Urinary NGAL at birth predicts early renal function in very low birth weight infants

Preterm infants are exposed to conditions that can impair renal function. We evaluated the ability of serum and urinary neutrophil gelatinase-associated lipocalin (sNGAL and uNGAL) to predict renal function in the first weeks of life. From September 2008 to July 2009, infants weighing ≤1500 g at birth with no major congenital anomalies or sepsis were eligible. We measured sNGAL and uNGAL levels at birth. To evaluate renal function, we determined changes in serum creatinine (sCreat) and estimated glomerular filtration rate (eGFR) from birth to day 21. Forty neonates (mean gestational age, 27±2 weeks) completed the study. Renal function improved in 32/40 (80%) infants (normal renal function, NRF group) (sCreat, from 0.97±0.2 to 0.53±0.13 mg/dl; eGFR, from 15.3±4.1 to 28.6±7.9 ml/min), whereas renal function worsened in 8/40 (20%) infants (impaired renal function, IRF group) (sCreat, from 0.71±0.27 to 0.98±0.43 mg/dl; eGFR from 23±14.7 to 16.4±9.1 ml/min). The uNGAL/urinary creatinine ratio at birth was higher in the IRF group (31.05 ng/mg) than the NRF group (6.0 ng/mg), and uNGAL was significantly higher in IRF group, detecting impaired renal function with a cut-off of 100 ng/ml. uNGAL levels at birth may have a predictive role in very low birth weight (VLBW) infants.