Changes in the cytokine network and complement parameters during open heart surgery

OBJECTIVES: During cardiac surgery with cardiopulmonary bypass (CBP) there is a systemic inflammatory reaction, involving enhanced release of inflammatory cytokines and complement. However, few studies have analysed the levels of anti-inflammatory mediators and chemokines after CPB. In this study we investigated the complexity of the cytokine network particularly focusing on the balance between interleukin (IL)-10 and inflammatory cytokines and chemokines. METHODS: Blood samples from 20 patients (seven females; 13 males, age 30-81 (median 65) years) who underwent CPB, were collected before, and at several time points after surgery ,and analyzed for plasma levels of inflammatory and anti-inflammatory cytokines and parameters of complement activation. RESULTS: A marked increase in the anti-inflammatory cytokine IL-10, rather than in inflammatory cytokines, characterized the initial phase after CBP. As for the early inflammatory response the most prominent feature was a rise in the inflammatory chemokines IL-8 and monocyte chemoattractant protein-1, while the increase in tumor necrosis factor-alpha was rather modest. In contrast to the rapid 'rise and fall' in most of the markers, significantly raised IL-6 levels persisted throughout the study. Immediately after CPB there was also a marked increase in complement activation, with return to baseline levels on the first postoperative day. CONCLUSION: The present study shows a complex pattern of changes in the cytokine network and complement parameters during CBP with a marked rise in both inflammatory and anti-inflammatory mediators. However, in contrast to cytokine pattern during various infections, the initial phase after CPB was dominated by a marked rise in anti-inflammatory cytokines (i.e. IL-10).