The association of rs187238, rs19465518 and rs1946519 IL-8 polymorphisms with acute kidney injury in preterm infants

Abstract

Background: Interleukin 18 (IL-18) promoter polymorphisms (–656G > T, –607C > A, and –137G > C) affect serum IL-18 (sIL-18) levels and are associated with renal injury. Purpose: This study aimed to determine the diagnostic utility of sIL-18 and urine IL-18 (uIL-18) as biomarkers for acute kidney injury (AKI) and analyse the association of IL-18 polymorphisms to AKI in preterm infants. Methods: Blood and urine samples were collected from 56 preterm infants with AKI and 56 without AKI to measure serum creatinine (SCr), sIL-18, and uIL-18. Genotyping of polymorphisms was performed and analysed, with AUCROCs analysis used to evaluate the diagnostic utility of s-/uIL-18 levels. Results: The median sIL-18 and uIL-18 levels were significantly higher than those without AKI. For a cutoff of >132 pg/ mL, the sIL-18 expression had sensitivity and specificity of 80.36% and 60.71%, respectively, while for uIL-18, a cutoff of >900.7 pg/mL had sensitivity and specificity of 51.79% and 78.57%, respectively. The odds ratio of sIL-18 and uIL-18 to predict AKI in preterm infants was 5.89 (95%CI:2.31–15.02) and 4.15 (95%CI:1.58–10.89), respectively. The polymorphisms –137G > C and –656G > T were significantly associated with sIL-18 expression. Conclusion: Serum and urine IL-18 levels are risk factors for and a moderate predictor of AKI in preterm infants.