The Diagnostic Potential of Extracellular Vesicles Derived From the Blood Plasma of Glioblastoma Patients

Döring, Katja; Malinova, Vesna; Bettag, Christoph; Rohde, Veit; Schulz, Matthias; Menck, Kerstin; Bleckmann, Annalen; Binder, Claudia; Büntzel, Judith

Abstract

Background/aim: Biomarkers for patients suffering from glioblastoma (GBM) are scarce. Extracellular vesicles (EV) are a promising candidate for a potential biomarker. Therefore, EV concentration could be a potential biomarker of tumor burden, volume, and prognosis. Patients and methods: Large EV (lEV) and small EV (sEV) were isolated from 36 GBM patients' blood plasma by differential centrifugation. Nanoparticle tracking was used to measure EV concentration. Quantitative analysis of tumor volume was performed by evaluating T2/FLAIR relaxation times. Results: The mean size of lEV was 173.3 nm ± 18.2 nm, while sEV measured 148.3 ± 9.0 nm. Patients with higher lEV concentrations showed a trend towards longer overall survival (36.1 vs. 16.5 months, p=0.08). Regarding inflammatory markers, higher leukocyte count was positively correlated with higher sEV concentration (r2=0.3887, DF 21, p=0.0015). No significant relationship was found between lEV or sEV concentration and tumor volume. Conclusion: Overall EV concentration in the peripheral blood is not a predictor of tumor volume. sEV concentration is associated with a potential pro-inflammatory metabolism.