Modulating IL-6 and IL-10 levels by pharmacologic strategies and the impact of different extracorporeal circulation parameters during cardiac surgery

Abstract

Postoperative morbidity after coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) can be influenced by pro- and anti-inflammatory cytokines like interleukin 6 (IL-6) and IL-10 triggering and balancing the acute phase response. The extent of cytokine release can be modulated by different methods. This prospective randomized study examines the effect of treatment of patients with steroid (group 1, 250 mg of prednisolone)(Solu-Decortin H)), aprotinin (group 2, 6 Mio. KIU [kallikrein inhibitory units] aprotinin [Trasylol]), and heparine coating of the artificial surface (group 3, Bioline) on the systemic release of IL-6 and IL-10 in four groups of 40 patients with coronary artery disease (CAD) scheduled for CABG. Group 4 (standard medication) served as control. Twenty hemodynamic and biochemical parameters of the CPB were analyzed regarding correlation to cytokine levels measured by enzyme-linked immunosorbent assay (ELISA). In group 1, IL-6 was suppressed compared to the control (P< 0.01). IL-10 was upregulated (P< 0.01). In group 2, cytokine release was similar to group 1. Using heparin-coated circuits in group 3 led to IL-10 upregulation (P < 0.05) and IL-6 suppression (P < 0.05). We found an exponential relationship between IL-10 levels (IL-6 levels) and cardiac ischemia time, duration of CPB, and the extent of negative base excess. An inverse relationship was found for IL-10 (IL-6) levels and venous O2 saturation (SvO2), and mean arterial pressure (MAP). Hypothermia (<34 degrees C) reduced IL-10 and IL-6 release, whereas long duration of hypothermia correlated with higher IL-10 and IL-6 release. Cytokine release after extracorporeal circulation (ECC) can be modulated pharmacologically and by distinct perfusion regimen.