title: Urinary hepcidin-25 and risk of acute kidney injury following cardiopulmonary bypass.
abstract: OBJECTIVE
  Acute kidney injury (AKI) complicating cardiopulmonary bypass (CPB) results in increased morbidity and mortality. Urinary hepcidin-25 has been shown to be elevated in patients who do not develop AKI after CPB using semiquantitative mass spectrometry (SELDI TOF-MS). The goals of this study were to quantitatively validate these findings with ELISA and evaluate the diagnostic performance of hepcidin-25 for AKI.
  
  
  METHODS
  A nested, case-control analysis of urinary hepcidin-25 in AKI (n = 22) and non-AKI (n = 22) patients was conducted to validate the SELDI TOF-MS data at the following times: preoperatively; the start of CPB; 1 hour on CPB; on arrival to the intensive care unit; and postoperative days (POD) 1 and 3 to 5. The diagnostic performance of hepcidin-25 was then evaluated in the entire prospective observational cohort (n = 338) at POD 1. AKI was defined as Cr >50% from baseline, within 72 hours postoperatively.
  
  
  RESULTS
  Urinary hepcidin-25/Cr ratio was significantly elevated in all patients at POD 1 compared with baseline (P < 0.0005) and was also significantly elevated in non-AKI versus AKI patients at POD 1 (P < 0.0005). Increased log(10) hepcidin-25/Cr ratio was strongly associated with avoidance of AKI on univariate analysis. On multivariate analysis, the log(10) hepcidin-25/Cr ratio (P < 0.0001) was associated with avoidance of AKI with an area under the curve of 0.80, sensitivity 0.68, specificity 0.68, and negative predictive value 0.96.
  
  
  CONCLUSIONS
  Elevated urinary hepcidin-25 on POD 1 is a strong predictor of avoidance of AKI beyond postoperative day 1.
authors: Sections of Nephrology & Biomedical Proteomics, Health Sciences Centre, GE421C, 820 Sherbrooke Street, Winnipeg, Manitoba, MB R3A 1R9, Canada. jho@hsc.mb.ca
authors: Julie
authors: J
authors: Ho
authors: Martina
authors: M
authors: Reslerova
authors: Brent
authors: B
authors: Gali
authors: Ang
authors: A
authors: Gao
authors: Jennifer
authors: J
authors: Bestland
authors: David N
authors: DN
authors: Rush
authors: Peter W
authors: PW
authors: Nickerson
authors: Claudio
authors: C
authors: Rigatto
mesh_terms: D058186:Acute Kidney Injury / Q000097:blood / Q000209:etiology* / Q000517:prevention & control / Q000652:urine*; D000368:Aged; D023181:Antimicrobial Cationic Peptides / Q000652:urine*; D015415:Biomarkers / Q000097:blood / Q000652:urine; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D016022:Case-Control Studies; D003404:Creatinine / Q000097:blood; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D064451:Hepcidins; D006801:Humans; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008350:Manitoba; D008875:Middle Aged; D016017:Odds Ratio; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D015203:Reproducibility of Results; D018570:Risk Assessment; D012307:Risk Factors; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013997:Time Factors
chemical_list: D023181:Antimicrobial Cationic Peptides; D015415:Biomarkers; D064451:Hepcidins; C545475:hepcidin 25, human; D003404:Creatinine