PURPOSEThe aim of the study was to assess the ability of plasma neutrophil gelatinase-associated lipocalin (pNGAL) to predict acute kidney injury (AKI) in adult intensive care unit (ICU) patients.METHODSAll consecutives patients admitted to 3 ICUs were enrolled in this prospective-observational study. Plasma neutrophil gelatinase-associated lipocalin was analyzed at ICU admission. Risk, injury, failure, loss, and end-stage kidney (RIFLE) criteria were calculated at admission and for each day during the first week. Patients were classified according to whether they met the threshold for RIFLE criteria (RIFLE 0 or 1) at admission and during the first week. Four groups were identified: RIFLE (0-0), (1-1), (1-0), and (0-1).RESULTSDuring this 1-month period, 88 patients were included in the study. Thirty-six patients met the criteria for RIFLE 0-0 with a mean pNGAL of 98 +/- 60 nmol/L, 22 for RIFLE 1-1 with a mean pNGAL of 516 +/- 221 nmol/L, and 20 patients had no AKI at admission but develop AKI at 48 hours (24-96 hours) (RIFLE 0-1) with a pNGAL of 342 +/- 183 nmol/L. Ten patients met the criteria for RIFLE 1-0 and had a mean pNGAL of 169 +/- 100 nmol/L. Using a cutoff of 155 nmol/L, sensitivity and specificity to predict AKI were 82% and 97%, respectively (area under the curve [AUC] = 0.92 [0.852-0.972]; P = .001). Looking at the patients without AKI at admission (n = 56) and who developed (n = 20) or did not develop (n = 36) AKI, receiver operating characteristic curve analysis was as follows: AUC = 0.956 (0.864-0.992). Sensitivity was 85% and specificity was 97%. Of the 7 patients who required renal replacement therapy, all of them had pNGAL of more than 303 nmol/L (AUC = 0.788 [0.687-0.868]).CONCLUSIONPlasma neutrophil gelatinase-associated lipocalin at ICU admission is an early biomarker of AKI in adult ICU patients. Plasma neutrophil gelatinase-associated lipocalin increased 48 hours before RIFLE criteria.