The "oldest and coldest" shipped living donor kidneys transplanted through kidney paired donation

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.

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.

The Impact of Cold Ischaemia Time on Outcomes of Living Donor Kidney Transplantation: A Systematic Review and Meta-Analysis

Studies have been carried out to investigate the effect of a prolonged cold ischaemia time (CIT) on the outcomes of living donor kidney transplantation (LDKT). There is no clear consensus in the literature about the effects of CIT on LDKT outcomes, and therefore, we performed a systematic review and meta-analysis to provide evidence on this subject. Searches were performed in five databases up to 12 July 2021. Articles comparing different CIT in LDKT describing delayed graft function (DGF), graft and patient survival, and acute rejection were considered for inclusion. This study is registered with PROSPERO, CRD42019131438. In total, 1452 articles were found, of which eight were finally eligible, including a total of 164,179 patients. Meta-analyses showed significantly lower incidence of DGF (odds ratio (OR) = 0.61, p < 0.01), and significantly higher 1-year graft survival (OR = 0.72, p < 0.001) and 5-year graft survival (OR = 0.88, p = 0.04), for CIT of less than 4 h. Our results underline the need to keep CIT as short as possible in LDKT (ideally < 4 h), as a shorter CIT in LDKT is associated with a statistically significant lower incidence of DGF and higher graft survival compared to a prolonged CIT. However, clinical impact seems limited, and therefore, in LDKT programmes in which the CIT might be prolonged, such as kidney exchange programmes, the benefits outweigh the risks. To minimize these risks, it is worth considering including CIT in kidney allocation algorithms and in general take precautions to protect high risk donor/recipient combinations.

Motivations and outcomes of compatible living donor-recipient pairs in paired exchange

Increasing numbers of compatible pairs are choosing to enter paired exchange programs, but motivations, outcomes, and system-level effects of participation are not well described. Using a linkage of the Scientific Registry of Transplant Recipients and National Kidney Registry, we compared outcomes of traditional (originally incompatible) recipients to originally compatible recipients using the Kaplan-Meier method. We identified 154 compatible pairs. Most pairs sought to improve HLA matching. Compared to the original donor, actual donors were younger (39 vs. 50 years, p < .001), less often female (52% vs. 68%, p < .01), higher BMI (27 vs. 25 kg/m², p = .03), less frequently blood type O (36% vs. 80%, p < .001), and had higher eGFR (99 vs. 94 ml/min/1.73 m², p = .02), with a better LKDPI (median 7 vs. 22, p < .001). We observed no differences in graft failure or mortality. Compatible pairs made 280 additional transplants possible, many in highly sensitized recipients with long wait times. Compatible pair recipients derived several benefits from paired exchange, including better donor quality. Living donor pairs should receive counseling regarding all options available, including kidney paired donation. As more compatible pairs choose to enter exchange programs, consideration should be given to optimizing compatible pair and hard-to-transplant recipient outcomes.

Understanding Patients' and Living Donors' Kidney Paired Donation Educational Experiences and Recommendations for Improvement

INTRODUCTION

Educating potential kidney patients and living donors about the risks and benefits of kidney paired donation to ensure they make informed decisions is complex. This study aimed to increase understanding of patients' and donors' decision-making about donation, the educational content they received, and their recommendations for educational improvements.

METHOD

We conducted a mixed methods study, including semistructured interviews and quantitative surveys, with 43 participants (25 living donors; 18 kidney recipients).

FINDINGS

Participants reported that the benefits of paired donation motivated them to participate (ie, helping multiple people, receiving a transplant sooner, flexible timing of donation). Although deciding to participate in paired donation was a systematic, logical, and carefully considered process for some. For most, it was a quickly made, often emotion-based decision. Paired donation educational content on different topics varied, with recipients reporting receiving less information than donors about donor protections and processes to ameliorate the challenges faced, such as broken swaps and chains, and delays in matching. Those who faced challenges requested more information about donor protections and support during and after paired donation. Although many acknowledged their transplant coordinators' helpfulness, participants also recommended being more proactive in learning about kidney paired donation and speaking to former donors and recipients beforehand.

DISCUSSION

Standardized, health literate educational content addressing the gaps and variability in education received may help increase paired donation informed decision-making.

The Impact of Cold Ischaemia Time On Outcomes of Living Donor Kidney Transplantation in the UK Living Kidney Sharing Scheme

OBJECTIVE

To assess the impact of cold ischaemia time (CIT) on living donor kidney transplantation (LDKT) outcomes in the UK living kidney sharing scheme (UKLKSS) versus outside the scheme.

BACKGROUND

LDKT provides the best treatment option for end-stage kidney disease (ESKD) patients. ESKD patients with an incompatible living donor still have an opportunity to be transplanted through Kidney Exchange Programmes (KEP). In KEPs where kidneys travel rather than donors, CIT can be prolonged.

METHODS

Data from all UK adult LDKT between 2007 and 2018 were analysed.

RESULTS

9969 LDKT were performed during this period, of which 1396 (14%) were transplanted through the UKLKSS, which we refer to as KEP. Median CIT was significantly different for KEP versus non-KEP (339 versus 182 minutes, p < 0.001). KEP LDKT had a higher incidence of delayed graft function (DGF) (4.08% versus 6.97%, p < 0.0001), lower 1-year (eGFR 57.90 versus 55.25 ml/min, p = 0.04) and 5-year graft function (eGFR 55.62 versus 53.09 ml/min, p = 0.01) compared to the non-KEP group, but 1- and 5-year graft survival were similar. Within KEP, a prolonged CIT was associated with more DGF (9.26% versus 4.80%, p = 0.03), and lower graft function at 1-year and 5-years (eGFR = 55 vs 50 ml/min, p = 0.02), but had no impact on graft survival.

CONCLUSION

Whilst CIT was longer in KEP, associated with more DGF and lower graft function, excellent 5-year graft survival similar to non-KEP was found.

Risk factors for delayed graft function and their impact on graft outcomes in live donor kidney transplantation

BACKGROUND

Delayed graft function (DGF) is a manifestation of acute kidney injury uniquely framed within the transplant process and a predictor of poor long-term graft function1. It is less common in the setting of living donor (LD) kidney transplantation. However, the detrimental impact of DGF on graft survival is more pronounced in LD2.

PURPOSE

To study the effects of DGF in the setting of LD kidney transplantation.

METHODS

We performed a retrospective analysis of LD kidney transplantations performed between 2010 and 2018 in the UNOS/OPTN database for DGF and its effect on graft survival.

RESULTS

A total of 42,736 LD recipients were identified, of whom 1115 (2.6%) developed DGF. Recipient dialysis status, male gender, diabetes, end-stage renal disease, donor age, right donor nephrectomy, panel reactive antibodies, HLA mismatch, and cold ischemia time were independent predictors of DGF. Three-year graft survival in patients with and without DGF was 89% and 95%, respectively. DGF was the greatest predictor of graft failure at three years (hazard ratio = 1.766, 95% CI: 1.514-2.059, P = 0.001) and was associated with higher rates of rejection (9% vs. 6.28%, P = 0.0003). Among patients with DGF, the graft survival rates with and without rejection were not different.

CONCLUSION

DGF is a major determinant of poor graft functional outcomes, independent of rejection.

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.

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.