Improving outcomes for donation after circulatory death kidney transplantation: Science of the times

Transplant Outcomes After Exposure of Deceased Kidney Donors to Contrast Medium

BACKGROUND

The administration of contrast medium is associated with acute kidney injury; however, the effect of exposure of a deceased organ donor to contrast medium on kidney transplant outcomes has been poorly studied.

METHODS

A retrospective analysis of all deceased kidney donors between 2011 and 2021 and their corresponding recipients in the Netherlands was conducted. Multivariable analyses were performed to assess the associations between contrast medium exposure and delayed graft function (DGF)/graft survival. Linear mixed models were used to assess the differences in mean estimated glomerular filtration rate values in recipients 1 to 6 y after transplantation.

RESULTS

In total, 2177 donors and 3638 corresponding kidney graft recipients were included. Twenty-four percent of the donors (n = 520) were exposed to contrast medium, corresponding to 23% of recipients (n = 832). DGF was observed in 36% (n = 1321) and primary nonfunction in 3% (n = 122) of recipients. DGF rates for donation after brain death (DBD) and donation after circulatory death (DCD) donors showed no significant effect of contrast medium exposure ( P  = 0.15 and P  = 0.60 for DBD and DCD donors, respectively). In multivariable analyses, contrast medium administration was not significantly associated with a higher DGF risk (odds ratio 1.06; 95% confidence interval, 0.86-1.36; P  = 0.63) nor was a significant predictor for death-censored graft failure (hazard ratio 1.01; 95% confidence interval, 0.77-1.33; P  = 0.93). Linear mixed models showed no difference in mean estimated glomerular filtration rate values in recipients 1 to 6 y posttransplantation ( P  = 0.78).

CONCLUSIONS

This study indicates that contrast medium administration in DBD and DCD donors has no negative effect on early and long-term kidney graft function.

Early kinetics of donor-derived cell-free DNA after transplantation predicts renal graft recovery and long-term function

BACKGROUND

Ischemia-reperfusion injury (IRI) upon transplantation is one of the most impactful events that the kidney graft suffers during its life. Its clinical manifestation in the recipient, delayed graft function (DGF), has serious prognostic consequences. However, the different definitions of DGF are subject to physicians' choices and centers' policies, and a more objective tool to quantify IRI is needed. Here, we propose the use of donor-derived cell-free DNA (ddcfDNA) for this scope.

METHODS

ddcfDNA was assessed in 61 kidney transplant recipients of either living or deceased donors at 24 h, and 7, 14 and 30 days after transplantation using the AlloSeq cfDNA Kit (CareDx, San Francisco, CA, USA). Patients were followed-up for 6 months and 7-year graft survival was estimated through the complete and functional iBox tool.

RESULTS

Twenty-four-hour ddcfDNA was associated with functional DGF [7.20% (2.35%-15.50%) in patients with functional DGF versus 2.70% (1.55%-4.05%) in patients without it, P = .023] and 6-month estimated glomerular filtration rate (r = -0.311, P = .023). At Day 7 after transplantation, ddcfDNA was associated with dialysis duration in DGF patients (r = 0.612, P = .005) and worse 7-year iBox-estimated graft survival probability (β -0.42, P = .001) at multivariable analysis. Patients with early normalization of ddcfDNA (<0.5% at 1 week) had improved functional iBox-estimated probability of graft survival (79.5 ± 16.8%) in comparison with patients with 7-day ddcfDNA ≥0.5% (67.7 ± 24.1%) (P = .047).

CONCLUSIONS

ddcfDNA early kinetics after transplantation reflect recovery from IRI and are associated with short-, medium- and long-term graft outcome. This may provide a more objective estimate of IRI severity in comparison with the clinical-based definitions of DGF.

Deceased donor availability for uterus transplantation in Australia

BACKGROUND

Uterus transplantation is an emerging treatment option for uterine factor infertility. Most uterus transplantation research programs use living donors, although this comes with considerable surgical and psychological risks and not all women desiring uterus transplantation will have an available living donor. A deceased donor program eliminates donor risks; however, the availability of deceased uterus donors is currently unknown in Australia.

AIMS

To establish the feasibility of a deceased donor uterus transplantation program in Australia and consider expanded inclusion criteria for this model.

MATERIALS AND METHODS

A retrospective review of the New South Wales (NSW) Organ and Tissue Donation Service database was undertaken to identify potential deceased uterus donors, with comparison to the broad deceased donor inclusion criteria from three international uterus transplantation trials including female, brain-dead, multi-organ donation, no major abdominal surgery, and <60 years of age.

RESULTS

Between January 1, 2018, and December 31, 2022, 648 deceased donors were available in NSW. Of these, 43% (279/648) were female and 67% of the women (187/279) were also multi-organ donors. When the brain-dead donor-only and age criteria (<60 years) were applied, a total of 107 deceased donors met the available criteria for uterus transplantation, with an average of 21 deceased donors per year in NSW.

CONCLUSIONS

There appears to be adequate deceased donor organ availability to establish a deceased uterus transplantation program in NSW, Australia. Should interest in uterus transplantation increase, including criteria such as older and nulliparous donors could increase organ availability for a uterus transplantation program.

Waitlist and Transplant Outcomes in Organ Donation After Circulatory Death: Trends in the United States

OBJECTIVES

To summarize waitlist and transplant outcomes in kidney, liver, lung, and heart transplantation using organ donation after circulatory death (DCD).

BACKGROUND

DCD has expanded the donor pool for solid organ transplantation, most recently for heart transplantation.

METHODS

The United Network for Organ Sharing registry was used to identify adult transplant candidates and recipients in the most recent allocation policy eras for kidney, liver, lung, and heart transplantation. Transplant candidates and recipients were grouped by acceptance criteria for DCD versus brain-dead donors [donation after brain death (DBD)] only and DCD versus DBD transplant, respectively. Propensity matching and competing-risks regression was used to model waitlist outcomes. Survival was modeled using propensity matching and Kaplan-Meier and Cox regression analysis.

RESULTS

DCD transplant volumes have increased significantly across all organs. Liver candidates listed for DCD organs were more likely to undergo transplantation compared with propensity-matched candidates listed for DBD only, and heart and liver transplant candidates listed for DCD were less likely to experience death or clinical deterioration requiring waitlist inactivation. Propensity-matched DCD recipients demonstrated an increased mortality risk up to 5 years after liver and kidney transplantation and up to 3 years after lung transplantation compared with DBD. There was no difference in 1-year mortality between DCD and DBD heart transplantation.

CONCLUSIONS

DCD continues to expand access to transplantation and improves waitlist outcomes for liver and heart transplant candidates. Despite an increased risk for mortality with DCD kidney, liver, and lung transplantation, survival with DCD transplant remains acceptable.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimize organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Organ Donation After Out-of-Hospital Cardiac Arrest: A Scientific Statement From the International Liaison Committee on Resuscitation

AIM OF THE REVIEW

Improving rates of organ donation among patients with out-of-hospital cardiac arrest who do not survive is an opportunity to save countless lives. The objectives of this scientific statement were to do the following: define the opportunity for organ donation among patients with out-of-hospital cardiac arrest; identify challenges and opportunities associated with organ donation by patients with cardiac arrest; identify strategies, including a generic protocol for organ donation after cardiac arrest, to increase the rate and consistency of organ donation from this population; and provide rationale for including organ donation as a key clinical outcome for all future cardiac arrest clinical trials and registries.

METHODS

The scope of this International Liaison Committee on Resuscitation scientific statement was approved by the International Liaison Committee on Resuscitation board and the American Heart Association, posted on ILCOR.org for public comment, and then assigned by section to primary and secondary authors. A unique literature search was completed and updated for each section.

RESULTS

There are a number of defining pathways for patients with out-of-hospital cardiac arrest to become organ donors; however, modifications in the Maastricht classification system need to be made to correctly identify these donors and to report outcomes with consistency. Suggested modifications to the minimum data set for reporting cardiac arrests will increase reporting of organ donation as an important resuscitation outcome. There are a number of challenges with implementing uncontrolled donation after cardiac death protocols, and the greatest impediment is the lack of legislation in most countries to mandate organ donation as the default option. Extracorporeal cardiopulmonary resuscitation has the potential to increase organ donation rates, but more research is needed to derive neuroprognostication rules to guide clinical decision-making about when to stop extracorporeal cardiopulmonary resuscitation and to evaluate cost-effectiveness.

CONCLUSIONS

All health systems should develop, implement, and evaluate protocols designed to optimise organ donation opportunities for patients who have an out-of-hospital cardiac arrest and failed attempts at resuscitation.

Children Are Not Small Adults: Similarities and Differences in Renal Transplantation Between Adults and Pediatrics

Kidney transplantation is the treatment of choice for all patients with end-stage kidney disease, including pediatric patients. Graft survival in pediatrics was lagging behind adults, but now is comparable with the adult cohort. Although many of the protocols have been adopted from adults, there are issues unique to pediatrics that one should be aware of to take care of this population. These issues include recipient size consideration, increased incidence of viral infections, problems related to growth, common occurrence of underlying urological issues, and psychosocial issues. This article addresses the similarities and differences in renal transplantation, from preparing a patient for transplant, the transplant process, to post-transplant complications.

Donation type and the effect of pre-transplant donor specific antibodies - Data from the Swiss Transplant Cohort Study

Introduction

The type of donation may affect how susceptible a donor kidney is to injury from pre-existing alloimmunity. Many centers are, therefore, reluctant to perform donor specific antibody (DSA) positive transplantations in the setting of donation after circulatory death (DCD). There are, however, no large studies comparing the impact of pre-transplant DSA stratified on donation type in a cohort with a complete virtual cross-match and long-term follow-up of transplant outcome.

Methods

We investigated the effect of pre-transplant DSA on the risk of rejection, graft loss, and the rate of eGFR decline in 1282 donation after brain death (DBD) transplants and compared it to 130 (DCD) and 803 living donor (LD) transplants.

Results

There was a significant worse outcome associated with pre-transplant DSA in all of the studied donation types. DSA directed against Class II HLA antigens as well as a high cumulative mean fluorescent intensity (MFI) of the detected DSA showed the strongest association with worse transplant outcome. We could not detect a significant additive negative effect of DSA in DCD transplantations in our cohort. Conversely, DSA positive DCD transplants appeared to have a slightly better outcome, possibly in part due to the lower mean fluorescent intensity (MFI) of the pre-transplant DSA. Indeed when DCD transplants were compared to DBD transplants with similar MFI (<6.5k), graft survival was not significantly different.

Discussion

Our results suggest that the negative impact of pre-transplant DSA on graft outcome could be similar between all donation types. This suggests that immunological risk assessment could be performed in a similar way regardless of the type of donor kidney transplantation.

Normothermic machine perfusion of kidneys: current strategies and future perspectives

PURPOSE OF REVIEW

This review aims to summarize the latest original preclinical and clinical articles in the setting of normothermic machine perfusion (NMP) of kidney grafts.

RECENT FINDINGS

Kidney NMP can be safely translated into the clinical routine and there is increasing evidence that NMP may be beneficial in graft preservation especially in marginal kidney grafts. Due to the near-physiological state during NMP, this technology may be used as an ex-vivo organ assessment and treatment platform. There are reports on the application of mesenchymal stromal/stem cells, multipotent adult progenitor cells and microRNA during kidney NMP, with first data indicating that these therapies indeed lead to a decrease in inflammatory response and kidney injury. Together with the demonstrated possibility of prolonged ex-vivo perfusion without significant graft damage, NMP could not only be used as a tool to perform preimplant graft assessment. Some evidence exists that it truly has the potential to be a platform to treat and repair injured kidney grafts, thereby significantly reducing the number of declined organs.

SUMMARY

Kidney NMP is feasible and can potentially increase the donor pool not only by preimplant graft assessment, but also by ex-vivo graft treatment.

Donor characteristics and their impact on kidney transplantation outcomes: Results from two nationwide instrumental variable analyses based on outcomes of donor kidney pairs accepted for transplantation

BACKGROUND

Donor-characteristics and donor characteristics-based decision algorithms are being progressively used in the decision process whether or not to accept an available donor kidney graft for transplantation. While this may improve outcomes, the performance characteristics of the algorithms remains moderate. To estimate the impact of donor factors of grafts accepted for transplantation on transplant outcomes, and to test whether implementation of donor-characteristics-based algorithms in clinical decision-making is justified, we applied an instrumental variable analysis to outcomes for kidney donor pairs transplanted in different individuals.

METHODS

This analysis used (dis)congruent outcomes of kidney donor pairs as an instrument and was based on national transplantation registry data for all donor kidney pairs transplanted in separate individuals in the Netherlands (1990-2018, 2,845 donor pairs), and the United Kingdom (UK, 2000-2018, 11,450 pairs). Incident early graft loss (EGL) was used as the primary discriminatory factor. It was reasoned that a scenario with a dominant impact of donor variables on transplantation outcomes would result in high concordance of EGL in both recipients, whilst dominance of asymmetrical outcomes could indicate a more complex scenario, involving an interaction of donor, procedural and recipient factors.

FINDINGS

Incidences of congruent EGL (Netherlands: 1·2%, UK: 0·7%) were slightly lower than the arithmetical (stochastic) incidences, suggesting that once a graft has been accepted for transplantation, donor factors minimally contribute to incident EGL. A long-term impact of donor factors was explored by comparing outcomes for functional grafts from donor pairs with asymmetrical vs. symmetrical outcomes. Recipient survival was similar for both groups, but a slightly compromised graft survival was observed for grafts with asymmetrical outcomes in the UK cohort: (10-years Hazard Ratio for graft loss: 1·18 [1·03-1·35] p<0·018); and 5 years eGFR (48·6 [48·3-49·0] vs. 46·0 [44·5-47·6] ml/min in the symmetrical outcome group, p<0·001).

INTERPRETATION

Our results suggest that donor factors for kidney grafts deemed acceptable for transplantation impact minimally on transplantation outcomes. A strong reliance on donor factors and/or donor-characteristics-based decision algorithms could result in unjustified rejection of grafts. Future efforts to optimize transplant outcomes should focus on a better understanding of the recipient factors underlying transplant outcomes.

FUNDING

None.

Radiological Screening Methods in Deceased Organ Donation: An Overview of Guidelines Worldwide

Organ transplantation is performed worldwide, but policies regarding donor imaging are not uniform. An overview of the policies in different regions is missing. This study aims to investigate the various protocols worldwide on imaging in deceased organ donation. An online survey was created to determine the current policies. Competent authorities were approached to fill out the survey based on their current protocols. In total 32 of the 48 countries approached filled out the questionnaire (response rate 67%). In 16% of the countries no abdominal imaging is required prior to procurement. In 50%, abdominal ultrasound (US) is performed to screen the abdomen and in 19% an enhanced abdominal Computed Tomography (CT). In 15% of the countries both an unenhanced abdominal CT scan and abdominal US are performed. In 38% of the countries a chest radiographic (CXR) is performed to screen the thorax, in 28% only a chest CT, and in 34% both are performed. Policies regarding radiologic screening in deceased organ donors show a great variation between different countries. Consensus on which imaging method should be applied is missing. A uniform approach will contribute to quality and safety, justifying (inter)national exchange of organs.

Kidney transplant outcome of expanded criteria donors after circulatory death

The increase in the number of patients on the kidney transplant waiting list has led to an attempt to increase the number of potential donors by incorporating candidates that previously would not have been considered optimal, including donors after cardiac death (DCD) and those with "expanded" criteria (ECD). Recipients of controlled DCD (cDCD) grafts suffer more delayed graft function (DGF), but have a long-term evolution comparable to those of brain-dead donors, which has allowed an increase in the number of cDCD transplants in different countries in recent years. In parallel, the use of cDCD with expanded criteria (cDCD/ECD) has increased in recent years in different countries, allowing the waiting list for kidney transplantation to be shortened. The use of these grafts, although associated with a higher frequency of DGF, offers similar or only slightly lower long-term graft survival than those of brain death donors with expanded criteria. Different studies have observed that cDCD/ECD graft recipients have worse kidney function than cDCD/standard and DBD/ECD. Mortality associated with cDCD/ECD graft transplantation mostly relates to the recipient age. Patients who receive a cDCD/≥60 graft have better survival than those who continue on the waiting list, although this fact has not been demonstrated in recipients of cDCD/>65 years. The use of this type of organ should be accompanied by the optimization of surgical times and the shortest possible cold ischemia.

Thymoglobulin versus Alemtuzumab versus Basiliximab Kidney Transplantation from Donors After Circulatory Death

Introduction

The Campath, Calcineurin inhibitor (CNI) reduction, and Chronic allograft nephropathy (3C), a study comparing alemtuzumab versus basiliximab induction immunosuppression in kidney transplants, has found lower acute rejection rate with alemtuzumab but same graft survival. The aim of the current study is to evaluate the effect of induction immunosuppression (thymoglobulin, alemtuzumab, basiliximab) on the outcome of kidneys of donors after circulatory death (DCD).

Methods

Data of the 274 DCD patients of the 3C obtained from the sponsor were compounded with the 140 DCD patients who received thymoglobulin in a single center with the same entry criteria as the 3C, giving 414 patients on 3 induction regimes.

Results

There were more male donors (P < 0.05) and human leukocyte antigen and DR mismatched patients in the thymoglobulin group (P < 0.001). Death-censored graft survival at 6 months was 98.6% in the thymoglobulin, 95.5% in the alemtuzumab (P = 0.08), and 95.7% in the basiliximab group (P = 0.09) and at 2 years 97.9% versus 94.8% (P = 0.13, hazard ratio [HR] 2.8, 95% CI 0.7–10.9) versus 94.3% (P = 0.06, HR 3.5, 95% CI 0.9–13.6), respectively.

The 2-year overall graft survival was 95% in the thymoglobulin versus 88% in the alemtuzumab (unadjusted P = 0.038, adjusted HR 2.4, 95% CI 0.99–5.9) and 91.4% in the basiliximab group (P = 0.21). The 2-year patient survival was numerically less in the alemtuzumab compared with the thymoglobulin group (91.8% vs. 97.1%, P = 0.052, HR 2.90, 95% CI 0.93–9.2). Acute rejection was 17% in the basiliximab, 4.3% in the thymoglobulin, and 6% in the alemtuzumab group (P < 0.001).

Conclusion

In DCD transplants, thymoglobulin induction may provide advantage over alemtuzumab in patient survival and the same advantage as alemtuzumab over basiliximab in terms of acute rejection. Differing maintenance immunosuppression may contribute to the difference found.

Novel Organ Perfusion and Preservation Strategies in Controlled Donation After Circulatory Death in Pancreas and Kidney Transplantation

BACKGROUND

Kidney and pancreatic transplants from controlled donation after circulatory death donors are vulnerable to ischemia-reperfusion injuries. In this context of transplant shortage, there is a need to optimize the function of these transplants and to develop novel perfusion and preservation strategies in controlled donation after circulatory death in kidney and pancreatic transplants.

IN SITU PERFUSION AND PRESERVATION STRATEGIES

In situ regional normothermic perfusion improves the outcome of kidney transplants from controlled donation after circulatory death and provides equivalent results for the kidney from brain-dead donors. In situ regional normothermic perfusion is under investigation for pancreatic transplants.

EX SITU PERFUSION AND PRESERVATION STRATEGIES

Perfusion on hypothermic machine perfusion is highly recommended for the kidney from controlled donation after cardiac death. Hypothermic oxygenated perfusion machine decreases the rate of graft rejection and graft failure in kidney transplantation. Ex situ normothermic perfusion is an easy way to assess renal function. In the future, kidney transplants could benefit from drug therapy during ex situ normothermic perfusion. In pancreas transplantation, hypothermic machine perfusion and ex situ normothermic perfusion present encouraging results in preclinical studies.

Advances in Kidney Preservation Techniques and Their Application in Clinical Practice

The use of cold preservation solutions to rapidly flush and cool the kidney followed by static cold storage in ice has been the standard kidney preservation technique for the last 50 y. Nonetheless, changing donor demographics that include organs from extended criteria donors and donation after circulatory death donors have led to the adoption of more diverse techniques of preservation. Comparison of hypothermic machine perfusion and static cold storage techniques for deceased donor kidneys has long been debated and is still contested by some. The recent modification of hypothermic machine perfusion techniques with the addition of oxygen or perfusion at subnormothermic or near-normothermic temperatures are promising strategies that are emerging in clinical practice. In addition, the use of normothermic regional perfusion to resuscitate abdominal organs of donation after circulatory death donors in situ before cold flushing is also increasingly being utilized. This review provides a synopsis of the different types of preservation techniques including their mechanistic effects and the outcome of their application in clinical practice for different types of donor kidney.

Kidney transplant outcomes in elderly recipients with controlled donation after circulatory death or donation after brain death donors: a registry cohort study

The number of kidney transplant (KT) procedures with controlled donation after circulatory death (cDCD) donors has exponentially increased in Spain in recent years, with a parallel increase in donor and recipient acceptance criteria. The outcomes of cDCD-KT have been reported to be comparable to those of KT with donation after brain death (DBD) donors. However, studies in elderly recipients have yielded contradictory results. We performed a registry analysis of 852 KT recipients aged ≥65 years (575 in the DBD-KT group, 277 in the cDCD-KT group) in Catalonia, Spain. Clinical outcomes and survival were compared between DBD-KT and cDCD-KT recipients. The donor and recipient ages were similar between the two groups (71.5 ± 8.7 years for donors, 70.8 ± 4.1 years for recipients). Delayed graft function (DGF) was more frequent among cDCD-KT recipients, without a difference in the rate of primary nonfunction. The 3-year patient and death-censored graft survival rates were similar between DBD-KT and cDCD-KT recipients (78.8% vs. 76.4% and 90.3% vs. 86.6%, respectively). In multivariable analysis, previous cardiovascular disease and DGF were independent risk factors for patient death. The type of donation (cDCD vs. DBD) was not an independent risk factor for patient survival or graft loss. cDCD-KT and DBD-KT provide comparable patient and graft survival in elderly recipients.

Donor-Recipient BSA Matching Is Prognostically Significant in Solitary and En Bloc Kidney Transplantation From Pediatric Circulatory Death Donors

Background.

As the rate of early postoperative complications decline after transplant with pediatric donation after circulatory death (DCD) kidneys, attention has shifted to the long-term consequences of donor–recipient (D-R) size disparity given the pernicious systemic effects of inadequate functional nephron mass.

Methods.

We conducted a retrospective cohort study using Organ Procurement and Transplantation Network data for all adult (aged ≥18 y) recipients of pediatric (aged 0–17 y) DCD kidneys in the United States from January 1, 2004 to March 10, 2020.

Results.

DCD pediatric allografts transplanted between D-R pairs with a body surface area (BSA) ratio of 0.10–0.70 carried an increased risk of all-cause graft failure (relative risk [RR], 1.36; 95% confidence interval [CI], 1.10–1.69) and patient death (RR, 1.32; 95% CI, 1.01–1.73) when compared with pairings with a ratio of >0.91. Conversely, similar graft and patient survivals were demonstrated among the >0.70–0.91 and >0.91 cohorts. Furthermore, we found no difference in death-censored graft survival between all groups. Survival analysis revealed improved 10-y patient survival in recipients of en bloc allografts (P = 0.02) compared with recipients of single kidneys with D-R BSA ratios of 0.10–0.70. A similar survival advantage was demonstrated in recipients of solitary allografts with D-R BSA ratios >0.70 compared with the 0.10–0.70 cohort (P = 0.02).

Conclusions.

Inferior patient survival is likely associated with systemic sequelae of insufficient renal functional capacity in size-disparate DCD kidney recipients, which can be overcome by appropriate BSA matching or en bloc transplantation. We therefore suggest that in DCD kidney transplantation, D-R BSA ratios of 0.10–0.70 serve as criteria for en bloc allocation or alternative recipient selection to optimize the D-R BSA ratio to >0.70.

Optimal donation of kidney transplants after controlled circulatory death

Controlled donation after circulatory death (cDCD) is used for "extended criteria" donors with poorer kidney transplant outcomes. The French cDCD program started in 2015 and is characterized by normothermic regional perfusion, hypothermic machine perfusion, and short cold ischemia time. We compared the outcomes of kidney transplantation from cDCD and brain-dead (DBD) donors, matching cDCD and DBD kidney transplants by propensity scoring for donor and recipient characteristics. The matching process retained 442 of 499 cDCD and 809 of 6185 DBD transplantations. The DGF rate was 20% in cDCD recipients compared with 28% in DBD recipients (adjusted relative risk [aRR], 1.43; 95% confidence interval [CI] 1.12-1.82). When DBD transplants were ranked by cold ischemia time and machine perfusion use and compared with cDCD transplants, the aRR of DGF was higher for DBD transplants without machine perfusion, regardless of the cold ischemia time (aRR with cold ischemia time <18 h, 1.57; 95% CI 1.20-2.03, vs aRR with cold ischemia time ≥18 h, 1.79; 95% CI 1.31-2.44). The 1-year graft survival rate was similar in both groups. Early outcome was better for kidney transplants from cDCD than from matched DBD transplants with this French protocol.

Kidney transplant outcome of expanded criteria donors after circulatory death

The increase in the number of patients on the kidney transplant waiting list has led to an attempt to increase the number of potential donors by incorporating candidates that previously would not have been considered optimal, including donors after cardiac death (DCD) and those with "expanded" criteria (ECD). Recipients of controlled DCD (cDCD) grafts suffer more delayed graft function (DGF), but have a long-term evolution comparable to those of brain-dead donors, which has allowed an increase in the number of cDCD transplants in different countries in recent years. In parallel, the use of cDCD with expanded criteria (cDCD/ECD) has increased in recent years in different countries, allowing the waiting list for kidney transplantation to be shortened. The use of these grafts, although associated with a higher frequency of DGF, offers similar or only slightly lower long-term graft survival than those of brain death donors with expanded criteria. Different studies have observed that cDCD/ECD graft recipients have worse kidney function than cDCD/standard and brain death/ECD. Mortality associated with cDCD/ECD graft transplantation mostly relates to the recipient age. Patients who receive a cDCD/≥60 graft have better survival than those who continue on the waiting list, although this fact has not been demonstrated in recipients of cDCD/>65 years. The use of this type of organ should be accompanied by the optimization of surgical times and the shortest possible cold ischemia.

Induction with ATG in DCD kidney transplantation; efficacy and relation of dose and cell markers on delayed graft function and renal function

AIM

We aimed to analyse the efficacy of the Thymoglobulin dose used for induction in controlled DCD kidneys, and its initial impact on blood cell and CD3 count, as predictors of efficacy.

METHODS

140 DCD patients who received ATG induction, were analysed. Intended dose was 1.25 mg/kg/day over 5 days, rounded to nearest 25 mg and not exceeding 125 mg/dose. Outcomes included the total dose in relation with rejection, DGF, graft survival, eGFR. The cell count response to ATG was assessed as predictors of outcome.

RESULTS

Graft survival, was 96.2%, 92.4%, 85% at 1, 3 and 5 years. Rejection was 7% at 1 year and associated with eGFR at 3 (p = 0.003) and 5 years. ATG dose was not predictive of rejection but was associated with the day5 leucocyte and lymphocyte count (p < 0.001) and negatively with DGF (p = 0.05). In 31 patients day3 CD3 count was available and it was associated with rejection (p = 0.002), less DGF (p = 0.09), and 3 years eGFR (p = 0.01).

CONCLUSION

Thymoglobulin provides excellent results in DCD kidneys that do not significantly differ with small dose variations. In higher doses it reduces DGF. Lymphocytes and CD3 count, may be useful surrogate markers of efficacy and outcome.