J Am Acad Dermatol 2019 Apr 19. Epub 2019 Apr 19.
Department of Dermatology, Northwestern University Feinberg School of Medicine, 676 North St. Clair Street, Chicago, IL 60611, USA. Electronic address:
Background: Despite increasing evidence that adults with longstanding atopic dermatitis (AD) have systemic inflammation, little is known about systemic inflammation in recent-onset early pediatric AD.
Objective: To analyze blood inflammatory proteins of early pediatric AD.
Methods: Using high-throughput proteomics (proximity extension assay), we assessed 257 inflammatory and cardiovascular risk proteins in blood of 30 children with moderate-to-severe AD <5 years of age (within 6 months of onset), compared to age-matched pediatric controls and adult AD.
Results: In pediatric AD blood, Th2 (CCL13, CCL22) and Th17 (PI3/elafin) markers were increased, together with markers of tissue remodelling (MMP3/9/10, uPAR), endothelial activation (E-Selectin), T-cell activation (IL2RA), neutrophil activation (myeloperoxidase), lipid metabolism (FABP4), and growth factors (FGF21, TGF-alpha). Total numbers of dysregulated proteins were smaller (n=22) than in adult AD (n=61). Clinical severity scores were positively correlated with receptors for IL-33 and IL-36, and inversely correlated with some Th1 markers (IFN-γ, CXCL11).
Limitations: Different baseline expression levels in healthy pediatric vs. adult samples.
Conclusions: Within months of pediatric AD onset, systemic immune activation is present, with Th2/Th17 skewing but otherwise different proteomic patterns from adult AD. Future correlation of proteomic patterns with disease course, comorbidity development, and drug response may yield predictive biomarkers.