Non‐Invasive Scalp Tape‐Strip RNA Sequencing Captures Disease Activity and Treatment‐Response Signatures in Alopecia Areata

ABSTRACT Background Tape‐strip RNA sequencing enables non‐invasive molecular profiling of inflammatory skin diseases. However, its ability to capture immune activity, disease severity, and treatment response in alopecia areata (AA)—a follicle‐centered autoimmune disorder—has not been systematically evaluated in relation to follicular immune activity and treatment response. Objectives To determine whether scalp tape‐strip RNA sequencing captures immune pathways associated with disease severity and treatment response in AA, and to assess its concordance with matched scalp biopsies. Methods We analyzed 61 RNA‐seq profiles, including 46 scalp tape‐strip samples (19 healthy controls, 17 active AA, and 10 post‐baricitinib samples—five responders and five non‐responders) and 15 lesional scalp biopsies. Nine tape‐strip–biopsy pairs were obtained from the same scalp region. Batch‐corrected expression data were analyzed using covariate‐adjusted linear models and gene set–based enrichment analyses interrogating immune, cytotoxic, and follicular epithelial programs. Results Tape‐strip RNA sequencing robustly recapitulated established AA‐associated immune signatures, including activation of interferon/JAK–STAT signaling and cytotoxic T/NK cell pathways, together with suppression of follicular epithelial programs. Increasing disease severity was associated with progressive immune activation and epithelial loss. Baricitinib responders showed partial normalization of inflammatory signatures, whereas non‐responders retained persistent immune activation, consistent with molecular non‐response. Covariate‐adjusted models identified treatment response–specific transcriptional changes. Tape‐strip and biopsy transcriptomes demonstrated high concordance. Conclusions Scalp tape‐strip RNA sequencing captures clinically relevant immune and treatment‐responsive molecular signatures in alopecia areata and represents a promising platform for longitudinal immune monitoring and biomarker‐driven stratification of treatment response in follicle‐centered autoimmune disease.