The kidney allocation score: methodological problems, moral concerns and unintended consequences

Preemptive kidney transplantation: why, when, and how?

Among renal replacement therapies, preemptive kidney transplantation (PKT) presents the best clinical, social, and economic results. However, it is still infrequently chosen as first therapy for patients with irreversible kidney failure. Initiatives in different parts of the world were developed to identify the reasons why PKT is still not widely used and to facilitate the access of patients with end-stage kidney disease to the advantages associated with it. This article addresses the main advantages and difficulties of PKT and discusses when it should be indicated and how to prepare potential recipients for PKT.

Transplante renal preemptivo: por que, quando e como?

Resumo Entre as terapias renais substitutivas, o transplante renal preemptivo (TRP) apresenta os melhores resultados clínicos, sociais e econômicos. No entanto, ainda é raramente escolhido como primeira terapia para pacientes com falência renal irreversível. Foram desenvolvidas iniciativas em diferentes partes do mundo para identificar as razões pelas quais o TRP ainda não é amplamente utilizado e para facilitar o acesso de pacientes com doença renal em estágio terminal às vantagens associadas ao mesmo. Este artigo aborda as principais vantagens e dificuldades do TRP e discute quando ele deve ser indicado e como preparar potenciais receptores para o TRP.

Prediction of three-year outcome of renal transplantation from optimal donors versus expanded criteria donors

BACKGROUND/AIMS

The shortage in organ supply has required the use of expanded criteria donors (ECD) for kidney transplantation. Current pre-transplant evaluations of ECD organs are based on histological, clinical or mixed criteria. This monocentric study investigates the predictivity of Karpinski's histological score on 3-year graft function in renal transplant. Ex-post classification using Nyberg's score was carried out to assess the reliability of a purely clinical score and its applicability for organ allocation.

METHODS

We evaluated 407 deceased donors (251 optimal and 156 ECD) for renal transplants performed between 2001 and 2006. The differences in creatinine levels and MDRD-GFR at transplant and 1, 2 and 3 years post-transplant between optimal donors and ECD were recorded. Amongst ECD organs, the effect of different Karpinski score classes (0-1, 2, 3, 4, double transplants) on 3-year graft outcomes was analyzed. We then compared renal function over time across the Nyberg grades (A, B, C, and D).

RESULTS

Karpinski scores 0-1 and 2 and double transplants were associated with improved graft function compared to scores 3 and 4. Nyberg's clinical score shows a good fit with medium-term outcome and Karpinski's score, but among the donors with a high Nyberg grade (C and D), it fails to differentiate between allocable or non-allocable organs (due to Karpinski's score ≥7).

CONCLUSIONS

Our data demonstrate a correlation of histological damage at the time of transplant with 3-year graft function, but at present we are unable to provide any supposition on the possible outcome of the discarded kidneys.

Kidney allocation for transplantation: some aspects of ethics and comparative law

The allocation of organs is a crucial ethical issue. The importance attached to different allocation criteria differs considerably among the various national and international organizations. The balance between justice-centered and utility-centered systems is shifting and there are signs of a possible swing away from systems centered mainly on waiting times to others centered mainly on criteria of utility. This evolution is very significant and seems to run counter to the main stream of modern bioethics. Examples from different national policies are given herein. Particular attention is given to Europe, where national bioethics committees have tended to ignore the aspect of organ allocation. By overemphasizing the issues related to informed consent, the ethical challenges arising from the problems of resource allocation are often relegated to second place.

The elderly as recipients of living donor kidneys, how old is too old?

PURPOSE OF REVIEW

Transplantation of the elderly often invokes strong and sometimes passionate arguments both in support and in opposition. Age alone has not been an absolute contraindication to a life-sustaining organ transplant for several decades. A comprehensive evaluation of the risks associated with surgery and suppression of the immune system in this often comorbid population becomes the focus. Risk for the recipient, however, must continually be evaluated and frequently updated in the context of that for the donor.

RECENT FINDINGS

Following careful and critical evaluation, elderly patients appreciate the increase in life expectancy and improvements in quality of life as demonstrated in their younger counterparts. The outcome of recipients receiving kidneys from living donors has demonstrated superior graft and patient survival compared to deceased donors. Careful monitoring of medication levels for prevention of rejection while avoiding over immunosuppression and infection is critical to ensure such benefit.

SUMMARY

Transplantation of the elderly via living donation is not only justified but in the appropriately chosen patient, with informed consent of both donor and recipient, is ethically sound. The expectations of both parties must be clearly stated and donor safety must remain the top priority. Living donors must be fully cognizant of the potential risk both in patient and graft survival prior to making such a life-changing decision to donate.

Analysis of four scoring systems and monocentric experience to optimize criteria for marginal kidney transplantation

There is a strong need among the transplantation community to identify common criteria to utilize the pool of expanded criteria donors (ECD), considering the disparity between organ demand and supply as well as the benefits of transplantation on long-term mortality compared with survival on dialysis, also in patients transplanted with these organs. The purpose of this article was to analyze scoring systems proposed in literature by Nyberg, Anglicheau, Rao (Kidney Donor Risk Index), and Schold, seeking to verify whether our clinical and histological allocation strategy matched the Nyberg score. Herein we have reported the results of a preliminary retrospective study on the 5-year outcomes of organs from 60 marginal donors, who were older than 50 years and histologically evaluated before implantation. The donors matched Nyberg class C and D, that is, marginal donors. We noted a tendency toward an association between global and vascular scores with class D (odds ratio 2.2 and 4.3, respectively). Kaplan-Meier graft survival curves were similar to Nyberg data: 83% for class C versus 73% for class D at 5 years. Without any comparison to the Nyberg score, the only feature that was predictive of renal function at 5 years in our population was hypertension in the donor. Further studies are required to identify which of the scoring systems--clinical and/or histological--is more suitable to allocate ECD kidneys and to predict recipient outcomes.

Wait list death and survival benefit of kidney transplantation among nonrenal transplant recipients

The disparity between the number of patients waiting for kidney transplantation and the limited supply of kidney allografts has renewed interest in the benefit from kidney transplantation experienced by different groups. This study evaluated kidney transplant survival benefit in prior nonrenal transplant recipients (kidney after liver, KALi; lung, KALu; heart, KAH) compared to primary isolated (KA1) or repeat isolated kidney (KA2) transplant. Multivariable Cox regression models were fit using UNOS data for patients wait listed and transplanted from 1995 to 2008. Compared to KA1, the risk of death on the wait list was lower for KA2 (p < 0.001;HR = 0.84;CI = 0.81-0.88), but substantially higher for KALu (p < 0.001; HR = 3.80;CI = 3.08-4.69), KAH (p < 0.001; HR = 1.92; CI = 1.66-2.22), and KALi (p < 0.001; HR = 2.69; CI = 2.46-2.95). Following kidney transplant, patient survival was greatest for KA1, similar among KA2, KALi, KAH, and inferior for KALu. Compared to the entire wait list, renal transplantation was associated with a survival benefit among all groups except KALu (p = 0.017; HR = 1.61; CI = 1.09-2.38), where posttransplant survival was inferior to the wait list population. Recipients of KA1 kidney transplantation have the greatest posttransplant survival and compared to the overall kidney wait list, the greatest survival benefit.

The right kidney for the right recipient: the status of deceased donor kidney allocation reform

How best to allocate the limited number of deceased donor kidneys has been the subject of intense debate over past several months in the United States. Most of the major stakeholders have expressed their viewpoints in a series of recent publications. This manuscript aims to examine some of the most important issues in this discussion and to outline a possible path forward.

Community preferences for the allocation of solid organs for transplantation: a systematic review

BACKGROUND

Organs for transplantation are a scarce community resource but community preferences and how they are incorporated into allocation policies are unclear. This systematic review aimed to ascertain community preferences for organ allocation and the principles underpinning these preferences.

METHODS

Medline, Embase, PsycINFO, EconLit, and gray literature databases were searched. Quantitative data were extracted, and a qualitative textual synthesis of the results and conclusions reported in each included study was performed.

RESULTS

Fifteen studies involving more than 5563 respondents were included. Seven themes describing community preferences for organ allocation were identified: (1) maximum benefit, to achieve maximum health gain in recipient survival and quality of life; (2) social valuation, to base preferences on societal gain; (3) moral deservingness, to consider the "worthiness" of recipients based on their social standing and lifestyle decisions; (4) prejudice, to make a judgement based on personal ideologic viewpoints; (5) "fair innings," to provide an organ preferentially to the younger recipient giving opportunity for a "normal" life span and to those waiting for a first organ rather than a retransplant; (6) "first come, first served," to allocate the organ to recipients wait-listed the longest; and (7) medical urgency, to allocate based on illness severity and saving life.

CONCLUSIONS

Community preferences for organ allocation hinge on a complex balance of efficiency, social valuation, morality, fairness, and equity principles. Being a community-held resource, effective ways to identify and incorporate community preferences into allocation algorithms for solid organ transplantation are warranted.