BACKGROUND: Cardiac surgery provokes a systemic inflammatory response in any patient. This complex body reaction involves also RANK/RANKL molecules which have been recently identified as principal regulators of bone metabolism. AIMS: To follow the changes in the expression of RANK/RANKL molecules on innate immune cells of cardiac surgical patients. PATIENTS AND METHODS: Twenty-six patients undergoing cardiac surgical were assigned to undergo coronary artery bypass grafting using either cardiopulmonary bypass ("on-pump") or modified "miniinvasive on-pump". The expression of RANK/RANKL was performed by flow cytometry. RESULTS: Significantly increased expression of RANK on monocytes of "miniinvasive on-pump" patients was found at the 1st, the 3nd, and 7th postoperative days. The similar pattern was found also for monocyte RANKL expression. In addition, RANKL expression was significantly increased at the 3rd postoperative day in "on-pump" patient. No significant differences between "miniinvasive on-pump" and "on-pump" cardiac surgical patients were found. CONCLUSION: The expression of both RANK and RANKL molecules is significantly enhanced on monocytes of "miniinvasive on-pump" cardiac surgical patients.

Department of Clinical Immunology and Allergology Charles University Prague Faculty of Medicine and University Hospital Hradec Králové Czech Republic