title: Urinary biomarkers TIMP-2 and IGFBP7 early predict acute kidney injury after major surgery.
abstract: OBJECTIVE
  To assess the ability of the urinary biomarkers IGFBP7 (insulin-like growth factor-binding protein 7) and TIMP-2 (tissue inhibitor of metalloproteinase 2) to early predict acute kidney injury (AKI) in high-risk surgical patients.
  
  
  BACKGROUND
  Postoperative AKI is associated with an increase in short and long-term mortality. Using IGFBP7 and TIMP-2 for early detection of cellular kidney injury, thus allowing the early initiation of renal protection measures, may represent a new concept of evaluating renal function.
  
  
  METHODS
  In this prospective study, urinary [TIMP-2]×[IGFBP7] was measured in surgical patients at high risk for AKI. A predefined cut-off value of [TIMP-2]×[IGFBP7] >0.3 was used for assessing diagnostic accuracy. Perioperative characteristics were evaluated, and ROC analyses as well as logistic regression models of risk assessment were calculated with and without a [TIMP-2]×[IGFBP7] test.
  
  
  RESULTS
  107 patients were included in the study, of whom 45 (42%) developed AKI. The highest median values of biomarker were detected in septic, transplant and patients after hepatic surgery (1.24 vs 0.45 vs 0.47 ng/l²/1000). The area under receiving operating characteristic curve (AUC) for the risk of any AKI was 0.85, for early use of RRT 0.83 and for 28-day mortality 0.77. In a multivariable model with established perioperative risk factors, the [TIMP-2]×[IGFBP7] test was the strongest predictor of AKI and significantly improved the risk assessment (p<0.001).
  
  
  CONCLUSIONS
  Urinary [TIMP-2]×[IGFBP7] test sufficiently detect patients with risk of AKI after major non-cardiac surgery. Due to its rapid responsiveness it extends the time frame for intervention to prevent development of AKI.
authors: Department of Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Ivan
authors: I
authors: Gocze
authors: Department of Trauma Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Matthias
authors: M
authors: Koch
authors: Department of Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Philipp
authors: P
authors: Renner
authors: Center for Clinical Studies, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Florian
authors: F
authors: Zeman
authors: Department of Anesthesiology, University Medical Center Regensburg, Franz-Josef- Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Bernhard M
authors: BM
authors: Graf
authors: Department of Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Marc H
authors: MH
authors: Dahlke
authors: Department of Trauma Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Michael
authors: M
authors: Nerlich
authors: Department of Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Hans J
authors: HJ
authors: Schlitt
authors: Center for Critical Care Nephrology and CRISMA (Clinical Research, Investigation, and Systems Modeling of Acute Illness) Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15621, United States of America.
authors: John A
authors: JA
authors: Kellum
authors: Department of Surgery, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany; Center for Clinical Studies, University Medical Center Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg, Germany.
authors: Thomas
authors: T
authors: Bein
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000652:urine*; D015415:Biomarkers / Q000652:urine; D059447:Cell Cycle Checkpoints; D005260:Female; D006801:Humans; D018969:Insulin-Like Growth Factor Binding Proteins / Q000652:urine*; D007668:Kidney / Q000473:pathology; D008297:Male; D008875:Middle Aged; D059035:Perioperative Period; D011183:Postoperative Complications / Q000175:diagnosis / Q000209:etiology / Q000473:pathology / Q000652:urine*; D012372:ROC Curve; D018570:Risk Assessment; D013997:Time Factors; D019716:Tissue Inhibitor of Metalloproteinase-2 / Q000652:urine*; D016482:Urinalysis
chemical_list: D015415:Biomarkers; D018969:Insulin-Like Growth Factor Binding Proteins; C560823:TIMP2 protein, human; C102529:insulin-like growth factor binding protein-related protein 1; D019716:Tissue Inhibitor of Metalloproteinase-2