title: Low CD8 T cells in neonates and infants prior to surgery, and health-care-associated infections: prospective observational study.
abstract: BACKGROUND
  Major surgery suppresses the cell-mediated immune response in children and adults. Data on preoperative and postoperative T-cell counts in pediatric surgical patients and their relationship to health-care-associated infection (HAI) are not yet known.
  
  
  METHODS
  A prospective observational study was carried out in a level III multidisciplinary neonatal and pediatric intensive care unit. Before and after, and in the first 3 days after surgery, lymphocyte subsets in peripheral blood were measured in 28 neonates and infants on flow cytometry. HAI were classified according to CDC/NHSN criteria.
  
  
  RESULTS
  Six out of 28 neonates and infants (21.4%) developed HAI (group I-HAI), while 22 out of 28 (78.6%) remained infection free (group II-non-HAI). In group I with HAI, the preoperative median cytotoxic T-lymphocyte (CD8-T-cell) level was found to be below normal, and remained very low throughout the study period. In addition, the median and interquartile CD8 T-cell range (358 cells/μL; 304-424 cells/μL) were twice as low compared to group II without HAI (822 cells/μL; 522-933 cells/μL; P = 0.013). No differences were found between the two groups with regard to patient demographics and clinical data.
  
  
  CONCLUSIONS
  Neonates and infants who underwent a major surgical procedure and who had a very low preoperative CD8 T-cell level, developed HAI postoperatively.
authors.affiliation: Department of Pediatric Surgery and Intensive Care, University Medical Centre Ljubljana, Ljubljana, Slovenia. stefan.grosek@kclj.si
authors.forename: Stefan
authors.initials: S
authors.lastname: Grosek
authors.forename: Ziva
authors.initials: Z
authors.lastname: Petrin
authors.forename: Andreja Natasa
authors.initials: AN
authors.lastname: Kopitar
authors.forename: Jan
authors.initials: J
authors.lastname: Grosek
authors.forename: Janez
authors.initials: J
authors.lastname: Erzen
authors.forename: Tanja Stopar
authors.initials: TS
authors.lastname: Gmeiner
authors.forename: Mirjana
authors.initials: M
authors.lastname: Petreska
authors.forename: Janez
authors.initials: J
authors.lastname: Primozic
authors.forename: Alojz
authors.initials: A
authors.lastname: Ihan
mesh_terms: D018414:CD8-Positive T-Lymphocytes / Q000276:immunology*; D003428:Cross Infection / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D005500:Follow-Up Studies; D006801:Humans; D007111:Immunity, Cellular / Q000276:immunology*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D057234:Preoperative Period; D011446:Prospective Studies; D013514:Surgical Procedures, Operative
keywords: cell-mediated immunity; children; critical care; hospital-acquired infection; immunosuppression; surgery