Deceased Donor Kidney Allocation Research Articles

Effects of the March 2021 Allocation Policy Change on Key Deceased-donor Kidney Transplant Metrics.

A major change to deceased-donor kidney allocation in the United States, Kidney Allocation System 250 (KAS250), was implemented on March 15, 2021. Evaluating the consequences of this policy on critical system performance metrics is critical to determining its success. We performed a retrospective analysis of critical performance measures of the kidney transplant system by reviewing all organs procured during a 4-y period in the United States. To mitigate against possible effects of the COVID-19 pandemic, Scientific Registry of Transplant Recipients records were stratified into 2 pre- and 2 post-KAS250 eras: (1) 2019; (2) January 1, 2020-March14, 2021; (3) March 15, 2021-December 31, 2021; and (4) 2022. Between-era differences in rates of key metrics were analyzed using chi-square tests with pairwise z-tests. Multivariable logistic regression and analysis of variations methods were used to evaluate the effects of the policy on rural and urban centers. Over the period examined, among kidneys recovered for transplant, nonuse increased from 19.7% to 26.4% (all between-era P < 0.05) and among all Kidney Donor Profile Index strata. Cold ischemia times increased (P < 0.001); however, the distance between donor and recipient hospitals decreased (P < 0.05). Kidneys from small-metropolitan or nonmetropolitan hospitals were more likely to not be used over all times (P < 0.05). Implementation of KAS250 was associated with increased nonuse rates across all Kidney Donor Profile Index strata, increased cold ischemic times, and shorter distance traveled.

#2425 A change in deceased donor allocation policy may provide gender equality in kidney transplantation

Abstract Background and Aims Overcoming gender disparity in access to kidney transplantation is a well-established universal challenge. The SRTR data showed a greater proportion of males than females for kidney transplant waitlists (61% vs 39%). Similarly, of 831 deceased donor kidney transplants (DDKT) conducted between 1997 and 2018 at IKDRC-ITS, 68% have been male and 32% female recipients while majority of donors in living donor kidney transplants (LDKT) were females. Prior to 2020, there duration on transplantation waitlist was the only criteria for deceased donor kidney allocation. In January 2020, SOTTO Gujarat was formed which implements a point system based deceased donor allocation policy including HLA mismatch, Panel Reactive Antibody, Donor Specific Antibody, age and duration on dialysis, amongst others. 2 additional points are allocated to female recipients in this allocation system. The aim is to study the impact of change in DDKT allocation policy on gender disparity. Method This is a retrospective, single-center, observational study. Number of male and female kidney transplant recipients was collected from the medical records held by the department of nephrology between January 2014 to December 2023. The data was categorized as before and after implementation of SOTTO Gujarat guidelines and analyzed. Results A total of 3182 kidney transplants were conducted at our centre over the study period, 2231 were LDKT while only 951 were DDKT. We found the percentage of female LDKT recipients to have remained disproportionately low as compared to male DDKT throughout the study period, while there was a gradually progressive increase in the percentage of female DDKT recipients with almost a doubling of female DDKT recipients from 27.57% in 2019 to 54.19% in 2023. This may be attributed to the compounding effect of allocating points to DSA, PRA, age of patient and gender as female patients tend to have higher PRA and DSA level after sensitization. Conclusion This study provides new insights into steps that can be taken to bridge the gender gap in DDKT. It shows that implementing a point based system for DDKT allocation policy with extra points for female recipients may increase the number of kidney transplants in them. Similar policy may be undertaken by other transplant centers as a bridge to achieve temporary solution till underlying factors leading to gender disparity are better understood and ways to overcome them are formed. Action should be taken to provide for equitable access to females at all stages, from diagnosis to treatment such as intensive and timely counselling. Policies for social empowerment of women must be formed including literacy, better maternal and child healthcare and financial independence. Raising awareness and education at a grassroot level must remain the key component to change public attitude regarding organ donation and ensure equitable access to transplantation for all.

Cytomegalovirus Matching in Deceased Donor Kidney Allocation: Results From a U.S. National Simulation Model.

Cytomegalovirus (CMV) infects >60% of adults and can pose an independent risk factor for allograft loss and mortality in solid organ transplant recipients. The purpose of this study is to evaluate the impact of a nationwide implementation of CMV seromatching (donor/recipient: D-/R- and D+/R+) in the U.S. deceased donor kidney allocation system (KAS). Adult candidates on the U.S. kidney-only transplant waiting list and deceased donor kidneys offered to the U.S. transplant centers were considered. A discrete-event simulation model, simulating the pre-COVID-19 period from January 1, 2015, to January 1, 2018, was used to compare the performances of currently employed KAS-250 policy (without CMV matching) to various simulated CMV matching policies parameterized by calculated panel reactive antibody exception threshold. Outcomes included CMV serodistribution, waiting time, access to transplantation among various groups, transplant rate, graft survival, kidney discard rate, and antigen-mismatch distribution, stratified by CMV serostatus. CMV matching policy with a calculated panel reactive antibody exception threshold of 50% (namely, the CMV">50%" policy) strikes a better balance between benefits and drawbacks of CMV matching. Compared with KAS-250, CMV">50%" reduced CMV high-risk (D+/R-) transplants (6.1% versus 18.1%) and increased CMV low-risk (D-/R-) transplants (27.2% versus 13.1%); increased transplant rate for CMV R- patients (11.54 versus 12.57) but decreased for R+ patients (10.68 versus 10.48), yielding an increase in aggregate (11.09 versus 10.94); and reduced mean time to transplantation (by 6 wk); and reduced kidney discard rate (25.7% versus 26.2%). Our findings underscore the feasibility and potential advantages of a nationwide CMV seromatching policy in kidney transplantation.

The Impact of the Donor Card Holder Prioritization Program on Kidney Allocation in Israel.

Since 2014, as part of a priority program within the Israeli Transplant Law, additional points were given to waitlisted candidates with donor cards. We assessed the impact on deceased donor kidney allocation. This study enrolled all patients older than 18 y who underwent deceased donor kidney transplantation (January 2016-December 2019). Data were obtained from the National HLA Tissue Laboratory registry at the Sheba Medical Center. Patients were grouped by donor card status (ADI group) (not signed, 0 points; relative signed, 0.1 points; patient signed, 2 points; and relative donated, 9 points). The primary outcome was waiting time until kidney transplantation with and without the additional score. Four hundred forty-four patients underwent kidney transplantation during the study period: 281 (63%) were donor card holders (DCH) and 163 (37%) were not DCH. DCH with extra points waited 68.0 (±47.0) mo on average, compared with 94.6 (±47.3) mo for not DCH (P < 0.001). Donor card signers had a shorter time until transplant in a multivariable model. Without extra points, 145 recipients (32.6%) would have missed organs allocated to higher-scored candidates. Allocation changes occurred in 1 patient because of an additional 0.1 points, in 103 candidates because of an additional 2 points, and in 41 candidates because of an additional 9 points. Additional DCH scores improved allocation and reduced waiting time for donor card signers and those with donating relatives. To enhance fairness, consideration should be given to reducing the score weight of this social criterion and raising scores for other factors, especially dialysis duration.

Outcomes with transplanting kidneys offered through expedited allocation.

Expedited out-of-sequence deceased donor kidney allocation is a strategy to avoid discards after early placement attempts have been unsuccessful. Our study aimed to assess outcomes and characteristics of these transplanted kidneys. KDPI matching was performed between expedited allocation (EA) and standard allocation (SA) deceased donor kidney transplants performed at our center. Between 2018 and 2021, there were 225 EA offers, and 189 (84%) were transplanted. EA recipients were older (p=.007) and had shorter dialysis vintage (p<.0001). EA kidneys were likely to be nationally allocated (p<.001), have AKI (p<.0001) and longer CIT (p<.0001). There were no differences in EA and SA time-zero kidney biopsies (ci, p=.07; ct, p=.89; cv, p=.95; ah, p=.79). EA kidneys had more DGF (p=.0006), but there were no differences in DGF duration (p=.83), hospital length of stay (p=.43), 1- and 2-year eGFR (p=.16, p=.99), patient (p=.34), or death-censored graft (p=.66) survival. During this study period, our center transplanted 189 kidneys through EA following local-regional declines. These kidneys often came from AKI donors and had more DGF but had similar outcomes to KDPI-matched SA kidneys. Although it has been suggested that EA has the potential to worsen transplant disparities, transplant center level decisions on organ acceptance contribute to these variations.

Adding epitope compatibility to deceased donor kidney allocation criteria: recommendations from a pan-Canadian online public deliberation

BackgroundThe widening supply–demand imbalance for kidneys necessitates finding ways to reduce rejection and improve transplant outcomes. Human leukocyte antigen (HLA) epitope compatibility between donor and recipient may minimize premature graft loss and prolong survival, but incorporating this strategy to deceased donor allocation criteria prioritizes transplant outcomes over wait times. An online public deliberation was held to identify acceptable trade-offs when implementing epitope compatibility to guide Canadian policymakers and health professionals in deciding how best to allocate kidneys fairly.MethodsInvitations were mailed to 35,000 randomly-selected Canadian households, with over-sampling of rural/remote locations. Participants were selected for socio-demographic diversity and geographic representation. Five two-hour online sessions were held from November–December 2021. Participants received an information booklet and heard from expert speakers prior to deliberating on how to fairly implement epitope compatibility for transplant candidates and governance issues. Participants collectively generated and voted on recommendations. In the final session, kidney donation and allocation policymakers engaged with participants. Sessions were recorded and transcribed.ResultsThirty-two individuals participated and generated nine recommendations. There was consensus on adding epitope compatibility to the existing deceased donor kidney allocation criteria. However, participants recommended including safeguards/flexibility around this (e.g., mitigating declining health). They called for a transition period to epitope compatibility, including an ongoing comprehensive public education program. Participants unanimously recommended regular monitoring and public sharing of epitope-based transplant outcomes.ConclusionsParticipants supported adding epitope compatibility to kidney allocation criteria, but advised safeguards and flexibility around implementation. These recommendations provide guidance to policymakers about incorporating epitope-based deceased donor allocation criteria.

Public values and guiding principles for implementing epitope compatibility in kidney transplantation allocation criteria: results from a Canadian online public deliberation

BackgroundEpitope compatibility in deceased donor kidney allocation is an emerging area of precision medicine (PM), seeking to improve compatibility between donor kidneys to transplant candidates in the hope of avoiding kidney rejection. Though the potential benefits of using epitope compatibility are promising, the implied modification of deceased organ allocation criteria requires consideration of significant clinical and ethical trade-offs. As a matter of public policy, these trade-offs should consider public values and preferences. We invited members of the Canadian public to participate in a deliberation about epitope compatibility in deceased donor kidney transplantation; to identify what is important to them and to provide recommendations to policymakers.MethodsAn online public deliberation was conducted with members of the Canadian public, in which participants were asked to construct recommendations for policymakers regarding the introduction of epitope compatibility to kidney allocation criteria. In the present paper, a qualitative analysis was conducted to identify the values reflected in participants’ recommendations. All virtual sessions were recorded, transcribed, and analyzed using NVivo 12 software.ResultsThirty-two participants constructed nine recommendations regarding the adoption of epitope compatibility into deceased donor kidney allocation. Five values were identified that drove participants’ recommendations: Health Maximization, Protection/Mitigation of Negative Impacts, Fairness, Science/Evidence-based Healthcare, and Responsibility to Maintain Trust. Conflicts between these values were discussed in terms of operational principles that were required for epitope compatibility to be implemented in an acceptable manner: the needs for Flexibility, Accountability, Transparent Communication and a Transition Plan. All nine recommendations were informed by these four principles. Participant deliberations were often dominated by the conflict between Health Maximization and Fairness or Protection/Mitigation of Negative Impacts, which was discussed as the need for Flexibility. Two additional values (Efficient Use of Resources and Logic/Rationality) were also discussed and were reasons for some participants voting against some recommendations.ConclusionsPublic recommendations indicate support for using epitope compatibility in deceased donor kidney allocation. A flexible approach to organ allocation decision-making may allow for the balancing of Health Maximization against maintaining Fairness and Mitigating Negative Impacts. Flexibility is particularly important in the context of epitope compatibility and other PM initiatives where evidence is still emerging.

March 2021 New Kidney Allocation: How Did the New Changes Affect the Deceased Donor Kidney Transplant Outcomes?

Given the shortage of kidney donations relative to the ever-increasing demand, there is an ongoing need to utilize available donor organs efficiently and fairly. The purpose of the deceased donor Kidney Allocation System is to optimize and equalize organ access for candidates nationwide. We investigated the outcomes of kidney transplant cases before and after the new allocation placement in March 2021 and the effect of the new allocation system on these outcomes. We retrospectively reviewed the medical records of the recipients. Outcomes in recipients of renal allografts were compared before and after the changes in March 2021 to the Kidney Allocation System. There were 333 (73.7%) renal allografts transplanted before the 2021 new allocation, and 119 (26.3%) recipients received their renal allografts after the new allocation. The rate of delayed graft function was 33.3% in the preallocation group and 38.65% in the postallocation group (P = .29). The rate for patient readmission within 30 days was compared between the groups and did not show a statistically significant difference (37.8% vs 39.5%; P = .75). The 1-year graft survival rate was 97.5% in the postallocation group and 95.5% in the preallocation group (P = .526). The 1-year patient survival rate was 98.3% in the postallocation group and 95.8% in the preallocation group (P = .499). This study provides reassurance in finding no statistically significant differences between patient outcomes before and after the implementation of the March 2021 change to the Kidney Allocation System. However, the new allocation measures would help for a more equal distribution of the kidneys.

The New Distance-Based Kidney Allocation System: Implications for Patients, Transplant Centers, and Organ Procurement Organizations.

Purpose of ReviewThe goal of deceased donor kidney allocation policy is to provide objective prioritization for donated kidneys, and policy has undergone a series of revisions in the past decade in attempt to achieve equity and utility in access to kidney transplantation. Most recently, to address geographic disparities in access to kidney transplantation, the Kidney Allocation System changed to a distance-based allocation system—colloquially termed “KAS 250”—moving away from donor service areas as the geographic basis of allocation. We review the early impact of this policy change on access to transplant for patients, and on complexity of organ allocation and transplantation for transplant centers and organ procurement organizations.Recent FindingsBroader sharing of kidneys has increased complexity of the allocation system, as transplant centers and OPOs now interact in larger networks. The increased competition resulting from this system, and the increased operational burden on centers and OPOs resulting from greater numbers of organ offers, may adversely affect organ utilization. Preliminary results suggest an increase in transplant rate overall but a trend toward higher kidney discard and increased cold ischemia time.SummaryThe KAS 250 allocation policy changed the geographic basis of deceased donor kidney distribution in a manner that is intended to reduce geographic disparities in access to kidney transplantation. Close monitoring of this policy’s impact on patients, transplant center behavior, and process measures is critical to the aim of maximizing access to transplant while achieving transplant equity.

P11.18: Allocating Deceased Donor Using Local vs Imported Renal Allografts: Logistics Are More Important Than Distance

Background: The deceased donor kidney allocation system (KAS) aims to optimize and equalize organ access for candidates nationwide and facilitate organ matching for candidates who are harder to match due to biologic reasons. In March 2021, UNOS implanted a new allocation of KT based on distance from the donor hospitals. A distance within 250 nautical miles will receive additional proximity points to access KT. Material and Method: This was a retrospective single-center study assessed the Cold ischemic time (CIT) and Delayed graft function (DGF) in allograft kidneys January 2014 to December 2020. We studied 221 import KT and compared the outcomes to locally procured KT (n=160) and finally compared the patients and grafts survival rates in 1-year and 5-years. Results: Donor and recipient demographics were similar in both groups. Induction and maintenance immunosuppression were similar in both groups. CIT was significantly higher in the imported group (27.6 vs. 15.9 hours, p< 0.0001). However, distance did not impact CIT significantly (R2= 0.07) in the imported KT’s. Distance also did not impact the rate of DGF in both groups (imported 21% vs. 22%, p=0.74). Patient and graft survivals were similar in the imported vs. local group. Conclusions: We conclude that distance alone has no correlation with CIT and DGF. There are many logistical factors and OPO factors that has significant impact on CIT which should take into consideration. Keywords: Kidney, Transplant, New allocation, distance, Survival rate.

The role of bypass filters in deceased donor kidney allocation in the United States

Kidney transplant centers set organ offer filters enabling all candidates at their center to be bypassed during allocation of deceased donor kidneys from the UNOS Organ Center. These filters aim to increase allocation efficiency by preemptively screening out offers unlikely to be accepted. National data were used to compare filter settings of 175 centers in 2007 and in 2019. We examined characteristics of centers whose settings became increasingly restrictive over time, and associations between filter settings and organ offer acceptance. Overall, centers became more open to receiving offers over time, from a median 62% of filters open to receiving national offers in 2007 to 73% in 2019. Intravenous drug use filter settings changed most, from 63 to 153 willing centers. Centers with more open filter settings had higher transplant volume and offer acceptance ratios across all risk categories despite preemptively screening out fewer offers compared to centers with less open settings, but similar transplant rates. There was significant geographic heterogeneity in the distribution of centers with more open filter settings. Current center bypass filters may impact patients' access to transplantation without achieving their full potential for improving allocation efficiency.

Deceased donor kidneys allocated out of sequence by organ procurement organizations

Deceased donor kidney allocation follows a ranked match-run of potential recipients. Organ procurement organizations (OPOs) are permitted to deviate from the mandated match-run in exceptional circumstances. Using match-run data for all deceased donor kidney transplants (Ktx) in the US between 2015 and 2019, we identified 1544kidneys transplanted from 933 donors with an OPO-initiated allocation exception. Most OPOs (55/58) used this process at least once, but 3 OPOs performed 64% of the exceptions and just 2 transplant centers received 25% of allocation exception Ktx. At 2 of 3 outlier OPOs these transplants increased 136% and 141% between 2015 and 2019 compared to only a 35% increase in all Ktx. Allocation exception donors had less favorable characteristics (median KDPI 70, 41% with history of hypertension), but only 29% had KDPI≥85% and the majority did not meet the traditional threshold for marginal kidneys. Allocation exception kidneys went to larger centers with higher offer acceptance ratios and to recipients with 2 fewer priority points-equivalent to 2less years of waiting time. OPO-initiated exceptions for kidney allocation are growing increasingly frequent and more concentrated at a few outlier centers. Increasing pressure to improve organ utilization risks increasing out-of-sequence allocations, potentially exacerbating disparities in access to transplantation.

Transplantation of Patients With Long Dialysis Vintage in the Current Deceased Donor Kidney Allocation System (KAS)

In 2014 the wait-time calculation for deceased donor kidney transplantation in the United States was changed from the date of first waitlisting to the date of first maintenance dialysis treatment with the aim of minimizing disparities in access to transplantation. This study examined the impact of this policy on access to transplantation, patient survival, and transplant outcomes among patients treated with maintenance dialysis for a prolonged duration before waitlisting. Retrospective cohort study. Patients identified in the US Renal Data System between 2008 and 2018 aged 18-70 years and in the 95th percentile of dialysis treatment duration (≥6.5 years) before waitlisting. Waitlisting for transplantation before versus after implementation of the policy. Time from date of waitlisting to deceased donor transplantation and death, and from date of transplantation to all cause graft loss. Univariate and multivariable time to event analyses. Patients waitlisted after the policy change had a higher likelihood of deceased donor transplantation (HR, 3.12 [95% CI, 2.90-3.37]) and lower risk of death (HR, 0.74 [95% CI, 0.63-0.87]). The risk of graft loss was lower in the post-kidney allocation system (KAS) cohort (HR, 0.66 [95% CI, 0.55-0.80]). The proportion of adult patients treated with dialysis≥6.5 years who were never waitlisted for transplantation remained high (73%) and did not decrease after the policy implementation. Cannot determine causality in this observational study. The policy change was associated with an increase in deceased donor transplantation and marked improvement in patient survival for patients waitlisted after long periods of dialysis treatment without decreasing the utility of available deceased donor kidney supply. The policy was not associated with increased waitlisting of this disadvantaged population.

Healthcare professional and community preferences in deceased donor kidney allocation: A best-worst scaling survey

Deceased donor kidneys are a scarce community resource; therefore, the principles underpinning organ allocation should reflect societal values. This study aimed to elicit community and healthcare professional preferences for principles guiding the allocation of kidneys from deceased donors and compare how these differed across the populations. A best-worst scaling survey including 29 principles in a balanced incomplete block design was conducted among a representative sample of the general community (n=1237) and healthcare professionals working in transplantation (n=206). Sequential best-worst multinomial logistic regression was used to derive scaled preference scores (PS) (range 0-100). Thematic analysis of free text responses was performed. Five of the six most valued principles among members of the community related to equity, including priority for the longest waiting (PS 100), difficult to transplant (PS 94.5) and sickest (PS 93.9), and equitable access for men and women (PS 94.0), whereas the top four principles for healthcare professional focused on maximizing utility (PS 89.9-100). Latent class analysis identified unmeasured class membership among community members. There are discordant views between community members and healthcare professionals. These should be considered in the design, evaluation, and implementation of deceased donor kidney allocation protocols.

Time to Move on: HLA Matching Should Be Reconsidered in Modern Deceased Donor Kidney Allocation.

Background.HLA matching has been the cornerstone of deceased donor kidney allocation policies worldwide but can lead to racial inequity. Although HLA matching has been shown to improve clinical outcomes, the long-term impacts of nonallogenic factors are being increasingly recognized. This has led some transplant programs to include points for nonallogenic factors, for example, age. Our study looks at long-term graft and patient outcomes based on allocation cohorts rather than individual number of HLA mismatches.Methods.Using the Australia and New Zealand Dialysis and Transplant Registry, we analyzed 7440 adult deceased donor transplant events from 2000 to 2018. Transplants were classified as HLA matched or nonmatched according to the OrganMatch score and the local allocation algorithms. Graft function was studied with linear mixed modeling and graft rejection with logistic and binomial regression. Time to graft failure and recipient survival were examined with Kaplan–Meier curve and Cox regression models.Results.Forty percent of transplants were HLA matched. Mean glomerular filtration rate was 1.76 mL/min/1.73 m2 higher in the matched transplants (P < 0.001). Matched transplants had longer time to graft failure (15.9 versus 12.7 y; P < 0.001) and improved recipient survival (risk of death hazard ratio, 0.83; P = 0.003). Matched recipients spent less time on dialysis (28.1 versus 44.8 mo; P < 0.001), and this significantly contributed to the benefits seen in graft loss and recipient survival. Caucasian recipients were more likely to receive a matched transplant than non-Caucasians.Conclusions.Matched transplants showed benefits in graft and recipient outcomes; however, some of these results were of small magnitude, whereas others seemed to be due in part to a reduction in time on dialysis. The benefit for the matched cohort came at the expense of the nonmatched cohort, who spent longer on dialysis and were more likely to be of a minority racial background.

Computational Eurotransplant kidney allocation simulations demonstrate the feasibility and benefit of T-cell epitope matching.

The EuroTransplant Kidney Allocation System (ETKAS) aims at allocating organs to patients on the waiting list fairly whilst optimizing HLA match grades. ETKAS currently considers the number of HLA-A, -B, -DR mismatches. Evidently, epitope matching is biologically and clinically more relevant. We here executed ETKAS-based computer simulations to evaluate the impact of epitope matching on allocation and compared the strategies. A virtual population of 400,000 individuals was generated using the National Marrow Donor Program (NMDP) haplotype frequency dataset of 2011. Using this population, a waiting list of 10,400 patients was constructed and maintained during simulation, matching the 2015 Eurotransplant Annual Report characteristics. Unacceptable antigens were assigned randomly relative to their frequency using HLAMatchmaker. Over 22,600 kidneys were allocated in 10 years in triplicate using Markov Chain Monte Carlo simulations on 32-CPU-core cloud-computing instances. T-cell epitopes were calculated using the www.pirche.com portal. Waiting list effects were evaluated against ETKAS for five epitope matching scenarios. Baseline simulations of ETKAS slightly overestimated reported average HLA match grades. The best balanced scenario maintained prioritisation of HLA A-B-DR fully matched donors while replacing the HLA match grade by PIRCHE-II score and exchanging the HLA mismatch probability (MMP) by epitope MMP. This setup showed no considerable impact on kidney exchange rates and waiting time. PIRCHE-II scores improved, whereas the average HLA match grade diminishes slightly, yet leading to an improved estimated graft survival. We conclude that epitope-based matching in deceased donor kidney allocation is feasible while maintaining equal balances on the waiting list.

Updating Deceased Donor Kidney Allocation—What Are the Challenges?

Updating Deceased Donor Kidney Allocation—What Are the Challenges?

The Introduction of cPRA and Its Impact on Access to Deceased Donor Kidney Transplantation for Highly Sensitized Patients in Australia.

In March 2016, Australia's deceased donor kidney allocation program introduced calculated panel reactive antibody (cPRA) based on antibody exclusions using multiplex assays to define sensitization for waitlisted candidates. We aimed to assess the impact of this change and review access to transplantation for highly sensitized patients under the current allocation rules. Registry data were used to reconstruct changes in panel reactive antibody (PRA)/cPRA for all patients active on the waiting list between 2013 and 2018. A multilevel, mixed-effects negative binomial regression model was used to determine the association between sensitization and transplantation rate in the cPRA era. Following the introduction of cPRA, there was an increase in the percentage of the waiting list classified as highly sensitized (PRA/cPRA ≥80%) from 7.2% to 27.8% and very highly sensitized (PRA/cPRA ≥99%) from 2.7% to 15.3%. Any degree of sensitization was associated with a decreased rate of transplantation with a marked reduction for those with cPRA 95%-98% (adjusted incidence rate ratio, 0.36 [95% confidence interval, 0.28-0.47], P < 0.001) and cPRA ≥99% (adjusted incidence rate ratio, 0.09 [95% confidence interval, 0.07-0.12], P < 0.001). The proportion of the waiting list classified as highly sensitized increased substantially following the introduction of cPRA, and despite current prioritization, very highly sensitized patients have markedly reduced access to deceased donor transplantation.

Association of High Burden of End-stage Kidney Disease With Decreased Kidney Transplant Rates With the Updated US Kidney Allocation Policy

The Organ Procurement and Transplantation Network (OPTN) approved changes to the US kidney allocation system in 2019. The potential effects of this policy change using transplant rates normalized to end-stage kidney disease (ESKD) incidence have not been investigated. To estimate how the OPTN kidney allocation policy will affect areas of the US currently demonstrating low rates of kidney transplant, when accounting for the regional burden of ESKD. This cross-sectional population-based economic evaluation analyzed access of patients with ESKD to kidney transplant in the US. Participants included patients with incident ESKD, those on the kidney transplant wait list, and those who received a kidney transplant. Data were collected from January 1 to December 31, 2017, and were analyzed in 2019. The probability of a patient with ESKD being placed on the transplant wait list or receiving a deceased donor kidney transplant. States and donor service areas (DSAs) were compared for gains and losses in rates of transplanted kidneys under the new allocation system. Transplant rates were normalized for ESKD burden. A total of 122 659 patients had incident ESKD in the US in 2017 (58.2% men; mean [SD] age, 62.8 [15.1] years). The probability of a patient with ESKD receiving a deceased donor kidney transplant varied 3-fold across the US (from 6.36% in West Virginia to 18.68% in the District of Columbia). Modeling of the OPTN demonstrates that DSAs from New York (124%), Georgia (65%), and Illinois (56%) are estimated to experience the largest increases in deceased donor kidney allocation. Other than Georgia, these states have kidney transplant rates per incident ESKD cases above the mean (of 50 states plus the District of Columbia, New York is 16th and Illinois is 24th). In contrast, DSAs from Nevada (-74%), Ohio (-67%), and North Carolina (-61%)-each of which has a transplant rate per incident ESKD cases significantly below the mean-are estimated to experience the largest decreases in deceased donor allocation (of 50 states plus the District of Columbia, North Carolina is 34th, Ohio is 38th, and Nevada is 47th). The new OPTN-approved kidney allocation policy may result in worsening geographic disparities in access to transplants when measured against the burden of ESKD within a particular region of the US.

The Role of Kidney Allocation Policy in Addressing Kidney Shortages

Compared to policies intended to increase donations, policymakers have largely ignored the role of allocation policies in addressing current kidney shortages. This paper examines the impacts of prioritizing certain types of candidates for deceased-donor kidney allocation. Using a regression discontinuity design, I find that increased access to deceased-donor kidneys dramatically decreases mortality rates (by 43 percent relative to baseline), while decreasing the likelihood of receiving a living-donor transplant. Both of these effects vary substantially across race, blood type, and dialysis status. The result implies that prioritizing for transplant candidates, who are less prone to crowd-out, in deceased-donor kidney allocation could make policies, designed to increase the number of deceased donors, more effective.