title: Urine NGAL predicts severity of acute kidney injury after cardiac surgery: a prospective study.
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
authors.affiliation: Nephrology & Hypertension, Cincinnati Children's Hospital Medical Center, University of Cincinnati School of Medicine, Cincinnati, OH 45229-3039, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Bennett
authors.forename: Catherine L
authors.initials: CL
authors.lastname: Dent
authors.forename: Qing
authors.initials: Q
authors.lastname: Ma
authors.forename: Sudha
authors.initials: S
authors.lastname: Dastrala
authors.forename: Frank
authors.initials: F
authors.lastname: Grenier
authors.forename: Ryan
authors.initials: R
authors.lastname: Workman
authors.forename: Hina
authors.initials: H
authors.lastname: Syed
authors.forename: Salman
authors.initials: S
authors.lastname: Ali
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barasch
authors.forename: Prasad
authors.initials: P
authors.lastname: Devarajan
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology / Q000401:mortality / Q000628:therapy / Q000652:urine*; D000209:Acute-Phase Proteins / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002138:Calibration; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002675:Child, Preschool; D003404:Creatinine / Q000097:blood; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007118:Immunoassay; D007902:Length of Stay; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D010865:Pilot Projects; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011518:Proto-Oncogene Proteins / Q000652:urine*; D011933:Reagent Kits, Diagnostic / Q000592:standards; D006435:Renal Dialysis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D015854:Up-Regulation
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D011933:Reagent Kits, Diagnostic; D003404:Creatinine