Abstract
Prurigo nodularis (PN) is a chronic inflammatory skin disease characterized by intense pruritus and skin nodules. Beyond the skin, PN involves circulating blood inflammation that may contribute to systemic disease comorbidities. Dupilumab was recently approved for treatment of PN, but its effects on systemic inflammation are unknown. Thus, we aimed to characterize changes in plasma concentrations of inflammatory proteins after dupilumab treatment. In this exploratory study, plasma samples were collected from 3 patients with moderate-to-severe PN before and after ≥6 months of dupilumab treatment. All patients exhibited clinically significant improvements after treatment. Of the 2569 proteins tested, 186 were differentially expressed after treatment (q < 0.1, fold change > 1.3). Downregulated proteins included cytokines associated with T helper (Th) 1 (IFN-γ, TNF-α), Th2 (IL-4, IL-13), and Th17/Th22 (IL-6, IL-22) signaling. Markers of innate immunity (IL-19, toll-like receptor 1, nitric oxide synthase 2), immune cell migration (CCL20, CD177), and fibrosis (IL-11, IL-22) were also decreased (q < 0.1). Gene set variation analysis of Th2, Th17, and epithelial-mesenchymal transition gene sets showed reduced pathway expression in the post-treatment cohort (P < .05). Plasma cytokine levels of IL-11, nitric oxide synthase 2, IL-13, IL-4, and IFNG (R(2) > 0.75, q < 0.10) showed the strongest correlations with pruritus severity. Dupilumab may reduce systemic inflammatory proteins associated with multiple immune and fibrosis pathways in patients with PN, potentially modulating the development of systemic disease comorbidities.