Urine NGAL predicts severity of acute kidney injury after cardiac surgery: a prospective study

Clin J Am Soc Nephrol. 2008 May;3(3):665-73. doi: 10.2215/CJN.04010907. Epub 2008 Mar 12.

Abstract

Background and objectives: The authors have previously shown that urine neutrophil gelatinase-associated lipocalin (NGAL), measured by a research ELISA, is an early predictive biomarker of acute kidney injury (AKI) after cardiopulmonary bypass (CPB). In this study, whether an NGAL immunoassay developed for a standardized clinical platform (ARCHITECT analyzer, Abbott Diagnostics Division, Abbott Laboratories, Abbott Park, IL) can predict AKI after CPB was tested.

Design, setting, participants, & measurements: In a pilot study with 136 urine samples (NGAL range, 0.3 to 815 ng/ml) and 6 calibration standards (NGAL range, 0 to 1000 ng/ml), NGAL measurements by research ELISA and by the ARCHITECT assay were highly correlated (r = 0.99). In a subsequent study, 196 children undergoing CPB were prospectively enrolled and serial urine NGAL measurements obtained by ARCHITECT assay. The primary outcome was AKI, defined as a > or = 50% increase in serum creatinine.

Results: AKI developed in 99 patients (51%), but the diagnosis using serum creatinine was delayed by 2 to 3 d after CPB. In contrast, mean urine NGAL levels increased 15-fold within 2 h and by 25-fold at 4 and 6 h after CPB. For the 2-h urine NGAL measurement, the area under the curve was 0.95, sensitivity was 0.82, and the specificity was 0.90 for prediction of AKI using a cutoff value of 100 ng/ml. The 2-h urine NGAL levels correlated with severity and duration of AKI, length of stay, dialysis requirement, and death.

Conclusions: Accurate measurements of urine NGAL are obtained using the ARCHITECT platform. Urine NGAL is an early predictive biomarker of AKI severity after CPB.

Publication types

  • Evaluation Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Kidney Injury / blood
  • Acute Kidney Injury / etiology
  • Acute Kidney Injury / mortality
  • Acute Kidney Injury / therapy
  • Acute Kidney Injury / urine*
  • Acute-Phase Proteins / urine*
  • Biomarkers / blood
  • Biomarkers / urine
  • Calibration
  • Cardiac Surgical Procedures*
  • Cardiopulmonary Bypass / adverse effects*
  • Child, Preschool
  • Creatinine / blood
  • Cross-Sectional Studies
  • Enzyme-Linked Immunosorbent Assay
  • Female
  • Humans
  • Immunoassay
  • Length of Stay
  • Lipocalin-2
  • Lipocalins / urine*
  • Male
  • Pilot Projects
  • Predictive Value of Tests
  • Prospective Studies
  • Proto-Oncogene Proteins / urine*
  • Reagent Kits, Diagnostic* / standards
  • Renal Dialysis
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Severity of Illness Index
  • Up-Regulation

Substances

  • Acute-Phase Proteins
  • Biomarkers
  • LCN2 protein, human
  • Lipocalin-2
  • Lipocalins
  • Proto-Oncogene Proteins
  • Reagent Kits, Diagnostic
  • Creatinine