{Reference Type}: Clinical Trial, Phase I
{Title}: Peanut oral immunotherapy results in increased antigen-induced regulatory T-cell function and hypomethylation of forkhead box protein 3 (FOXP3).
{Author}: Syed A;Garcia MA;Lyu SC;Bucayu R;Kohli A;Ishida S;Berglund JP;Tsai M;Maecker H;O'Riordan G;Galli SJ;Nadeau KC;
{Journal}: J Allergy Clin Immunol
{Volume}: 133
{Issue}: 2
{Year}: Feb 2014
{Factor}: 14.29
{DOI}: 10.1016/j.jaci.2013.12.1037
{Abstract}: <B>BACKGROUND: </B>The mechanisms contributing to clinical immune tolerance remain incompletely understood. This study provides evidence for specific immune mechanisms that are associated with a model of operationally defined clinical tolerance.<BR><B>OBJECTIVE: </B>Our overall objective was to study laboratory changes associated with clinical immune tolerance in antigen-induced T cells, basophils, and antibodies in subjects undergoing oral immunotherapy (OIT) for peanut allergy.<BR><B>METHODS: </B>In a phase 1 single-site study, we studied participants (n = 23) undergoing peanut OIT and compared them with age-matched allergic control subjects (n = 20) undergoing standard of care (abstaining from peanut) for 24 months. Participants were operationally defined as clinically immune tolerant (IT) if they had no detectable allergic reactions to a peanut oral food challenge after 3 months of therapy withdrawal (IT, n = 7), whereas those who had an allergic reaction were categorized as nontolerant (NT; n = 13).<BR><B>RESULTS: </B>Antibody and basophil activation measurements did not statistically differentiate between NT versus IT participants. However, T-cell function and demethylation of forkhead box protein 3 (FOXP3) CpG sites in antigen-induced regulatory T cells were significantly different between IT versus NT participants. When IT participants were withdrawn from peanut therapy for an additional 3 months (total of 6 months), only 3 participants remained classified as IT participants, and 4 participants regained sensitivity along with increased methylation of FOXP3 CpG sites in antigen-induced regulatory T cells.<BR><B>CONCLUSIONS: </B>In summary, modifications at the DNA level of antigen-induced T-cell subsets might be predictive of a state of operationally defined clinical immune tolerance during peanut OIT.