Neutrophil gelatinase-associated lipocalin (NGAL) as a biomarker for acute renal injury after cardiac surgery.
BACKGROUND
The scarcity of early biomarkers for acute renal failure has hindered our ability to launch preventive and therapeutic measures for this disorder in a timely manner. We tested the hypothesis that neutrophil gelatinase-associated lipocalin (NGAL) is an early biomarker for ischaemic renal injury after cardiopulmonary bypass.


METHODS
We studied 71 children undergoing cardiopulmonary bypass. Serial urine and blood samples were analysed by western blots and ELISA for NGAL expression. The primary outcome measure was acute renal injury, defined as a 50% increase in serum creatinine from baseline.


RESULTS
20 children (28%) developed acute renal injury, but diagnosis with serum creatinine was only possible 1-3 days after cardiopulmonary bypass. By contrast, urine concentrations of NGAL rose from a mean of 1.6 microg/L (SE 0.3) at baseline to 147 microg/L (23) 2 h after cardiopulmonary bypass, and the amount in serum increased from a mean of 3.2 microg/L (SE 0.5) at baseline to 61 microg/L (10) 2 h after the procedure. Univariate analysis showed a significant correlation between acute renal injury and the following: urine and serum concentrations of NGAL at 2 h, and cardiopulmonary bypass time. By multivariate analysis, the amount of NGAL in urine at 2 h after cardiopulmonary bypass was the most powerful independent predictor of acute renal injury. For concentration in urine of NGAL at 2 h, the area under the receiver-operating characteristic curve was 0.998, sensitivity was 1.00, and specificity was 0.98 for a cutoff value of 50 microg/L.


CONCLUSIONS
Concentrations in urine and serum of NGAL represent sensitive, specific, and highly predictive early biomarkers for acute renal injury after cardiac surgery.
Mishra
Jaya
J
Division of Nephrology and Hypertension, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229-3039, USA.
Dent
Catherine
C
Tarabishi
Ridwan
R
Mitsnefes
Mark M
MM
Ma
Qing
Q
Kelly
Caitlin
C
Ruff
Stacey M
SM
Zahedi
Kamyar
K
Shao
Mingyuan
M
Bean
Judy
J
Mori
Kiyoshi
K
Barasch
Jonathan
J
Devarajan
Prasad
P
D058186:Acute Kidney Injury / Q000175:diagnosis*; D000209:Acute-Phase Proteins / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D015153:Blotting, Western; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D000071068:Lipocalin-2; D054834:Lipocalins; D008297:Male; D015513:Oncogene Proteins / Q000032:analysis*; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins; D012680:Sensitivity and Specificity
D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D015513:Oncogene Proteins; D011518:Proto-Oncogene Proteins