title: Post-cardiac arrest serum levels of glial fibrillary acidic protein for predicting neurological outcome.
abstract: OBJECTIVE
  To investigate serum levels of glial fibrillary acidic protein (GFAP) for evaluation of neurological outcome in cardiac arrest (CA) patients and compare GFAP sensitivity and specificity to that of more studied biomarkers neuron-specific enolas (NSE) and S100B.
  
  
  METHODS
  A prospective observational study was performed in three hospitals in Sweden during 2008-2012. The participants were 125 CA patients treated with therapeutic hypothermia (TH) to 32-34 °C for 24 hours. Samples were collected from peripheral blood (n=125) and the jugular bulb (n=47) up to 108 hours post-CA. GFAP serum levels were quantified using a novel, fully automated immunochemical method. Other biomarkers investigated were NSE and S100B. Neurological outcome was assessed using the Cerebral Performance Categories scale (CPC) and dichotomized into good and poor outcome.
  
  
  RESULTS
  GFAP predicted poor neurological outcome with 100% specificity and 14-23% sensitivity at 24, 48 and 72 hours post-CA. The corresponding values for NSE were 27-50% sensitivity and for S100B 21-30% sensitivity when specificity was set to 100%. A logistic regression with stepwise combination of the investigated biomarkers, GFAP, did not increase the ability to predict neurological outcome. No differences were found in GFAP, NSE and S100B levels when peripheral and jugular bulb blood samples were compared.
  
  
  CONCLUSIONS
  Serum GFAP increase in patients with poor outcome but did not show sufficient sensitivity to predict neurological outcome after CA. Both NSE and S100B were shown to be better predictors. The ability to predict neurological outcome did not increased when combining the three biomarkers.
authors.affiliation: Department of Surgical Sciences-Anaesthesiology & Intensive Care, Uppsala University, SE- 751 85 Uppsala, Sweden. Electronic address: ing-marie.larsson@surgsci.uu.se.
authors.forename: Ing-Marie
authors.initials: IM
authors.lastname: Larsson
authors.affiliation: Department of Surgical Sciences-Anaesthesiology & Intensive Care, Uppsala University, SE- 751 85 Uppsala, Sweden.
authors.forename: Ewa
authors.initials: E
authors.lastname: Wallin
authors.affiliation: Faculty of Health and Occupational Studies, Department of Health and Caring Sciences, University of Gävle, SE- 801 76 Gävle, Sweden; Department of Public Health and Caring Sciences, Uppsala University, SE- 751 22 Uppsala, Sweden.
authors.forename: Marja-Leena
authors.initials: ML
authors.lastname: Kristofferzon
authors.affiliation: Roche Diagnostics GmbH, Penzberg, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Niessner
authors.affiliation: Department of Psychiatry and Neurochemistry, the Sahlgrenska Academy at the University of Gothenburg, Institute of Neuroscience and Physiology, Mölndal, Sweden; UCL Institute of Neurology, Queen Square, London WC1N 3BG, United Kingdom.
authors.forename: Henrik
authors.initials: H
authors.lastname: Zetterberg
authors.affiliation: Department of Surgical Sciences-Anaesthesiology & Intensive Care, Uppsala University, SE- 751 85 Uppsala, Sweden.
authors.forename: Sten
authors.initials: S
authors.lastname: Rubertsson
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood* / Q000453:epidemiology / Q000209:etiology; D005260:Female; D005500:Follow-Up Studies; D005904:Glial Fibrillary Acidic Protein / Q000097:blood*; D006323:Heart Arrest / Q000150:complications / Q000401:mortality / Q000628:therapy*; D006801:Humans; D007036:Hypothermia, Induced / Q000379:methods*; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D012151:Resuscitation / Q000379:methods*; D064568:S100 Calcium Binding Protein beta Subunit / Q000097:blood; D015996:Survival Rate / Q000639:trends; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D015415:Biomarkers; D005904:Glial Fibrillary Acidic Protein; D064568:S100 Calcium Binding Protein beta Subunit; C579160:S100B protein, human
keywords: Biomarkers; Cardiac arrest; Prognostication; Therapeutic hypothermia