Neutrophil Extracellular Traps and Lupus Nephritis

In recent years, growing evidence has emphasized the role of innate immune dysregulation in the pathogenesis of lupus nephritis, particularly the involvement of neutrophils and aberrant cell death pathways. Among these mechanisms, neutrophil extracellular traps (NETs) have emerged as key mediators of autoimmune-driven inflammation. NETs are extracellular chromatin networks composed of DNA, histones, and granular proteins released by activated neutrophils during NETosis. Although originally described as antimicrobial defense structures, excessive NET formation and impaired degradation have been strongly implicated in systemic autoimmunity. In lupus nephritis, NETs contribute to renal injury through multiple mechanisms, including exposure of nuclear autoantigens, amplification of type I interferon signaling, activation of complement pathways, and direct cytotoxic effects on endothelial cells and podocytes. Moreover, impaired NET clearance has been demonstrated in SLE, further promoting persistent immune activation and renal inflammation. Recent studies have also suggested that circulating NETs levels are elevated in patients with renal involvement and may correlate with disease activity and outcomes. However, most available data are cross-sectional, and limited evidence exists regarding the dynamic changes of NETs in response to therapy. Therefore, evaluating NETs before and after treatment may provide important insights into their role as predictive and prognostic biomarkers and potential therapeutic targets in lupus nephritis.