title: Urinary neutrophil gelatinase-associated lipocalin distinguishes pre-renal from intrinsic renal failure and predicts outcomes.
abstract: In established acute kidney injury (AKI), serum creatinine poorly differentiates prerenal from intrinsic AKI. In this study, we tested whether urinary neutrophil gelatinase-associated lipocalin (NGAL) distinguishes between intrinsic and prerenal AKI, and tested its performance in predicting a composite outcome that included progression to a higher RIFLE (Risk, Injury, Failure, Loss of function, End stage renal disease) class, dialysis, or death. Urinary NGAL was measured using a standardized clinical platform in 161 hospitalized patients with established AKI. Sixteen patients were excluded because of postrenal obstruction or insufficient clinical information. Of the remaining 145 patients, 75 had intrinsic AKI, 32 had prerenal AKI, and 38 patients could not be classified. Urinary NGAL levels effectively discriminated between intrinsic and prerenal AKI (area under the receiver-operating characteristic curve 0.87). An NGAL level over 104 μg/l indicated intrinsic AKI (likelihood ratio 5.97), whereas an NGAL level <47 μg/l made intrinsic AKI unlikely (likelihood ratio 0.2). Patients experiencing the composite outcome had significantly higher median urinary NGAL levels on inclusion. In logistic regression analysis, NGAL independently predicted the composite outcome when corrected for demographics, comorbidities, creatinine, and RIFLE class. Hence, urinary NGAL is useful in classifying and stratifying patients with established AKI.
authors.affiliation: Experimental and Clinical Research Center, a joint institution of the Charité Medical Faculty and the Max-Delbrück Center for Molecular Medicine, Berlin, Germany.
authors.forename: Eugenia
authors.initials: E
authors.lastname: Singer
authors.forename: Antje
authors.initials: A
authors.lastname: Elger
authors.forename: Saban
authors.initials: S
authors.lastname: Elitok
authors.forename: Ralph
authors.initials: R
authors.lastname: Kettritz
authors.forename: Thomas L
authors.initials: TL
authors.lastname: Nickolas
authors.forename: Jonathan
authors.initials: J
authors.lastname: Barasch
authors.forename: Friedrich C
authors.initials: FC
authors.lastname: Luft
authors.forename: Kai M
authors.initials: KM
authors.lastname: Schmidt-Ott
mesh_terms: D058186:Acute Kidney Injury / Q000150:complications / Q000175:diagnosis / Q000401:mortality / Q000628:therapy / Q000652:urine*; D000209:Acute-Phase Proteins / Q000652:urine*; D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood / Q000652:urine; D016009:Chi-Square Distribution; D003404:Creatinine / Q000097:blood; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D017052:Hospital Mortality; D006760:Hospitalization; D006801:Humans; D007676:Kidney Failure, Chronic / Q000209:etiology / Q000401:mortality / Q000628:therapy / Q000652:urine; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012372:ROC Curve; D051437:Renal Insufficiency / Q000209:etiology / Q000401:mortality / Q000628:therapy / Q000652:urine; D017582:Renal Replacement Therapy; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine