title: Urinary L-FABP predicts poor outcomes in critically ill patients with early acute kidney injury.
abstract: Biomarker studies for early detection of acute kidney injury (AKI) have been limited by nonselective testing and uncertainties in using small changes in serum creatinine as a reference standard. Here we examine the ability of urine L-type fatty acid-binding protein (L-FABP), neutrophil gelatinase-associated lipocalin (NGAL), interleukin-18 (IL-18), and kidney injury molecule-1 (KIM-1) to predict injury progression, dialysis, or death within 7 days in critically ill adults with early AKI. Of 152 patients with known baseline creatinine examined, 36 experienced the composite outcome. Urine L-FABP demonstrated an area under the receiver-operating characteristic curve (AUC-ROC) of 0.79 (95% confidence interval 0.70-0.86), which improved to 0.82 (95% confidence interval 0.75-0.90) when added to the clinical model (AUC-ROC of 0.74). Urine NGAL, IL-18, and KIM-1 had AUC-ROCs of 0.65, 0.64, and 0.62, respectively, but did not significantly improve discrimination of the clinical model. The category-free net reclassification index improved with urine L-FABP (total net reclassification index for nonevents 31.0%) and urine NGAL (total net reclassification index for events 33.3%). However, only urine L-FABP significantly improved the integrated discrimination index. Thus, modest early changes in serum creatinine can help target biomarker measurement for determining prognosis with urine L-FABP, providing independent and additive prognostic information when combined with clinical predictors.
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Sharidan K
authors.initials: SK
authors.lastname: Parr
authors.affiliation: Albert Einstein College of Medicine, Bronx, New York, USA.
authors.forename: Amanda J
authors.initials: AJ
authors.lastname: Clark
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Aihua
authors.initials: A
authors.lastname: Bian
authors.affiliation: Department of Biostatistics, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Ayumi K
authors.initials: AK
authors.lastname: Shintani
authors.affiliation: Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Nancy E
authors.initials: NE
authors.lastname: Wickersham
authors.affiliation: 1] Division of Allergy, Pulmonary, and Critical Care Medicine, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA [2] Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Lorraine B
authors.initials: LB
authors.lastname: Ware
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: T Alp
authors.initials: TA
authors.lastname: Ikizler
authors.affiliation: Division of Nephrology and Hypertension, Department of Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA.
authors.forename: Edward D
authors.initials: ED
authors.lastname: Siew
mesh_terms: D018806:APACHE; D058186:Acute Kidney Injury / Q000175:diagnosis / Q000628:therapy / Q000652:urine*; D000209:Acute-Phase Proteins / Q000652:urine; D000368:Aged; D019540:Area Under Curve; D015415:Biomarkers / Q000097:blood / Q000652:urine; D003404:Creatinine / Q000097:blood; D016638:Critical Illness; D018450:Disease Progression; D042241:Early Diagnosis; D050556:Fatty Acid-Binding Proteins / Q000652:urine*; D005260:Female; D000072596:Hepatitis A Virus Cellular Receptor 1; D006801:Humans; D020382:Interleukin-18 / Q000652:urine; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine; D008297:Male; D008562:Membrane Glycoproteins / Q000652:urine; D008875:Middle Aged; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000652:urine; D012372:ROC Curve; D011991:Receptors, Virus; D006435:Renal Dialysis
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C493319:FABP1 protein, human; D050556:Fatty Acid-Binding Proteins; C491143:HAVCR1 protein, human; D000072596:Hepatitis A Virus Cellular Receptor 1; D020382:Interleukin-18; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D008562:Membrane Glycoproteins; D011518:Proto-Oncogene Proteins; D011991:Receptors, Virus; D003404:Creatinine