Whole blood transcriptomics identifies gene expression associated with peanut allergy in infants at high risk.

Abstract

Evidence suggests early oral introduction of peanut prevents peanut allergy, particularly in a high risk infant population. Despite early oral introduction guidelines, there will continue to be infants and young children who develop peanut allergy. Current testing modalities utilized for evaluation of peanut allergy have poor positive predictive value, particularly when applied to patients with no history of oral exposure to peanut. The oral food challenge is a procedure conducted to confirm a food allergy diagnosis. This procedure is not without risk and has particular unique challenges in the younger patient population. We sought to identify key differentially expressed genes that may distinguish peanut allergic infants among those at high risk for peanut allergy. Twenty infants aged 4-11 months with egg allergy and/or severe atopic dermatitis (i.e. high risk) were prospectively recruited from a tertiary care clinic. Infants were classified as peanut allergic, peanut sensitized, but tolerant, or peanut non-allergic based on clinical history, skin prick testing, specific IgE, and/or oral food challenge. RNA was isolated from whole blood and samples underwent RNA-seq library preparation and sequencing. Differential expression analysis was performed. Eight genes were differentially expressed in peanut sensitized, but tolerant subjects compared to the peanut non-allergic subjects. Four genes were differentially expressed in peanut allergic versus peanut non-allergic subjects and in peanut allergic versus peanut sensitized, but tolerant subjects. Differential gene expression in whole peripheral blood was identified between these three groups of high risk infants, however, whole blood may not be an optimal biospecimen for detection of relevant, subtle gene expression changes.