Bootcongres

Background: In kidney transplantation, no specific early biomarker is available for evaluating kidney damage. Both neutrophil gelatinase-associated lipocalin (NGAL) and kidney injury marker-1 (KIM-1) have been shown to increase after oxidative kidney injury. In this study, we evaluated their role as potential biomarkers for delayed graft function (DGF).

Patients/methods: Twenty recipients of a donation-after-circulatory death (DCD) kidney transplantation were included. Recipient serum creatinine, eGFR, C-reactive protein, as well as the incidence and duration of DGF were monitored. Graft perfusate was collected at the end of cold ischemia time. Serum samples were collected before transplantation, at end of surgery, and 1, 4 and 7 days after transplantation. NGAL and KIM-1 were measured by ELISA.
Results: Seventeen of the 20 patients experienced DGF (85%). NGAL in perfusate correlated with donor age (r2=0.094, p=0.01) and donor serum creatinine r2=0.243, p=0.05), both known risk factors for DGF. Perfusate NGAL levels were higher when kidneys came from donors with a cardiac cause of death (77.4 ± 22.5 ng/ml versus 41.9 ± 29.4 ng/ml, p=0.04). Serum NGAL levels at day one post-transplantation were significantly higher in patients with DGF compared to patients with immediate graft function (IGF) (730ng/ml [490-1655] vs. 417ng/ml [232-481]; p=0.01), whereas this was not seen at the other time points. Serum NGAL at 1, 4 and 7 days posttransplantation correlated with duration of DGF. No associations between NGAL and other serum markers were observed. KIM-1 was not detectable in the perfusate and serum until day 4 after transplantation in most cases (80%). No associations between KIM-1 levels and DGF were observed. 

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