title: Inflammatory markers and poor outcome after stroke: a prospective cohort study and systematic review of interleukin-6.
abstract: BACKGROUND
  The objective of this study was to determine whether: (a) markers of acute inflammation (white cell count, glucose, interleukin-6, C-reactive protein, and fibrinogen) are associated with poor outcome after stroke and (b) the addition of markers to previously validated prognostic models improves prediction of poor outcome.
  
  
  RESULTS
  We prospectively recruited patients between 2002 and 2005. Clinicians assessed patients and drew blood for inflammatory markers. Patients were followed up by postal questionnaire for poor outcome (a score of>2 on the modified Rankin Scale) and death through the General Register Office (Scotland) at 6 mo. We performed a systematic review of the literature and meta-analysis of the association between interleukin-6 and poor outcome after stroke to place our study in the context of previous research. We recruited 844 patients; mortality data were available in 844 (100%) and functional outcome in 750 (89%). After appropriate adjustment, the odds ratios for the association of markers and poor outcome (comparing the upper and the lower third) were interleukin-6, 3.1 (95% CI: 1.9-5.0); C-reactive protein, 1.9 (95% CI: 1.2-3.1); fibrinogen, 1.5 (95% CI: 1.0-2.36); white cell count, 2.1 (95% CI: 1.3-3.4); and glucose 1.3 (95% CI: 0.8-2.1). The results for interleukin-6 were similar to other studies. However, the addition of inflammatory marker levels to validated prognostic models did not materially improve model discrimination, calibration, or reclassification for prediction of poor outcome after stroke.
  
  
  CONCLUSIONS
  Raised levels of markers of the acute inflammatory response after stroke are associated with poor outcomes. However, the addition of these markers to a previously validated stroke prognostic model did not improve the prediction of poor outcome. Whether inflammatory markers are useful in prediction of recurrent stroke or other vascular events is a separate question, which requires further study. Please see later in the article for the Editors' Summary.
authors.affiliation: Division of Clinical Neurosciences, Western General Hospital, University of Edinburgh, Edinburgh, United Kingdom. william.whiteley@ed.ac.uk
authors.forename: William
authors.initials: W
authors.lastname: Whiteley
authors.forename: Caroline
authors.initials: C
authors.lastname: Jackson
authors.forename: Steff
authors.initials: S
authors.lastname: Lewis
authors.forename: Gordon
authors.initials: G
authors.lastname: Lowe
authors.forename: Ann
authors.initials: A
authors.lastname: Rumley
authors.forename: Peter
authors.initials: P
authors.lastname: Sandercock
authors.forename: Joanna
authors.initials: J
authors.lastname: Wardlaw
authors.forename: Martin
authors.initials: M
authors.lastname: Dennis
authors.forename: Cathie
authors.initials: C
authors.lastname: Sudlow
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D001786:Blood Glucose / Q000378:metabolism; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007249:Inflammation / Q000097:blood*; D015850:Interleukin-6 / Q000097:blood*; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011379:Prognosis; D011446:Prospective Studies; D020521:Stroke / Q000097:blood*
chemical_list: D015415:Biomarkers; D001786:Blood Glucose; D015850:Interleukin-6; D005340:Fibrinogen; D002097:C-Reactive Protein