title: Reduced capacity of whole blood leucocytes to express tumour necrosis factor-alpha and interleukin-10 following major orthopaedic surgery.
abstract: BACKGROUND
  Severe trauma is a challenge to the immune response and may cause reduced immune capacity. As a marker of decreased cellular activity, studies with ex vivo lipopolysaccharide (LPS) stimulation of whole blood or isolated mononuclear cells from injured patients have revealed reduced production of inflammatory cytokines. To gain further insight into immune alterations in orthopaedic surgery, we studied LPS-induced tumour necrosis factor (TNF)-alpha and interleukin (IL)-10 in whole blood of patients during peri- and postoperative phases of total hip replacement.
  
  
  METHODS
  Four females and 3 males undergoing elective total hip replacement were included in the study. Ex vivo LPS-induced TNF-alpha and IL-10 were measured in a whole blood assay before, during and at 1 and 6 days after operation. In addition, the counts of white blood cells were determined.
  
  
  RESULTS
  During the operation, there were significant reductions in the number of monocytes, but at day 1 and 6 after surgery, there were significant increases as compared to the levels before surgery. The capacity of whole blood to express TNF-alpha and IL-10 did not change significantly during the operation and the following postoperative day. At day 6, however, there were significant reductions in expression of both TNF-alpha and IL-10 as compared to the levels before the operation. In relation to the values of monocytes, there was a significant reduction in the expression of TNF-alpha also at day 1 after operation.
  
  
  CONCLUSIONS
  Our data indicate that in the course of at least 6 days after a major orthopaedic trauma, there is suppression of the whole blood capacity to express the inflammatory cytokine TNF-alpha and the anti-inflammatory cytokine IL-10 when exposed to LPS. During this time, then, the patient is particular susceptible to septic complications.
authors.affiliation: Department of Orthopaedics, Rikshospitalet University Clinic, Oslo, Norway. olav.reikeras@ikshospitalet.no
authors.forename: O
authors.initials: O
authors.lastname: Reikeraas
authors.forename: J
authors.initials: J
authors.lastname: Sun
authors.forename: C D
authors.initials: CD
authors.lastname: Krohn
authors.forename: J E
authors.initials: JE
authors.lastname: Wang
authors.forename: A O
authors.initials: AO
authors.lastname: Aasen
mesh_terms: D000328:Adult; D000368:Aged; D019644:Arthroplasty, Replacement, Hip; D005260:Female; D006801:Humans; D016753:Interleukin-10 / Q000276:immunology*; D008070:Lipopolysaccharides / Q000276:immunology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000166:cytology / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*
chemical_list: D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha; D016753:Interleukin-10