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.

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.

This review addresses some of the immunological issues surrounding the complex problem of perioperative sepsis. It identifies an immunological paradox between the relative immunosuppression of the immediate postoperative period and the relative immune activation of established sepsis, in addition to discussing current knowledge of the mechanisms surrounding these phenomena. Much remains unknown about perioperative immunoregulation; there are a number of potential mechanisms, however, whereby local and systemic immune defences can be modified or enhanced. Provided patients at risk can be identified, such manipulations may find application in preventing infection and sepsis after surgery.

Interleukin-10 gene expression correlates with the fall in monocyte HLA-DR antigen expression in patients undergoing major abdominal surgery and may account for the immunosuppression associated with surgical injury.