Expression of urokinase plasminogen activator receptor on monocytes and granulocytes is modulated by cardiac surgery

Abstract

Coronary artery bypass grafting (CABG) is linked to the induction of the blood coagulation/fibrinolysis cascade, which is an integral component of inflammation induced by cardiac surgery. We followed the modulation of urokinase plasminogen activator receptor uPAR (CD87) separately for monocytes and granulocytes in blood of cardiac surgery patients. Expression of uPAR, analyzed as Median Fluorescence Intensity (MFI), on blood monocytes and granulocytes was determined by flow cytometry. Changes in uPAR expression in patients undergoing CABG using standard cardiopulmonary bypass ("on-pump") were compared to the changes in uPAR expression in patients undergoing CABG using mini-invasive cardiopulmonary bypass ("mini on-pump"). In "on-pump" patients, the median of uPAR expression on granulocytes before surgery was 18.1 (InterQuartile Range (IQR): 15.6-20.4). uPAR expression was significantly decreased after surgery (p<0.001), on the first postoperative day (p<0.001), and on the third postoperative day (p<0.05). In "mini on-pump" patients, the median of uPAR expression on granulocytes before surgery was 15.2 (IRQ: 13.8-19.4). The significantly decreased uPAR expression was found only at the end of surgery (p<0.05). The similar pattern of uPAR expression was also found for monocytes. The preoperative level in "on-pump" patients was 23.3 (IRQ: 18.9-30.2). There was significantly decreased uPAR expression at the end of surgery (p<0.01) and at the first postoperative day (p<0.05). In "mini on-pump" patients, the preoperative uPAR expression was 16.9 (IQR: 14.5-20.2). Expression of uPAR was significantly decreased only after surgery (p<0.05). When comparing "onpump" patients to "mini on-pump" patients, no significant differences in the expression of uPAR were found. uPAR expression on granulocytes and monocytes is significantly modulated by cardiac surgery.