NETosis activity in patients with glioblastoma multiforme compared to healthy controls

Neutrophil extracellular traps derived from NETosis are present in various clinical conditions characterized by elevated concentrations of circulating DNA (cirDNA), including glioblastoma multiforme (GBM). Therefore, the study was designed to explain whether activated neutrophils are the primary source of cirDNA release into the bloodstream and to explore the associations between the cirDNA fragments and clinicopathological characteristics. Preoperative plasma samples from 50 patients (GBM 65.7 ± 10.5 years) and 80 healthy individuals (HC 70.3 ± 5.2 years) were used to determine the levels of total cirDNA, methylated cirDNA, oxidative cirDNA, and myeloperoxidase (MPO). The GBM patients demonstrated significantly higher cirDNA and MPO compared to HC. In GBM, methylated cfDNA represented 7% of total cirDNA whereas in HC it accounted for 12%. The Kaplan-Meier survival curve analysis showed a higher mortality risk with cirDNA of 958-2540 ng/mL. The ROC analysis indicated the optimal cirDNA threshold of 930 ng/mL for cfDNA (AUC = 0.951, p < 0.001), indicating a very high diagnostic value (sensitivity 88% and specificity 91.2%). Elevated plasma concentrations of total cirDNA and MPO may reflect the intensity of NETosis, with high MPO level supporting the concept that activated neutrophils contribute substantially to the pool of circulating cirDNA pool in GBM.