title: Time course of early and late changes in plasma DNA in trauma patients.
abstract: BACKGROUND
  Cell-free DNA concentrations increase in the circulation of patients after trauma and may have prognostic potential, but little is know concerning the temporal changes or clearance of the DNA or its relationships with posttraumatic complications. We investigated temporal changes in plasma DNA concentrations in patients after trauma with use of real-time quantitative PCR.
  
  
  METHODS
  Serial plasma samples were taken from two trauma populations. In the first study, samples were collected every 20 min from 25 patients within the first 3 h of trauma. In the second study, samples were collected every day from 36 other trauma patients admitted to the intensive care unit (ICU).
  
  
  RESULTS
  In the first study, plasma DNA was increased within 20 min of injury and was significantly higher in patients with severe injury and in patients who went on to develop organ failure. In patients with less severe injuries, plasma DNA concentrations decreased toward reference values within 3 h. In the second study, plasma DNA concentrations were higher in patients who developed multiple organ dysfunction syndrome between the second and fourth days of admission than in patients who did not develop the syndrome. In patients who remained in the ICU with continuing organ dysfunction, plasma DNA remained higher than in healthy controls even at 28 days after injury. Most survivors with multiple organ dysfunction syndrome showed an initial very high peak followed by a prolonged smaller increase.
  
  
  CONCLUSIONS
  Plasma DNA concentrations increase early after injury and are higher in patients with severe injuries and in those who develop organ failure. Increased plasma DNA persists for days after injuries, especially in patients with multiple organ dysfunction syndrome.
authors.affiliation: Accident & Emergency Medicine Academic Unit, Department of Chemical Pathology, The Chinese University of Hong Kong, Prince of Wales Hospital, Shatin, New Territories, Hong Kong SAR.
authors.forename: Nicole Y L
authors.initials: NY
authors.lastname: Lam
authors.forename: Timothy H
authors.initials: TH
authors.lastname: Rainer
authors.forename: Lisa Y S
authors.initials: LY
authors.lastname: Chan
authors.forename: Gavin M
authors.initials: GM
authors.lastname: Joynt
authors.forename: Y M Dennis
authors.initials: YM
authors.lastname: Lo
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000097:blood; D004247:DNA / Q000097:blood*; D005260:Female; D005914:Globins / Q000032:analysis / Q000235:genetics; D006801:Humans; D007362:Intensive Care Units; D008297:Male; D009102:Multiple Organ Failure / Q000097:blood / Q000175:diagnosis / Q000401:mortality; D016133:Polymerase Chain Reaction; D013997:Time Factors; D014947:Wounds and Injuries / Q000097:blood / Q000175:diagnosis* / Q000401:mortality
chemical_list: D015415:Biomarkers; D005914:Globins; D004247:DNA