Non-Invasive Transcriptomic Profiling of Inflammatory Skin Diseases Using Four Tape Strips.

Tape strip-based transcriptomics shows promise for precision medicine in inflammatory skin diseases, but methodological variation limits reproducibility and clinical use. This study investigates whether four or eight tape strips are sufficient for transcriptomic profiling across three inflammatory skin diseases. As part of the Danish cohort study BIOSKIN, patients with atopic dermatitis (AD), contact dermatitis (CD), psoriasis, and healthy controls (n = 8 per group) were enrolled. Two sets of eight consecutive tape strips were obtained from each participant from lesional skin (patients) or healthy skin (controls) and pooled for RNA sequencing as strips 1-8, 1-4, or 5-8. Despite low RNA yield, sequencing was successful across all disease groups. Gene detectability was consistent across tape strip strategies, with 78.1%, 73.1%, and 67.7% overlap across strips 1-4, 5-8, and 1-8 for psoriasis, AD, and CD, respectively. Principal component analysis distinguished patients with psoriasis and AD from healthy controls, and enrichment analysis captured biologically relevant pathways across all three disease groups. In psoriasis, tape strip transcriptomics captured a core psoriatic transcriptome consistent with paired biopsy data. Four tape strips were sufficient for RNA sequencing and detection of disease-relevant inflammatory responses, supporting their use in longitudinal cohort studies and split-sampling designs. Performance was most robust for psoriasis and AD; optimization may benefit CD given the challenges of palmar sampling.