Background: There is increasing evidence that cytokine-inducible leukocyte-endothelial adhesion molecules are instrumental in the postoperative inflammatory response following cardiopulmonary bypass (CPB). L-selectin was shown to be one of those neutrophil-endothelial cell adhesion molecules. This study aimed to investigate the relationship of the soluble adhesion molecule, sL-selectin, and the postoperative course in children undergoing CPB.
Material/Methods: To determine the time course of sL-selectin after CPB, serial blood samples of 9 children undergoing CPB were collected from the arterial line or from the bypass circuits preoperatively, on initiation of CPB and 1, 6, 12, 18, 24, and 48 hours postoperatively. Plasma was recovered immediately, aliquoted and frozen at -70°C until use. Circulating sL-selectin molecules were measured with a sandwich enzyme-linked immunoabsorbent assay (ELISA) technique. There were significant changes in plasma levels of sL-selectin in patients following CPB, and these levels were associated with patient characteristics, operative variables and postoperative course. Low values of sL-selectin significantly correlated with inotropic support, low PRISM score, postoperative hypotension and fever. There was a significant association between the development of postoperative sepsis and low sL-selectin levels. No correlation was found between sL-selectin values and lactate concentration or neutrophil count.
Conclusions: Our results suggest a relation between CPB-induced mediators and both early and late clinical effects. Although the mechanism for the changes of sL-selectin remains undetermined, the down-regulation of sL-selectin indicates neutrophil activation and supports the possibility that anti-adhesion therapies might participate in the prevention and treatment of the inflammatory response associated with CPB.

Keywords: children, Cardiopulmonary Bypass, circulating sL-selectin