Background: Cardiopulmonary bypass (CPB) has been demonstrated to provoke a systemic inflammatory response believed to be responsible for some of the serious postoperative complications such as renal dysfunction. Therefore, we tested the hypothesis suggesting that the serum levels of IL- 17A (IL-17), as an inflammatory cytokine, and its gene variants are associated with acute kidney injury after CPB (AKI-CPB).
Methods: A total of 135 Iranian patients undergoing cardiopulmonary bypass were included in this study, of whom 65 (48.1%) developed AKI. Blood specimens were collected preoperatively and at 12 hours postoperatively. The IL-17 gene polymorphisms (rs2275913 and rs3819024) were determined using sequence-specific primers (PCR-SSP) technique.Pre- and postoperative IL-17 levels were measured and analyzed in relation to polymorphisms.
Results: IL-17 concentrations in CBP subjects, were increased after cardiopulmonary bypass (P<0.00001)but there were no statistically significant differences in IL-17 serum level between AKI and non-AKI groups. Different genotypes of IL-17 rs2275913 SNP (G→A) were associated with different circulating IL-17 levels before bypass and also after AKI development. There were no associations between gene polymorphisms (rs2275913and rs3819024) and incidence of AKI- CPB. There was an association between thers2275913 SNP and the severity of AKI.
Conclusion: This study clarified that the rs2275913 SNP to some extent determines plasma IL-17 concentrations in CPB patients. No significant association was found between IL-17 levels or gene polymorphisms (rs2275913and rs3819024) and incidence of AKI-CPB. Our results suggest that there is an association between rs2275913 and the severity of AKI- CPB.
Keywords: Acute kidney injury, cardiac surgery, cardiopulmonary bypass, polymorphism, IL-17, inflammation.