Introduction

Atopic dermatitis (AD) is a common inflammatory skin disease1 that can significantly impact the quality of life in affected patients2. Recent advances in biomarker research have allowed for personalized medicine3. In oncology, cancer survival rates increased dramatically in patients presenting genetic traits known to respond to certain therapies4. Similarly, the discovery of biomarkers for inflammatory skin diseases could facilitate their personalized care in the future5. AD is not a homogeneous entity6, therefore, the identification of biomarkers for disease endotypes may be of great value for proper diagnosis7.
Dupilumab is a monoclonal antibody that targets the interleukin-4 receptor alpha (IL-4Rα) and is used to treat moderate-to-severe AD by blocking the signaling pathways that are involved in inflammation and allergic reactions8. In clinical trials, dupilumab was effective in reducing the severity of AD symptoms including itch, and improving the quality of life in many patients9. However, not all patients respond well to the treatment, and some may experience side effects. The clinical response to dupilumab in AD patients can vary, and there are currently no reliable biomarkers that can predict which patients will respond well to the treatment. Factors that may affect the response to dupilumab include the severity and duration of the disease, certain genetic mutations, and other medical conditions9.
A thorough review by Renert-Yuval et al. summarized the body of knowledge on the biomarkers in AD10. The authors indicated that CCL17 and CCL22 are potential biomarkers that correlate with clinical therapeutic response. One of the more recently suggested biomarkers of AD severity is the skin microbiome11. It has been shown that patients suffering from AD display a higher colonization rate with Staphylococcus aureus (S. aureus ) which is further increased during exacerbation of the disease12. We previously investigated the microbiome of atopic dermatitis patients13 but did not evaluate it upon systemic treatment with biologic therapeutics.
In this study, we aimed to identify biomarkers in AD patients and to analyze their profile upon systemic therapy with dupilumab.