The Canadian kidney paired donation program: a national program to increase living donor transplantation. Transplantation. 2015;99:985-990. [PMID: 25340607 DOI: 10.1097/tp.0000000000000455]

Kidney Paired Donation-European Transnational Experience in Adults and Opportunities for Pediatric Kidney Transplantation

BACKGROUND

Live donor kidney transplantation is considered the optimal choice for renal replacement therapy, providing established benefits, such as superior patient survival and improved quality of life. However, immunological challenges, including ABO blood group incompatibility and, particularly, donor-specific HLA antibodies, may impact long-term outcomes considerably or even prevent safe direct transplantation with the intended donor.

METHODS

In this review, the authors discuss kidney paired donation (KPD) as a viable strategy to overcome immunological barriers to living donation through organ exchanges. We thereby lay special focus on the Czech-Austrian transnational KPD program.

RESULTS

While the benefits of KPD programs are well established for adult recipients, recent data suggest that this may hold true also for pediatric patients. Complex algorithms, considering factors like the intricate patterns of HLA sensitization, play a pivotal role in predicting suitable matches, but for pediatric patients also non-immunological factors including age and weight match may play a role. As pool size proves crucial for program efficacy, several countries in Europe have now initiated transnational collaborations to maximize match rates. Among those, the Czech-Austrian transnational joint program, established in 2015 and now expanded to a cooperation with the Israel transplant program to further increase transplant rates, represents a successful example.

CONCLUSION

KPD programs, with their innovative approaches and international partnerships, hold promise for enhancing outcomes and addressing the increasing demand for kidney transplantation.

Kidney paired donation in developing countries: A global perspective

Purpose of review

We review the key principles of kidney paired donation (KPD) and discuss the status and unique considerations for KPD in developing countries.

Recent findings

Despite the advantages of KPD programs, they remain rare among developing nations, and the programs that exist have many differences with those of in developed countries. There is a paucity of literature and lack of published data on KPD from most of the developing nations. Expanding KPD programs may require the adoption of features and innovations of successful KPD programs. Cooperation with national and international societies should be encouraged to ensure endorsement and sharing of best practices.

Summary

KPD is in the initial stages or has not yet started in the majority of the emerging nations. But the logistics and strategies required to implement KPD in developing nations differ from other parts of the world. By learning from the KPD experience in developing countries and adapting to their unique needs, it should be possible to expand access to KPD to allow more transplants to happen for patients in need world-wide.

Increasing Kidney-Exchange Options Within the Existing Living Donor Pool With CIAT: A Pilot Implementation Study

Computerized integration of alternative transplantation programs (CIAT) is a kidney-exchange program that allows AB0- and/or HLA-incompatible allocation to difficult-to-match patients, thereby increasing their chances. Altruistic donors make this available for waiting list patients as well. Strict criteria were defined for selected highly-immunized (sHI) and long waiting (LW) candidates. For LW patients AB0i allocation was allowed. sHI patients were given priority and AB0i and/or CDC cross-match negative HLAi allocations were allowed. A local pilot was established between 2017 and 2022. CIAT results were assessed against all other transplant programs available. In the period studied there were 131 incompatible couples; CIAT transplanted the highest number of couples (35%), compared to the other programs. There were 55 sHI patients; CIAT transplanted as many sHI patients as the Acceptable Mismatch program (18%); Other programs contributed less. There were 69 LW patients; 53% received deceased donor transplantations, 20% were transplanted via CIAT. In total, 72 CIAT transplants were performed: 66 compatible, 5 AB0i and 1 both AB0i and HLAi. CIAT increased opportunities for difficult-to-match patients, not by increasing pool size, but through prioritization and allowing AB0i and "low risk" HLAi allocation. CIAT is a powerful addition to the limited number of programs available for difficult-to-match patients.

Recommendations for living donor kidney transplantation

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

Compatible Donor and Recipient Pairs' Perspectives on Participation in Kidney Paired Donation Programs: A Mixed-Methods Study

Background:

Compatible pair participation in kidney paired donation (KPD) may increase the likelihood of finding suitable matches for all registered pairs. Retrospective studies have shown variable enthusiasm for participating in KPD in compatible pairs.

Objective:

The study objective was to gather potential living donor (PLD) and transplant candidate (TC) perspectives on compatible pair participation in KPD.

Design:

Surveys and qualitative interviews.

Setting:

Three transplant programs in Canada: Centre hospitalier de l’Université de Montréal in Montreal (Québec), Vancouver General Hospital, and St. Paul’s Hospital in Vancouver (British Columbia).

Patients:

Both PLDs and TCs undergoing evaluation for donation/transplantation between 2016 and 2018 at 3 transplant programs in Canada.

Methods:

Descriptive statistical analysis was performed for the results of the survey and thematic and content analysis method was used for the content of the qualitative interviews.

Results:

A total of 116 PLDs and 111 TCs completed surveys and an additional 18 PLDs and 17 TCs underwent semi-directed interviews. Of those surveyed, 61.2% of PLDs and 76.6% of TCs reported a willingness to participate in KPD as a compatible pair. The possibility of a more optimally matched kidney for the TC and policies ensuring prioritization of the TC for repeat transplantation in the event of early graft failure increased willingness to participate in KPD. Major concerns expressed during the interviews included the desire to retain the emotional bond of directed donation, the fear of chain breaks or donor reneging, delays in transplantation, and additional travel associated with participation in KPD.

Limitation:

The limitations of this study are that it was conducted in only 3 Canadian transplant programs and that the interviews and surveys were in French and in English. As a consequence, the results may not be reflective of the views of individuals not living in these 2 provinces and from ethnic minority populations.

Conclusion:

Most of the compatible PLDs and TCs surveyed were willing to participate in KPD. Ensuring timely transplantation and a more optimal match for TCs and offering a policy of reciprocity to ensure timely repeat transplantation for compatible recipients if their allograft fails post KPD transplant may further increase compatible pair participation in KPD.

Creating Options for Difficult-to-match Kidney Transplant Candidates

BACKGROUND

Most transplantation centers recognize a small patient population that unsuccessfully participates in all available, both living and deceased donor, transplantation programs for many years: the difficult-to-match patients. This population consists of highly immunized and/or ABO blood group O or B patients.

METHODS

To improve their chances, Computerized Integration of Alternative Transplantation programs (CIAT) were developed to integrate kidney paired donation, altruistic/unspecified donation, and ABO and HLA desensitization. To compare CIAT with reality, a simulation was performed, including all patients, donors, and pairs who participated in our programs in 2015-2016. Criteria for inclusion as difficult-to-match, selected-highly immunized (sHI) patient were as follows: virtual panel reactive antibody >85% and participating for 2 years in Eurotransplant Acceptable Mismatch program. sHI patients were given priority, and ABO blood group incompatible (ABOi) and/or HLA incompatible (HLAi) matching with donor-specific antigen-mean fluorescence intensity (MFI) <8000 were allowed. For long-waiting blood group O or B patients, ABOi matches were allowed.

RESULTS

In reality, 90 alternative program transplantations were carried out: 73 compatible, 16 ABOi, and 1 both ABOi and HLAi combination. Simulation with CIAT resulted in 95 hypothetical transplantations: 83 compatible (including 1 sHI) and 5 ABOi combinations. Eight sHI patients were matched: 1 compatible, 6 HLAi with donor-specific antigen-MFI <8000 (1 also ABOi), and 1 ABOi match. Six/eight combinations for sHI patients were complement-dependent cytotoxicity cross-match negative.

CONCLUSIONS

CIAT led to 8 times more matches for difficult-to-match sHI patients. This offers them better chances because of a more favorable MFI profile against the new donor. Besides, more ABO compatible matches were found for ABOi couples, while total number of transplantations was not hampered. Prioritizing difficult-to-match patients improves their chances without affecting the chances of regular patients.

The First North American Experience Using Glycosorb Immunoadsorption Columns for Blood Group-Incompatible Kidney Transplantation

Background:

Blood group incompatibility (ABOi) is the most common barrier to living donor kidney transplantation. Options for such recipients include kidney paired donation (KPD) or desensitization methodology to reduce blood antibody response.

Objective:

The objective of this study is to report on the first North America experience in ABOi living donor kidney transplantation using Glycosorb ABO immunoadsorption columns.

Design:

Retrospective observational cohort study.

Setting:

Renal transplant program at St. Michael’s Hospital, Unity Health Toronto, University of Toronto.

Patients:

Twenty-six ABOi living donor transplants from August 2011 through February 2020 were undertaken at our center.

Measurements:

Renal allograft and patient survival postdesensitization for ABOi living donor transplants and isohemagglutinin titer reduction.

Methods:

Preoperative immunosuppressive regimen consisted of a single dose of Rituximab 375 mg/m² IV on day −28; tacrolimus, mycophenolic acid, and prednisone to start on day −7. Immunoadsorption treatments with Glycosorb A or B columns were performed on day −7 through day −1 based on anti-A or anti-B titers on Spectra Optia Apheresis System. Immunosuppression included basiliximab, solumedrol followed by oral prednisone, once-daily tacrolimus, and mycophenolic acid. The mean follow-up was 53 months (3-96 months).

Results:

A total of 26 individuals underwent an attempt at desensitization of whom 24 patients underwent immediate transplant. One patient had a rebound in titers and subsequently was transplanted from a blood group compatible living donor. A second patient had an unrelated medical issue and desensitization was discontinued. Five-year patient survival was 96% and death censored allograft survival was 92%. Posttransplant anti-A or anti-B titers were monitored daily for the first 7 days posttransplant and every 2 days from days 7 to 14. There were no acute rejections seen in this cohort of transplant recipients.

Limitations:

As our protocol was first initiated as proof of concept, a few recipients had low initial isohemagglutinin titers. This may have contributed to improved clinical outcomes.

Conclusions:

ABO column immunoadsorption with specific columns is a safe and effective method for ABOi living donor kidney transplantation, and an option when KPD is less than ideal.

Trial not registered as this was a retrospective cohort review.

What have we learned about how to prevent and treat antibody-mediated rejection in kidney transplantation?

Antibody-mediated rejection (ABMR) in kidney transplantation is a major cause of late graft loss, and despite all efforts to date the "standard of care" remains plasmapheresis, IVIg, and steroids, which itself is based on low quality evidence. This review focuses on the risk factors leading to memory and de novo donor-specific antibody (DSA)-associated ABMR, the optimal prevention strategies for ABMR, and advances in  adjunctive and emerging therapies for ABMR. Because new agents require regulatory approval via a Phase 3 randomized control trial (RCT), an overview of progress in innovative trial design for ABMR is provided. Finally, based on the insights gained in the biology of ABMR, current knowledge gaps are identified for future research that could significantly affect our understanding of how to optimally treat ABMR.

Early graft losses in paired kidney exchange: Experience from 10 years of the National Kidney Registry

Cooperative kidney paired donation (KPD) networks account for an increasing proportion of all living donor kidney transplants in the United States. There are sparse data on the rate of primary nonfunction (PNF) losses and their consequences within KPD networks. We studied National Kidney Registry (NKR) transplants (February 14, 2009 to December 31, 2017) and quantified PNF, graft loss within 30 days of transplantation, and graft losses in the first-year posttransplant and assessed potential risk factors. Of 2364 transplants, there were 38 grafts (1.6%) lost within the first year, 13 (0.5%) with PNF. When compared to functioning grafts, there were no clinically significant differences in blood type compatibility, degree of HLA mismatch, number of veins/arteries, cold ischemia, and travel times. Of 13 PNF cases, 2 were due to early venous thrombosis, 2 to arterial thrombosis, and 2 to failure of desensitization and development of antibody-mediated rejection (AMR). Given the low rate of PNF, the NKR created a policy to allocate chain-end kidneys to recipients with PNF following event review and attributable to surgical issues of donor nephrectomy. It is expected that demonstration of low incidence of poor early graft outcomes and the presence of a "safety net" would further encourage program participation in national KPD.

The 6-year clinical outcomes for patients registered in a multiregional United States Kidney Paired Donation program - a retrospective study

We examined what happened during a 6-year period to 1121 end-stage renal disease patients who registered with their willing/incompatible living donors for kidney exchanges with the Alliance for Paired Donation (APD). Of all patients, 65% were transplanted: 37% in kidney paired donation (APD-KPD, APD-other-KPD); 10% with compatible live donors (APD-LD); and 18% with deceased donors (APD-DD). The remaining patients were withdrawn (sick/died/others; 15%), or were still waiting (20%). For those patients with a cPRA 0-94%, 72% received a transplant. In contrast, only 49% of very highly sensitized (VHS; cPRA 95-100%) were transplanted. Of the VHS patients, 50% were transplanted by KPD/APD-LD while 50% benefited through prioritization of deceased donors in the modified kidney allocation system (KAS introduced in 2014). All APD transplanted groups had similar death-censored 4-year graft survivals as their relevant Organ Procurement and Transplantation Network (OPTN) groups. It is noteworthy that VHS graft and patient survival results were comparable to less sensitized and nonsensitized patients. All patients should be encouraged to search for compatible donors through different options. Expanding the donor pool through KPD and the new KAS of the OPTN increases the likelihood of transplantation for VHS patients.

The first 9 years of kidney paired donation through the National Kidney Registry: Characteristics of donors and recipients compared with National Live Donor Transplant Registries

The practice of kidney paired donation (KPD) is expanding annually, offering the opportunity for live donor kidney transplant to more patients. We sought to identify if voluntary KPD networks such as the National Kidney Registry (NKR) were selecting or attracting a narrower group of donors or recipients compared with national registries. For this purpose, we merged data from the NKR database with the Scientific Registry of Transplant Recipients (SRTR) database, from February 14, 2008, to February 14, 2017, encompassing the first 9 years of the NKR. Compared with all United Network for Organ Sharing (UNOS) live donor transplant patients (49 610), all UNOS living unrelated transplant patients (23 319), and all other KPD transplant patients (4236), the demographic and clinical characteristics of NKR transplant patients (2037) appear similar to contemporary national trends. In particular, among the NKR patients, there were a significantly (P < .001) greater number of retransplants (25.6% vs 11.5%), hyperimmunized recipients (22.7% vs 4.3% were cPRA >80%), female recipients (45.9% vs 37.6%), black recipients (18.2% vs 13%), and those on public insurance (49.7% vs 41.8%) compared with controls. These results support the need for greater sharing and larger pool sizes, perhaps enhanced by the entry of compatible pairs and even chains initiated by deceased donors, to unlock more opportunities for those harder-to-match pairs.

Temporal changes in the composition of a large multicenter kidney exchange clearinghouse: Do the hard-to-match accumulate?

One criticism of kidney paired donation (KPD) is that easy-to-match candidates leave the registry quickly, thus concentrating the pool with hard-to-match sensitized and blood type O candidates. We studied candidate/donor pairs who registered with the National Kidney Registry (NKR), the largest US KPD clearinghouse, from January 2012-June 2016. There were no changes in age, gender, BMI, race, ABO blood type, or panel-reactive antibody (PRA) of newly registering candidates over time, with consistent registration of hard-to-match candidates (59% type O and 38% PRA ≥97%). However, there was no accumulation of type O candidates over time, presumably due to increasing numbers of nondirected type O donors. Although there was an initial accumulation of candidates with PRA ≥97% (from 33% of the pool in 2012% to 43% in 2014, P = .03), the proportion decreased to 17% by June 2016 (P < .001). Some of this is explained by an increase in the proportion of candidates with PRA ≥97% who underwent a deceased donor kidney transplantation (DDKT) after the implementation of the Kidney Allocation System (KAS), from 8% of 2012 registrants to 17% of 2015 registrants (P = .02). In this large KPD clearinghouse, increasing participation of nondirected donors and the KAS have lessened the accumulation of hard-to-match candidates, but highly sensitized candidates remain hard-to-match.

Kidney Paired Donation and the "Valuable Consideration" Problem: The Experiences of Australia, Canada, and the United States

As organ donation rates remain unable to meet the needs of individuals waiting for transplants, it is necessary to identify reasons for this shortage and develop solutions to address it. The introduction of kidney paired donation (KPD) programs represents one such innovation that has become a valuable tool in donation systems around the world. Although KPD has been successful in increasing kidney donation and transplantation, there are lingering questions about its legality. Donation through KPD is done in exchange for-and with the expectation of-a reciprocal kidney donation and transplantation. It is this reciprocity that has caused concern about whether KPD complies with existing law. Organ donation systems around the world are almost universally structured to legally prohibit the commercial exchange of organs. Australia, Canada, and the United States have accomplished this goal by prohibiting the exchange of an organ for "valuable consideration," which is a legal term that has not historically been limited to monetary exchange. Whether or not KPD programs violate this legislative prohibition will depend on the specific legislative provision being considered, and the legal system and case law of the particular jurisdiction in question. This article compares the experiences of Australia, Canada, and the United States in determining the legality of KPD and highlights the need for legal clarity and flexibility as donation and transplantation systems continue to evolve.

Kidney exchange transplantation current status, an update and future perspectives

Kidney exchange transplantation is well established modality to increase living donor kidney transplantation. Reasons for joining kidney exchange programs are ABO blood group incompatibility, immunological incompatibility (positive cross match or donor specific antibody), human leukocyte antigen (HLA) incompatibility (poor HLA matching), chronological incompatibility and financial incompatibility. Kidney exchange transplantation has evolved from the traditional simultaneous anonymous 2-way kidney exchange to more complex ways such as 3-way exchange, 4-way exchange, n-way exchange,compatible pair, non-simultaneous kidney exchange,non-simultaneous extended altruistic donor, never ending altruistic donor, kidney exchange combined with desensitization, kidney exchange combined with ABO incompatible kidney transplantation, acceptable mismatch transplant, use of A2 donor to O patients, living donor-deceased donor list exchange, domino chain, non-anonymous kidney exchange, single center, multicenter, regional, National, International and Global kidney exchange. Here we discuss recent advances in kidney exchanges such as International kidney exchange transplantation in a global environment, three categories of advanced donation program, deceased donors as a source of chain initiating kidneys, donor renege myth or reality, pros and cons of anonymity in developed world and (non-) anonymity in developing world, pros and cons of donor travel vs kidney transport, algorithm for management of incompatible donor-recipient pairs and pros and cons of Global kidney exchange. The participating transplant teams and donor-recipient pairs should make the decision by consensus about kidney donor travel vs kidney transport and anonymity vs non-anonymity in allocation as per local resources and logistics. Future of organ transplantation in resource-limited setting will be liver vs kidney exchange, a legitimate hope or utopia?

Risk Taking and Decision Making in Kidney Paired Donation: A Qualitative Study by Semistructured Interviews

INTRODUCTION

Despite excellent outcomes of kidney paired donation (KPD), little is known about how a patient's frame (apply cognitive bias) or weight (attribute value) and concerns relating to risk, justice, and equity affect his or her decision-making process.

MATERIALS AND METHODS

A pilot study consisting of 3 KPD transplant recipients and 3 KPD kidney donors in the last year was conducted to identify and explore themes in decision making and risk taking. The pilot study was followed by the main study comprised of 20 recipients who had already undergone KPD transplantation and 20 donors who had undergone donor nephrectomy. We conducted semistructured interviews in this cohort and analyzed the data thematically. Each donor-recipient pair was interviewed together to facilitate dyadic conversation and provide deeper insight into the decision-making process leading to transplant and donation.

RESULTS

Common themes to both recipient and donor decision making included quality of life; characteristics of the unknown donor and post-transplant expectations. Recipient-specific themes included failure to reach life span milestones, experiences of fellow patients, and altruistic desire to expand the donor pool. Donor-specific themes included balancing existing life commitments with the recipient's need for a kidney, equity and mental accounting in kidney exchange (comparable quality of the kidney received versus the kidney donated), and logistical justice for the recipient.

DISCUSSION

Donors and recipients frame and weight the concepts of risk, justice, and equity differently. This may have direct implications to facilitating patient-centered communication and engagement in KPD pairs.

Shipping living donor kidneys and transplant recipient outcomes

Kidney paired donation (KPD) is an important tool to facilitate living donor kidney transplantation (LDKT). Concerns remain over prolonged cold ischemia times (CIT) associated with shipping kidneys long distances through KPD. We examined the association between CIT and delayed graft function (DGF), allograft survival, and patient survival for 1267 shipped and 205 nonshipped/internal KPD LDKTs facilitated by the National Kidney Registry in the United States from 2008 to 2015, compared to 4800 unrelated, nonshipped, non-KPD LDKTs. Shipped KPD recipients had a median CIT of 9.3 hours (range = 0.25-23.9 hours), compared to 1.0 hour for internal KPD transplants and 0.93 hours for non-KPD LDKTs. Each hour of CIT was associated with a 5% increased odds of DGF (adjusted odds ratio: 1.05, 95% confidence interval [CI], 1.02-1.09, P < .01). However, there was not a significant association between CIT and all-cause graft failure (adjusted hazard ratio [aHR]: 1.01, 95% CI: 0.98-1.04, P = .4), death-censored graft failure ( [aHR]: 1.02, 95% CI, 0.98-1.06, P = .4), or mortality (aHR 1.00, 95% CI, 0.96-1.04, P > .9). This study of KPD-facilitated LDKTs found no evidence that long CIT is a concern for reduced graft or patient survival. Studies with longer follow-up are needed to refine our understanding of the safety of shipping donor kidneys through KPD.

A Scoping Review for Strategies to Increase Living Kidney Donation

BACKGROUND AND OBJECTIVES

The literature on strategies to increase the number of potential living kidney donors is extensive and has yet to be characterized. Scoping reviews are a novel methodology for systematically assessing a wide breadth of a given body of literature and may be done before conducting a more targeted systematic review.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We performed a scoping review and summarized the evidence for existing strategies to increase living kidney donation.

RESULTS

Our review identified seven studies that tested interventions using rigorous methods (i.e., randomized, controlled trials) and outcome measures, all of which focused on using education targeted at potential recipients to increase living donation. Of these, two studies that targeted the potential recipients' close social network reported statistically significant results. Other interventions were identified, but their effect was assessed through quasiexperimental or observational study designs.

CONCLUSIONS

We identified an important gap in the literature for evidence-based strategies to increase living kidney donation. From the limited data available, strategies directed at potential recipients and their social networks are the most promising. These results can inform transplant programs that are considering strategies to increase living kidney donation and highlight the need for conduct of high-quality study to increase living donation.

Reciprocity to Increase Participation of Compatible Living Donor and Recipient Pairs in Kidney Paired Donation

Inclusion of compatible living donor and recipient pairs (CPs) in kidney paired donation (KPD) programs could increase living donor transplantation. We introduce the concept of a reciprocity-based strategy in which the recipient of a CP who participates in KPD receives priority for a repeat deceased donor transplant in the event their primary living donor KPD transplant fails, and then we review the practical and ethical considerations of this strategy. The strategy limits prioritization to CPs already committed to living donation, minimizing the risk of unduly influencing donor behavior. The provision of a tangible benefit independent of the CP's actual KPD match avoids many of the practical and ethical challenges with strategies that rely on finding the CP recipient a better-matched kidney that might provide the CP recipient a future benefit to increase KPD participation. Specifically, the strategy avoids the potential to misrepresent the degree of future benefit of a better-matched kidney to the CP recipient and minimizes delays in transplantation related to finding a better-matched kidney. Preliminary estimates suggest the strategy has significant potential to increase the number of living donor transplants. Further evaluation of the acceptance of this strategy by CPs and by waitlisted patients is warranted.

Providing Better-Matched Donors for HLA Mismatched Compatible Pairs Through Kidney Paired Donation

BACKGROUND

Participation of compatible pairs (CP) in kidney paired donation (KPD) could be attractive to CPs who have a high degree of HLA mismatch, if the CP recipient will gain a better HLA match. Because KPD programs were not designed to help CP, it is important to define allocation metrics that enable CP to receive a better-matched kidney, without disadvantage to incompatible pairs (ICP).

METHODS

Simulations using 46 ICPs and 11 fully HLA-mismatched CPs were undertaken using the Australian KPD matching algorithm. Allocations were preformed adding 1 CP at a time or all 11 CPs at once, and with and without exclusion of unacceptable antigens selected to give a virtual calculated panel-reactive antibody ranging 70% to 80% to improve HLA matching in CP recipients.

RESULTS

On average, most CP recipients could be matched and had a lower eplet mismatch (EpMM) with the matched donor (57 ± 15) than with their own donor (78 ± 19, P < 0.02). However, only recipients who had an EpMM to own donor greater than 65 achieved a significant reduction in the EpMM with the matched donor. The gain in EpMM was larger when CPs were listed with unacceptable antigens. Furthermore, inclusion of 1 CP at a time increased matching in ICP by up to 33%, and inclusion of all 11 CPs at once increased ICP matching by 50%.

CONCLUSIONS

Compatible pair participation in KPD can increase match rates in ICP and can provide a better immunological profile in CP recipients who have a high EpMM to their own donor when using allocation based on virtual crossmatch.

Seventy-seven kidney paired donation transplantations at a single transplant centre in India led to an increase in living donor kidney transplantations in 2015

Background

To ascertain the validity of kidney paired donations (KPDs) as an alternative strategy for increasing living donor kidney transplantations (LDKTs) in an LDKT-dominated transplant programme since directed kidney transplantation, ABO-incompatible or crossmatch-positive pairs are not feasible due to costs and infectious complications.

Methods

This was a prospective single-centre study of 77 KPD transplantations (25 two-way, 7 three-way and 1 six-way exchange) from 1 January 2015 to 1 January 2016 of 158 registered donor recipient pairs. During this period, a total of 380 kidney transplantations [71 deceased donor kidney transplantations (DDKTs), 309 LDKTs] were performed. The reasons for opting for KPD were ABO incompatibility (n = 45), sensitization (n = 26) and better matching (n = 6).

Results

KPD matching was facilitated in 62% (n = 98) of transplants. In all, 48.7% (n = 77) of the transplants were completed in 2015, whereas 13.3% (n = 21) of the matched patients were to undergo transplant surgery in early 2016 after getting legal permission. The waiting time for KPD was shorter compared with DDKT. The death-censored graft survival and patient survival were 98.7% (n = 76) and 93.5% (n = 72), respectively. In all, 14.2% (n = 11) of patients had acute rejection. Match rates among sensitized (n = 60) and O group patients (n = 62) were 58.3% (n = 35) and 41.9% (n = 26), respectively. Of these, 43.3% (n = 26) and 29% (n = 18) of transplants were completed and 15% (n = 9) and 12.9% (n = 8), respectively, are waiting for legal permission.

Conclusions

LDKT increased by 25% in 1 year in our single-centre KPD programme. Our key to success was the formation of a KPD registry, awareness and active counselling programs and developing a dedicated team.

Past, present and future of kidney paired donation transplantation in India

One third of healthy willing living kidney donors are rejected due to ABO blood group incompatibility and donor specific antibody. This increases pre-transplant dialysis duration leading to increased morbidity and mortality on the kidney transplantation waiting list. Over the last decade kidney paired donation is most rapidly increased source of living kidney donors. In a kidney transplantation program dominated by living donor kidney transplantation, kidney paired donation is a legal and valid alternative strategy to increase living donor kidney transplantation. This is more useful in countries with limited resources where ABO incompatible kidney transplantation or desensitization protocol is not feasible because of costs/infectious complications and deceased donor kidney transplantation is in initial stages. The matching allocation, ABO blood type imbalance, reciprocity, simultaneity, geography were the limitation for the expansion of kidney paired donation. Here we describe different successful ways to increase living donor kidney transplantation through kidney paired donation. Compatible pairs, domino chain, combination of kidney paired donation with desensitization or ABO incompatible transplantation, international kidney paired donation, non-simultaneous, extended, altruistic donor chain and list exchange are different ways to expand the donor pool. In absence of national kidney paired donation program, a dedicated kidney paired donation team will increase access to living donor kidney transplantation in individual centres with team work. Use of social networking sites to expand donor pool, HLA based national kidney paired donation program will increase quality and quantity of kidney paired donation transplantation. Transplant centres should remove the barriers to a broader implementation of multicentre, national kidney paired donation program to further optimize potential of kidney paired donation to increase transplantation of O group and sensitized patients. This review assists in the development of similar programs in other developing countries.

Impact of single centre kidney paired donation transplantation to increase donor pool in India: a cohort study

In a living donor kidney transplantation (LDKT) dominated transplant programme, kidney paired donation (KPD) may be a cost-effective and valid alternative strategy to increase LDKT in countries with limited resources where deceased donation kidney transplantation (DDKT) is in the initial stages. Here, we report our experience of 300 single-centre KPD transplantations to increase LDKT in India. Between January 2000 and July 2016, 3616 LDKT and 561 DDKT were performed at our transplantation centre, 300 (8.3%) using KPD. The reasons for joining KPD among transplanted patients were ABO incompatibility (n = 222), positive cross-match (n = 59) and better matching (n = 19). A total of 124 two-way (n = 248), 14 three-way (n = 42), one four-way (n = 4) and one six-way exchange (n = 6) yielded 300 KPD transplants. Death-censored graft and patient survival were 96% (n = 288) and 83.3% (n = 250), respectively. The mean serum creatinine was 1.3 mg/dl at a follow-up of 3 ± 3 years. We credit the success of our KPD programme to maintaining a registry of incompatible pairs, counselling on KPD, a high-volume LDKT programme and teamwork. KPD is legal, cost effective and rapidly growing for facilitating LDKT with incompatible donors. This study provides large-scale evidence for the expansion of single-centre LDKT via KPD when national programmes do not exist.

Cold ischemia time up to 16 hours has little impact on living donor kidney transplant outcomes in the era of kidney paired donation

In living donor transplantation, cold ischemia time is a concern in transplants involving kidney paired donation. The impact of cold ischemia time over eight hours is unknown. Here we examined the association of cold ischemia time with delayed graft function and allograft loss among 48,498 living recipients in the Scientific Registry of Transplant Recipients registry. The incidence of delayed graft function was low but significantly higher among patients with longer cold ischemia times (0-2.0 hours: 3.3%; 2.1-4.0 hours: 3.9%; 4.1-8.0 hours: 4.3%; 8.1-16.0 hours: 5.5%). In multivariate analyses, only those with cold ischemia times of 8.1-16.0 hours had increased odds of delayed graft function (odds ratio 1.47; 95% confidence interval 1.05-2.05) compared to patients with times of 0-2.0 hours. In multivariate time-to-event analyses, cold ischemia times of 16 hours or less were not associated with allograft loss from any cause including death or death-censored graft loss with hazard ratios for cold ischemia times between 8.0-16.0 hours of 0.97 (95% confidence interval 0.74-1.26) and 1.09 (0.81-1.48) compared to patients with times of 0-2.0 hours). The results were consistent in paired and non-kidney paired donation transplants and in those with living donors over 50 years of age. In subgroup analysis restricted to kidney paired donation recipients, there was no difference in the risk of delayed graft function with an odds ratio of 1.40 (0.88, 2.40) or all-cause graft loss with a hazard ratio of 0.89 (0.62, 1.30) in transplant recipients who received kidneys that were shipped versus not shipped. Thus, a cold ischemia time up to 16 hours has limited impact on living donor outcomes. These findings may help expand living donor transplantation through kidney paired donation.

Changing Paradigms in the Management of Rejection in Kidney Transplantation: Evolving From Protocol-Based Care to the Era of P4 Medicine

PURPOSE OF REVIEW

P4 medicine denotes an evolving field of medicine encompassing predictive, preventive, personalized, and participatory medicine. Using the example of kidney allograft rejection because of donor-recipient incompatibility in human leukocyte antigens, this review outlines P4 medicine's relevance to the various stages of the kidney transplant cycle.

SOURCES OF INFORMATION

A search for English articles was conducted in Medline via OvidSP (up to August 18, 2016) using a combination of subject headings (MeSH) and free text in titles, abstracts, and author keywords for the concepts kidney transplantation and P4 medicine. The electronic database search was expanded further on particular subject headings.

FINDINGS

Available histocompatibility methods exemplify current applications of the predictive and preventive domains of P4 medicine in kidney transplant recipients' care. Pharmacogenomics are discussed as means to facilitate personalized immunosuppression regimens and promotion of active patient participation as a means to improve adherence.

LIMITATIONS

For simplicity, this review focuses on rejection. P4 medicine, however, should more broadly address health concerns in kidney transplant recipients, including competing outcomes such as infections, malignancies, and cardiovascular disease. This review highlights how biomarkers to evaluate these competing outcomes warrant validation and standardization prior to their incorporation into clinical practice.

IMPLICATIONS

Consideration of all 4 domains of the P4 medicine framework when caring for and/or studying kidney transplant recipients has the potential of increasing therapeutic efficiency, minimizing adverse effects, decreasing health care costs, and maximizing wellness. Technologies to gauge immune competency, immunosuppression requirements, and early/reversible immune-mediated injuries are required to optimize kidney transplant care.

Expanding living kidney donor criteria with ex-vivo surgery for renal anomalies

INTRODUCTION

Renal transplantation remains the gold standard treatment for end-stage renal disease, with living donor kidneys providing the best outcomes in terms of allograft survival. As the number of patients on the waitlist continues to grow, solutions to expand the donor pool are ongoing. A paradigm shift in the eligibility of donors with renal anomalies has been looked at as a potential source to expand the living donor pool. We sought to determine how many patients presented with anatomic renal anomalies at our transplant centre and describe the ex-vivo surgical techniques used to render these kidneys suitable for transplantation.

METHODS

A retrospective review was performed of all patients referred for surgical suitability to undergo laparoscopic donor nephrectomy between January 2011 and January 2015. Patient charts were analyzed for demographic information, perioperative variables, urological histories, and postoperative outcomes.

RESULTS

96 referrals were identified, of which 81 patients underwent laparoscopic donor nephrectomy. Of these patients, 11 (13.6%) were identified as having a renal anomaly that could potentially exclude them from the donation process. These anomalies included five patients with unilateral nephrolithiasis, four patients with large renal cysts (>4 cm diameter), one patient with an angiomyolipoma (AML) and one patient with a calyceal diverticulum filled with stones. A description of the ex-vivo surgical techniques used to correct these renal anomalies is provided.

CONCLUSIONS

We have shown here that ex-vivo surgical techniques can safely and effectively help correct some of these renal anomalies to render these kidneys transplantable, helping to expand the living donor pool.

Utilization of Deceased Donor Kidneys to Initiate Living Donor Chains

We propose that some deceased donor (DD) kidneys be allocated to initiate nonsimultaneous extended altruistic donor chains of living donor (LD) kidney transplants to address, in part, the huge disparity between patients on the DD kidney waitlist and available donors. The use of DD kidneys for this purpose would benefit waitlisted candidates in that most patients enrolled in kidney paired donation (KPD) systems are also waitlisted for a DD kidney transplant, and receiving a kidney through the mechanism of KPD will decrease pressure on the DD pool. In addition, a LD kidney usually provides survival potential equal or superior to that of DD kidneys. If KPD chains that are initiated by a DD can end in a donation of an LD kidney to a candidate on the DD waitlist, the quality of the kidney allocated to a waitlisted patient is likely to be improved. We hypothesize that a pilot program would show a positive impact on patients of all ethnicities and blood types.

cPRA Increases With DQA, DPA, and DPB Unacceptable Antigens in the Canadian cPRA Calculator

A calculated panel reactive antibody (cPRA) estimates the percentage of donors with unacceptable antigens (UA) for a recipient. cPRA may be underestimated in transplant candidates with UA to DQA, DPA, and DPB if these are not included in the calculation program. To serve the National Canadian Transplant Programs, a cPRA calculator was developed with complete molecular typing for all donors at HLA-A, B, C, DRB1, DRB3/4/5, DQA1, DQB1, DPA1, and DPB1, all resolved to serologic equivalents. The prevalence of UA at DQA, DPA and DPB was evaluated in a sensitized regional population. The impact of adding these additional UA to cPRA was calculated alone and in combination, and compared to the baseline cPRA for UA at A, B, C, DR, DR51/52/53, and DQ. Of 740 sensitized transplant candidates, 18% of total and 32% with cPRA≥95% had DQA UA. Twenty-seven percent of total and 54% with cPRA≥95% had DPB UA. Of 280/740 subjects with these UA, 36/280 (13%) had cPRA increase of >20% when they were included, 7% increased cPRA to ≥80% and 6% to ≥95%. Inclusion of DQA, DPA, and DPB UA in Canadian cPRA calculations improves the accuracy of cPRA where these are relevant in allocation.

Alternative Living Kidney Donation Programs Boost Genetically Unrelated Donation

Donor-recipient ABO and/or HLA incompatibility used to lead to donor decline. Development of alternative transplantation programs enabled transplantation of incompatible couples. How did that influence couple characteristics? Between 2000 and 2014, 1232 living donor transplantations have been performed. In conventional and ABO-incompatible transplantation the willing donor becomes an actual donor for the intended recipient. In kidney-exchange and domino-donation the donor donates indirectly to the intended recipient. The relationship between the donor and intended recipient was studied. There were 935 conventional and 297 alternative program transplantations. There were 66 ABO-incompatible, 68 domino-paired, 62 kidney-exchange, and 104 altruistic donor transplantations. Waiting list recipients (n = 101) were excluded as they did not bring a living donor. 1131 couples remained of whom 196 participated in alternative programs. Genetically unrelated donors (486) were primarily partners. Genetically related donors (645) were siblings, parents, children, and others. Compared to genetically related couples, almost three times as many genetically unrelated couples were incompatible and participated in alternative programs (P < 0.001). 62% of couples were genetically related in the conventional donation program versus 32% in alternative programs (P < 0.001). Patient and graft survival were not significantly different between recipient programs. Alternative donation programs increase the number of transplantations by enabling genetically unrelated donors to donate.