title: Urinary neutrophil gelatinase-associated lipocalin (NGAL) as an early marker of acute kidney injury in critically ill multiple trauma patients.
abstract: BACKGROUND
  Neutrophil gelatinase-associated lipocalin (NGAL), an iron-transporting protein rapidly accumulating in the kidney tubules and urine after nephrotoxic and ischemic insults, has been put forward as an early, sensitive, non-invasive biomarker for acute kidney injury (AKI). The aim of this study was to evaluate urinary NGAL levels as a predictor of early AKI (first 5 days after injury) in multi-trauma patients.
  
  
  METHODS
  We studied multi-trauma adult patients admitted to the intensive care unit of a trauma hospital. Exclusion criteria were a) known cardiac or chronic kidney disease, and b) initial evaluation after more than 24 h had elapsed from injury. Urinary NGAL was measured using an ELISA technique upon admission and at 24 and 48 h. Presence of AKI was defined by the risk injury failure loss and end-stage kidney classification (RIFLE) criteria. Data are reported as median and interquartile range.
  
  
  RESULTS
  A total of 31 patients (25 male, 6 female) were studied. NGAL levels at admission were significantly higher among patients who subsequently developed AKI [155.5 (50.5-205.9) ng/mL vs. 8.0 (5.7-17.7) ng/mL, p=0.0000] and these higher levels persisted over the following 2 days. On the basis of receiver-operating characteristic analysis both NGAL and serum creatinine baseline measurements could predict AKI [area under the curve (95% confidence interval) 0.977 (0.823-0.980) and 0.789 (0.556-0.906), respectively], but the area under the curve for NGAL was significantly larger (p=0.024). A cut-off point >25 ng/mL for NGAL had a sensitivity of 0.91 and specificity of 0.95 in predicting AKI.
  
  
  CONCLUSIONS
  Urinary NGAL can be used from the 1st day of injury as a reliable predictor of early AKI in multi-trauma patients.
authors.affiliation: Clinical Biochemistry Department, KAT General Hospital, Kiffissia, Athens, Greece. knmakris@hol.gr
authors.forename: Konstantinos
authors.initials: K
authors.lastname: Makris
authors.forename: Nikos
authors.initials: N
authors.lastname: Markou
authors.forename: Effimia
authors.initials: E
authors.lastname: Evodia
authors.forename: Eleni
authors.initials: E
authors.lastname: Dimopoulou
authors.forename: Ioannis
authors.initials: I
authors.lastname: Drakopoulos
authors.forename: Konstantina
authors.initials: K
authors.lastname: Ntetsika
authors.forename: Demetrios
authors.initials: D
authors.lastname: Rizos
authors.forename: George
authors.initials: G
authors.lastname: Baltopoulos
authors.forename: Alexander
authors.initials: A
authors.lastname: Haliassos
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis* / Q000209:etiology / Q000401:mortality; D000209:Acute-Phase Proteins / Q000652:urine*; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000652:urine; D003404:Creatinine / Q000097:blood; D016638:Critical Illness; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007362:Intensive Care Units; D007668:Kidney / Q000293:injuries*; D000071068:Lipocalin-2; D054834:Lipocalins / Q000652:urine*; D008297:Male; D008875:Middle Aged; D009104:Multiple Trauma / Q000150:complications*; D011237:Predictive Value of Tests; D011518:Proto-Oncogene Proteins / Q000652:urine*; D012680:Sensitivity and Specificity; D012720:Severity of Illness Index; D013997:Time Factors
chemical_list: D000209:Acute-Phase Proteins; D015415:Biomarkers; C489506:LCN2 protein, human; D000071068:Lipocalin-2; D054834:Lipocalins; D011518:Proto-Oncogene Proteins; D003404:Creatinine