title: Blood glutathione S-transferase-π as a time indicator of stroke onset.
abstract: BACKGROUND
  Ability to accurately determine time of stroke onset remains challenging. We hypothesized that an early biomarker characterized by a rapid increase in blood after stroke onset may help defining better the time window during which an acute stroke patient may be candidate for intravenous thrombolysis or other intravascular procedures.
  
  
  METHODS
  The blood level of 29 proteins was measured by immunoassays on a prospective cohort of stroke patients (N = 103) and controls (N = 132). Mann-Whitney U tests, ROC curves and diagnostic odds ratios were applied to evaluate their clinical performances.
  
  
  RESULTS
  Among the 29 molecules tested, GST-π concentration was the most significantly elevated marker in the blood of stroke patients (p<0.001). More importantly, GST-π displayed the best area under the curve (AUC, 0.79) and the best diagnostic odds ratios (10.0) for discriminating early (N = 22, <3 h of stroke onset) vs. late stroke patients (N = 81, >3 h after onset). According to goal-oriented distinct cut-offs (sensitivity(Se)-oriented: 17.7 or specificity(Sp)-oriented: 65.2 ug/L), the GST-π test obtained 91%Se/50%Sp and 50%Se/91%Sp, respectively. Moreover, GST-π showed also the highest AUC (0.83) and performances for detecting patients treated with tPA (N = 12) compared to ineligible patients (N = 103).
  
  
  CONCLUSIONS
  This study demonstrates that GST-π can accurately predict the time of stroke onset in over 50% of early stroke patients. The GST-π test could therefore complement current guidelines for tPA administration and potentially increase the number of patients accessing thrombolysis.
authors.affiliation: Biomedical Proteomics Research Group, Department of Human Protein Sciences, Faculty of Medicine, Geneva, Switzerland. natacha.turck@unige.ch
authors.forename: Natacha
authors.initials: N
authors.lastname: Turck
authors.forename: Xavier
authors.initials: X
authors.lastname: Robin
authors.forename: Nadia
authors.initials: N
authors.lastname: Walter
authors.forename: Catherine
authors.initials: C
authors.lastname: Fouda
authors.forename: Alexandre
authors.initials: A
authors.lastname: Hainard
authors.forename: Roman
authors.initials: R
authors.lastname: Sztajzel
authors.forename: Ghislaine
authors.initials: G
authors.lastname: Wagner
authors.forename: Denis F
authors.initials: DF
authors.lastname: Hochstrasser
authors.forename: Joan
authors.initials: J
authors.lastname: Montaner
authors.forename: Pierre R
authors.initials: PR
authors.lastname: Burkhard
authors.forename: Jean-Charles
authors.initials: JC
authors.lastname: Sanchez
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D005260:Female; D051549:Glutathione S-Transferase pi / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D020521:Stroke / Q000097:blood* / Q000175:diagnosis* / Q000188:drug therapy; D013997:Time Factors; D010959:Tissue Plasminogen Activator / Q000627:therapeutic use
chemical_list: D015415:Biomarkers; D051549:Glutathione S-Transferase pi; D010959:Tissue Plasminogen Activator