Increased interleukin-6 levels in neuron-derived plasma small extracellular vesicles of subarachnoid haemorrhage patients

Abstract Background: Aneurismal subarachnoid hemorrhage (aSAH) is a serious type of stroke with high mortality and disability. Identifying circulating biomarkers is helpful to improve theranostics of aSAH. In this study, we are for the first time to report circulating interleukin-6(IL-6) in neuron-derived small extracellular vesicles(NDSEVs) were identified to be the potential biomarkers in prognosis of aSAH. Methods: We extracted small extracellular vesicles from the plasma of aSAH patients and healthy controls and were enriched by sequential precipitation and anti-L1CAM antibody immunoabsorption. Subsequently,we determined IL-6 levels by an enzyme-linked immunosorbent assay (ELISA). Result: Plasma IL-6 NDSEVs showed distinct pattern differences between aSAH patients and healthy controls. The IL-6 NDSEVs levels were increased and positively associated with disease monitoring and prognosis of aSAH patients. These data suggest an elevated neuroinflammatory cascade in aSAH patients. Conclusion: The IL-6 NDSEVs maybe prospective biomarkers to indicate its progression, and thus may own great potential in applications such as prognostic evaluation of aSAH in the near future.