Greater increase in urinary hepcidin predicts protection from acute kidney injury after cardiopulmonary bypass

John R. Prowle, Vaughn Ostland, Paolo Calzavacca, Elisa Licari, E. Valentina Ligabo, Jorge E. Echeverri, Sean M. Bagshaw, Anja Haase-Fielitz, Michael Haase, Mark Westerman, Rinaldo Bellomo

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35 Citations (Scopus)

Abstract

Background. Acute kidney injury (AKI) is a common and serious complication of cardiopulmonary bypass (CPB) surgery. Hepcidin, a peptide hormone that regulates iron homeostasis, is a potential biomarker of AKI following CPB. Methods. We investigated the association between post-operative changes in serum and urinary hepcidin and AKI in 93 patients undergoing CPB. Results. Twenty-five patients developed AKI based on the Risk, Injury, Failure, Loss, End-stage kidney disease (RIFLE) criteria in the first 5 days. Serum hepcidin, urine hepcidin concentration, the urinary hepcidin:creatinine ratio and fractional excretion of hepcidin in urine rose significantly after surgery. However, urine hepcidin concentration and urinary hepcidin:creatinine ratio were significantly lower at 24 h in patients with RIFLE-Risk, Injury or Failure compared to those without AKI (P = 0.0009 and P < 0.0001, respectively). Receiver operator characteristic analysis showed that lower 24-h urine hepcidin concentration and urinary hepcidin:creatinine ratio were sensitive and specific predictors of AKI. The urinary hepcidin:creatinine ratio had an area under the curve for the diagnosis of RIFLE ≥ risk at 24 h of 0.77 and of 0.84 for RIFLE ≥ injury. Urinary hepcidin had similar predictive accuracy. Such predictive ability remained when patients with early creatinine increases were excluded.Conclusions.Urinary hepcidin and hepcidin:creatinine ratio are biomarkers of AKI after CPB, with an inverse association between its increase at 24 h and risk of AKI in the first five post-operative days. Measuring hepcidin in the urine on the first day following surgery may deliver earlier diagnosis and interventions.

Original languageEnglish
Pages (from-to)595-602
Number of pages8
JournalNephrology Dialysis Transplantation
Volume27
Issue number2
DOIs
Publication statusPublished - Feb 2012
Externally publishedYes

Keywords

  • acute kidney injury
  • biomarkers
  • cardiopulmonary bypass
  • critical illness
  • hepcidin

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