The Role of IL-17 in Systemic Autoinflammatory Diseases: Mechanisms and Therapeutic Perspectives.

Interleukin (IL)-17, a pro-inflammatory cytokine, plays a pivotal role in immune regulation by bridging innate and adaptive responses. Beyond its canonical involvement in T helper-17 cells-mediated immunity, IL-17 contributes significantly to the pathogenesis of systemic autoinflammatory diseases (SAIDs) including Familial Mediterranean Fever (FMF), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3)-associated autoinflammatory diseases, and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome. Dysregulated IL-17 signaling drives inflammasome activation, neutrophil recruitment, and chronic tissue inflammation. IL-17 inhibitors have demonstrated efficacy in refractory SAIDs, though challenges such as increased infection risks, paradoxical inflammatory reactions, and uncertainties regarding long-term safety persist. Currently, there is insufficient data to support the use of IL-17 inhibitors as first-line treatments, and their role in managing SAIDs is yet to be fully defined. This review highlights the mechanistic role of IL-17 in SAIDs and emerging therapeutic strategies, including IL-17-targeted monotherapies and combination approaches with IL-1 or tumor necrosis factor (TNF) inhibitors. Future research should focus on biomarker development, combination therapies, and long-term studies to optimize the safety and efficacy of IL-17-targeted therapies in SAIDs.