title: Innate immune function predicts the development of nosocomial infection in critically injured children.
abstract: BACKGROUND
  Critical injury has been associated with reduction in innate immune function in adults, with infection risk being related to degree of immune suppression. This relationship has not been reported in critically injured children.
  
  
  OBJECTIVE
  Innate immune function will be reduced in critically injured children, and the degree of reduction will predict the subsequent development of nosocomial infection.
  
  
  METHODS
  Children (≤18 years old) were enrolled in this longitudinal, prospective, observational, single-center study after admission to the pediatric intensive care unit following critical injury, along with a cohort of outpatient controls. Serial blood sampling was performed to evaluate plasma cytokine levels and innate immune function as measured by ex vivo lipopolysaccharide-induced tumor necrosis factor α (TNF-α) production capacity.
  
  
  RESULTS
  Seventy-six critically injured children (and 21 outpatient controls) were enrolled. Sixteen critically injured subjects developed nosocomial infection. Those subjects had higher plasma interleukin 6 and interleukin 10 levels on posttrauma days 1-2 compared with those who recovered without infection and outpatient controls. Ex vivo lipopolysaccharide-induced TNF-α production capacity was lower on posttrauma days 1-2 (P = 0.006) and over the first week following injury (P = 0.04) in those who went on to develop infection. A TNF-α response of less than 520 pg/mL at any time in the first week after injury was highly associated with infection risk by univariate and multivariate analysis. Among transfused children, longer red blood cell storage age, not transfusion volume, was associated with lower innate immune function (P < 0.0001). Trauma-induced innate immune suppression was reversible ex vivo via coculture of whole blood with granulocyte-macrophage colony-stimulating factor.
  
  
  CONCLUSIONS
  Trauma-induced innate immune suppression is common in critically injured children and is associated with increased risks for the development of nosocomial infection. Potential exacerbating factors, including red blood cell transfusion, and potential therapies for pediatric trauma-induced innate immune suppression are deserving of further study.
authors: *Pediatric Critical Care Medicine, Department of Pediatrics, and †The Research Institute, Nationwide Children's Hospital, Columbus, Ohio; ‡Critical Care Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio; §Department of Pathology, Nationwide Children's Hospital, Columbus, Ohio; and ║Pediatric Surgery, Nationwide Children's Hospital, Columbus, Ohio; ¶Department of Neurological Surgery, University of California, San Francisco, San Francisco, California; and **Division of Hematology, The Ohio State University College of Medicine, Columbus; ††Emergency Medicine, Department of Pediatrics, Akron Children's Hospital, Akron, Ohio.
authors: Jennifer A
authors: JA
authors: Muszynski
authors: Ryan
authors: R
authors: Nofziger
authors: Kristin
authors: K
authors: Greathouse
authors: Jyotsna
authors: J
authors: Nateri
authors: Lisa
authors: L
authors: Hanson-Huber
authors: Lisa
authors: L
authors: Steele
authors: Kathleen
authors: K
authors: Nicol
authors: Jonathan I
authors: JI
authors: Groner
authors: Gail E
authors: GE
authors: Besner
authors: Corey
authors: C
authors: Raffel
authors: Susan
authors: S
authors: Geyer
authors: Osama
authors: O
authors: El-Assal
authors: Mark W
authors: MW
authors: Hall
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D016638:Critical Illness; D003428:Cross Infection / Q000276:immunology*; D005260:Female; D006801:Humans; D007113:Immunity, Innate; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D014947:Wounds and Injuries / Q000276:immunology*