Effect Of Cardiopulmonary Bypass On Neutrophil CD11b And Endothelial ICAM-1 And NF-κB Expression In Children

Cardiopulmonary bypass (CPB) produces an injury which is associated with systematic inflammation response syndrome (SIRS) in a great degree. This inflammation may contribute to the development of postoperative complications, including respiratory failure, renal dysfunction, bleeding disorders, neurologic dysfunction, altered liver function, and ultimately, multiple organ failure (MOF). Whatever the mechanism by which the inflammatory pathways are either initiated or stimulated, neutrophils, and their close relation with the endothelium, have a key role in the mechanism of injury to the endothelium and capillary wall that is associated with bypass. In inflammation, the first and capital step is neutrophils adhering to the vessel endothelium, which is also the key link to lead to injury of endothelium a subsequent neutrophils trans-endothelium migration. Activated neutrophils adhere to vessel endothelial cells and release oxygen free radical and enzymes of cell disruption. The molecule basis of neutrophils and endothelial cells interaction are CD11b which expressed in the surface of neutrophils and intercellular adhesion molecules (ICAM-1) which expressed in the surface of endothelial cells. Integrin CD11b and ICAM-1 are two different kind of adhesion molecules and they are receptor-ligand each other. They play an important role in the process of neutrophils adhesion to endothelial cells and participate in the inflammation.Despite the increasing evidence for the role of neutrophils in inflammation subsequent to bypass, the exact pathophysiology of the damage to this remains poorly understood. Therefore, in order to investigate the mechanism of inflammation subsequent to CPB, in our study neutrophils expression of integrin CD11b and endothelial expression of ICAM-1, and NF-κB and neutrophils adhesion were assayed in humans.Objective To study the effect of neutrophil integrin CD11b and endothelial intercellular adhesion molecule ICAM-1 and NF-κB expression on inflammatory response subsequent to cardiopulmonary bypass (CPB), and to investigate the probable mechanism of inflammation subsequent to CPB.Methods Twenty children scheduled for cardiac procedure with CPB were included. Blood samples were taken from the artery before operation, at the onset of CPB, at 30 min of CPB, at 1 h, 4 h, 12 h, and 24 h after CPB to isolate circulating Neutrophil and endothelial cells. Neutrophil integrin CD11b and endothelial ICAM-1 expression was detected with flow cytometry. Endothelial ICAM-1 mRNA expression was assayed with RT-PCR. NF-κB was analyzed with EMSA. Neutrophil adhesion was observed with a light microscope.Results Neutrophil CD11b, endothelial ICAM-1, ICAM-1 mRNA and NF-κB expression and neutrophil adhesion increased markedly from 30 min of CPB until 24 h after CPB compared with the values before CPB, respectively. Conclusions The expression of intercellular adhesion molecules on the neutrophil and endothelial cell surfaces and the activation of NF-κB play an important role in the inflammatory response subsequent to CPB.