PLASMA MACROPHAGE-COLONY-STIMULATING FACTOR LEVELS DURING CARDIOPULMONARY BYPASS WITH EXTRACORPOREAL-CIRCULATION

Leukocytosis and thrombocytopenia occur during cardiopulmonary bypass (CPB) with extracorporeal circulation (ECC). Elevated circulating conc entrations of macrophage colony-stimulating factor (M-CSF) are reporte d during thrombocytopenia and leukopenia of different origins. We have assessed M-CSF concentrations in 40 patients undergoing CPB with ECC. Plasma M-CSF concentrations were stable during ECC and increased at t he 6th (7.3 +/- 0.7 IU/mu g protein) and 24th (8.6 +/- 0.8 IU/mu g pro tein) postoperative hour compared with pre-ECC values (4.9 +/- 0.5 IU/ mu g protein). A deep thrombocytopenia was found during ECC and until the 24th postoperative hour. A drop of leukocyte counts was found duri ng ECC followed by an increase after ECC weaning. While no correlation was found between M-CSF concentrations and the leukocyte counts, III- CSF values were positively correlated with platelet counts only before and during ECC. Thus, M-CSF is not implicated in the thrombocytopenia and the leukopenia generated during CPB with ECC. However the elevate d levels of M-CSFa few hours after the end of ECC might play a role in the inflammatory process often observed after CPB.