Soluble VCAM-1 is a very early marker of endothelial cell activation in cardiopulmonary bypass

Cardiopulmonary bypass causes a systemic inflammatory reaction, which leads to endothelial activation with increased expression of adhesion molecules. The study aim was to test whether activated endothelial cells secrete measurable amounts of soluble adhesion molecules during the time course of routine heart surgery, and whether these markers correlate with cellular activation responses. Endothelial cells from human umbilical cords were cultured by standard methods and stimulated with endotoxin. After 2 h, the expression of membrane-bound E-selectin on the cells had increased significantly (p=0.04), whereas soluble VCAM-1 (sVCAM-1) had increased significantly in the culture media (p=0.03). In agreement with these findings, sVCAM-1 increased from 399 ng/ml (median) to 581 ng/ml within 3 h postoperatively in sera from 11 patients undergoing open heart surgery (p=0.003). sVCAM-1, therefore, may be suitable as an early marker of endothelial activation related to the systemic inflammation after open heart surgery. The clinical significance of sVCAM-1 measurements must be further evaluated in future patient studies.