New national allocation policy for deceased donor kidneys in the United States and possible effect on patient outcomes.

In 2013, the Organ Procurement and Transplantation Network in the United States approved a new national deceased donor kidney allocation policy that introduces the kidney donor profile index (KDPI), which gives scores of 0%-100% based on 10 donor factors. Kidneys with lower KDPI scores are associated with better post-transplant survival. Important features of the new policy include first allocating kidneys from donors with a KDPI≤20% to candidates in the top 20th percentile of estimated post-transplant survival, adding waiting time from dialysis initiation, conferring priority points for a calculated panel-reactive antibody (CPRA)>19%, broader sharing of kidneys for candidates with a CPRA≥99%, broader sharing of kidneys from donors with a KDPI>85%, eliminating the payback system, and allocating blood type A2 and A2B kidneys to blood type B candidates. We simulated the distribution of kidneys under the new policy compared with the current allocation policy. The simulation showed increases in projected median allograft years of life with the new policy (9.07 years) compared with the current policy (8.82 years). With the new policy, candidates with a CPRA>20%, with blood type B, and aged 18-49 years were more likely to undergo transplant, but transplants declined in candidates aged 50-64 years (4.1% decline) and ≥65 years (2.7% decline). These simulations demonstrate that the new deceased donor kidney allocation policy may improve overall post-transplant survival and access for highly sensitized candidates, with minimal effects on access to transplant by race/ethnicity and declines in kidney allocation for candidates aged ≥50 years.

The kidney allocation system.

The current kidney allocation system for transplants is outdated and has not evolved to reflect the changing demographics of patients on the waiting list. This article proposes a new system for kidney allocation, which more appropriately incorporates the biology of highly sensitized patients into the waiting-time scoring algorithm. This system will significantly reduce mismatches between possible donor kidney longevity and life expectancy of recipients, and makes incremental advances toward more geographic sharing. The proposed system makes significant progress toward eliminating deficiencies in the current system, and has the potential to increase the supply of available kidneys.