Inter-individual differences in cytokine release in patients undergoing cardiac surgery with cardiopulmonary bypass

Cardiac surgery with cardiopulmonary bypass (CPB) leads to a systemic infla mmatory response with secretion of cytokines (e.g. IL-6, TNF-alpha, IL-1 be ta and sIL-2R). The objective of the following study was to investigate in vitro and in vivo cytokine responses and white blood cell counts (WBC) of p atients with high versus low cytokine secretion after a coronary artery byp ass grafting (CABG) procedure. Twenty male patients undergoing elective CAB G surgery with CPB under general anaesthesia were enrolled in the study. On the day of surgery (postoperatively), serum levels of TNF-alpha and IL-1 b eta were significantly higher in patients of the high IL-6 level group comp ared to the respective values in the patient group with low IL-6 levels. Th e inter-individual differences in IL-6 release in patients undergoing CABG surgery with CPB were accompanied by differences in the release of other cy tokines, such as TNF-alpha, IL-1 beta and sIL-2R. To understand whether gen etic background plays a role in influencing cytokine plasma levels under su rgical stress, we examined the distribution of polymorphic elements within the promoter regions of the TNF-alpha and IL-6 genes, and determined their genotype regarding the BAT2 gene and TNF-beta intron polymorphisms. Our pre liminary data suggests that regulatory polymorphisms in or near the TNF loc us, more precisely the allele set 140/150 of the BAT2 microsatellite marker combined with the G allele at -308 of the TNF-alpha gene, could be one of the genetic constructions providing for a less sensitive response to variou s stimuli. Our results suggest: (1) close relationships between cytokine re lease in the postoperative period, and (2) inter-individually varying patte rns of cytokine release in patients undergoing CABG surgery with CPB.