Liver fatty acid-binding protein as a biomarker of acute kidney injury after cardiac surgery.
Acute kidney injury (AKI) is a major complication of cardiac bypass surgery. We examined whether levels of liver fatty acid-binding protein (L-FABP) can be an early biomarker for ischemic injury by measuring this protein in the urine of 40 pediatric patients prior to and following cardiopulmonary bypass surgery. AKI was defined as a 50% increase in the serum creatinine from baseline, which was normally not seen until 24-72 h after surgery. Enzyme-linked immunosorbent assay analysis showed increased L-FABP levels (factored for creatinine excretion) of about 94- and 45-fold at 4 and 12 h, respectively, following surgery in the 21 patients who developed AKI with western blot analysis, confirming L-FABP identity. Univariate logistic regression analyses showed that both bypass time and urinary L-FABP were significant independent risk indicators for AKI. After excluding bypass time from the model and using a stepwise multivariate logistic regression analysis, urinary L-FABP levels at 4 h after surgery were an independent risk indicator with the area under the receiver-operating characteristic curve 0.810, sensitivity 0.714, and specificity 0.684 for a 24-fold increase in urinary L-FABP. Our study shows that urinary L-FABP levels represent a sensitive and predictive early biomarker of AKI after cardiac surgery.
Portilla
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Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare System, Little Rock, Arkansas 72205, USA. portilladidier@uams.edu
Dent
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Sugaya
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Nagothu
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Kundi
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Moore
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Noiri
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Devarajan
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D000208:Acute Disease; D000209:Acute-Phase Proteins / Q000652:urine; D000419:Albuminuria / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D002675:Child, Preschool; D050556:Fatty Acid-Binding Proteins / Q000097:blood / Q000652:urine*; D005260:Female; D006801:Humans; D007511:Ischemia / Q000175:diagnosis* / Q000209:etiology; D007668:Kidney / Q000098:blood supply*; D007674:Kidney Diseases / Q000175:diagnosis* / Q000209:etiology; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine; D008297:Male; D011183:Postoperative Complications / Q000175:diagnosis* / Q000209:etiology; D011518:Proto-Oncogene Proteins / Q000652:urine
D000209:Acute-Phase Proteins; D015415:Biomarkers; D050556:Fatty Acid-Binding Proteins; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins