Paired kidney exchange transplantation: Maximizing the donor pool

Impact of single centre kidney-exchange transplantation to increase living donor pool in India: A cohort study involving non-anonymous allocation

AIM

In India, 85% of organ donations are from living donors and 15% are from deceased donors. One-third of living donors were rejected because of ABO or HLA incompatibility. Kidney exchange transplantation (KET) is a cost-effective and legal strategy to increase living donor kidney transplantation (LDKT) by 25%-35%.

METHODS

We report our experience with 539 KET cases and the evolution of a single-centre program to increase the use of LDKT.

RESULTS

Between January 2000 and 13 March, 2024, 1382 deceased donor kidney transplantations and 5346 LDKT were performed at our centre, including 10% (n = 539) from KET. Of the 539 KET, 80.9% (n = 436) were ABO incompatible pairs, 11.1% (n = 60) were compatible pairs, and 8% (n = 43) were sensitized pairs. There were 75% 2-way (n = 2 × 202 = 404), 16.2% 3-way (n = 3 × 29 = 87), 3% 4-way (n = 4 × 4 = 16), 1.8% 5-way (n = 5 × 2 = 10), 2.2% 6-way (n = 6 × 2 = 12), and 1.8% 10-way KET (n = 10 × 1 = 10). Of the recipients 81.2% (n = 438) were male and 18.8% (n = 101) were female, while of the donors, 78.5% (n = 423) were female and 21.5% (n = 116) were male. All donors were near relatives; wives (54%, n = 291) and mothers (20%, n = 108) were the most common donors. At a median follow-up of 8.2 years, patient survival, death censored graft survival, acute rejection, and median serum creatinine levels of functioning grafts were 81.63% (n = 440), 91% (n = 494), 9.8% (n = 53) and 1.3 mg/dL respectively. We credited the success to maintaining a registry of incompatible pairs, high-volume LDKT programs, non-anonymous allocation and teamwork.

CONCLUSION

This is the largest single-centre KET program in Asia. We report the challenges and solutions to replicate our success in other KET programs.

HLA Desensitization Based on Results of the Luminex Technique in Kidney Transplant - A Single-center Experience

Background:

There is little experience of human leucocyte antigen (HLA) desensitization in India based on the Luminex single-antigen bead (SAB) testing. We retrospectively analyzed our patients, who underwent HLA desensitization based on Luminex SAB results.

Method:

Between 2014 and 2018, patients with complement-dependent cytotoxicity cross-match (CDC-XM) negativity but flow cytometry crossmatch (FC-XM) positivity were further analyzed with Luminex SAB for donor-specific antibodies (DSAs). A total of 12 patients who had DSA mean fluorescent intensity (MFI) of >1000 and <10,000 were included in the study. Our protocol for desensitization consisted of plasmapheresis (PP) followed by low dose intravenous immunoglobulin (IV IG) 100 mg/kg and induction with antithymocyte globulin (ATG). Patients were taken for transplant when either MFI was <1000 and/or FC-XM was negative.

Results:

All 12 patients were first transplant and 10 had a history of some sensitizing event; pregnancy in 4, blood transfusions in 4, and both in 2 patients. FC-XM was positive for T-cell in 4, B-cell in 6, and both in 2 patients. On evaluation by Luminex SAB, 6 patients had MFI from 1000 to 2000, and 6 had MFI of >2000. All underwent desensitization successfully. Two patients had an increase in posttransplant DSA titers requiring posttransplant PP. The mean follow-up was 26.6 ± 13.9 months. On follow-up, only one patient developed acute T cell-mediated rejection 1 year after transplant, which responded to pulse steroids. There was no graft or patient loss until the last follow-up.

Conclusion:

This study shows that HLA desensitization is feasible and successful in the Indian setting if patients are properly selected.

A retrospective multi-center experience of renal transplants from India during COVID-19 pandemic

INTRODUCTION

Coronavirus disease 2019 (COVID-19) pandemic led to a sudden drop in renal transplant numbers across India in the initial months of 2020. Although the transplant numbers increased with easing of lockdown, the outcome of these transplants remains unknown.

METHODS

This was a retrospective, observational, multi-center study done across eight different transplant centers in India. All the transplants done from January 30, 2020 to December 31, 2020 were included. The primary outcomes studied were patient and death censored graft survival as well as incidence of COVID-19 infection and its outcomes.

RESULTS

During the study period a total of 297 kidney transplants were done. After a median follow up of 265 days the patient and death censored graft survival was 95.3% and 97.6%, respectively. Forty-one patients (13.8%) developed COVID-19 post-transplant. Majority (58.5%) were asymptomatic to mildly symptomatic and the case fatality ratio was 14.6%. On multivariable logistic regression analysis older age was associated with higher likelihood of COVID-19 infection (odds ratio 1.038; CI 1.002-1.077).

CONCLUSIONS

Patient and graft outcome of kidney transplants done during the COVID-19 pandemic in India was acceptable. The incidence of COVID-19 was 13.8% with a high case fatality ratio.

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.

Paired kidney exchange transplantation - pushing the boundaries

The scarcity of living organ donors makes it imperative to develop newer innovations to optimize and maximize the utilization of the available pool. ABO and HLA sensitization are important immunological barriers in renal transplant and can potentially lead to rejection of almost one-third of the willing living donors. Paired kidney exchange (PKE) is a rapidly growing method used to overcome these barriers and has grown in popularity over the last three decades since its introduction in 1986. Evolution of the matching strategies and use of complex algorithms has led to increase in the number of possible matches thereby benefiting multiple recipients. The use of altruistic donors and compatible pairs has also helped in increasing the possible exchanges. This review provides an in-depth analysis of the evolution, the present global scenario, and the future of PKE. It also discusses the recent trends of advanced donation, trans-organ paired exchange and global kidney exchange and the associated ethical concerns.

Renal transplantation in HLA sensitized patients: Traversing the immunological barrier

Successful renal transplantation across HLA barrier in sensitized individuals has been on the rise during the past decade, primarily due to improved desensitization regimes. The aim of this study was to share outcome of desensitization in renal transplant recipients with donor-specific anti-HLA antibodies (DSA). This was a retrospective analysis of all HLA immunized individuals who were prospective renal transplant recipients. All such patients underwent preconditioning as per the institutional desensitization protocol. Complement-dependent cytoxicity-based crossmatch (CDC-XM), luminex-based crossmatch (LM-XM) and flowcytometry-based crossmatch (FC-XM) were done in all cases. If any of these tests turned out positive, single antigen bead assay (SAB) was performed. Desensitization for DSA was performed in 55 patients and all patients were followed-up for 1 year to assess graft function and patient outcome. CDC-XM being a less sensitive assay, could not detect incompatibility in 29 (52.73%) cases. After desensitization, even though SAB and LM-XM results revealed an MFI within acceptable range, FC-XM being an extremely sensitive assay, continued to give a positive result in eight (14.55%) cases. The mean ± SD number of pretransplant TPE were 3.44 ± 0.98 (2-11). Out of 55, there were 10 patients who were lost to follow up. Patient and graft survival of 45 patients at 1 year was found to be 100%. Preconditioning for renal transplants in the form of immunosuppression with TPE is an extremely useful auxiliary for transplantation in HLA sensitized renal transplant recipients.

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.

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.

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.

Successful Renal Transplantation Across HLA Barrier: Report from India

Organ donors are sometimes found “unsuitable” due to the presence of donor-specific anti-HLA antibodies in the recipient. In recent years, improved desensitization protocols have successfully helped to overcome HLA incompatibility hurdle. We present three cases where optimum desensitization was achieved in patients with the donor-specific anti-HLA antibody (DSA) leading to successful renal transplantation. All patient–donor pair underwent HLA typing, complement dependent cytotoxicity crossmatch (CDC-XM), flow cytometry XM (FC-XM), and panel reactive antibody. If any of the three tests was positive, single antigen bead assay was performed to determine the specificity of the anti-HLA antibody (s). Patients with DSA were offered organ-swap or anti-HLA antibody desensitization followed by transplantation. Desensitization protocol consisted of single dose rituximab and cascade plasmapheresis (CP) along with standard triple immunosuppression. The target DSA mean fluorescence index (MFI) was <500, along with negative CDC-XM and FC-XM for both T- and B-cells. Three patients with anti-HLA DSA, who did not find a suitable match in organ swap program, consented to anti-HLA antibody desensitization, followed by transplantation. Mean pre-desensitization antibody MFI was 1740 (1422–2280). Mean number of CP required to achieve the target MFI was 2.3 (2–3). All the three patients are on regular follow-up and have normal renal function test at a mean follow-up of 8 months. This report underlines successful application of desensitization protocol leading to successful HLA-antibody incompatible renal transplants and their continued normal renal functions.