Plasma neutrophil gelatinase-associated lipocalin in kidney transplantation and early renal function prediction.

Background: This prospective observational study aimed to assess the relevance of serial postoperative plasma neutrophil gelatinase-associated lipocalin (NGAL) measurements on prediction of early renal transplant function.

Methods: Plasma NGAL (pNGAL) was measured (Triage NGAL Test; Biosite Inc., Inverness Medical) in 41 patients scheduled for kidney transplantation from deceased or living donors, immediately before and after surgery, and at 12 hr, day 1, day 3, and day 7. A delayed graft function (DGF) was defined as the need for dialysis during the first week. The results were expressed as median (Q1, Q3).

Results: Of the 41 consecutive patients enrolled, all had a high preoperative pNGAL level: 453 ng/mL (382, 595). Fifteen (36.6%) presented a DGF. In patients with DGF, pNGAL was significantly higher at 12 hr (571 [467, 634] vs. 242 [158, 299] ng/mL, P<0.0001) and at day 1 (466 [356, 627] vs. 165 [91, 248] ng/mL, P<0.0001). A pNGAL higher than 400 ng/mL 12 hr after transplantation predicted DGF with a sensitivity of 93.3%, a specificity of 88.5%, and an odds ratio of 63.2 (P=0.0004). This predictive performance was higher than for plasma creatinine.

Conclusions: pNGAL level early and accurately predicted DGF after renal transplantation. pNGAL measurements allowed monitoring of the renal function in this striking situation of ischemia-reperfusion aggression. Early identification of patients at risk of DGF, before graft lesions are consolidated, opens the field of a precise monitoring of renal injury and the impact of future protective therapeutics.