Clinical Utility of Rapid Plasma Neutrophil Gelatinase-Associated Lipocalin Assays for Diagnosing Acute Kidney Injury in Critically Ill Newborn Infants

Abstract

Purpose: Neutrophil gelatinase-associated lipocalin (NGAL) has been identified as an early marker of acute kidney injury (AKI). This study was designed to evaluate the clinical utility of the rapid plasma NGAL assay for diagnosing AKI in critically ill newborn infants in the neonatal intensive care unit (NICU). Methods: The medical records of 178 critically ill newborn infants >34 weeks of gestational age who underwent plasma NGAL measurement during the first week of life in the Korea University Ansan Hospital NICU from February 2011 to August 2015 were retrospectively reviewed. Plasma NGAL levels were measured at bedside by using a commercial competitive immunoassay kit simultaneously with serum creatinine (Cr) level determination. Results: Of 178 newborn infants enrolled in this study (study group), 25 infants had AKI (AKI group) while 153 infants had no AKI (control group). The plasma NGAL level in the AKI group (114.0 [76.5–281.5] ng/mL) was significantly higher than that in the control group (74.0 [52.5–122.5] ng/mL, P=0.001). Moreover, plasma NGAL levels were found to be correlated with serum Cr levels in the study group (r=0.208, P= 0.005). Plasma NGAL achieved an area under the receiver operating characteristic curve of 0.705 for detecting AKI (95% confidence interval: 0.593–0.817). The best cutoff plasma NGAL level for AKI diagnosis was 100 ng/mL. Conclusion: The rapid plasma NGAL assay has diagnostic value for AKI in critically ill newborn infants >34 weeks of gestational age. Further investigations with a larger population are needed to confirm the potential use of plasma NGAL levels for diagnosing AKI in newborn infants.