Urine and serum neutrophil gelatinase-associated lipocalin cut-off point for the prediction of acute kidney injury

The aim of the present study was to determine the optimum cut-off point of urine and serum neutrophil gelatinase-associated lipocalin (NGAL) for the predictive diagnosis of acute kidney injury (AKI).

This study was a prospective observational study which was performed at Alzahra hospital and Emam Hussein Hospital, Isfahan, Iran. During a period of 4 months, from February 2012 to May 2012, consecutive patients admitted to pediatric intensive care unit (PICU) aged between 1 month and 15 years with glomerular filtration rate (GFR) more than 90 ml/min were enrolled in the study. In all the patients who were enrolled in the study, blood and urine samples were attained on the first, third, and fifth day of admission. Serum and urine NGAL were assessed and compared between patients who developed AKI and who didn't.

Of 25 patients who enrolled in the study, 13 developed AKI. For the serum NGAL, the most accurate cut-off point was the fifth day cut-off point which was 163 375 pg/ml (sensitivity: 61.5%, specificity: 94.6%, AUC: 0.76) and urine NGAL cut-off point was 86 040 pg/ml (sensitivity: 50%, specificity: 92.5%, AUC: 0.73).

In conclusion, we deduced that serum NGAL level significantly elevates in critically ill patients admitted in PICU who develop AKI. Serum and urine NGAL on the fifth day are the best predictors for the AKI with cut-off points 163 375 and 86 040.