Genotype and interleukin-10 responses after cardiopulmonary bypass

Background. The pro- and anti-inflammatory cytokine balancehas been implicated in outcome from inflammatory conditions,and cardiopulmonary bypass is associated with a marked inflammatoryresponse. Interleukin-10 (IL-10) is an anti-inflammatory cytokineand levels have been shown to be highest in those patients whodevelop sepsis after trauma or surgery. IL-10 levels vary betweenindividuals and genotype may dictate the IL-10 response. Wetherefore investigated IL-10 genotype, circulating IL-10 concentrationsand outcome in terms of organ dysfunction 24 h after cardiopulmonarybypass. Methods. Blood samples were obtained from 150 patients before,and 3, and 24 h after cardiopulmonary bypass. IL-10 wasmeasured by enzyme immunoassay. The single nucleotide polymorphismat –1082 base pairs was detected by restriction fragmentlength polymorphism analysis. Post-bypass organ system dysfunctionwas defined prospectively. Results. IL-10 concentrations were increased 3 h afterbypass (P<0.0001) and were still increased at 24 h (P<0.0001).Homozygosity for the G allele was associated with lower median(range) maximal IL-10 levels at 3 h (44 (13–136)pg ml^–1) compared with the A allele (118 (39–472)pg ml^–1; P=0.042). Those patients who developed atleast one organ dysfunction (n=33) had higher IL-10 levels 3 hafter surgery (242 (18–694) pg ml^–1) comparedwith those without organ dysfunction (77 (7–586) pg ml^–1;P=0.001, n=117). Conclusions. The G allele of the –1082 base pair singlenucleotide polymorphism in the IL-10 gene is associated withlower IL-10 release after cardiopulmonary bypass. High levelsof IL-10 secretion are associated with organ dysfunction 24 hafter surgery. Br J Anaesth 2003; 91: 424–6