Peripheral blood monocyte activation during coronary artery bypass grafting with or without cardiopulmonary bypass.
OBJECTIVE
The aim of this prospective, randomized study was to investigate the impact of coronary artery bypass grafting (CABG) on peripheral monocytes and to evaluate the additional effect of cardiopulmonary bypass (CPB).


METHODS
Twenty patients admitted for elective CABG were randomized to either on-pump (ONCAB, n = 9) or off-pump (OFFCAB, n = 11) surgery and blood samples were drawn before, during and 24 h after the operation. The total number of monocytes and the proportion of the more mature CD16+/CD14+ monocytes were measured. Expression of activation markers (CD11b, CD35 and CD62L) and oxidative burst were determined using flow cytometry on both resting and in vitro stimulated cells. Serum concentrations of soluble CD14 and monocytes/macrophage chemotactic protein 1 (MCP-1) were analysed.


RESULTS
During surgery there was a selective decrease in the proportion of CD16+/CD14+ monocytes compared to total monocytes. These had returned to preoperative values 24 h after surgery while the total number of monocytes had increased more than 100%. Intracellular production of oxygen free radical H2O2 was increased in the ONCAB group during surgery compared to OFFCAB. Monocyte expression and in vitro mobilization of complement receptors, CD11b and CD35, were similar in both study groups during and after surgery as was the expression of CD62L. Serum levels of MCP-1 decreased during surgery as did soluble CD14, both with increased levels again the day after surgery.


CONCLUSIONS
It is concluded that the circulating monocyte population is activated during and as a consequence of CABG. There were few apparent additional effects of CPB found in this study. In this setting the inflammation caused by the surgery procedure per se probably surpasses the impact of the CPB on circulating blood monocytes.
Wehlin
Lena
L
Department of Clinical Immunology, Institution of Medicine, Karolinska Institutet, Stockholm, Sweden. Lena.Wehlin@medks.ki.se
Vedin
Jenny
J
Vaage
Jarle
J
Lundahl
Joachim
J
D000368:Aged; D015415:Biomarkers / Q000097:blood; D002315:Cardiopulmonary Bypass / Q000009:adverse effects / Q000379:methods*; D054407:Chemokine CCL4; D017023:Coronary Angiography; D047549:Coronary Artery Bypass, Off-Pump / Q000009:adverse effects / Q000379:methods*; D023921:Coronary Stenosis / Q000000981:diagnostic imaging / Q000401:mortality / Q000601:surgery*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007432:Intraoperative Period; D018950:Lipopolysaccharide Receptors / Q000097:blood*; D019402:Macrophage Inflammatory Proteins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D009000:Monocytes; D011182:Postoperative Care; D011300:Preoperative Care / Q000379:methods; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015996:Survival Rate; D016896:Treatment Outcome
D015415:Biomarkers; D054407:Chemokine CCL4; D018950:Lipopolysaccharide Receptors; D019402:Macrophage Inflammatory Proteins