title: Plasma concentrations of defensins and lactoferrin in children with severe sepsis.
abstract: BACKGROUND
  We hypothesized that systemic release of endogenous leukocyte-derived polypeptide antimicrobial defensins (polymorphonuclear leukocyte-specific) and lactoferrin (polymorphonuclear leukocyte and epithelial cell derived) occurs in nonneutropenic children with severe sepsis.
  
  
  METHODS
  We performed a prospective cross-sectional and longitudinal study in a university children's hospital pediatric intensive care unit. Ninety-two consecutive children meeting criteria for sepsis and 14 critically ill children without sepsis (controls) were enrolled, and plasma defensins and lactoferrin concentrations were measured on Days 1 and 3 of sepsis.
  
  
  RESULTS
  Nonneutropenic sepsis patients (n = 71) had increased defensins and lactoferrin plasma concentrations compared with critically ill control patients [defensins, 450 ng/ml vs. 150 ng/ml; lactoferrin, 332 ng/ml vs. 176 ng/ml (median values); P < 0.05] and neutropenic sepsis patients [n = 21; defensins, 450 ng/ml vs. 50 ng/ml; lactoferrin, 332 ng/ml vs. 20 ng/ml (median values); P < 0.05]. Neutropenic sepsis patients had similar plasma defensin concentrations and a decrease in plasma lactoferrin concentrations compared with control patients (P < 0.05). Defensins and lactoferrin plasma concentrations correlated to total white blood cell and absolute neutrophil count (P < 0.05). There was no association between plasma defensin concentration and organ failure or outcome; however, increased plasma lactoferrin concentrations were observed with the development of organ failure (P < 0.05).
  
  
  CONCLUSIONS
  These data suggest that increased circulating defensins and lactoferrin release are dependent in part on neutrophil count and might play a role in host defense in children with severe sepsis.
authors.affiliation: Department of Anesthesiology and Critical Care Medicine, University of Pittsburgh School of Medicine and Children's Hospital of Pittsburgh, Pittsburgh, PA 15213, USA.
authors.forename: Neal J
authors.initials: NJ
authors.lastname: Thomas
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Carcillo
authors.forename: Lesley A
authors.initials: LA
authors.lastname: Doughty
authors.forename: Howell
authors.initials: H
authors.lastname: Sasser
authors.forename: R Phillip
authors.initials: RP
authors.lastname: Heine
mesh_terms: D000293:Adolescent; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D023082:Defensins / Q000097:blood*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D015278:Intensive Care Units, Pediatric; D007781:Lactoferrin / Q000097:blood*; D008297:Male; D009503:Neutropenia / Q000209:etiology* / Q000276:immunology; D011446:Prospective Studies; D018805:Sepsis / Q000276:immunology* / Q000473:pathology; D012720:Severity of Illness Index
chemical_list: D023082:Defensins; D007781:Lactoferrin