Serum soluble selectins in patients undergoing cardiopulmonary bypass. Relationship with circulating blood cells and inflammation-related cytokines

Background: Membrane-bound selectins mediate the adhesion among leukocytes, platelets and endothelial cells, while circulating (soluble) selectins may function as competitive inhibitors of them. Open heart surgery is known to induce activation of these cells. Methods: We studied the acute responses of soluble selectins, circulating blood cells and inflammation-related cytokines in 12 patients undergoing elective open heart surgery with cardiopulmonary bypass. Serial blood samples were withdrawn before, during and after surgery. Results: Serum soluble E-selectin concentrations did not change significantly during all the perioperative period. In contrast, P-selectin decreased after the initiation of cardiopulmonary bypass and remained low until the end of surgery. L-selectin showed a similar course. A decrease in platelet count and albumin was found during the perioperative period and an increase in leukocyte count was found after cardiopulmonary bypass. Clear elevations in circulating IL (Interleukin)-6, IL-8, and IL-10 were found after the end of surgery, while IL-12 levels remained undetectable. Conclusions: While serum inflammatory cytokines clearly rise in response to open heart surgery, soluble selectins do not change (E) or decrease (P and L). Correcting for haemodilution, E-selectin rises postoperatively, but the decrease in P- and L-selectins is not explained by haemodilution.