Kidney exchange in the U.S. from 2006-2021

 Here's an interesting look at the (ongoing) development of kidney exchange in the U.S

Temporal trends in kidney paired donation in the United States: 2006-2021 UNOS/OPTN database analysis, by Neetika Garg, Carrie Thiessen, Peter P. Reese, Matthew Cooper, Ruthanne Leishman, John Friedewald, Asif A. Sharfuddin, Angie G. Nishio Lucar, Darshana M. Dadhania, Vineeta Kumar, Amy D. Waterman, and Didier A. Mandelbrot, American Journal of Transplantation,  24, 1, P46-56, JANUARY 2024.

Abstract: Kidney paired donation (KPD) is a major innovation that is changing the landscape of kidney transplantation in the United States. We used the 2006-2021 United Network for Organ Sharing data to examine trends over time. KPD is increasing, with 1 in 5 living donor kidney transplants (LDKTs) in 2021 facilitated by KPD. The proportion of LDKT performed via KPD was comparable for non-Whites and Whites. An increasing proportion of KPD transplants are going to non-Whites. End-chain recipients are not identified in the database. To what extent these trends reflect how end-chain kidneys are allocated, as opposed to increase in living donation among minorities, remains unclear. Half the LDKT in 2021 in sensitized (panel reactive antibody ≥ 80%) and highly sensitized (panel reactive antibody ≥ 98%) groups occurred via KPD. Yet, the proportion of KPD transplants performed in sensitized recipients has declined since 2013, likely due to changes in the deceased donor allocation policies and newer KPD strategies such as compatible KPD. In 2021, 40% of the programs reported not performing any KPD transplants. Our study highlights the need for understanding barriers to pursuing and expanding KPD at the center level and the need for more detailed and accurate data collection at the national level.

"Kidney paired donation (KPD) is rapidly evolving and reshaping the landscape of living donor kidney transplantation (LDKT). Since the initial KPD transplants performed in the United States in 1999,1 the scope of KPD has expanded substantially. With the inclusion of nondirected donor,2 it has progressed from simple 2-way or multiple-way exchanges to nonsimultaneous kidney donor chains3 and, more recently, to advanced and voucher donations.4 Downstream from nondirected donors, chains often conclude with end-chain kidneys allocated to candidates on the deceased kidney donor waitlist without a living donor (LD).5 Historically used to overcome the barrier of ABO/human leukocyte antigens (HLA) incompatibility, KPD is being increasingly used by compatible donor-recipient pairs to obtain more suitable kidneys for the respective recipients.6 KPD programs can be single center or internal, regional, or national.7,8 The largest multicenter or national KPD programs in the United States are the National Kidney Registry,9 the Alliance for Paired Donation,10 the MatchGrid/Medsleuth program,11 and the program operated by the Organ Procurement and Transplantation Network (OPTN).12 While multicenter KPD often expands the pool of candidates to improve match possibilities, there are examples of very successful single-center programs."