title: Chronic Inflammation After Severe Traumatic Brain Injury: Characterization and Associations With Outcome at 6 and 12 Months Postinjury.
abstract: OBJECTIVE
  Examine associations between chronic inflammatory profiles and outcome 6 to 12 months following severe traumatic brain injury (TBI).
  
  
  METHODS
  University-affiliated level 1 trauma center and community.
  
  
  METHODS
  Adults with severe TBI (n = 87); healthy controls (n = 7).
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Glasgow Outcome Scale; serum cytokines (interleukin [IL]-1β, IL-4, IL-5, IL-6, IL-7, IL-8, IL-10, IL-12, tumor necrosis factor α), 2 weeks to 3 months, 4- to 6-month averages, 6- and 12-month levels.
  
  
  RESULTS
  Serum levels of IL-1β, IL-6, IL-8, IL-10, and tumor necrosis factor α were elevated over 3 months following TBI. Multivariate analysis showed that increased cytokine load score was associated with a 1.21 (95% confidence interval, 1.06-1.38) and 1.18 (95% confidence interval, 1.02-1.37) increase in odds of unfavorable Glasgow Outcome Scale score at 6 and 12 months, respectively. Also, elevated IL-6/IL-10 ratios were associated with increased odds of unfavorable outcomes at 6 months (adjusted odds ratio = 1.76; 95% confidence interval, 1.08-2.88).
  
  
  CONCLUSIONS
  Chronic inflammation has not been well characterized following TBI. Our subacute cytokine load score classifies individuals at risk for unfavorable outcomes following injury. Higher proinflammatory burden with IL-6, relative to the anti-inflammatory marker IL-10, is significantly associated with outcome. Further research should examine whether inflammatory genes and other inflammatory biomarkers affect risk for unfavorable outcomes and TBI complications.
authors.affiliation: Department of Physical Medicine and Rehabilitation (Mr Kumar, Ms Boles, and Dr Wagner), Center for Neuroscience (Dr Wagner), and Safar Center for Resuscitation Research (Dr Wagner), University of Pittsburgh, Pittsburgh, Pennsylvania.
authors.forename: Raj G
authors.initials: RG
authors.lastname: Kumar
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Boles
authors.forename: Amy K
authors.initials: AK
authors.lastname: Wagner
mesh_terms: D000046:Academic Medical Centers; D000328:Adult; D015415:Biomarkers / Q000097:blood; D001930:Brain Injuries / Q000097:blood* / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D016022:Case-Control Studies; D002908:Chronic Disease; D016001:Confidence Intervals; D016207:Cytokines / Q000097:blood; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D015600:Glasgow Coma Scale; D006801:Humans; D007249:Inflammation / Q000097:blood* / Q000209:etiology / Q000401:mortality / Q000503:physiopathology; D015601:Injury Severity Score; D007378:Interleukins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010414:Pennsylvania; D011446:Prospective Studies; D018570:Risk Assessment; D016019:Survival Analysis; D013997:Time Factors; D014193:Trauma Centers; D016896:Treatment Outcome; D014409:Tumor Necrosis Factor-alpha
chemical_list: D015415:Biomarkers; D016207:Cytokines; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha