title: 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 24h 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 24h 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 24h 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.
authors.affiliation: Critical Care Medicine Research Group, Department of Intensive Care, Tampere University Hospital, Tampere, Finland; NeuroGroup, BioMediTech, University of Tampere, Tampere, Finland. Electronic address: heikki.kiiski@fimnet.fi.
authors.forename: Heikki
authors.initials: H
authors.lastname: Kiiski
authors.affiliation: Critical Care Medicine Research Group, Department of Intensive Care, Tampere University Hospital, Tampere, Finland; Department of Surgical Sciences, Division of Anesthesiology and Intensive Care, Uppsala University, Uppsala, Sweden.
authors.forename: Jyrki
authors.initials: J
authors.lastname: Tenhunen
authors.affiliation: Critical Care Medicine Research Group, Department of Intensive Care, Tampere University Hospital, Tampere, Finland.
authors.forename: Marika
authors.initials: M
authors.lastname: Ala-Peijari
authors.affiliation: School of Health Sciences, University of Tampere, Tampere, Finland.
authors.forename: Heini
authors.initials: H
authors.lastname: Huhtala
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine, Tampere University Hospital, Tampere, Finland.
authors.forename: Mari
authors.initials: M
authors.lastname: Hämäläinen
authors.affiliation: Critical Care Medicine Research Group, Department of Intensive Care, Tampere University Hospital, Tampere, Finland.
authors.forename: Jaakko
authors.initials: J
authors.lastname: Långsjö
authors.affiliation: The Immunopharmacology Research Group, University of Tampere School of Medicine, Tampere University Hospital, Tampere, Finland.
authors.forename: Eeva
authors.initials: E
authors.lastname: Moilanen
authors.affiliation: NeuroGroup, BioMediTech, University of Tampere, Tampere, Finland.
authors.forename: Susanna
authors.initials: S
authors.lastname: Narkilahti
authors.affiliation: Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Öhman
authors.affiliation: Department of Neurosciences and Rehabilitation, Tampere University Hospital, Tampere, Finland.
authors.forename: Jukka
authors.initials: J
authors.lastname: Peltola
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D005260:Female; D006801:Humans; D006849:Hydrocephalus / Q000097:blood / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011446:Prospective Studies; D013345:Subarachnoid Hemorrhage / Q000097:blood / Q000150:complications / Q000175:diagnosis*; D043222:Ubiquitin Thiolesterase / Q000097:blood*
chemical_list: D015415:Biomarkers; C482860:UCHL1 protein, human; D043222:Ubiquitin Thiolesterase
keywords: Aneurysmal subarachnoid hemorrhage; Biomarkers; Neurological outcome; Secondary brain injury; UCH-L1