Urinary neutrophil gelatinase-associated lipocalin is an early predictor of acute kidney injury in premature infants

Abstract

Urinary neutrophil gelatinase-associated lipocalin (uNGAL) is produced in response to tubular epithelial injury and is a biomarker of tubulointerstitial injury. The aim of the present study was to examine whether acute kidney injury (AKI) could be predicted by measuring uNGAL in very low-birth weight (VLBW) infants. Forty VLBW infants with birthweight below 1,500 g were enrolled in the present study. uNGAL and serum creatinine (sCre) were measured daily from postnatal days 0 to 8. Infants with sCre ≥1.2 mg/dl were diagnosed with AKI. The relationship of uNGAL with sCre was measured on the day after uNGAL measurement (next-day sCre) was examined. The results showed that 16 infants had sCre ≥1.2 mg/dl in this period. Logistic regression analysis revealed that uNGAL on postnatal days 2,3,4,5 and 6 was correlated with next-day sCre (P<0.05). uNGAL corrected by urinary Cre (uCre) (uNGAL/uCre) was only correlated with an increase in next-day sCre on postnatal days 5 and 6 (P<0.05). For the logistic analysis,subjects with high and low uNGAL levels based on the median value for each day,uNGAL on postnatal days 2,3 and 6 in the high uNGAL group was correlated with an increase in next-day sCre. Thus,AKI may be predicted by measuring uNGAL in VLBW infants. This measurement was non-invasive,and is potentially useful for the evaluation of renal function in VLBW infants.