title: IL-6 is a predictive biomarker for stroke associated infection and future mortality in the elderly after an ischemic stroke.
abstract: OBJECTIVE
  Stroke associated infection (within the first seven days) occurs in approximately half of stroke patients and is associated with a worse prognosis, especially in the elderly. It is uncertain what factors predict stroke associated infection, yet identification of a suitable biomarker for infection may allow early and appropriate intervention with antibiotics. The aims of this study were to: a) identify independent risk factors for stroke associated infection, and b) test relationships between these risk factors and mortality at 2 years.
  
  
  METHODS
  Eight-two elderly patients were assessed within 72 h of stroke. Data on stroke severity (Barthel Index), stroke associated infection and mortality at 2 years were collected. Inflammatory biomarkers at baseline and 6 months were measured by ELISA. Logistic regression was used to identify risk factors for stroke associated infection and death.
  
  
  RESULTS
  Patients with stroke associated infection, especially pneumonia, had increased IL-6, more severe strokes, and higher mortality. IL-6 was independently associated with stroke associated infection (OR = 19.2, [95%CI 3.68, 100], p < 0.001), after adjustment for other risk factors and cytokines. IL-6 was also independently associated with 2 year mortality (OR = 9.2, [1.0, 85.1], p = 0.031).
  
  
  CONCLUSIONS
  These data suggest that IL-6 may be a key biomarker for predicting stroke associated infection and mortality in the first two years post stroke.
authors.affiliation: School of Health and Social Care, Bournemouth University, UK.
authors.forename: Joseph
authors.initials: J
authors.lastname: Kwan
authors.forename: Gill
authors.initials: G
authors.lastname: Horsfield
authors.forename: Timothy
authors.initials: T
authors.lastname: Bryant
authors.forename: Mary
authors.initials: M
authors.lastname: Gawne-Cain
authors.forename: Giles
authors.initials: G
authors.lastname: Durward
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Byrne
authors.forename: Nicola A
authors.initials: NA
authors.lastname: Englyst
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D002545:Brain Ischemia / Q000097:blood / Q000150:complications / Q000401:mortality; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D007249:Inflammation / Q000150:complications; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009894:Opportunistic Infections / Q000150:complications* / Q000175:diagnosis / Q000401:mortality; D011014:Pneumonia / Q000150:complications / Q000175:diagnosis; D011379:Prognosis; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D020521:Stroke / Q000097:blood / Q000150:complications* / Q000401:mortality
chemical_list: D015415:Biomarkers; D015850:Interleukin-6
keywords: 95% CIs; 95% confidence intervals; BI; BMI; BP; Barthel Index; Biomarker; Blood pressure; Body mass index; CT; Computed tomography; HPAA; Hypothalamic–pituitary–adrenal axis; IL-6; Infection; Modified Rankin score; Mortality; NIHSS; National Institute of Health Stroke Score; OR; Odds ratios; Risk factors; SAI; Stroke; Stroke associated infection; mRS