Evolution of pathologic T-cell subsets in atopic dermatitis from infancy to adulthood

Abstract Background The circulating immune phenotype was defined in adults and young children with early atopic dermatitis/AD, but chronologic changes in blood of AD infants and children through adolescence have not been explored. Objective To compare immune activation and cytokine polarization in blood of 0-5y/o (n=39), 6-11y/o (n=26), 12-17y/o (n=21) and ≥18y/o (n=43) patients with AD vs. age-matched controls. Methods Flow cytometry was used to measure interferon-γ, interleukin (IL)-9, IL-13, IL-17, and IL-22 cytokines in CD4+/CD8+ T-cells, with ICOS and HLA-DR defining mid- and long-term T-cell activation, respectively, within skin-homing/CLA+ vs. systemic/CLA- T-cells. Unsupervised clustering differentiated patients based on their blood biomarker frequencies. Results While CLA+ Th1 frequencies were significantly lower in infants with AD vs. all older patients (P Conclusions The adult AD phenotype is achieved only in adulthood. Unique cytokine signatures characterizing individual pediatric age endotypes may require age-specific therapies. Future longitudinal studies, comparing the profile of cleared vs. persistent pediatric AD, may define age-specific changes that predict AD clearance.