Introduction: Kidney transplantation is frequently complicated by delayed graft function (DGF). DGF is associated with more frequent rejection episodes, increased need of post-transplantation biopsies, dialysis sessions and prolonged hospitalization. These complications may have negative impact on long-term survival of transplanted kidney.Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is regarded as acute kidney injury marker.This preliminary study aimed at evaluating whether uNGAL may be early predictor of DGF in kidney transplanted patients.
Subjects and methods: Urine samples were collected from renal transplant recipients on day 1 post-transplantation to determine 24/h urinary NGAL and creatinine excretion. On same day, routine blood chemistry was assessed.
Results: N. 20 renal transplant recipients were evaluated. DGF was observed in n. 6 patients (DGF-patients). In DGF-patients compared to NO-DGF-patients, mean age was higher (586 Vs 5111, p=0.001), while 24/h urine output (5735 Vs 4150 2230 ml/24h; p=0.001) and urinary creatinine excretion (191184 Vs 683660 mg/24h; p=0.001) were lower. No difference was found between DGF- and NO-DGF-patients in 24/h urinary NGAL excretion (1,202,20 Vs 2,444,0 mg/24h; p<0.20). In univariate analysis, DGF was inversely associated to 24/h urine output (r2=-0.795, p=0.001) and urinary creatinine excretion (r2=-0.480, p=0.037) and positively to age (r2=0.446, p=0.049). In multivariate analysis 24/h urine output (p=0.014) and 24/h urinary creatinine excretion (p=0.039) were associated to DGF.
Conclusion: This preliminary study suggests that 24/h urinary NGAL excretion, measured 1 day after kidney transplantation, is not a reliable predictor of DGF. Larger study with longer observation period is mandatory.