Compatible pairs are (slowly) benefitting from kidney exchange

 Two articles forthcoming in the American Journal of Tranplantation consider the slowly increasing use of kidney exchange by compatible pairs (which is a good thing, but has been a long time in coming).  Compatible pairs can get better-matched kidneys through exchange (which has long term benefits), and because compatible pairs are largely easy to match, they additionally help create matches for hard to match pairs.

Motivations and outcomes of compatible living donor-recipient pairs in paired exchange, by Valerie Chipman, Matthew Cooper, Alvin G. Thomas, Matthew Ronin, Brian Lee, Stuart Flechner, David Leeser, Dorry L. Segev, Didier A. Mandelbrot, Tyler Lunow-Luke, Shareef Syed, Garet Hil, Chris E. Freise, Amy D. Waterman, Garrett R. Roll  First published: 01 September 2021 https://doi.org/10.1111/ajt.16821

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi:10.1111/ajt.16821

Abstract: Increasing numbers of compatible pairs are choosing to enter paired exchange programs, but motivations, outcomes, and system-level effects of participation is not well described. Using a linkage of the SRTR and National Kidney Registry, we compared outcomes of traditional (originally incompatible) recipients to originally compatible recipients using the Kaplan-Meier method. We identified 154 compatible pairs. Most pairs sought to improve HLA matching. Compared to the original donor, actual donors were younger (39 vs. 50 years, p<0.001), less often female (52% vs. 68%, p<0.01), higher BMI (27 vs 25 kg/m², p=0.03), less frequently blood type O (36% vs. 80%, p<0.001), and had higher eGFR (99 vs. 94 mL/min/1.73 m², p=0.02), with a better LKDPI (median 7 vs. 22, p<0.001). We observed no differences in graft failure or mortality. Compatible pairs made 280 additional transplants possible, many in highly sensitized recipients with long wait times. Compatible pair recipients derived several benefits from paired exchange including better donor quality. Living donor pairs should receive counseling regarding all options available including kidney paired donation. As more compatible pairs choose to enter exchange programs, consideration should be given to optimizing compatible pair and hard-to-transplant recipient outcomes.

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Rethinking incompatibility in kidney transplantation  Kyle R. Jackson, Dorry L. Segev

First published: 31 August 2021 https://doi.org/10.1111/ajt.16826

This article has been accepted for publication and undergone full peer review but has not been through the copyediting, typesetting, pagination and proofreading process, which may lead to differences between this version and the Version of Record. Please cite this article as doi:10.1111/ajt.16826

Abstract: Donor/recipient incompatibility in kidney transplantation classically refers to ABO/HLA-incompatibility. Kidney paired donation (KPD) was historically established to circumvent ABO/HLA-incompatibility, with the goal of identifying ABO/HLA-compatible matches. However, there is a broad range of donor factors known to impact recipient outcomes beyond ABO/HLA-incompatibility, such as age and weight, and quantitative tools are now available to empirically compare potential living donors across many of these factors, such as the living donor kidney donor profile index (LKDPI). Moreover, the detrimental impact of mismatch at other HLA antigens (such as DQ) and epitope mismatching on post-transplant outcomes has become increasingly recognized. Thus, it is time for a new paradigm of incompatibility that considers all of these risks factors together in assessing donor/recipient compatibility and the potential utility for KPD. Under this new paradigm of incompatibility, we show how the LKDPI and other tools can be used to identify donor/recipient incompatibilities that could be improved through KPD, even for those with a traditionally ‘compatible’ living donor.