Plasma NET-associated readouts and a multidomain neuroimmune injury axis after experimental subarachnoid hemorrhage: response to dual-pathway modulation.

BACKGROUND: Early neurological dysfunction defines early brain injury after subarachnoid hemorrhage (SAH). Neutrophil extracellular trap (NET) formation increasingly appears to operate as a neuroimmune amplifier rather than a passive marker. We tested whether dual-pathway attenuation of NETosis is associated with suppression of immunothrombotic, redox, and blood-CSF barrier injury and with improved early neurological function after experimental SAH. METHODS: Male Sprague-Dawley rats underwent endovascular perforation SAH and were allocated to Sham+Vehicle, SAH + Vehicle, SAH + DNase-L (2.5 mg/kg q12h, i.p.), SAH + DNase-H (5 mg/kg q12h, i.p.), SAH + Colchicine (0.5 mg/kg q24h, i.p.), or SAH + DNase-H + Colchicine. Treatments started 1 h after SAH. Behavior at 24 h (mNSS, open-field) was assessed in a pre-specified, blinded subcohort (n = 6/group). Multidomain biomarker quantification used a parallel blinded subcohort (n = 6/group). One-way ANOVA with Tukey's HSD was used; biomarker panels were Benjamini-Hochberg FDR-corrected. RESULTS: SAH was associated with rapid increases in plasma NET-associated markers, with cfDNA peaking at 3 h (520 ± 60 vs 135 ± 12 ng/mL in Sham; p < 0.001). Immunothrombotic, redox and blood-CSF barrier indices were markedly elevated at 24 h. The combination group showed the most favorable profile: mNSS 4.17 ± 0.75 vs 11.50 ± 1.05 (Hedges' g = 7.42, 95% CI 5.90-8.94; p < 0.001). Composite z-score correlated with mNSS (Spearman ρ = 0.92, p < 0.001). CONCLUSIONS: Dual-pathway modulation of NETosis is associated with attenuated multidomain neuroimmune readouts and improved early neurological function after experimental SAH, consistent with NETosis as a candidate mechanistic node in early brain injury.