#NephMadness 2019: Concepcion Chooses Her Champion for Plasma Exchange

Posted on March 27, 2019 by AJKDblog in NephMadness // 0 Comments

Beatrice P. Concepcion @KidneyBea_n

Beatrice P. Concepcion is a transplant nephrologist at Vanderbilt University Medical Center in Nashville, Tennessee. In addition to her clinical responsibilities, she is actively involved in the education of 3rd and 4th year medical students. Among her research interests are the health-related quality of life and neurocognitive function of kidney transplant recipients.

Competitors for the Plasma Exchange Region

ANCA Vasculitis vs Light Chains

Pre-Transplantation vs Post-Transplantation

Every year during March Madness, there is usually a team that no one talks about but quietly makes its way through the bracket into the final round of the tournament. The same can be said for NephMadness. This year, the teams in the Plasma Exchange region seem to be getting less hype than some of their more “exciting” competitors. It’s probably because Plasma Exchange (or “PLEX” as we refer to it on rounds) has been around the block for quite a while, so it’s not surprising that the teams in this region can be taken for granted.

I believe, however, that this region is a sleeper. After all, we nephrologists should take pride in the fact that as experts in extracorporeal therapy, we can count PLEX not only as a treatment for certain kidney diseases but also as a therapy that we can routinely administer for a wide spectrum of immune-mediated conditions that may not necessarily be kidney-related. With the advent of membrane-based PLEX in particular, this should definitely be right up our alley.

As a transplant nephrologist, I have an admitted bias of focusing on the second matchup of this region. In particular, I vote for Pre-transplant PLEX to advance deep into the tournament.

The reason is simple: kidney transplantation is superior to dialysis and one of the biggest challenges continues to be how to get patients to transplant (see The Untransplantables Team of NephMadness 2018). The ability to traverse immunologic barriers through PLEX-based desensitization and proceeding with HLA-incompatible (HLAi) or ABO-incompatible transplantation (ABOi) has broad implications, including improved survival for patients and increased utilization of available donor kidneys.

In HLAi transplantation, the Hopkins experience demonstrated that getting patients off dialysis and transplanted through PLEX-based desensitization was superior to remaining on the waiting list for an HLA=compatible kidney. Even with paired exchange available as an option, desensitization can still play a role in helping patients find a suitable match.

In ABOi transplantation, most of the early data comes from Japan, where almost all kidney transplants are from living donors. Currently, however, ABOi transplantation has also become quite relevant in the United States due to the (not so new) Kidney Allocation System (KAS) that took effect in December 2014. With KAS, blood type A2 kidneys are preferentially allocated to blood type B recipients (most of whom are ethnic minorities) in an effort to reduce the disparity in waiting times between patients with blood types A and B (the national median waiting time for blood type B is 4.6 years versus 2.2 years for blood type A). Blood type A2 kidneys, estimated to be about 20% of all blood type A donors, can be successfully transplanted into B recipients due to markedly reduced levels of A antigen on cell surfaces. Although additional immunosuppression is usually not required in recipients with low anti-A titers, PLEX and additional antibody-directed therapy have been utilized in those with high anti-A titers. The implication of this is that more blood type B patients can potentially become eligible to receive A2 kidneys, although the level of acceptable anti-A titers remains unclear and is dependent on individual transplant center criteria.

In summary, we all have patients who we know would be do better with a transplant but due to immunologic barriers, remain on dialysis and continue to wait for a kidney. Without a doubt, having PLEX in our armamentarium to help get patients to transplant can be quite empowering and when successfully utilized, extremely rewarding. For this reason, I believe Pre-transplant PLEX should go all the way.

– Guest Post written by Beatrice P. Concepcion @KidneyBea_n

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