Kidneys at Higher Risk of Discard: Expanding the Role of Dual Kidney Transplantation

Abstract

Half of the recovered expanded criteria donor (ECD) kidneys are discarded in the United States. A new kidney allocation system offers kidneys at higher risk of discard, Kidney Donor Profile Index (KDPI) >85%, to a wider geographic area to promote broader sharing and expedite utilization. Dual kidney transplantation (DKT) based on the KDPI is a potential option to streamline allocation of kidneys which otherwise would have been discarded. To assess the clinical utility of the KDPI in kidneys at higher risk of discard, we analyzed the OPTN/UNOS Registry that included the deceased donor kidneys recovered between 2002 and 2012. The primary outcomes were allograft survival, patient survival and discard rate based on different KDPI categories (<80%, 80–90% and >90%). Kidneys with KDPI >90% were associated with increased odds of discard (OR = 1.99, 95% CI 1.74–2.29) compared to ones with KDPI <80%. DKTs of KDPI >90% were associated with lower overall allograft failure (HR = 0.74, 95% CI 0.62–0.89) and better patient survival (HR = 0.79, 95% CI 0.64–0.98) compared to single ECD kidneys with KDPI >90%. Kidneys at higher risk of discard may be offered in the up-front allocation system as a DKT. Further modeling and simulation studies are required to determine a reasonable KDPI cutoff percentile.

New Solutions to Reduce Discard of Kidneys Donated for Transplantation

“…Currently, only 2% of donated kidneys are transplanted as dual organs. 36 This proposal might only generate a small number of additional transplants, but would increase survival for patients who received them. The second set of remedies would change report cards so that they do not disincentivize aggressive acceptance of kidneys.…”

R Open Source Programming Code for Calculation of the Kidney Donor Profile Index and Kidney Donor Risk Index

“…Of note, even the recipients of kidneys with KDPI > 85% were at a much lower risk of death 2 years after transplant compared to those remaining on dialysis waiting for low-KDPI kidneys [13]. Moreover, such ECDs could be considered for the double kidney transplantation to a single recipient that provide better patient and graft survival in comparison to transplantation of such kidneys to 2 recipients [14, 15], and the use of the additional pre-transplant donor biopsy morphology score [16] secures the kidney transplantation from a high KDPI donor that otherwise may be discarded [17-20] and helps to allocate a donor organ to single or double transplantation. The results of the aforementioned studies highlight the important limitation of the current version of KDPI that could overestimate the prognostic weight of age based on the generalization from the total deceased donor population, and do not assume the specific constellation of parameters of a given donor.…”

Successful Transplantation of Kidneys From Elderly Circulatory Death Donors by Using Microscopic and Macroscopic Characteristics to Guide Single or Dual Implantation

“…Although dual implantation of DCD kidneys from suboptimal donors appears a rational development of practices that are now standard for DBD kidneys, there are surprisingly few publications that have reported outcomes (19,20 (19), but this report analyzed results for all dual kidney transplants; donor demographics and transplant outcomes for the DCD cohort were not reported separately. Recent analysis of the UKTR dataset highlighted outcomes for DCD transplants from donors over 60 years of age, but dual transplants were excluded from the analysis (6) and, thus, to our knowledge, our series is the first report of outcomes for DCD kidneys transplanted from donors over 70 years of age and which includes comparison of single and dual implants.…”