Plasma neutrophil gelatinase-associated lipocalin and Interleukin-18 as predictors of acute kidney injury in renal transplant recipients: A pilot study.

Abstract

Urine neutrophil gelatinase-associated lipocalin (NGAL) and interleukin-18 (IL- 18) have shown promise for predicting renal graft recovery. However, urinary flow rate variations may cause variable biomarker dilution. Plasma NGAL and IL-18 may form a biomarker panel that may help predict delayed graft function and slow graft function (SGF) in renal transplant recipients within the first two postoperative days earlier than serum creatinine. There are only a few studies in the literature using plasma NGAL for predicting renal graft recovery. Hence, we planned this study. This observational single-center, prospective cohort study was conducted in renal transplant recipients above 18 years of age. In 22 consecutive renal transplant recipients, we collected ethylenediaminetetraacetic acid-plasma samples 1 h before surgery and subsequently at 6 h, 24 h, and 48 h after surgery for NGAL and IL-18 by sandwich enzyme-linked immuno-sorbent assay technique. Serum creatinine was measured as a part of routine transplant protocol. In renal transplant recipients, neither serum levels of NGAL and IL-18 nor their trends could reliably predict SGF. The only significant correlation existed between serum creatinine at day 2 and IL-18 at day 2 with P = 0.023. Serum NGAL did not correlate with serum creatinine in this setting of renal transplantation. Patients with immediate graft function had a greater percentage decrease of creatinine at day 1 and day 2 (P = 0.002 and 0.001) The percentage change in IL-18 at 24 h and 48 h after transplant from baseline could predict the occurrence of early graft loss (EGL) (P = 0.05, 0.04). The cutoffs were -4.12% at day 1 and +3.39% at day 2 with area under receiver operator characteristics of 0.82 and 0.83, respectively. The percentage change in IL-18 may be a useful marker of EGL in renal transplant recipients. Serum NGAL and creatinine were not able to predict EGL.