title: Pre-implant biopsy predicts outcome of single-kidney transplantation independent of clinical donor variables.
abstract: BACKGROUND
  Pre-implant biopsy findings account for the discard of many donor kidneys although their clinical value is not fully understood. We retrospectively investigated the predictive value of pre-implant histology, which in our center was obtained for protocol purposes, not for transplant decisions, on long-term allograft and recipient outcome after single-kidney transplantation.
  
  
  METHODS
  This single-center study included 628 consecutive adult recipients of 174 Expanded Criteria Donor (ECD) and 454 Standard Criteria Donor kidneys. Chronic donor organ injury was assessed applying a chronic lesion score differentiating between mild, moderate, and severe histologic organ injury based on the integration of glomerular, vascular, tubular, and interstitial lesions. Recipients were followed over a median time of 7.8 years.
  
  
  RESULTS
  Donor kidneys exhibiting mild or moderate chronic lesions yielded almost identical graft and recipient survival independent of ECD status or other clinical covariables (HR 1.20, 95% CI 0.83-1.74, P=0.326, and HR 1.27, 95% CI 0.83-1.95, P=0.274, respectively). However, if allograft injury was severe, occurring in 3% of transplanted kidneys, graft and recipient survival was significantly reduced (HR 3.13, 95% CI 1.61-6.07, P<0.001 and HR 2.42, 95% CI 1.16-5.04, P=0.005, respectively).
  
  
  CONCLUSIONS
  The results suggest that donor kidneys displaying moderate chronic injury can safely be transplanted as single kidneys, while organs displaying severe injury should be discarded. Thus, pre-implant biopsy might offer an effective approach to increase the utilization of renal donor organs, especially from ECD and donors with cerebrovascular accident as cause of death, and to improve overall graft outcome.
authors.affiliation: 1 Institute of Clinical Pathology, Medical University of Vienna, Vienna, Austria. 2 Institute of Immunology, Medical University of Vienna, Vienna, Austria. 3 Division of Nephrology and Dialysis, Department of Medicine III, Medical University of Vienna, Vienna, Austria. 4 Competence Centre for Clinical Trials, University of Bremen, Bremen, Germany. 5 Department of Surgery, Medical University of Vienna, Vienna, Austria. 6 Department of Medicine III, SMZ-Ost/Donauspital, Vienna, Austria. 7 Address correspondence to: Josef Kletzmayr, M.D., Department of Medicine III, SMZ-Ost/Donauspital, Langobardenstrasse 122, 1220 Vienna, Austria.
authors.forename: Johannes
authors.initials: J
authors.lastname: Hofer
authors.forename: Heinz
authors.initials: H
authors.lastname: Regele
authors.forename: Georg A
authors.initials: GA
authors.lastname: Böhmig
authors.forename: Georg
authors.initials: G
authors.lastname: Gutjahr
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Kikić
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Mühlbacher
authors.forename: Josef
authors.initials: J
authors.lastname: Kletzmayr
mesh_terms: D000328:Adult; D000368:Aged; D001706:Biopsy; D015331:Cohort Studies; D005260:Female; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000293:injuries / Q000473:pathology*; D016030:Kidney Transplantation / Q000379:methods* / Q000401:mortality; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D051437:Renal Insufficiency / Q000401:mortality / Q000628:therapy*; D012189:Retrospective Studies; D012306:Risk; D016896:Treatment Outcome; D055815:Young Adult