Intrapatient comparison of atopic dermatitis skin transcriptome shows differences between tape‐strips and biopsies

Abstract Background Our knowledge of etiopathogenesis of atopic dermatitis (AD) is largely derived from skin biopsies, which are associated with pain, scarring and infection. In contrast, tape‐stripping is a minimally invasive, nonscarring technique to collect skin samples. Methods To construct a global AD skin transcriptomic profile comparing tape‐strips to whole‐skin biopsies, we performed RNA‐seq on tape‐strips and biopsies taken from the lesional skin of 20 moderate‐to‐severe AD patients and the skin of 20 controls. Differentially expressed genes (DEGs) were defined by fold‐change (FCH) ≥2.0 and false discovery rate <0.05. Results We detected 4104 (2513 Up; 1591 Down) and 1273 (546 Up; 727 Down) DEGs in AD versus controls, in tape‐strips and biopsies, respectively. Although both techniques captured dysregulation of key immune genes, tape‐strips showed higher FCHs for innate immunity (IL‐1B, IL‐8), dendritic cell (ITGAX/CD11C, FCER1A), Th2 (IL‐13, CCL17, TNFRSF4/OX40), and Th17 (CCL20, CXCL1) products, while biopsies showed higher upregulation of Th22 associated genes (IL‐22, S100As) and dermal cytokines (IFN‐γ, CCL26). Itch‐related genes (IL‐31, TRPV3) were preferentially captured by tape‐strips. Epidermal barrier abnormalities were detected in both techniques, with terminal differentiation defects (FLG2, PSORS1C2) better represented by tape‐strips and epidermal hyperplasia changes (KRT16, MKI67) better detected by biopsies. Conclusions Tape‐strips and biopsies capture overlapping but distinct features of the AD molecular signature, suggesting their respective utility for monitoring specific AD‐related immune, itch, and barrier abnormalities in clinical trials and longitudinal studies.