title: The evolving use of higher risk grafts is associated with an increased incidence of acute kidney injury after liver transplantation.
abstract: OBJECTIVE
  The growing discrepancy between supply and demand for liver transplantation has necessitated a greater use of higher risk grafts. Donation after Circulatory Death (DCD) liver transplant recipients have an increased frequency of acute kidney injury (AKI). We hypothesised that other higher risk grafts might also impact negatively on renal function. Our aim was to examine the effect of the evolving use of higher risk grafts on the incidence of post liver transplant AKI.
  
  
  METHODS
  Single-centre study of 1152 patients undergoing first-single-organ liver transplantation for chronic liver disease 01/2000-12/2011. To assess the impact of the evolution of graft quality over time; donor/graft/recipient variables were compared over three 4-year periods.
  
  
  RESULTS
  Pretransplant recipient renal function improved during follow-up (p<0.001), and the median postoperative day-1 (p<0.001), -2 (p<0.001), and -3 (p<0.001) tacrolimus trough levels fell. The proportion of patients receiving a higher risk graft was 31.8% in 2000-2003, 40.9% in 2004-2007, and 59.1% in 2008-2011 (p<0.001). There was a progressive increase in AKI (2000-2003, OR 1.00; 2004-2007, OR 1.43; 2008-2011, OR 2.40, p<0.001). After adjusting for recipient variables increasing recipient warm ischaemic time (p=0.019), DCD transplantation (p<0.001), donor age ≥60 years (p=0.020), and donor body mass index ≥30 kg/m(2) (p<0.001) were independent predictors of AKI.
  
  
  CONCLUSIONS
  The increasing use of higher risk liver grafts is associated with an increased incidence of AKI. These findings support the need for therapies that minimise the hepatic ischaemia-reperfusion injury.
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, Birmingham, UK; NIHR Biomedical Research Unit and Centre for Liver Research, University of Birmingham, Birmingham, UK. Electronic address: j.a.leithead@bham.ac.uk.
authors.forename: Joanna A
authors.initials: JA
authors.lastname: Leithead
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Neil
authors.initials: N
authors.lastname: Rajoriya
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, Birmingham, UK; NIHR Biomedical Research Unit and Centre for Liver Research, University of Birmingham, Birmingham, UK.
authors.forename: Bridget K
authors.initials: BK
authors.lastname: Gunson
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: Paolo
authors.initials: P
authors.lastname: Muiesan
authors.affiliation: Liver Unit, Queen Elizabeth Hospital, Birmingham, UK.
authors.forename: James W
authors.initials: JW
authors.lastname: Ferguson
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology* / Q000401:mortality; D000328:Adult; D015992:Body Mass Index; D058625:End Stage Liver Disease / Q000401:mortality / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006085:Graft Survival; D006801:Humans; D015994:Incidence; D016031:Liver Transplantation / Q000009:adverse effects* / Q000401:mortality; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D009765:Obesity / Q000401:mortality; D015427:Reperfusion Injury / Q000401:mortality; D012307:Risk Factors; D014019:Tissue Donors; D016896:Treatment Outcome; D052096:Warm Ischemia / Q000401:mortality
keywords: Acute kidney injury; Chronic kidney disease; Donor; Higher risk graft; Liver transplantation