Identification of Epidermal Signatures in Patients With Atopic Dermatitis

Atopic dermatitis (AD) is a highly pruritic, chronic inflammatory skin disease that affects up to 25% of children and 10% of adults. Atopic skin disease is associated with significant morbidity as well as physical, psychological, and economical quality-of-life impairment. The economical impact of AD and the requirement for family support can be extraordinary and may be greater than what is typically found for asthma and type I diabetes, respectively. In many patients, the early onset of AD is the first clinical manifestation of allergic disease and often triggers the atopic march, the subsequent development of food allergy, allergic rhinitis, and asthma. The skin of AD patients is characterized by an increased Th2 axis, cellular infiltration and significant epithelial inflammation. These factors permit increased penetration of invading allergens and pathogens that further drive AD pathogenesis and pruritus (itch). Approximately 90% of AD patients are colonized with S. aureus, while only 5 - 30% of non-atopic individuals are colonized. Novel therapeutic approaches are currently in clinical trials which provide the opportunity to target pathways integral to AD disease pathogenesis. In recent years, it has been shown that AD is more heterogeneous than initially perceived. Since novel therapeutics target different pathways, one therapeutic approach may not work for all AD patients and each therapy may provide a different level of clinical benefit. Additionally, since AD manifests primarily in the skin, blood collection and analysis may not be the most indicative measurement to determine which therapy is best for each patient. Despite improved understanding of AD, validated methods to non-invasively diagnose and monitor the development or progression of AD are sorely lacking. Additionally, a non-invasive method is needed to understand inflammation at the site of disease manifestation and potentially identify which biological pathways are most relevant for a given patient. This will allow a more personalized approach to treatment of patients with AD.

The investigator has hypothesized that skin proteins are differentially expressed in the upper layers of disease versus non-disease skin tissue and that these may be used as biomarkers for skin changes linked to the development of AD. Previously a method for comparing expression of skin proteins by extracting proteins from tape strips and evaluating differences using mass spectrometry-based proteomics was developed. This non-invasive method is suitable for use in all AD patients and has been used to show an increase in specific skin proteins in AD patients versus normal controls. Despite this success, additional studies are needed to compare gene and protein expression obtained from tape strips with genomic and proteomic profiles from full thickness skin and whole blood. This proposed study will determine the validity of using non-invasive tape stripping, as a surrogate for skin biopsy and whole blood collection, to identify the inflammatory pathway most up-regulated in a given AD patient. This information will be used in defining biomarkers that will facilitate personalized medicine approaches using emerging novel therapeutics.