Living donor exchange programs: theory and practice

First Successful Three-Way Kidney Exchange Transplantation in North India

Kidney paired donation is the most cost-effective approach in incompatible donor-recipient pairs. Incompatibility may be due to blood group, human leucocyte antigen crossmatch or both. In many cases of a living donor kidney transplant, there is only one potential donor who becomes unsuitable due to any of the above mentioned factors. In kidney paired donation, donor-recipient pairs are exchanged to sort out the incompatibility. We report our first successful three-way kidney exchange transplantation from North India. As deceased donor program is still in evolving stage in most parts of our country and transplant with desensitization protocol is associated with financial constraints, infections, and lack of availability in many centers, kidney paired donation is a valuable approach to expand the donor pool.

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.

Current protocols and outcomes of ABO-incompatible kidney transplantation

One of the principal obstacles in transplantation from living donors is that approximately 30% are immunologically incompatible because of the presence in the recipient of antibodies directed against the human leukocyte antigen system of the donor or because of the incompatibility of the ABO system. The aim of this review is to describe the more recent data from the literature on the different protocols used and the clinical outcomes of ABO-incompatible kidney transplantation. Two different strategies are used to overcome these barriers: desensitization of the recipient to remove the antibodies and to prevent their rebound after transplantation and the exchange of organs between two or more pairs. The largest part of this review is dedicated to describing the techniques of desensitization. Even if the first reports of successful renal transplantation between ABO-incompatible pairs have been published by 1980, the number of ABO-incompatible transplants increased substantially in this century because of our improved knowledge of the immune system and the availability of new drugs. Rituximab has substantially replaced splenectomy. The technique of apheresis has improved and more recently a tailored desensitization proved to be the more efficient strategy avoiding an excess of immunosuppression with the related side effects. Recent reports document outcomes for such transplantation similar to the outcomes of standard transplantation.

Improving HLA matching in living donor kidney transplantation using kidney paired exchange program

BACKGROUND

The inclusion of compatible pairs within kidney paired exchange programs has been described as a way to enhance these programs. Improved immunological matching for the recipient in compatible pair has been described to be a possible benefit.

METHODS

The main purpose of our study was to determine if the introduction of compatible pairs in the Portuguese kidney paired exchange program would result in a better match for these patients, but also to assess if this strategy would increase the number of incompatible pairs with a possible match. We included 17 compatible pairs in kidney paired exchange pool of 35 pairs and performed an in-silico simulation determining HLA eplet mismatch load between the co-registered and matched pairs using HLA MatchMaker, version 3.0.

RESULTS

Our study showed that the inclusion of fully HLA-A, -B, -DR mismatched compatible pairs within the national Portuguese KEP increased matched rate within ICP (0.71%) and improved HLA eplet matching within compatible pairs. 16 of 17 (94.12%) of the CP obtained one or more transplants possibilities and 13 (81.25%) would have been transplanted with significantly lower HLA class I and class II total and antibody-verified eplet mismatch load (83.9 ± 16.9 vs. 59.8 ± 12.2, P = .002 and 30.1 ± 5.5 vs. 21.2 ± 3.0, P = .003, respectively).

CONCLUSIONS

This strategy is a viable alternative for compatible pairs seeking a better matched kidney and Portuguese KEP program should allow them this possibility.

Increasing access to kidney transplantation for sensitized recipient through three-way kidney paired donation with desensitization: The first Indian report

The combination of kidney paired donation (KPD) with desensitization represents a promising method of increasing the rate of living donor kidney transplantation (LDKT) in immunologically challenging patients. Patients who are difficult to match and desensitize due to strong donor specific antibody are may be transplanted by a combination of desensitization and KPD protocol with more immunologically favorable donor. We present our experience of combination of desensitization protocol with three-way KPD which contributed to successful LDKT in highly sensitized end stage renal disease patient. All recipients were discharged with normal and stable allograft function at 24 mo follow up. We believe that this is first report from India where three-way KPD exchange was performed with the combination of KPD and desensitization. The combination of desensitization protocol with KPD improves access and outcomes of LDKT.

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.

Successful three-way kidney paired donation transplantation: The first Indian report

Providing transplantation opportunities for patients with incompatible live donors through kidney paired donation (KPD) is an important strategy for easing the crisis in organ availability. KPD is can overcome the barriers when the only living potential donors are deemed unsuitable owing to an incompatibility of blood type, of human leukocyte antigen cross-match, or both. In KPD, the incompatibility problems with two donor recipient pairs can be solved by exchanging donors. In the absence of well-organized deceased donor program, or transplantation with desensitization protocol and ABO incompatible transplantation, living donor KPD promises hope to the growing number of patients suffering from end-stage renal disease in India. We report our first successful three-way KPD transplantation from India. In an era of organ shortage, this approach is relevant to encourage wider participation from KPD donors and transplant centers to prevent commercial transplantation.

Unspecified kidney donation--a review of principles, practice and potential

Unspecified kidney donation is an emerging resource to bridge the gap between supply and demand of kidneys for transplantation. However, uncertainty remains among both the transplantation community and lay public with regard to the intention, motivation, and legitimacy of such donors. Even within programs that use unspecified kidney donors, there is a lack of consensus regarding how to optimize the potential of the gifted kidney (and indirectly potentiate the altruistic benefit for the donor). Despite emerging guidance on how to work up unspecified donors, centers have adopted individualized unspecified donor pathways with regards to assessment, evaluation, and use. There are a variety of models for unspecified kidney donation, ranging from donation directly to deceased-donor waiting lists to benefit one recipient or chain transplantations occurring simultaneously (domino-paired donation) or nonsimultaneously (extended altruistic donor chains) to benefit many. After a brief exploration on the basis of altruism, this review will discuss the assessment, evaluation, and reported outcomes associated with unspecified kidney donation. It will also critique current utilization models and highlight some unresolved controversies. The aim is to highlight the principles, practice, and potential of unspecified kidney donation to bridge the current disparate international practice.

Dynamic challenges inhibiting optimal adoption of kidney paired donation: findings of a consensus conference

While kidney paired donation (KPD) enables the utilization of living donor kidneys from healthy and willing donors incompatible with their intended recipients, the strategy poses complex challenges that have limited its adoption in United States and Canada. A consensus conference was convened March 29-30, 2012 to address the dynamic challenges and complexities of KPD that inhibit optimal implementation. Stakeholders considered donor evaluation and care, histocompatibility testing, allocation algorithms, financing, geographic challenges and implementation strategies with the goal to safely maximize KPD at every transplant center. Best practices, knowledge gaps and research goals were identified and summarized in this document.

Five-year outcomes in living donor kidney transplants with a positive crossmatch

Renal transplant candidates with high levels of donor-specific anti-HLA antibodies have low transplantation rates and high mortality rates on dialysis. Using desensitization protocols, good short-term outcomes are possible in "positive crossmatch kidney transplants (+XMKTx)", but long-term outcome data are lacking. The aim of the current study was to determine actual 5-year graft outcomes of +XMKTx. We compared graft survival and the functional and histologic status of 102 +XMKTx to 204 -XMKTx matched for age and sex. Actual 5-year death-censored graft survival was lower in the +XMKTx group (70.7% vs. 88.0%, p < 0.01) and chronic injury (glomerulopathy) was present in 54.5% of surviving grafts. Graft survival was higher in recipients with antibody against donor class I only compared with antibody against class II (either alone or in combination with class I) (85.3% vs. 62.6%, p = 0.05) and was similar to -XMKTx (85.3 vs. 88.0%, p = 0.64). Renal function and proteinuria ranged across a wide spectrum in all groups reflecting the different histological findings at 5 years. We conclude that when compared to -XMKTx, +XMKTx have inferior outcomes at 5 years, however, almost half of the surviving grafts do not have glomerulopathy and avoiding antibodies against donor class II may improve outcomes.

Controversies in kidney paired donation

Kidney paired donation represented 10% of living kidney donation in the United States in 2011. National registries around the world and several separate registries in the United States arrange paired donations, although with significant variations in their practices. Concerns about ethical considerations, clinical advisability, and the quantitative effectiveness of these approaches in paired donation result in these variations. For instance, although donor travel can be burdensome and might discourage paired donation, it was nearly universal until convincing analysis showed that living donor kidneys can sustain many hours of cold ischemia time without adverse consequences. Opinions also differ about whether the last donor in a chain of paired donation transplants initiated by a nondirected donor should donate immediately to someone on the deceased donor wait-list (a domino or closed chain) or should be asked to wait some length of time and donate to start another sequence of paired donations later (an open chain); some argue that asking the donor to donate later may be coercive, and others focus on balancing the probability that the waiting donor withdraws versus the number of additional transplants if the chain can be continued. Other controversies in paired donation include simultaneous versus nonsimultaneous donor operations, whether to enroll compatible pairs, and interactions with desensitization protocols. Efforts to expand public awareness of and participation in paired donation are needed to generate more transplant opportunities.

Paired exchange kidney donation in India: a five-year single-center experience

INTRODUCTION

Paired exchange kidney donation (PKD) is an evolving strategy for overcoming the barriers that confront patients with end-stage renal disease, when the only living potential donors who are willing to donate to them are deemed to be unsuitable as donors for them owing to an incompatibility of blood type, of HLA cross-match, or of both. In the PKD, the incompatibility problems with two donor recipient pairs can be solved by exchanging donors. Although PKD is increasing worldwide, we in India have not nearly reached the estimated potential of this modality. Herein, we have reported our results with a living donor exchange program in past 5 years.

MATERIALS AND METHODS

Between March 2006 and June 2011, we performed 44 living PKD transplantations. All donor and recipient procedures were performed successfully. ABO incompatibility or positive lymphocyte cross-match were found in 20 pairs and 2 pairs, respectively.

RESULTS

The mean recipient age was 42.5 years (range 33-59 years). The mean donor age was 38 years (range 31-56 years). At a median follow-up of 33 months (range 1-59 months), graft survival rate was 100 %. All patients have functioning grafts with a median serum Creatinine level of 1.13, 1.5, and 1.35 mg/dl at 3 month, 1 year, and 3 years, respectively. One patient died after 4 month of transplant due to pneumonitis with sepsis. Allograft dysfunction was not seen in any of the recipients.

CONCLUSION

The PKD transplantation is a viable procedure medically and economically, which can be promoted in centers with a low deceased donor transplantation rate and a high number of incompatible related donors. We achieved excellent graft outcome by using the PKD transplantation program as an option to reduce the donor organ shortage.