Background:
In kidney transplantation (KT), no specific biomarker is available for kidney damage. NGAL and KIM-1 have shown to increase after kidney injury. We evaluated their role as biomarker for delayed graft function (DGF).

Material and Methods:
Twenty recipients of a DCD KT were included. Recipient serum creatinine, eGFR, C-reactive protein and incidence and duration of DGF were monitored. Perfusate was collected before transplantation. Serum samples were collected at five time points. NGAL and KIM-1 were measured by ELISA.

Result:
Seventeen patients experienced DGF (85%). pNGAL correlated with donor age (p=0.01) and serum creatinine (p=0.05), both risk factors for DGF. pNGAL was higher in kidneys from donors with a cardiac cause of death (p=0.03). sNGAL at day one post-transplantation was significantly higher in patients with DGF compared to immediate graft function (IGF) (730ng/ml [490-1655] vs. 417ng/ml [232-481] p=0.01). sNGAL correlated with duration of DGF at 1, 4 and 7 days post-transplantation. KIM-1 was not detectable in perfusate and serum until day 4 after transplantation in most cases (80%).

Conclusion:
NGAL in perfusate correlates with risk factors for DGF. Serum NGAL levels at day one can discriminate between DGF and IGF. Serum levels at day 1, 4 and 7 correlate with duration of DGF. Serum NGAL appears to be a valuable biomarker for (the duration of) DGF. NGAL levels in perfusate may reflect graft quality. More studies are needed to determine the clinical potential. No role for serum KIM-1 levels were found.