title: Expanding the use of expanded criteria donors in kidney transplantation.
abstract: OBJECTIVE
  Although the use of kidney allografts from expanded criteria donors (ECD) has increased in recent years, the reported discard rates are also growing. The influence of ECD characteristics on transplant outcomes is still underevaluated.
  
  
  METHODS
  This retrospective study investigated the influence of preimplantation biopsy findings and delayed graft function (DGF) on patient and graft survivals and renal function at 36 months in a cohort of 372 ECD kidney transplant recipients.
  
  
  RESULTS
  Patient and graft survivals were 91.6 and 68.9 %. The incidence of biopsy-proven acute rejection was 31 %. There were no differences in patient (88.6 vs. 91.1 vs. 94.7 vs. 78.6 %, p = 0.10) or graft (78.1 vs. 72.2 vs. 60.5 vs. 62.6 %, p = 0.14) survivals and renal function (41.7 ± 25.6 vs. 39.9 ± 29.9 vs. 38.1 ± 30.6 vs. 37.4 ± 29.2 mL/min, p = 0.79) comparing ECD kidneys with mild, moderate, and severe histological changes or with no preimplantation biopsy, respectively. However, severe scored transplants had the worst death-censored graft survival (OR 3.1, 95 % CI 1.4-6.9, p = 0.007). No significant differences in patient (86.2 vs. 83.4 %, p = 0.17) or graft (73.7 vs. 65.9 %, p = 0.06) survivals and renal function (38.9 ± 28.6 vs. 39.9 ± 28.4 mL/min, p = 0.72) were observed comparing patients with or without DGF. Multivariable analysis found diabetes history as the only independent risk factor for graft loss (OR 2.1, 95 % CI 1.3-3.3, p = 0.003) or patient death (OR 3.1, 95 % CI 1.5-5.8, p < 0.001).
  
  
  CONCLUSIONS
  Within the limitations of sample size and short follow-up time, in this cohort of ECD kidney transplant recipients the severity of histological changes observed in preimplantation biopsies was independently associated with graft loss.
authors.affiliation: Transplant Division, Hospital do Rim e Hipertensão, UNIFESP, São Paulo, SP, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Assis-Borba
authors.forename: Marina P
authors.initials: MP
authors.lastname: Cristelli
authors.forename: Mayara I
authors.initials: MI
authors.lastname: Paula
authors.forename: Marcelo F
authors.initials: MF
authors.lastname: Franco
authors.forename: Helio
authors.initials: H
authors.lastname: Tedesco-Silva
authors.forename: Jose O
authors.initials: JO
authors.lastname: Medina-Pestana
mesh_terms: D000368:Aged; D001706:Biopsy; D051799:Delayed Graft Function / Q000150:complications / Q000503:physiopathology*; D048909:Diabetes Complications / Q000150:complications; D046148:Donor Selection / Q000592:standards; D005260:Female; D006084:Graft Rejection / Q000209:etiology* / Q000473:pathology; D006085:Graft Survival; D006801:Humans; D007668:Kidney / Q000473:pathology* / Q000503:physiopathology; D016030:Kidney Transplantation / Q000009:adverse effects; D008297:Male; D008875:Middle Aged; D057234:Preoperative Period; D012189:Retrospective Studies; D012307:Risk Factors; D015996:Survival Rate; D009927:Tissue and Organ Procurement / Q000592:standards