Transcriptomic evaluation of skin tape‐strips in children with allergic asthma uncovers epidermal barrier dysfunction and asthma‐associated biomarkers abnormalities

Abstract Introduction Tape‐strips, a minimally invasive method validated for the evaluation of several skin diseases, may help identify asthma‐specific biomarkers in the skin of children with allergic asthma. Methods Skin tape‐strips were obtained and analyzed with RNA‐Seq from children with moderate allergic asthma (MAA) ( n = 11, mean age 7.00; SD = 1.67), severe allergic asthma (SAA) ( n = 9, mean age 9.11; SD = 2.37), and healthy controls (HCs) ( n = 12, mean age 7.36; SD = 2.03). Differentially expressed genes (DEGs) were identified by fold change ≥2 with a false discovery rate <0.05. Transcriptomic biomarkers were analyzed for their accuracy in distinguishing asthma from HCs, their relationships with asthma‐related outcomes (exacerbation rate, lung function‐FEV1, IOS‐R5‐20, and lung inflammation‐FeNO), and their links to skin (barrier and immune response) and lung (remodeling, metabolism, aging) pathogenetic pathways. Results RNA‐Seq captured 1113 in MAA and 2117 DEGs in SAA. Epidermal transcriptomic biomarkers for terminal differentiation (FLG/filaggrin), cell adhesion (CDH19, JAM2), lipid biosynthesis/metabolism (ACOT2, LOXL2) were significantly downregulated. Gene set variation analysis revealed enrichment of Th1/IFNγ pathways ( p < .01). MAA and SAA shared downregulation of G‐protein‐coupled receptor (OR4A16, TAS1R3), upregulation of TGF‐β/ErbB signaling‐related (ACVR1B, EGFR, ID1/2), and upregulation of mitochondrial‐related (HIGD2A, VDAC3, NDUFB9) genes. Skin transcriptomic biomarkers correlated with the annualized exacerbation rate and with lung function parameters. A two‐gene classifier (TSSC4‐FAM212B) was able to differentiate asthma from HCs with 100% accuracy. Conclusion Tape‐strips detected epithelial barrier and asthma‐associated signatures in normal‐appearing skin from children with allergic asthma and may serve as an alternative to invasive approaches for evaluating asthma endotypes.