Peripheral Immune Modulation in Atopic Dermatitis During Dupilumab or Baricitinib Treatment Is Limited, as Assessed by Proteomic, Transcriptomic, and Torque Teno Virus Analyses

Atopic dermatitis is a common inflammatory skin disease affecting up to 10% of adults. Whether atopic dermatitis exhibits a strong systemic inflammatory signature remains debated. We characterized peripheral whole-blood alterations in adults with moderate-to-severe atopic dermatitis undergoing treatment with dupilumab or baricitinib therapy. Blood samples were collected at weeks 0, 4, and 16. Whole-blood proteins were measured using Olink, transcriptomic profiling was performed by RNA sequencing, and torque teno virus plasma levels were quantified by qPCR. During targeted atopic dermatitis therapy with dupilumab or baricitinib, clustering of samples based on gene expression levels showed no separation by time or treatment, with only a limited number of differentially expressed genes. Proteomic changes were similarly modest; however, treatment was consistently associated with decreased CCL17/TARC levels. Teno torque virus plasma load remained stable throughout therapy, indicating preserved immunocompetence. These findings suggest that the dominant inflammatory processes in atopic dermatitis may be largely tissue-restricted, supporting the use of peripheral biomarkers for pragmatic monitoring rather than mechanistic discovery.