S100B, NSE and MMP-9 fail to predict neurologic outcome while elevated S100B associates with milder initial clinical presentation after aneurysmal subarachnoid hemorrhage

Abstract Objective Despite advances in the treatment of aneurysmal subarachnoid hemorrhage (aSAH) one-year mortality remains approximately 50%. Making an accurate prognosis at the early phase of the disease is notoriously difficult. A clinically reliable biomarker that could be used for better prediction of prognosis and/or as a surrogate for developing complications after aSAH is still lacking. In this study, we evaluated the prognostic values of three promising biomarkers, i.e. S100B, NSE, and MMP-9 in aSAH. Methods In this prospective population-based study, S100B, NSE, and MMP-9 levels were measured in 47 aSAH patients for up to five days. Blood samples were taken at 0, 12 and 24 h after the admission to the intensive care unit (ICU) and daily after that until the patient was transferred from the ICU. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH. Results Biomarker-levels measured during the first 24 h were not associated with neurological outcome. S100B levels during the first 24 h were elevated in patients with a non-severe initial clinical presentation. Otherwise, there was no association between selected clinical variables and the early biomarker levels. In 22 patients, whose ICU follow-up lasted for up to five days, the total release of biomarkers was not associated with the neurological outcome. Conclusions None of the measured biomarkers were associated with the neurological outcome evaluated at six months after aSAH. Elevated levels of S100B in patients with non-severe initial presentation suggest an adaptive role of this biomarker in aSAH. Based on our findings it is not advisable to use these biomarkers to guide clinical decision-making in patients with aSAH.