title: Evaluation of new acute kidney injury biomarkers in a mixed intensive care unit.
abstract: OBJECTIVE
  Biomarkers for detection of acute kidney injury and prediction of mortality will be useful to improve the outcomes of critically ill patients. Although several promising acute kidney injury biomarkers have been reported, evaluation in heterogeneous disease-oriented populations is necessary to confirm their reliability before their translation to clinical use. This study was undertaken to evaluate the reliability of new acute kidney injury biomarkers including urinary L-type fatty acid-binding protein with heterogeneous intensive care unit populations.
  
  
  METHODS
  Prospective observational cohort study.
  
  
  METHODS
  Single-center study, 15-bed medical-surgical mixed intensive care unit at a university hospital.
  
  
  METHODS
  Three hundred thirty-nine adult critically ill patients who had been admitted to the intensive care unit were studied prospectively.
  
  
  METHODS
  None.
  
  
  RESULTS
  Five urinary biomarkers (L-type fatty acid-binding protein, neutrophil gelatinase-associated lipocalin, interleukin-18, N-acetyl-β-D-glucosaminidase, and albumin) were measured at intensive care unit admission. By the RIFLE (Risk, Injury, Failure, Loss, End-stage kidney disease) criteria, 131 patients (39%) were diagnosed as acute kidney injury. Urinary L-type fatty acid-binding protein detected acute kidney injury better than the other biomarkers did (the area under the receiver operating characteristic curves for L-type fatty acid-binding protein 0.75, neutrophil gelatinase-associated lipocalin 0.70, interleukin-18 0.69, N-acetyl-β-D-glucosaminidase 0.62, albumin 0.69). Urinary L-type fatty acid-binding protein predicted later-onset acute kidney injury after intensive care unit admission with the highest area under the receiver operating characteristic curve value of 0.70. Furthermore, L-type fatty acid-binding protein, neutrophil gelatinase-associated lipocalin, and interleukin-18 were able to predict 14-day mortality with higher area under the receiver operating characteristic curves than acute kidney injury detection (area under the receiver operating characteristic curve for L-type fatty acid-binding protein 0.90, neutrophil gelatinase-associated lipocalin 0.83, interleukin-18 0.83). The combination of L-type fatty acid-binding protein and neutrophil gelatinase-associated lipocalin improved mortality prediction (area under the receiver operating characteristic curve 0.93).
  
  
  CONCLUSIONS
  This prospective observational study with a cohort of heterogeneous patients treated in a mixed intensive care unit revealed that new acute kidney injury biomarkers have a significantly and moderately predictive use for acute kidney injury diagnosis and that urinary L-type fatty acid-binding protein and neutrophil gelatinase-associated lipocalin can serve as new biomarkers of mortality prediction in critical care.
authors.affiliation: Department of Nephrology and Endocrinology, The University of Tokyo, Tokyo, Japan.
authors.forename: Kent
authors.initials: K
authors.lastname: Doi
authors.forename: Kousuke
authors.initials: K
authors.lastname: Negishi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Ishizu
authors.forename: Daisuke
authors.initials: D
authors.lastname: Katagiri
authors.forename: Toshiro
authors.initials: T
authors.lastname: Fujita
authors.forename: Takehiro
authors.initials: T
authors.lastname: Matsubara
authors.forename: Naoki
authors.initials: N
authors.lastname: Yahagi
authors.forename: Takeshi
authors.initials: T
authors.lastname: Sugaya
authors.forename: Eisei
authors.initials: E
authors.lastname: Noiri
mesh_terms: D000118:Acetylglucosaminidase / Q000652:urine; D058186:Acute Kidney Injury / Q000652:urine*; D000368:Aged; D000419:Albuminuria; D015415:Biomarkers; D016638:Critical Illness; D050556:Fatty Acid-Binding Proteins / Q000652:urine; D005260:Female; D006785:Hospitals, University; D006801:Humans; D007362:Intensive Care Units; D020382:Interleukin-18 / Q000652:urine; D054834:Lipocalins / Q000652:urine; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D012680:Sensitivity and Specificity
chemical_list: D015415:Biomarkers; D050556:Fatty Acid-Binding Proteins; D020382:Interleukin-18; D054834:Lipocalins; D000118:Acetylglucosaminidase