Genetic polymorphisms of Interleukin-18 are not associated with allograft function in kidney transplant recipients

Interleukin 18 (IL-18) is a proinflammatory cytokine that plays a role in host defense by upregulating both innate and acquired immune responses. Analysis of IL18 polymorphisms may be clinically important since their roles have been recognized in a variety of inflammatory and autoimmune disorders. However, the role of this cytokine polymorphisms in kidney transplant still remains unclear. In this study, we evaluated the associations between IL18 polymorphisms and graft function assessed by creatinine clearance in kidney transplant recipients. A total of 82 kidney transplant recipients and 183 healthy controls were enrolled, and frequencies of alleles, genotypes and haplotypes for IL18 polymorphisms were determined and compared with creatinine clearance. The -607C/A (rs1946518) and -137C/G (rs187238) variant alleles in the IL18 gene were determined by polymerase chain reaction. In our study, no significant association was found between the IL18 variants and creatinine clearance (p > 0.05). Nonetheless, polymorphism analysis revealed an increase in the frequency of the IL18 major haplotype -607C/-137G in kidney transplant patients (odds ratio 2.57, 95% confidence interval 1.45-4.55, p = 0.0014). Finally, we found that IL18 polymorphisms did not influence the renal function and that IL18 haplotype -607C/-137G seems to be associated with kidney transplant recipients.