Eurotransplant Kidney Allocation System Research Articles

Allocation Rules and Age-Dependent Waiting Times for Kidney Transplantation—an Analysis of Data From the German Transplantation Registry.

Rigid age limits in the current allocation system for post-mortem donor kidneys in Germany may have problematic effects. The new German national transplantion registry enables data analysis with respect to this question. Using anonymized data from the German national transplantion registry, we extracted and evaluated information on the recipients and postmortem donors of kidneys that were allocated in Germany through Eurotransplant over the period 2006-2020. Data on 19 664 kidney transplantations in Germany from 2006 to 2020 were analyzed. The median waiting time for kidney transplantation was 5.8 years. Persons under age 18 waited a median of 1.7 years; persons aged 18 to 64, 7.0 years; and persons aged 65 and older, 3.8 years. Over the period of observation, post-mortem kidneys were transplanted into 401 people of age 64 (2.0% of all organ recipients) and 1,393 people of age 65 (7.1% of all organ recipients). The difference in waiting times between allocation programs for persons under age 65 (ETKAS, "Eurotransplant Kidney Allocation System") and those aged 65 and older (ESP, "Eurotransplant Senior Program") increased over the period of observation, from 2.6 years in 2006-2010 to 4.1 years in 2017-2020. The rigid age limits in the current allocation rules for post-mortem kidney donations in Germany are prolonging the waiting times for transplants among patients aged 18 to 64. We think these rules need to be fundamentally reassessed.

Positive Long-Term Outcome of Kidney Allocation via Acceptable Mismatch Program in Highly Sensitized Patients

Introduction: Eurotransplant established the acceptable mismatch (AM) program to facilitate timely kidney transplantations of highly sensitized patients, but long-term granular clinical and immunological outcomes regarding overall graft survival and de novo DSA (dnDSA) formation are still intensively researched. The right choice of induction therapy in patients with differing immunological risk is not conclusively determined, as well as the impact of human leukocyte antigen (HLA) epitope matching on dnDSA formation. Methods: This monocentric, retrospective study analyzed 94 patients transplanted within the AM program between 2000 and 2019 compared to case-control matched cohorts of non- (PRA 0–5%; PRA-0) and intermediately sensitized (PRA 6–84%; PRA-6/84) patients transplanted through Eurotransplant Kidney Allocation System. Results: Estimated 10-year overall graft survival between the PRA-0 and AM cohorts was similar, whereas PRA-6/84 was significantly disadvantageous compared to PRA-0. Estimated 10-year incidence of antibody-mediated rejection rates was significantly lower in the PRA-0 group compared to AM and PRA-6/84 groups. Compared to the AM group, estimated incidence of de novo donor-specific antibody (dnDSA) was significantly lower in PRA-0 patients, with no differences between the AM and PRA-6/84 cohorts. The PRA-6/84 cohort was the only subgroup in which interleukin-2 receptor antagonist (IL2RA) induction was associated with longer overall graft survival, patient survival, and graft survival compared to depleting induction (ATG or OKT3). Broad HLA-A, -B, -DR mismatches (mmABDR) and HLA epitope mismatches determined by Eplets and PIRCHE-II were predictive for dnDSA formation in the total cohort, and the AM subgroup. Discussion: The high efforts expended on AM patients are justified to allow timely organ transplantation with acceptable risk profile and non-inferior outcomes. IL2RA induction in intermediately sensitized patients is associated with superior overall graft survival, patient survival, and graft survival compared to ATG/OKT3 induction, without negative effects on rejection episodes or dnDSA formation. In silico epitope matching might further help reduce dnDSA formation, particularly in high-risk AM patients.

Rescue Allocation Modes in Eurotransplant Kidney Transplantation: Recipient Oriented Extended Allocation Versus Competitive Rescue Allocation-A Retrospective Multicenter Outcome Analysis.

Whenever the kidney standard allocation (SA) algorithms according to the Eurotransplant (ET) Kidney Allocation System or the Eurotransplant Senior Program fail, rescue allocation (RA) is initiated. There are 2 procedurally different modes of RA: recipient oriented extended allocation (REAL) and competitive rescue allocation (CRA). The objective of this study was to evaluate the association of patient survival and graft failure with RA mode and whether or not it varied across the different ET countries. The ET database was retrospectively analyzed for donor and recipient clinical and demographic characteristics in association with graft outcomes of deceased donor renal transplantation (DDRT) across all ET countries and centers from 2014 to 2021 using Cox proportional hazards methods. Seventeen thousand six hundred seventy-nine renal transplantations were included (SA 15 658 [89%], REAL 860 [4.9%], and CRA 1161 [6.6%]). In CRA, donors were older, cold ischemia times were longer, and HLA matches were worse in comparison with REAL and especially SA. Multivariable analyses showed comparable graft and recipient survival between SA and REAL; however, CRA was associated with shorter graft survival. Germany performed 76% of all DDRTs after REAL and CRA and the latter mode reduced waiting times by up to 2.9 y. REAL and CRA are used differently in the ET countries according to national donor rates. Both RA schemes optimize graft utilization, lead to acceptable outcomes, and help to stabilize national DDRT programs, especially in Germany.

Equity matrix for kidney transplant allocation

There is a general agreement that the distribution of kidneys for transplantation should balance utility criteria with justice. Moreover, a kidney allocation system must be based on transparent policies and seen as an ongoing process.This study aims to present an allocation system grounded on an equity matrix that balances the criteria of utility and justice.Synthetic data for a waiting list with 2000 transplant candidates and a pool of 280 donors were generated. A color priority system, the Eurotransplant (ET) kidney allocation system, and the proposed Equity Matrix (EQM) allocation system were compared after 1000 iterations of kidney allocations. Distributions of variables like the age difference, Human Leukocyte Antigens (HLA) mismatches (mmHLA), recipients' time on dialysis, cPRA, and a transplant score obtained by different allocation models were compared graphically and with Cohen's d effect size.For the analyzed variables, when we compare only the selected recipients from ET with the selected recipients from the EQM neutral model, we can conclude that the former model selects more hypersensitized recipients, a higher number of 65+ years' old recipients with 65+ years' old donors and higher number of recipients with 0 mmHLA. While recipients from EQM neutral are slightly older, have a lower age difference with their donors, have a lower number of mmHLA, are less likely to have 6 mmHLA with their donors, and have more time on dialysis.The proposed EQM model attempts to provide a simple, transparent, and equitable response to a complex question with results that outperform established practices.

Regional Differences in Waiting Times Before Kidney Transplantation in Germany.

In order to achieve short ischemia times between organ donation and transplantation, regional organ allocation has been assigned priority in the development of allocation rules for kidney transplantation. It is unclear whether this leads to differences in regional waiting times in Germany. A retrospective cohort study over a 24-month observation period was conducted, including all patients who received a kidney-only graft allocated via the standard Eurotransplant Kidney Allocation System (ETKAS) (n = 1487) or the Eurotransplant Senior Program (ESP) (n = 566). Multiple linear regression analyses were performed to investigate differences in waiting times across the regions (ETKAS) or subregions (ESP) as defined by the German Organ Procurement Organization (DSO). Associations between the number of regionally procured kidneys (n = 1444) and regional waiting times were investigated. In ETKAS, the median waiting time was 8.9 years (interquartile range [IQR] 6.7-10.6); in ESP, it was 3.9 (2.4 -5.3) years. Compared with the reference region with the shortest waiting time, waiting times in other regions were 0.6 to 1.7 years longer in ETKAS and 1.3 to 4.4 years longer in ESP. The ratio of the number of patients on the waiting list for a particular region to the number of organs donated in that region was associated with the waiting time in ETKAS (R2 = 0.70). In ESP, this association was markedly less pronounced (R2 = 0.45). In Germany, waiting times depend strongly on the region where a patient is listed for kidney transplantation, especially in ESP. These findings call the current allocation algorithms into question and imply a need for suitable modification.

Immunized Patients Face Reduced Access to Transplantation in the Eurotransplant Kidney Allocation System.

The presence of donor-specific HLA antibodies before transplantation is associated with poor transplantation outcomes. Unacceptable antigens can be assigned for Eurotransplant kidney transplant candidates to prevent kidney offers against which the candidate has developed clinically relevant HLA antibodies. This retrospective cohort study aimed to assess to what degree unacceptable antigens affect access to transplantation in the Eurotransplant Kidney Allocation System (ETKAS). Candidates who underwent kidney-only transplantation between 2016 and 2020 were included (n = 19 240). Cox regression was used to quantify the relationship between the relative transplantation rate and virtual panel-reactive antibodies (vPRAs), which is the percentage of the donor pool with unacceptable antigens. Models used accrued dialysis time as the timescale; were stratified by country and blood group of patient and were adjusted for nontransplantable status, patient age, sex, history of kidney transplantations, and prevalence of 0 HLA-DR-mismatched donors. Transplantation rates were 23% lower for vPRA 0.1% to 50%, 51% lower for vPRA 75% to 85%, and decreased rapidly for vPRA of >85%. Prior studies showed significantly lower ETKAS transplantation rates only for highly sensitized patients (vPRA of >85%). The inverse relationship between transplantation rate and vPRA is independent of Eurotransplant country, listing time, and 0 HLA-DR-mismatched donor availability. Results were similar when quantifying the relationship between vPRA and attainment of a sufficiently high rank for an ETKAS offer, suggesting lower transplantation rates for immunized patients are due to current ETKAS allocation. Immunized patients face lower transplantation rates across Eurotransplant. The current ETKAS allocation mechanism inadequately compensates immunized patients for reduced access to transplantation.

Allokation von Nieren im Zeitalter des Organmangels in Deutschland

Due to the opt-in solution currently in place in Germany, there is a substantial shortage of deceased organ donors. Therefore, it is critical that the allocation of available organs follows an optimized algorithm and that the potential of living donations is maximized; however, in this respect the current German legislation has major shortcomings. The human leukocyte antigen (HLA) matching system has a large impact on the standard kidney allocation (Eurotransplant kidney allocation system, ETKAS), that is no longer necessary to this extent in the era of modern immunosuppression but continues to put patients with rare HLA types at a disadvantage. As most points are effectively awarded for the accrual of waiting time, kidneys are often awarded to recipients with poor perspectives for organ survival. The aim of the Eurotransplant Senior Program (ESP) is primarily to minimize the cold ischemia time (CIT) even though it has been shown that CIT can be increased to up to 18 h without impairing allograft survival, also for high-risk organs from ≥ 70-year-old donors. At the same time, the preferential allocation of ESP organs within one subregion results in greatly different waiting times within Germany. Also, the only inclusion criterion for the ESP is recipient age, whereas other medical conditions and thus other recipient risk groups (e.g., diabetics) are disadvantaged. The ban on altruistic living kidney donations in Germany impairs the implementation of modern strategies, such as crossover donations, that have become standard internationally. In turn, the full potential of living kidney donations cannot currently be exploited in Germany. The allocation system should be modernized by incorporating new advances from transplantation research, e.g., by allocation according to life years gained.

Impact of Sensitization on Waiting Time Prior to Kidney Transplantation in Germany.

Assignment of unacceptable HLA mismatches (UAMs) prevents transplantation of incompatible grafts but potentially prolongs waiting time. Whether this is true in the Eurotransplant Kidney Allocation System (ETKAS) and the Eurotransplant Senior Program in Germany is highly debated and relevant for UAM policies. Donor pool restriction due to UAM was expressed as percent virtual panel-reactive antibodies (vPRAs). Kaplan-Meier estimates and multivariable Cox regression models were used to analyze the impact of vPRA levels on waiting time and transplant probability during a period of 2 y in all patients eligible for a kidney graft unter standard circumstances in Germany on February 1, 2019 (n = 6533). Utility of the mismatch probability score to compensate for sensitization in ETKAS was also investigated. In ETKAS, donor pool restriction resulted in significant prolongation of waiting time and reduction in transplant probability only in patients with vPRA levels above 85%. This was most evident in patients with vPRA levels above 95%, whereas patients in the acceptable mismatch program had significantly shorter waiting times and higher chances for transplantation than nonsensitized patients. In the Eurotransplant Senior Program, vPRA levels above 50% resulted in significantly longer waiting times and markedly reduced the chance for transplantation. Compensation for sensitization by the mismatch probability score was insufficient. Donor pool restriction had no significant impact on waiting time in most sensitized patients. However, despite the existence of the acceptable mismatch program, the majority of highly sensitized patients is currently disadvantaged and would benefit from better compensation mechanisms.

Improving Access to Renal Transplantation for Highly Sensitized Patients.

Transplantation is accepted to be the best form of treatment for end-stage renal disease, and it is also clear that the longer the patients wait on dialysis, the worse their overall graft and patient outcomes are, posttransplantation. The presence of increasing levels of anti-HLA antibodies progressively increases waiting times, especially highly sensitized patients (HSP) with panel reactivity (PRA) >85%. Currently, in the EuroTransplant (ET) allocation programs, the presence of antibody, even at a low level as detected by single antigen beads, generates a virtual PRA (vPRA). This results in unacceptable antigen matches so that offers are not made to these patients, increasing their expected wait time. ET allocates organs in three different systems. The Acceptable match program is successful in transplanting sensitized patients, but only a tiny percentage of potential recipients are eligible. The standard ET kidney allocation system integrates patients’ PRA into a mismatch probability (MMP), which generates additional points with the aim of assisting HSP to be transplanted. However, despite this, and partly because of the low donor rates in Germany, the median waiting time for patients with a vPRA of >95% is 13.2 y (and >10 y for patients with vPRA <95%). The ET senior programme that allocates kidneys on the basis of blood group, waiting time, and region (to minimize ischemic time) also disadvantages HSP. In this article, Zecher et al1 have analyzed the impact of vPRA levels of the various ET allocation systems in Germany and the factors disadvantaging HSP, including the effectiveness of the MMP to compensate for sensitization. Many of their findings are not surprising. For HSP, the higher their vPRA, the longer their median wait times are, except organs offered in the acceptable match system. This is only open to about 2% of patients, and the shorter waiting times reflect that the German patients in this program are in a pool with all ET countries, most of whom have much shorter waiting times. The MMP was designed to compensate for sensitization (as well as blood group and HLA type), and although incorporation of vPRA in 2020 did improve the correlation between vPRA and the score, the effect was not marked, and a high score could be generated with low or even zero vPRA. Furthermore, the maximum MMP score is only 100 out of a total of 800 points, thus limiting its efficacy to significantly reduce waiting times for HSP. The analysis of their cohort of patients on the waiting list, therefore, demonstrated that the MMP compensation was very inadequate. They also found that there was a high organ rejection rate in transplant centers for immunological reasons, suggesting inadequate or incorrect unacceptable antigen mismatches data provided to ET. Finally, the authors found large (> 2-fold) differences in the probability of transplantation between the 7 regions within Germany. This may partly be explained by variation in donation rate but is likely to represent different approaches to listing unacceptable antigen mismatches, including single antigen beads data. Clearly, HSP are and will always be disadvantaged by their sensitization, but in the interest of equity, their waiting times should be reduced as much as possible to improve long-term outcomes. Zecher et al1 highlight several important issues resulting in excessive waiting times, especially for HSP. There should be considerable scope to modify reporting of acceptable and unacceptable antigens to ET, and modification of the allocation algorithms could significantly improve waiting times for these severely disadvantaged patients. Comparison of individual center practice is also likely to identify factors that might reduce center and regional variation. German (and all ET) data could be used to model alterations to the allocation algorithms to improve waiting times for HSP and for better equity to other groups of patients, such as ethnic minorities. Lessons may be learned from offering algorithms in other countries. For instance, one of the key objectives for the 2019 UK Kidney Offering Scheme was to avoid prolonged waiting times that are predictable, which is particularly relevant to HSP. In the development of the scheme, different methods of prioritization were considered. These included priority tiers and different points weightings based on factors including sensitization, matchability, and waiting time, and the methods were evaluated by analyzing simulated data across different potential schemes. The 2019 UK scheme is expected to significantly reduce variation in waiting time in sensitized patients, and this reduction is also expected to be seen across other factors, including ethnicity. Although this paper highlights inequities in the ET system and Germany in particular, it highlights the need for all organ allocation algorithms to be reviewed and alternatives extensively modeled to generate algorithms to improve overall equity.

Evaluation of Deceased Donor Kidney Transplantation in the Eurotransplant Senior Program in Comparison to Standard Allocation.

BackgroundThe organ shortage and long waiting times have dramatically increased the age of potential kidney transplant recipients. The Eurotransplant Senior Program (ESP) was initiated to allocate kidneys from deceased donors aged ≥65 years to recipients with a comparable age independent of pre-transplant human leucocyte antigen (HLA) matching; however, parameters affecting the long-term benefits of this strategy remain poorly defined.Material/MethodsWe retrospectively evaluated outcome and risk factors for mortality in kidney recipients aged ≥65 years that were transplanted according to the ESP protocol relative to patients aged >50 years transplanted according to the Eurotransplant kidney allocation system (ETKAS) criteria at the University Freiburg Medical Center, Germany, between 2008 and 2018.ResultsGraft survival, graft function, the maintenance immunosuppressive therapy, and the incidence of rejections and infections did not differ between groups. Infectious diseases were the main cause of death in both groups; however, infection-associated mortality was more than double in the ESP group, and 5-year patient survival was 61.4% in the ESP group compared to 83.2% in the ETKAS group. Multivariate analysis identified age, the number of HLA mismatches, and the CMV serostatus with a seropositive donor and negative recipient as the main risk factors for mortality.ConclusionsA comparable immunosuppressive regimen used in ESP and ETKAS patients was associated with similar rejection rates and infectious disease complications, and infections were the most common cause of death in both groups. CMV-negative patients receiving an organ from a CMV-positive donor and patients with a high number of HLA mismatches require close follow-up to reduce mortality.

Kidney Transplantation After Rescue Allocation-the Eurotransplant Experience: A Retrospective Multicenter Outcome Analysis.

At Eurotransplant (ET), kidneys are transferred to "rescue allocation" (RA), whenever the standard allocation (SA) algorithms Eurotransplant Kidney Allocation System (ETKAS) and Eurotransplant Senior Program (ESP) fail. We analyzed the outcome of RA. Retrospective patient clinical and demographic characteristics association analyses were performed with graft outcomes for 2422 recipients of a deceased donor renal transplantation (DDRT) after RA versus 25 481 after SA from 71 centers across all ET countries from 2006 to 2018. Numbers of DDRTs after RA increased over the time, especially in Germany. RA played a minor role in ESP versus ETKAS (2.7% versus 10.4%). RA recipients and donors were older compared with SA recipients and donors, cold ischemia times were longer, waiting times were shorter, and the incidence of primary nonfunction was comparable. Among ETKAS recipients, HLA matching was more favorable in SA (mean 3.7 versus 2.5). In multivariate modeling, the incidence of graft loss in ETKAS recipients was reduced in RA compared with SA (subdistribution hazard ratio, 0.80; 95% confidence interval [0.70-0.91], P < 0.001), whereas other outcomes (mortality, death with functioning graft (DwFG)) were not significantly different. None of the 3 outcomes were significantly different when comparing RA with SA within the ESP program. Facing increased waiting times and mortality on dialysis due to donor shortage, this study reveals encouragingly positive DDRT outcomes following RA. This supports the extension of RA to more patients and as an alternative tool to enable transplantation in patients in countries with prohibitively long waiting times or at risk of deterioration.

Kidney Transplantation Outcome Predictions (KTOP): A Risk Prediction Tool for Kidney Transplants from Brain-dead Deceased Donors Based on a Large European Cohort

BackgroundEuropean kidney donation shortages mandate efficient organ allocation by optimizing the prediction of success for individual recipients. ObjectiveTo develop the first European online risk tool for kidney transplant outcomes on the basis of recipient-only and recipient plus donor characteristics. Design, setting, and participantsWe used individual recipient and donor risk factors and three outcomes (death, death with functioning graft [DWFG], and graft loss) for 32 958 transplants within the Eurotransplant kidney allocation system and the Eurotransplant senior program between January 2006 and May 2018 in eight European countries to develop and validate a risk tool. Outcome measurements and statistical analysisCox proportional-hazards models were used to analyze the association of risk factors with overall patient mortality, and proportional subdistribution hazard regression models for their association with graft loss and DWFG. Prediction models were developed with recipient-only and recipient-donor risk factors. Sensitivity analyses based on time-specific area under the receiver operating characteristic curve (AUC) with leave-one-country-out validation were performed and calibration plots were generated. Results and limitationsThe 10-yr cumulative incidence rate was 37% for mortality, 12% for DWFG, and 41% for graft loss. In recipient-donor models the leading risk factors for mortality were recipient diabetes (hazard ratio [HR] 10.73), retransplantation (HR 3.08 per transplant), and recipient age (HR 1.08). Effects were similar for DWFG. For graft loss, diabetes (subdistributional HR [SHR] 1.32), increased donor age (SHR 1.02), and prolonged cold ischemia time (SHR 1.02) had increased SHRs. All p values were <0.001. ConclusionsPreviously identified risk factors for outcomes following kidney transplants allow for outcome prediction with 10-yr AUC values of up to 0.81. Patient summaryUsing European data, we estimated individual risks to predict the success of kidney transplants and support physicians in decision-making. An online tool is now available (https://riskcalc.org/ktop/) for predicting kidney transplant outcomes both before and after a donor has been identified.

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.

Repeated kidney re-transplantation-the Eurotransplant experience: a retrospective multicenter outcome analysis.

In Eurotransplant kidney allocation system (ETKAS), candidates can be considered unlimitedly for repeated re-transplantation. Data on outcome and benefit are indeterminate. We performed a retrospective15-year patient and graft outcome data analysis from 1464 recipients of a third or fourth or higher sequential deceased donor renal transplantation (DDRT) from 42 transplant centers. Repeated re-DDRT recipients were younger (mean 43.0 vs. 50.2years) compared to first DDRT recipients. They received grafts with more favorable HLA matches (89.0% vs. 84.5%) but thereby no statistically significant improvement of patient and graft outcome was found as comparatively demonstrated in 1st DDRT. In the multivariate modeling accounting for confounding factors, mortality and graft loss after 3rd and ≥4th DDRT (P<0.001 each) and death with functioning graft (DwFG) after 3rd DDRT (P=0.001) were higher as compared to 1st DDRT. The incidence of primary nonfunction (PNF) was also significantly higher in re-DDRT (12.7%) than in 1st DDRT (7.1%; P<0.001). Facing organ shortage, increasing waiting time, and considerable mortality on dialysis, we question the current policy of repeated re-DDRT. The data from this survey propose better HLA matching in first DDRT and second DDRT and careful selection of candidates, especially for ≥4th DDRT.

Identification and weighting of kidney allocation criteria: a novel multi-expert fuzzy method

BackgroundKidney allocation is a multi-criteria and complex decision-making problem, which should also consider ethical issues in addition to the medical aspects. Leading countries in this field use a point scoring system to allocate kidneys. Hence, the purpose of this study is to identify and weight the kidney allocation criteria considering the balance between utility and equity.MethodsTo do this, a new fuzzy hybrid approach is proposed, which consists of two steps: In the first step, Fuzzy Delphi Method (FDM) is used to identify the effective criteria in the kidney allocation algorithm. In the second step, Intuitionistic Fuzzy Analytic Hierarchy Process (IF-AHP) is employed to determine the weight of the criteria.ResultsThe results showed that the highest weight belongs to “Medical emergency” criterion and the lowest weight to “5 HLA mismatches”, which is similar to Euro-transplant kidney allocation system (ETKAS). The developed method is evaluated in two steps. First, the proposed model is implemented using a real case study from the Iranian Kidney Allocation System. It was shown that the proposed model has the potential to improve allocation outcome. Second, the proposed model’s superiority to the current model is approved by the experts using the results display in the profile matrix. Finally, sensitivity analysis is performed to check the robustness of the proposed model.ConclusionsThis paper contributes to the kidney allocation literature by doing the following: (a) developing a comprehensive framework for identification and weightings of criteria for kidney allocation, (b) using, for the first time, the IF-AHP technique to consider hesitancy of decision makers and uncertainty in organ allocation, and (c) proposing an appropriate framework for the countries that intend to improve or modify their organ allocation system.

Results and reflections from the PROfiling Consortium on Antibody Repertoire and Effector functions in kidney transplantation: A mini-review.

Kidney transplantation is the best treatment option for patients with end‐stage renal disease (ESRD). The waiting time for a deceased donor kidney in the Netherlands is approximately 3 years. Mortality among patients on the waiting list is high. The aim of the PROCARE consortium (PROfiling Consortium on Antibody Repertoire and Effector functions) was to decrease the waiting time by providing a matching algorithm yielding a prolonged graft survival and less HLA‐immunization compared with the currently used Eurotransplant Kidney allocation system. In this study, 6097 kidney transplants carried out between January 1995 and December 2005 were re‐examined with modern laboratory techniques and insights that were not available during that time period. In this way, we could identify potential new parameters that can be used to improve the matching algorithm and prolong graft survival. All eight University Medical Centers in the Netherlands participated in this multicenter study. To improve the matching algorithm, we used as central hypothesis that the combined presence of class‐I and ‐II single‐antigen bead (SAB)‐defined donor‐specific HLA antibodies (DSA) prior to transplantation, non‐HLA antibodies, the number of B‐ and/or T‐cell epitopes recognized on donor HLA, and specific polymorphisms in effector mechanisms of IgG were associated with an increased risk for graft failure. The purpose of this article is to relate the results obtained from the PROCARE consortium study to other studies published in recent years. The clinical relevance of SAB‐defined DSA, complement‐fixing DSA, non‐HLA antibodies, and the effector functions of (non)‐HLA‐antibodies will be discussed.

Analysis of the Eurotransplant Kidney Allocation Algorithm: How Should We Balance Utility and Equity?

BackgroundSince 2014, expected graft and recipient survival are matched by the U.S. kidney allocation system to improve organ utility. This mechanism is based on the kidney donor profile index (KDPI) and the estimated posttransplant survival score (EPTS). Here we analyzed 1. the transferability of these scores into the Eurotransplant (ET) region and 2. the extent to which the ET kidney allocation algorithm promotes utility. MethodsWe studied data of 262 kidney transplantations performed at the University Hospital Kiel between 2000 and 2009 (median follow-up, 9.94 years). ResultsMultivariable Cox regression analysis revealed that only the variables donor age of the KDPI and recipient's age of the EPTS have a significant value as predictors of posttransplant graft and recipient survival. The other variables showed no additional predictive value. Analyzing all kidneys allocated in the ET kidney allocation system and the European Senior Program, we found that donor and recipient's age and KDPI and EPTS were weakly correlated (rage-age = 0.5, P < .001; rKDPI-EPTS = 0.4, P < .01). If both programs were analyzed separately, no correlation between donor and recipient's age and between KDPI and EPTS was detected. ConclusionThe ET kidney allocation algorithm poorly matched predicted graft and recipient survival at our center. A better age-matching may improve organ utility.

The 'blood group O problem' in kidney transplantation--time to change?

Patients with blood group O have disadvantages in the allocation of deceased donor organs in the Eurotransplant Kidney Allocation System and fewer ABO-compatible living donors. In order to investigate the consequences of this dilemma, we analysed the outcome of patients with blood group O in our transplantation programme. A single-centre analysis of 1186 waitlisted patients for first deceased donor kidney transplantations between 1996 and 2008 was performed, and the mechanisms of blood group-dependent differences for graft and recipient outcome were assessed. Median follow-up time until death or end of observation for all waitlisted patients was 66 months (range, 0-158 months) and for 589 recipients of a kidney graft was 61 months (range, 0-158 months). Patients with blood group O had significantly longer waiting times for deceased donor kidney grafts, compared to non-group O recipients (median waiting time, 85 vs 59 months). As a consequence, blood group O patients had an increased risk for death without transplantation (13.1% for O patients vs 9.6% for non-O patients; P < 0.05). Despite a good human leukocyte antigen match, graft outcome tended to be worse in O recipients; 14.1% (95% CI, 8.2-19.9%) of all O kidneys from deceased donors were transplanted into non-O recipients, leading to the accumulation of O recipients on the waiting list. The export of blood group O donor kidneys to other blood groups leads to longer waiting times, to a higher death rate and to accumulation of blood group O patients on the waiting list, which will further aggravate the problem in the future. Our results should prompt further research on the issues associated with blood group O. Current allocation systems and living donor kidney exchange programmes should be re-evaluated to address this problem.

Enhanced Kidney Allocation to Highly Sensitized Patients by the Acceptable Mismatch Program

). Highly sensitized patientshave only a small chance to receive a crossmatch negativedonor kidney, because they have developed antibodiesagainstmanydifferentHLAantigensresultingfrompreviouscontacts with allogeneic cells by pregnancy, blood transfu-sions,orprevioustransplants.Ifnospecialmeasurementsaretaken, these patients will accumulate on the transplant wait-ing lists. More and more transplant centers are developingstrategiestoremovecirculatingHLAalloantibodiesinthesepa-tients to be able to transplant the patient with a donor kidneydespite a positive crossmatch (

Renal transplantation in the elderly: surgical complications and outcome with special emphasis on the Eurotransplant Senior Programme

The purpose of this retrospective study was to evaluate the results of the Eurotransplant Senior Programme (ESP) within our centre compared to elderly recipients >or=60 years from the regular Eurotransplant Kidney Allocation System (ETKAS), specifically focusing on surgical aspects. Data from 73 ESP patients (average donor/recipient age: 71.1/67.1) were compared with those from 51 patients (49.7/63.6) treated within the framework of the ETKAS program between the years 1999 and 2006. The mean follow-up was 39.5 months. Cold ischaemic time (ESP versus ETKAS: 10.3 versus 15.0 h), duration of renal replacement therapy (42.2 versus 76.8 months), donor glomerular filtration rate (81.7 versus 109.9 ml/min/1.73 m(2)) and HLA mismatches (4.1 versus 2.4) were significantly different between the two groups (all P < 0.001). Primary graft function was seen in 74% ESP versus 69% of ETKAS patients (P > 0.05). The rate of surgical complications in the ESP versus ETKAS group was 47% versus 28% (P = 0.031) and the revision rate, 33% versus 24% (P = 0.259). Three-year patient and censored graft survival was 84% versus 92% and 85% versus 88% in the ESP and ETKAS group, respectively (all P > 0.05). Ninety-five percent of all deceased patients died with a functioning graft. The donor and recipient pool has been markedly expanded through ESP with similar patient and graft survival compared to elderly recipients grafted according to ETKAS criteria. However, patients and their physicians should be aware of the high surgical complication rate in elderly recipients, particularly when receiving elderly donor kidneys. This might seriously influence postoperative patient management but ultimately does not compromise the transplant outcome.