Increased plasma UCH-L1 after aneurysmal subarachnoid hemorrhage is associated with unfavorable neurological outcome

Abstract Objective Aneurysmal subarachnoid hemorrhage (aSAH) is a common cause of long-term disability and death. After primary hemorrhage, secondary brain injury is the main cause of mortality and morbidity. Despite extensive research, reliable prognostic biomarkers are lacking. We measured ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) levels in aSAH patients to evaluate its prognostic potential. This is the first time that plasma UCH-L1 has been studied as a potential prognostic biomarker in patients with aSAH. Methods In this prospective population-based study, UCH-L1 levels were measured in aSAH patients (n = 47) for up to five days. UCH-L1 was measured at 0, 12 and 24 h after the admission to the intensive care unit (ICU) and daily thereafter until the patient was transferred from the ICU. Only patients whose UCH-L1 was measured within 24 h from aSAH were included in the study. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH. Results UCH-L1 levels during the first 24 h after aSAH were not significantly different between the groups with favorable (mRS 0–2) and unfavorable (mRS 3–6) neurological outcome. In 22 patients, UCH-L1 levels were obtained for up to five days. In this subgroup, UCH-L1 measured at day five showed significant elevation from baseline levels in patients with unfavorable outcome (p = 0.026). Elevated UCH-L1 levels at day five were higher in patients with unfavorable outcome than in patients with favorable outcome (p = 0.001). Conclusions Elevated UCH-L1 levels during the five-day follow-up were associated with unfavorable neurological outcome. Repetitive measurements of UCH-L1 concentrations with an emphasis on change relative to the individual baseline could be the optimal approach for future clinical studies.