Background <p>Primary biliary cholangitis (PBC) is a chronic autoimmune liver disease in which many patients respond inadequately to ursodeoxycholic acid (UDCA) and may progress to liver failure. Although research on PBC has primarily centered on lymphocyte-mediated mechanisms, increasing evidence implicates neutrophils in autoimmunity, yet their role in PBC remains unclear.</p> Methods <p>Cytokine screening of patient sera collected from our medical center was performed to identify NETs-inducing factors. Transcriptomic profiling was conducted to determine the molecular effects of NETs on cholangiocytes. The therapeutic effects of the neutrophil elastase inhibitor sivelestat on NETs-associated injury were evaluated in dnTGFβRII and 2OA–BSA murine models of PBC.</p> Results <p>We identify NETs as a critical mediator linking immune activation to biliary injury. NETs formation was markedly elevated in PBC patient samples and murine models. Exploratory cytokine profiling of patient serum samples prioritized resistin as a leading candidate mediator of NETs formation, and elevated circulating resistin levels were confirmed in an independent clinical cohort. Further analysis of patient clinical data revealed that circulating resistin levels were positively correlated with cholestasis. Transcriptomic profiling demonstrated that NETs exposure downregulated ZNF709 and activated the TP53–MDM2 pathway in cholangiocytes, leading to epithelial injury and PBC-like phenotypic changes. In vivo, treatment with sivelestat significantly reduced biliary inflammation and fibrosis, while combination therapy with UDCA produced synergistically therapeutic benefits.</p> Conclusions <p>These findings identify a resistin–NETs–ZNF709 axis that links neutrophil activation to cholangiocyte injury in PBC and suggest that targeting NETs-associated injury with sivelestat may represent a potential strategy to improve current PBC therapies.</p> Graphical abstract <p></p>