Investigation of the RS187238 single nucleotide polymorphism and urinary IL-18 levels in kidney transplant recipients – evaluation of graft function

Abstract

Objective: this study aimed to evaluate the influence of urinary IL-18 levels and the rs187238 polymorphism on graft function in kidney transplant recipients. Methods: sociodemographic, clinical, and laboratory data were obtained from the analysis of medical records of renal allograft recipients at a university hospital in Fortaleza, Brazil, from 2023 to 2025. Urinary biomarkers NGAL and IL-18 were measured in samples collected one month after
transplantation. Genotyping of the rs187238 polymorphism was performed by polymerase chain reaction from leukocyte DNA. Results: statistical analysis considered p < 0.05 as significant. Ninety-three kidney transplant recipients were evaluated, with a mean urinary IL-18 level of 2.13 ng/mL in the first month after transplantation. No differences in clinical parameters of renal function were observed between the tertiles of urinary IL-18 or between the genotypes of the rs187238 polymorphism. Furthermore, no significant correlation was identified between urinary IL-18 levels and renal function markers. Conclusion: it is concluded that urinary IL-18 is not characterized as a biomarker of renal injury in this period and that the rs187238 polymorphism did
not impact renal function markers in transplant patients.