Cardiopulmonary bypass elicits a pro- and anti-inflammatory cytokine response and impaired neutrophil chemotaxis in neonatal pigs

Background: Cardiopulmonary bypass (CPB) induces a systemic inflammatory response and organ dysfunction, especially in children. Plasma concentration of inflammatory markers are increased in response to the trauma of cardiac surgery and CPB. The aim of time present study was to investigate whether the CPB procedure in itself elicits increased levels of inflammatory markers in neonatal pigs. Methods: The inflammatory response was measured in piglets undergoing sternotomy alone (sham group, n=13) or sternotomy and CPB (n=14). Inflammatory mediators were measured at baseline and at fixed time-points during and after CPB. IL-8, IL-10 and TNF-a levels and C-reactive protein (CRP) concentrations were measured in plasma samples. Polymorphonuclear neutrophils (PMN) chemotaxis was measured ex vivo, and CD-18 expression using an immunofluorescence technique. Results: Immediately after the CPB procedure increased IL-8 levels were found in the CFB group, but not in sham operated animals (P=0.005). Simultaneously, a marked IL-10 response was measured in the CPB group. Concurrently, PMN chemotaxis decreased in CPB animals but not in the sham group (P= 0.04). CD-18 expression and CRP levels were not significantly different between groups and TNF-alpha showed no changes in either group. The chemotactic response did not correlate with plasma IL-8 or IL-10, nor with CD-18 expression. Conclusion:The CPB procedure elicited a systemic inflammatory response in terms of significantly elevated plasma levels of IL-8 and IL-10. Furthermore, a temporary and simultaneous decrease in PMN chemotaxis was observed immediately after CPB.