title: Monocyte activation after open and laparoscopic surgery.
abstract: BACKGROUND
  The level of expression of major histocompatibility complex class II antigens, human leucocyte antigen (HLA)-DR, on monocytes correlates with the development of sepsis after surgery or trauma. Normally interferon (IFN) gamma can increase monocyte HLA-DR expression and thus may be a potential biological prophylactic antisepsis agent in patients suffering from accidental or surgical trauma. The purpose of this study was to determine the capacity of monocytes to respond to IFN-gamma after conventional open surgery and laparoscopic surgery of similar magnitude.
  
  
  METHODS
  A whole blood flow cytometric assay was used to measure monocyte HLA-DR antigen expression before and after monocyte activation with either IFN-gamma or bacterial lipopolysaccharide (LPS). Blood was obtained before operation and on postoperative day 1 from 43 patients undergoing conventional open surgery and from 15 undergoing laparoscopic surgery of similar magnitude.
  
  
  RESULTS
  Whole blood monocyte HLA-DR expression fell significantly after both conventional open and laparoscopic surgery. IFN-gamma caused monocyte HLA-DR expression to rise by a median (interquartile range) of 43 (26-60) per cent and 63 (10-124) per cent before operation in the open and laparoscopic groups respectively. However, after operation the corresponding values were 20 (6-41) per cent and 26 (9-74) per cent (P < 0.003 in all cases). Identical findings but of greater magnitude were observed with LPS stimulation before and after operation in the two surgical groups.
  
  
  CONCLUSIONS
  Monocyte HLA-DR expression is diminished by surgical operations and is relatively refractory to further stimulation by IFN-gamma or LPS after surgery. Laparoscopic surgery is as suppressive as conventional surgery in this regard. The resistance of postoperative monocytes to further activation by IFN-gamma suggests that this agent may be ineffective as a biological response modifier after major surgery or trauma.
authors.affiliation: Professorial Surgical Unit, St James's University Hospital, Leeds, UK.
authors.forename: A
authors.initials: A
authors.lastname: Klava
authors.forename: A
authors.initials: A
authors.lastname: Windsor
authors.forename: A W
authors.initials: AW
authors.lastname: Boylston
authors.forename: J V
authors.initials: JV
authors.lastname: Reynolds
authors.forename: C W
authors.initials: CW
authors.lastname: Ramsden
authors.forename: P J
authors.initials: PJ
authors.lastname: Guillou
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D004306:Dose-Response Relationship, Immunologic; D017558:Elective Surgical Procedures; D005260:Female; D006684:HLA-DR Antigens / Q000378:metabolism*; D000949:Histocompatibility Antigens Class II / Q000378:metabolism; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D010535:Laparoscopy; D007958:Leukocyte Count; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D009000:Monocytes / Q000276:immunology*; D011184:Postoperative Period; D011994:Recombinant Proteins; D013514:Surgical Procedures, Operative
chemical_list: D006684:HLA-DR Antigens; D000949:Histocompatibility Antigens Class II; D008070:Lipopolysaccharides; D011994:Recombinant Proteins; D007371:Interferon-gamma