Monocyte Fc gamma receptor expression in patients undergoing coronary artery bypass grafting.
BACKGROUND
Cardiopulmonary bypass is associated with an inflammatory response with potential deleterious effects. The white cell subpopulation mostly investigated so far is the neutrophil. To date very little has been investigated regarding the role of the monocyte/macrophage. This study focuses on the expression of Fc gamma receptors I, II, and III by monocytes in patients undergoing cardiopulmonary bypass.


METHODS
We studied the surface expression of Fc gamma receptors I, II, and III by flow cytometry on gated monocyte subpopulations in the whole blood of adult patients undergoing elective coronary artery bypass grafting. Blood samples were drawn preoperatively and at 15 minutes, 1, 2, 4, 24, 48, and 72 hours, and 6 days postoperatively. A second group of patients undergoing lung resection surgery were studied in a similar fashion.


RESULTS
Neither Fc receptor I nor receptor II expression were significantly changed throughout the time points studied. Fc receptor III expression was reduced at 2 and 4 hours (p = 0.016 and 0.002) and increased at 24, 48, and 72 hours after commencement of CPB on a selected subpopulation (15%-35%) of monocytes (p = 0.004, < 0.001, and < 0.001, respectively). This expression returned to preoperative levels by the sixth postoperative day. There were no statistically significant changes in the lung resection group.


CONCLUSIONS
Our study demonstrated that cardiopulmonary bypass is associated with a biphasic Fc gamma receptor III expression on a subpopulation of peripheral blood monocytes up to 3 days postoperatively.
British Heart Foundation, Cardiothoracic Surgery Unit and Cardiovascular Medicine Unit, National Heart and Lung Institute, Imperial College Faculty of Medicine, Hammersmith Hospital Campus, London, England, UK.
Demetrios C
DC
Stefanou
George
G
Asimakopoulos
Darshna R
DR
Yagnik
Dorian O
DO
Haskard
Jon R
JR
Anderson
Pandelis
P
Philippidis
R Clive
RC
Landis
Kenneth M
KM
Taylor
D000368:Aged; D002315:Cardiopulmonary Bypass; D001026:Coronary Artery Bypass; D017558:Elective Surgical Procedures; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D008297:Male; D009000:Monocytes / Q000276:immunology*; D011013:Pneumonectomy; D017452:Receptors, IgG / Q000032:analysis*; D013997:Time Factors
D017452:Receptors, IgG