RORC gene polymorphism is associated with acute kidney injury following cardiac surgery.

BACKGROUND: Acute kidney injury (AKI) is a common complication of cardiopulmonary bypass (CPB), associated with increased mortality in surgical patients. It is well proven that Th17 and its hallmark cytokine, IL-17, contribute to AKI development. Since the RAR-related orphan receptor C (RORC) gene is a master regulator of the Th17 differentiation, we aimed to evaluate the association between its polymorphisms, CPB-AKI and plasma IL-17 levels among Iranian patients undergoing cardiopulmonary bypass.

METHOD:  Totally, 138 patients undergoing cardiopulmonary bypass in Bandar Abbas, Iran, were enrolled. The allele and genotype frequencies of the selected SNPs were determined using PCR-SSP. IL-17 serum level was determined using an enzyme-linked immunosorbent assay.

RESULTS:  Rs9017 GG genotype and G allele were associated with increased risk of CPB-AKI (OR=3, 95% CI=1.4-6.6 and OR=2.3, 95% CI=1.3-3.9 respectively) while A allele was protective against the disease (OR=0.4, 95% CI=0.3-0.7, P=0.02). There was not a statistically significant interaction between the three genotypes of rs9017 and AKI disease with IL-17 serum level before (P=0.9) and after (P=0.6) the operation. The IL-17 serum level before surgery was significantly higher in patients carrying GG genotype compared to GA genotype (P=0.017).

CONCLUSION:  Our results showed that the rs9017 GG genotype was associated with an increased level of IL-17 and risk of CBP-AKI in the Iranian population. Our current results suggest that the rs9017 GG genotype could be a probable predictor of AKI after cardiac surgery.