Perfusate Neutrophil Gelatinase-Associated Lipocalin, Kidney Injury Molecular-1, Liver-Type Fatty Acid Binding Protein, and Interleukin-18 as Potential Biomarkers to Predict Delayed Graft Function and Long-Term Prognosis in Kidney Transplant Recipients: A Single-Center Retrospective Study.

BACKGROUND Delayed graft function (DGF) caused by ischemia-reperfusion injury is a common pathophysiological process that should be monitored by specific biomarkers in addition to serum creatinine. Thus, this single-center retrospective study aimed to investigate the association between levels of neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecular-1 (KIM-1), liver-type fatty acid binding protein (L-FABP), and interleukin-18 (IL-18) in DGF associated with acute kidney injury in kidney transplant recipients (KTRs) and estimated glomerular filtration rate (eGFR) at 3 years post-transplant. MATERIAL AND METHODS A total of 102 KTRs [14(13.7%) of DGF and 88(86.3%) of NON-DGF] were enrolled. DGF was defined as "dialysis is needed within 1 week after kidney transplantation". NGAL, KIM-1, L-FABP, and IL-18 were obtained from perfusate samples of donation-after-cardiac-death (DCD) kidneys, and measured by ELISA. RESULTS Compared to the NON-DGF group, KTRs in the DGF group had a statistically significant increase in levels of NGAL (P<0.001) and KIM-1 (P<0.001). Multiple logistic regression analyses showed that NGAL (OR=1.204, 95% CI 1.057-1.372, P=0.005) and KIM-1 (OR=1.248, CI=1.065-1.463, P=0.006) could be regarded as independent risk factors. The accuracy of NGAL and KIM-1 was 83.3% and 82.1%, respectively, calculated using the area under the receiver operating characteristic curve. Furthermore, the eGFR at 3 years post-transplant had a moderate negative correlation with NGAL (r=-0.208, P=0.036) and KIM-1 (r=-0.260, P=0.008). CONCLUSIONS Our results support those from previous studies showing that perfusate levels of NGAL and KIM-1 are associated with DGF in KTRs and also with reduced eGFR at 3 years post-transplant.