D1.495 - Noninvasive Monitoring of Cutaneous Molecular Changes During Improvement of Infantile Atopic Dermatitis: Application of Skin Surface Lipid RNA (SSL-RNA) Analysis

Early-onset infant eczema and persistent eczema have been shown to increase the risk of food allergies, and early appropriate intervention and continuous management of eczema are important for preventing atopic march. Proactive therapy has been recommended for the treatment of atopic dermatitis (AD) which strategy to suppress the "flares" and maintain long-term remission. However, treatment efficacy is mainly evaluated by clinical indices and blood tests, and the molecular changes occurring within the skin—particularly in young infants—remain insufficiently understood. Recently, we developed a technique for comprehensive analysis of measurable level of RNA present in sebum (skin surface lipid RNA; SSL-RNA) collected with a single oil‑blotting film, suggesting the potential to detect molecular profile from the skin. We used this method to understand the molecular changes in infant skin following 16 weeks of proactive eczema management. 

Ten infants diagnosed with AD at 2 months (median EASI score of 12.37 ± 7.01 and a median head and neck EASI score of 2.94 ± 2.02) received outpatient proactive therapy, comprising topical corticosteroid ointments and heparinoid-containing moisturizers. To assess treatment efficacy, we analyzed clinical outcomes and longitudinal SSL‑RNA profiles.

All ten infants with AD exhibited marked improvement in clinical scores.  SSL-RNA analysis revealed improvements in gene expression signatures associated with immune response and skin barrier function corresponding to AD pathology. Genes associated with Th2, Th17, and Treg, as well as skin barrier–related genes, were found to correlate strongly with AD severity. Importantly, although clinical signs of eczema appeared well controlled, SSL-RNA analysis revealed inter-individual variability in molecular response trajectories despite similar clinical improvement.

Proactive therapy with topical corticosteroids and heparinoid moisturizers was associated with clinical improvement and favorable shifts in skin molecular signatures, as determined by non-invasive SSL-RNA profiling. SSL-RNA profiling may facilitate detailed, non-invasive monitoring of molecular skin states in eczema management.