Outcomes of kidney paired donation transplants in relation to shipping and cold ischaemia time

Kidney transplantation in Icelandic patients, 2000-2019: are outcomes affected by low volume?

Background

In Iceland, a small number of kidney transplants from living donors (LDs) are performed at Landspitali University Hospital (LUH) in Reykjavik, while deceased donor transplants have until recently invariably been carried out abroad. In this study, we evaluated the outcome of kidney transplantation in Icelandic patients.

Methods

This was a retrospective study that included all Icelandic residents who underwent kidney transplantation between 1 January 2000 and 31 December 2019. Data were obtained from the Icelandic End-Stage Kidney Disease Registry, medical records at LUH, and the Scandiatransplant database. The Chronic Kidney Disease Epidemiology Collaboration equation was used to calculate estimated glomerular filtration rate from serum creatinine for recipients and donors aged >18 years, and the modified Schwartz equation for those aged ≤18 years. Survival was estimated using the Kaplan-Meier method, and the log-rank test was employed for group comparisons.

Results

A total of 229 kidney transplants in 221 patients were performed during the 20-year period, of which 135 (58.9%) were from LDs. Transplants carried out at LUH were 118 (51.5%), of which 116 were from LDs. During a median follow-up of 7.4 years (range 0.1-20), 27 (12.2%) patients died, 20 (74%) of whom had a functioning graft. One-year patient survival was 99.1% [95% confidence interval (CI), 97.9-100], 5-year survival was 95.7% (95% CI, 92.7-98.7), and 10-year survival was 87.7% (95% CI, 82.4-93.4). Death-censored graft survival was 98.3% (95% CI, 96.6-100), 96.8% (95% CI, 94.4-99.2), and 89.2% (95% CI, 84.1-94.7) at 1, 5, and 10 years, respectively.

Conclusions

Patient and graft survival are comparable with those of large transplant centers, demonstrating the feasibility of running a quality kidney transplant program in a small nation in collaboration with a larger center abroad.

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.

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.

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

To date, thousands of living donor kidneys have been shipped through kidney paired donation (KPD). To expand on this growing segment of living donor transplantation, we evaluated the effect of advanced age donation ("oldest kidneys") and prolonged cold ischemia time ("coldest kidneys") on graft function and survival using the National Kidney Registry database from February 2008 to May 2018. Donors were stratified by age at time of donation (<65 or ≥65 years) and kidneys were stratified by cold ischemia time (<16 or ≥16 hours). We evaluated delayed graft function and death-censored graft failure (DCGF) for up to seven posttransplant years. Of the 2363 shipped living donor kidney transplants, 4.1% of donors were ≥65 years and 6.0% of transplanted kidneys had cold ischemia times ≥16 hours. Delayed graft function and DCGF occurred in 5.2% and 4.7% of cases. There were no significant associations between delayed graft function and donor age (P = .947) or cold ischemia (P = .532). Donor age and cold ischemia time were not predictive of delayed graft function (OR = 0.86,1.20; P = .8, .6) or DCGF (HR = 1.38,0.35, P = .5, .1). These findings may alleviate concerns surrounding the utilization of kidneys from older donors or those originating from distant transplant centers.

Time of Cold Ischemia and Delayed Graft Function in a Cohort of Renal Transplant Patients in a Reference Center

There are many factors involved in the delayed graft function of a renal graft, with prolonged cold ischemia time being one of the most relevant. The aim of this study is to evaluate the relationship between the time of cold ischemia and the delayed graft function, and acute rejection and graft loss at 1 year of follow-up. A retrospective cohort of 347 renal transplant patients were evaluated during the years 2009-2013. The incidence of delayed graft function was 18.4% (n = 65). The cold ischemia time was an independent risk factor for delayed graft function (odds ratio [OR] 1.10, 95% confidence interval [CI] 1.04-1.16). By grouping the time of cold ischemia by intervals, the risk of delayed graft function was greater in the 12-18 hours group (OR 2.06, 95% CI 1.02-4.15) and in the >18 hours group (OR 3.38, 95% CI 1.57-7.27). The risk of acute rejection did not increase with longer cold ischemia (p = 0.69), and cold ischemia time was not a risk factor for renal graft loss at 1-year follow-up (hazard ratio 0.97, 95% CI 0.88-1.06). In conclusion the time of cold ischemia (>12 hours) in renal transplant recipients of optimal deceased donors increases the risk of delayed graft function; however, this does not negatively impact the results in acute rejection or graft loss in the first year of the transplant.

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?

Kidney exchange match rates in a large multicenter clearinghouse

Kidney paired donation (KPD) can facilitate living donor transplantation for candidates with an incompatible donor, but requires waiting for a match while experiencing the morbidity of dialysis. The balance between waiting for KPD vs desensitization or deceased donor transplantation relies on the ability to estimate KPD wait times. We studied donor/candidate pairs in the National Kidney Registry (NKR), a large multicenter KPD clearinghouse, between October 2011 and September 2015 using a competing-risk framework. Among 1894 candidates, 52% were male, median age was 50 years, 66% were white, 59% had blood type O, 42% had panel reactive antibody (PRA)>80, and 50% obtained KPD through NKR. Median times to KPD ranged from 2 months for candidates with ABO-A and PRA 0, to over a year for candidates with ABO-O or PRA 98+. Candidates with PRA 80-97 and 98+ were 23% (95% confidence interval , 6%-37%) and 83% (78%-87%) less likely to be matched than PRA 0 candidates. ABO-O candidates were 67% (61%-73%) less likely to be matched than ABO-A candidates. Candidates with ABO-B or ABO-O donors were 31% (10%-56%) and 118% (82%-162%) more likely to match than those with ABO-A donors. Providers should counsel candidates about realistic, individualized expectations for KPD, especially in the context of their alternative treatment options.

Challenges for the Travelling Donor: Variability Between Donor Workup and Donor Surgery in the Canadian Kidney Paired Exchange Program

BACKGROUND

A primary obstacle to providing renal transplantation is limited access to donated kidneys. The living-donor pool for renal allografts was greatly expanded through implementation of a kidney paired donation program. Whereas some programs ship donor kidneys to the site of renal transplantation, others send the donor to the site of transplantation. Performing the nephrectomy and transplantation at the same location may optimize functional renal outcomes, but preferred surgical approaches may differ between surgical teams performing the donor workup and donor surgery. Our objective was to identify incongruence between the surgery planned by the team that performed the donor's workup, and the surgery that took place at the site of donation.

METHODS

A retrospective chart review was performed between the site of preoperative surgical planning, and the site of surgery for kidney donors in the Canadian kidney paired donation program.

RESULTS

Fifty-one donors were preoperatively prepared in any of six Canadian provinces, and then underwent surgery in a different province. The surgical procedure performed for 31% of the patients' nephrectomies differed from the procedure suggested by the surgical team who conducted the preoperative workup. Half of these differences were between left laparoscopic and left laparoscopic hand-assisted, but the remainder included more substantial changes of sides and/or laparoscopic versus open procedures.

CONCLUSION

Optimal patient care is challenged in a kidney paired donation program that uses the "traveling donor" approach due to differing surgical techniques selected by the surgeon at the site of donor workup and the surgeon at the site of donation.

Early experience with hypothermic machine perfusion of living donor kidneys - a retrospective study

Although hypothermic machine perfusion (HMP) has been shown to be beneficial to deceased donor kidneys, the effect of HMP on living donor kidneys (LDK) is unknown. LDK are subjected to minutes of normothermic ischemia at the time of recovery. Comparison of 16 LDK preserved by HMP with 16 LDK preserved by static cold storage (SCS). Outcomes of interest are resistive indices (RI), both while on HMP and postoperatively, and creatinine clearance (CrCl). Injury markers NGAL and LDH were seen in the perfusate of LDK in amounts similar to what is found for donation after neurological determination of death kidneys. Compared to SCS kidneys, CrCl was significantly higher in the HMP group from days 2 through 7 post-transplant [ie: day 7 (78.8 ± 5.4 vs. 54.0 ± 4.6 ml/min, P = 0.005)]. CrCl at 1 year was higher in the HMP group (81.2 ± 5.8 vs. 70.0 ± 5.3 ml/min, P = 0.03). Early post-transplant RI was significantly lower in the HMP group (0.61 ± 0.02 vs. 0.71 ± 0.02, P < 0.0001). Our data support the assertion that injury does occur during LDK procurement and suggest that some of this injury may be reversed with HMP, resulting in more favorable early RI and graft function compared to SCS kidneys.

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.

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.

International kidney paired donation transplantations to increase kidney transplant of O group and highly sensitized patient: First report from India

AIM

To report the first international living related two way kidney paired donation (KPD) transplantation from India which occurred on 17^th February 2015 after legal permission from authorization committee.

METHODS

Donor recipient pairs were from Portugal and India who were highly sensitized and ABO incompatible with their spouse respectively. The two donor recipient pairs had negative lymphocyte cross-matching, flow cross-match and donor specific antibody in two way kidney exchange with the intended KPD donor. Local KPD options were fully explored for Indian patient prior to embarking on international KPD.

RESULTS

Both pairs underwent simultaneous uneventful kidney transplant surgeries and creatinine was 1 mg/dL on tacrolimus based immunosuppression at 11 mo follow up. The uniqueness of these transplantations was that they are first international KPD transplantations in our center.

CONCLUSION

International KPD will increases quality and quantity of living donor kidney transplantation. This could be an important step to solving the kidney shortage with additional benefit of reduced costs, improved quality and increased access for difficult to match incompatible pairs like O blood group patient with non-O donor and sensitized patient. To the best of our knowledge this is first international KPD transplantation from India.

Six end-stage renal disease patients benefited from first non-simultaneous single center 6-way kidney exchange transplantation in India

AIM

To avoid desensitization protocols and ABO incompatible kidney transplantation (KT) due to high costs and increased risk of infections from intense immunosuppression.

METHODS

We present institutional ethical review board - approved study of single center 6-way kidney exchange transplantation. The participants comprised ABO incompatibility (n = 1); positive cross-match and/or presence of donor specific antibody (n = 5). The average time required from registration in kidney paired donation (KPD) registry to find suitable donors was 45 d and time required to perform transplants after legal permission was 2 mo.

RESULTS

Graft and patient survival were 100%, and 100%, respectively. One patient had biopsy-proven acute borderline T cell rejection (Banff update 2013, type 3). Mean serum creatinine was 0.8 mg/dL at 9 mo follow-up. The waiting time in KPD was short as compared to deceased donor KT.

CONCLUSION

We report first non-simultaneous, single center, 6-way kidney exchange transplantation from India. Our experience will encourage other centers in India to undertake this practice.