9 of them attained maintained unresponsiveness after stopping OIT for 4 weeks. As early as day 90, basophil hyporesponsiveness—characterized by decreased CD63 expression—was seen. The expression of CD63 was associated with pSYK, and by day 250, pSYK had significantly decreased. Throughout treatment, CD203c expression remained unaltered. Contrary to popular belief, basophil activation did not link with specific clinical outcomes despite the fact that it reduced throughout the group throughout OIT. Throughout treatment, serum levels of IgG4 and IgA, but not IgE, that are specific to peanuts rose.

Within the first 90 days of peanut OIT, basophil activation is suppressed, which ultimately resulted in the reduction of pSYK signaling.