Systemic immune activation is present within months of pediatric atopic dermatitis (AD) onset, with Th2/Th17 skewing but otherwise different proteomic patterns from adult AD, a new study found. Using high-throughput proteomics, researchers assessed 257 inflammatory and cardiovascular (CV) risk proteins in blood of 30 children with moderate-to-severe AD aged <5 years (within 6 months of onset), compared to age-matched pediatric controls and adult AD. They found:
- In pediatric AD blood, Th2 and Th17 markers were increased, together with markers of tissue remodeling, T-cell activation, neutrophil activation, lipid metabolism, and growth factors.
- Total numbers of dysregulated proteins were smaller (n=22) than in adult AD (n=61).
- Clinical severity scores were positively associated with receptors for IL-33 and IL-36, and inversely correlated with some Th1 markers.
Brunner PM, He H, Pavel AB, et al. The blood proteomic signature of early-onset pediatric atopic dermatitis shows systemic inflammation and is distinct from adult, longstanding disease. [Published online ahead of print April 19, 2019]. J Am Acad Dermatol. doi:10.1016/j.jaad.2019.04.036.
While it is known that a variety of inflammation-related conditions occur in older atopic patients, this study shows that markers of inflammation are present even in young children with AD. However, only about one-third of the number of dysregulated proteins present in adults were found in infants. Interestingly, AD severity correlated with elevated receptors for IL-33 and IL-36, thus lending support to the concept of targeting these interleukins and/or their receptors therapeutically. — Joseph Fowler, Jr., MD, Clinical Professor of Dermatology, University of Louisville, KY