Clinical validity of urinary interleukin 18 and interleukin 6 determinations in preterm newborns.

INTRODUCTION: Preterm newborns are at a particular risk of acute kidney injury (AKI) and sepsis. PURPOSE: Assessment of urinary interleukin 18 (ulL-18) and urinary interleukin 6 (ulL-6) concentrations in association with AKI and sepsis respectively in newborns hospitalized in Neonatal Intensive Care Unit (NICU). MATERIAL AND METHODS: An evaluation was carried out of the dependence of ulL-18 on neonatal birth weight (BW) and AKI as well as ulL6 on sepsis. In prospective study, the evaluation included 58 children with BW up to 2000 g. Clinical observations spanned the period between the 1st and 28th day of life. RESULTS: The mean gestational age was 30.3 Hbd, mean BW was 1361.9 g. AKI was diagnosed in 35 (60.3%), sepsis in 22 (39.7%) neonates. For median values of uIL-18 and ulL-18/mgCr, as well as for mean logarithmically transformed values of ulL-18 and ulL-18/mgCr, negative, statistically significant linear correlations were demonstrated for BW. In population, median value of ulL-18 and ulL-18/mgCr decreased respectively by 8.21 pg/ml and 84.8 pg/mgCr per each 100 g increment of BW. A negative, statistically significant linear correlation with an average strength was noted for the dependency of the duration of AKI and BW. No significant differences were observed in uIL-18 and ulL-181 mgCr values between the investigated days of AKI and reference group. There was noted a significant increase of the values of uIL-6 and uIL-6/ mgCr on day 0 of sepsis confirmed by the ROC analysis with AUROC 78% and 74%, respectively. CONCLUSIONS: ulL-18 and ulL-18/mgCr values might be a reliable marker of renal tubules maturation in newborns; ulL-18 is not a reliable marker in diagnosing AKI in neonatal population; ulL-6 and uIL-6/ mgCr concentration values measured on actual days may be regarded an early marker of sepsis; AKI duration in preterm neonates is negatively correlated with BW.