title: Increased urinary neutrophil gelatinase-associated lipocalin in very-low-birth-weight infants with oliguria and normal serum creatinine.
abstract: In infants, oliguria is defined as a urine output of <1.5 mL/kg/h. The aim of our study was to assess the impact of oliguria on urinary neutrophil gelatinase-associated lipocalin (NGAL) and serum cystatin C (CysC) levels in very-low-birth-weight infants (VLBWIs) with a normal serum creatinine (Cr) level.
  
  
  
  Fifty-seven VLBWIs were enrolled in the study. Urinary NGAL, serum CysC and Cr levels and urinary NGAL/Cr ratios were measured. Infants with Apgar scores of >5 at 5 min and/or a serum Cr level of >1.5 mg/dL or those treated for patent ductus arteriosus were excluded. In case of antibiotic treatment, blood and urine samples were collected at ≥48 h after discontinuation of antibiotic treatment.
  
  
  
  There was a significant difference in gestational age between infants with oliguric episodes during hospitalization and those without, but not in birth weight, perinatal or postnatal factors. Gestational age was negatively correlated with urinary NGAL and serum CysC levels and urinary NGAL/Cr ratio (p < 0.05), whereas postnatal age was negatively correlated with serum Cr level and urinary NGAL/Cr ratio (p < 0.05). Of the 117 urine and blood samples collected, 25 (21.4%) were obtained from neonates with oliguric episodes. After adjusting for gestational age and postnatal age, comparison of samples collected in infants with and without oliguric episodes revealed significant differences in the mean level of urinary NGAL and in the urinary NGAL/Cr ratio, but not in mean serum CysC or serum Cr levels. The urinary NGAL level [area under the curve (AUC) 0.886, 95% confidence interval (CI) 0.814-0.937] and urinary NGAL/Cr ratio (AUC 0.853, 95% CI 0.775-0.911) showed significantly greater discrimination for oliguria than serum CysC (AUC 0.610, 95% CI: 0.515-0.699) or serum Cr (AUC 0.747, 95%CI 0.659-0.823) levels.
  
  
  
  Urinary NGAL level and urinary NGAL/Cr ratio were more sensitive markers for the presence of oliguria in VLBWIs with normal serum Cr levels than serum CysC level.
authors.affiliation: Department of Pediatrics, Dongsan Medical Center, Keimyung University School of Medicine, 56 Dalseong-Ro, Jung-gu, Daegu, 700-712, South Korea.
authors.forename: So Young
authors.initials: SY
authors.lastname: Shin
authors.affiliation: Department of Urology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Ji Yong
authors.initials: JY
authors.lastname: Ha
authors.affiliation: Department of Pediatrics, Dongsan Medical Center, Keimyung University School of Medicine, 56 Dalseong-Ro, Jung-gu, Daegu, 700-712, South Korea.
authors.forename: Sang Lak
authors.initials: SL
authors.lastname: Lee
authors.affiliation: Department of Laboratory Medicine, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, South Korea.
authors.forename: Won Mok
authors.initials: WM
authors.lastname: Lee
authors.affiliation: Department of Pediatrics, Dongsan Medical Center, Keimyung University School of Medicine, 56 Dalseong-Ro, Jung-gu, Daegu, 700-712, South Korea. jhpark.neo@gmail.com.
authors.forename: Jae Hyun
authors.initials: JH
authors.lastname: Park
mesh_terms: D001034:Apgar Score; D019540:Area Under Curve; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000097:blood*; D055316:Cystatin C / Q000097:blood*; D005865:Gestational Age; D006760:Hospitalization / Q000706:statistics & numerical data; D006801:Humans; D007231:Infant, Newborn; D019102:Infant, Very Low Birth Weight / Q000097:blood / Q000652:urine*; D007363:Intensive Care Units, Neonatal / Q000706:statistics & numerical data; D007677:Kidney Function Tests; D000071068:Lipocalin-2 / Q000652:urine*; D009846:Oliguria / Q000097:blood / Q000175:diagnosis / Q000652:urine*; D011518:Proto-Oncogene Proteins; D012189:Retrospective Studies
chemical_list: D015415:Biomarkers; C525030:CST3 protein, human; D055316:Cystatin C; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D011518:Proto-Oncogene Proteins; D003404:Creatinine
keywords: Neutrophil gelatinase-associated lipocalin; Oliguria; Renal biomarkers; Serum cystatin C; Very-low-birth-weight infant