Plasma cellular prion protein concentrations correlate with severity and prognosis of aneurysmal subarachnoid hemorrhage

•Plasma PrPc levels are significantly elevated after aSAH.•Plasma PrPc levels are highly correlated with severity of aSAH.•Plasma PrPc emerges as an independent predictor of 90-day poor outcome after aSAH.•Plasma PrPc levels efficiently distinguish 90-day poor outcome after aSAH. Cellular prion protein (PrPc) is greatly expressed in injured brain tissues. We investigates correlation of plasma PrPc concentrations with severity, delayed cerebral ischemia (DCI) plus prognosis following aneurysmal subarachnoid hemorrhage (aSAH). Plasma PrPc concentrations were measured in 110 aSAH patients and 110 healthy controls. The World Federation of Neurological Surgeons scale (WFNS) score, Glasgow coma scale (GCS) score, Hunt-Hess score and modified Fisher score were utilized to assess hemorrhagic severity. Relations of plasma PrPc concentrations to DCI and 90-day poor outcome (Glasgow outcome scale score of 1–3) were analyzed using multivariate analysis. Prognostic predictive capabilities were determined under receiver operating characteristic curve. Plasma PrPc concentrations were significantly higher in patients than in controls. Plasma PrPc concentrations were tightly correlated with WFNS score, GCS score, Hunt-Hess score and modified Fisher score. Plasma PrPc emerged as an independent predictor for 90-day poor outcome, but not for DCI. Plasma PrPc concentrations exhibited similar prognostic predictive abilities, as compared to WFNS score, GCS score, Hunt-Hess score and modified Fisher score. Plasma PrPc concentrations are highly associated with severity and poor outcome after hemorrhagic stroke, indicating that plasma PrPc may serve as a useful prognostic biomarker for aSAH.