Urinary NGAL, but not L-FABP, in Early Post-Transplant Period, Predicts Graft Outcome Up to 1 Year after Kidney Transplantation

Abstract

Background: Several recent reports demonstrated the usefulness of new biomarkers in early post-transplant period for predicting delayed graft function (DGF) after kidney transplantation. However, the usefulness of these biomarkers in predicting long-term graft outcome has scarcely been assessed. Methods: This was a prospective observational study, and only recipients without evidence of DGF, a well-known risk factor for poor long-term outcome, were included for the analysis (n=62). Urine samples at 0 hr, day 2 and 6 were obtained. Results: Urinary neutrophil gelatinase-associated lipocalin (u-NGAL) level on day 2, but not liver type fatty acid binding protein (L-FABP) or serum creatinine, was significantly higher in slow graft function (SGF) compared to immediate graft function (IGF) group. Higher day 2 u-NGAL level was associated with more frequent development of SGF and in addition, it was also associated with significantly lower 1yr estimated glomerular filtratrion rate (eGFR). In multivariate logistic regression analysis, day 2 u-NGAL was a significant, independent factor for predicting poor long-term graft function (1yr eGFR< 60ml/min/1.73m2). Conclusions: This study first demonstrated the possibility that u-NGAL might also be useful in predicting long-term graft outcome as well as short-term function even in patients who showed favorable early clinical course with early graft function (EGF).