Determination of reference values for urinary neutrophil gelatinase-associated lipocalin in premature infants

Background: The aim of this study is to determine the reference values of urinary neutrophil gelatinase-associated lipocalin (uNGAL) in healthy very preterm infants. Method: The study was performed on 30 preterm infants whose gestational ages (GA) were between 28 and 34 weeks. They were divided into three groups according to the GA as group 1: GA 28-29 weeks, group 2: 30-32 weeks and group 3: 33-34 weeks. Blood and urine samples were obtained on postnatal (PN) days 1 and 7. uNGAL was measured by ELISA. Results: There were 10 preterm infants for each group. The median values of uNGAL on PN Days 1 were 19.80 (8.6-25.7) ng/ml, 9.25 (1.42-30.3) ng/ml, and 7.95 (1.60-27.8) ng/ml in group 1, group 2 and group 3, respectively. Multivariate linear regression analysis showed that uNGAL values are not associated with GA, birth weight, and gender in preterm infants on PN Days 1 and 7. Conclusion: Our study indicated that normal values of uNGAL concentrations in healthy very preterm infants, and older children or adults are similar preterm infants.