Outcomes of Transplantation Using Kidneys From Donors Meeting Expanded Criteria in Australia and New Zealand, 1991 to 2005

Porcine anti-human lymphocyte immunoglobulin depletes the lymphocyte population to promote successful kidney transplantation

Introduction

Porcine anti-human lymphocyte immunoglobulin (pALG) has been used in kidney transplantation, but its impacts on the lymphocyte cell pool remain unclear.

Methods

We retrospectively analyzed 12 kidney transplant recipients receiving pALG, and additional recipients receiving rabbit anti-human thymocyte immunoglobulin (rATG), basiliximab, or no induction therapy as a comparison group.

Results

pALG showed high binding affinity to peripheral blood mononuclear cells (PBMCs) after administration, immediately depleting blood lymphocytes; an effect that was weaker than rATG but stronger than basiliximab. Single-cell sequencing analysis showed that pALG mainly influenced T cells and innate immune cells (mononuclear phagocytes and neutrophils). By analyzing immune cell subsets, we found that pALG moderately depleted CD4+T cells, CD8+T cells, regulatory T cells, and NKT cells and mildly inhibited dendritic cells. Serum inflammatory cytokines (IL-2, IL-6) were only moderately increased compared with rATG, which might be beneficial in terms of reducing the risk of untoward immune activation. During 3 months of follow-up, we found that all recipients and transplanted kidneys survived and showed good organ function recovery; there were no cases of rejection and a low rate of complications.

Discussion

In conclusion, pALG acts mainly by moderately depleting T cells and is thus a good candidate for induction therapy for kidney transplant recipients. The immunological features of pALG should be exploited for the development of individually-optimized induction therapies based on the needs of the transplant and the immune status of the patient, which is appropriate for non-high-risk recipients.

Baseline Characteristics and Representativeness of Participants in the BEST-Fluids Trial: A Randomized Trial of Balanced Crystalloid Solution Versus Saline in Deceased Donor Kidney Transplantation

Delayed graft function (DGF) is a major complication of deceased donor kidney transplantation. Saline (0.9% sodium chloride) is a commonly used intravenous fluid in transplantation but may increase the risk of DGF because of its high chloride content. Better Evidence for Selecting Transplant Fluids (BEST-Fluids), a pragmatic, registry-based, double-blind, randomized trial, sought to determine whether using a balanced low-chloride crystalloid solution (Plasma-Lyte 148) instead of saline would reduce DGF. We sought to evaluate the generalizability of the trial cohort by reporting the baseline characteristics and representativeness of the trial participants in detail.

METHODS

We compared the characteristics of BEST-Fluids participants with those of a contemporary cohort of deceased donor kidney transplant recipients in Australia and New Zealand using data from the Australia and New Zealand Dialysis and Transplant Registry. To explore potential international differences, we compared trial participants with a cohort of transplant recipients in the United States using data from the Scientific Registry of Transplant Recipients.

RESULTS

During the trial recruitment period, 2373 deceased donor kidney transplants were performed in Australia and New Zealand; 2178 were eligible' and 808 were enrolled in BEST-Fluids. Overall, trial participants and nonparticipants were similar at baseline. Trial participants had more coronary artery disease (standardized difference [d] = 0.09; P = 0.03), longer dialysis duration (d = 0.18, P < 0.001), and fewer hypertensive (d = -0.11, P = 0.03) and circulatory death (d = -0.14, P < 0.01) donors than nonparticipants. Most key characteristics were similar between trial participants and US recipients, with moderate differences (|d| ≥ 0.2; all P < 0.001) in kidney failure cause, diabetes, dialysis duration, ischemic time, and several donor risk predictors, likely reflecting underlying population differences.

CONCLUSIONS

BEST-Fluids participants had more comorbidities and received slightly fewer high-risk deceased donor kidneys but were otherwise representative of Australian and New Zealand transplant recipients and were generally similar to US recipients. The trial results should be broadly applicable to deceased donor kidney transplantation practice worldwide.

Long-term outcomes of kidney transplantation from expanded criteria donors with Chinese novel donation policy: donation after citizens' death

Introduction

The Chinese Government initiated the Donation after Citizens' Death policy in 2010. To now, it has been a major source of organs for transplant. Since it is still a young policy, corresponding clinical evidence is still urgently needed for its improvement. Compared to kidneys donated by SCD (standard criteria donor), increasing the use of ECD (expanded criteria donor) derived kidneys is a way to expand the donor pool but is also a result of the aging demography of China. This study is based on the data of kidney transplantation in our center with the Donation after Citizens' Death policy, aiming to provide a reference for the clinical use of ECD kidneys.

Method

A retrospective study enrolled 415 kidney transplants derived from 211 donors performed between October 2011 and October 2019. A total of 311 (74.9%) organs were donated from 159 (75.4%) SCDs, and the remaining 104 (25.1%) were from 52 (24.6%) ECDs. The log-rank test was used to compare the difference in survival and postoperative complications. The Chi-square test was used to compare the occurrence of postoperative complications and postoperative renal function. The Cox regression analysis was used for risk factor screening.

Result

Analysis showed that grafts from ECD were poorer in survival (P = 0.013), while their recipients had comparable (P = 0.16) survival. Moreover, it also was an independent risk factor for graft loss (HR 2.27, P = 0.044). There were significantly more AR occurrences in the ECD group compared with SCD group (25.0% vs. 15.8%, P = 0.004), but no significant difference was found in infection (51.9% vs. 47.6%, P = 0.497) and DGF (26.0% vs. 21.9%, P = 0.419) between them. Similarly, fewer recipients in the ECD group were free from AR within 1 year after transplantation (P = 0.040), with no statistical difference in all-cause infection prevalence in 1 year (P = 0.168). The eGFR in the ECD group was significantly worse than that in the SCD group at 3 months, 6 months, 1 year, 3 years, and the highest value posttransplant (all < 0.05), but no difference at 5 years posttransplant. Besides, results showed cardiac arrest (uncontrolled vs. controlled, HR 2.49, P = 0.049), HLA mismatch (4–6 loci vs. 0–3 loci, HR 3.61, P = 0.039), and AR occurrence (HR 2.91, P = 0.006) were demonstrated to be independent risk factors for graft loss.

Conclusion

The ECD-derived kidney was worse than the SCD-derived kidney in terms of graft survival and AR occurrence, and trend to an inferior renal function postoperative. However, the recipient survival, DGF occurrence, and all-cause infection occurrence were similar.

Adult Living-Donor Kidney Transplantation, Donor Age, and Donor-Recipient Age

INTRODUCTION

Owing to organ shortage, the number of kidney transplantation (KT) involving older adult living donors is increasing. We aimed to investigate the effects of living-donor age and donor-recipient age differences on KT outcomes.

METHODS

This single-center, retrospective cohort study involved 853 adult LDKTs performed between January 2008 and December 2018. Recipients were stratified into the following 5 groups based on donor age and donor-recipient age difference: donor age, 30 to 49 years and age difference, -10 to 15 years; donor age, 50 to 69 years and age difference, -10 to 15 years; donor age, 50 to 69 years and age difference, 15 to 40 years; donor age, 70 to 89 years and age difference, -10 to 15 years; and donor age, 70 to 89 years and age difference, 15 to 40 years (groups 1, 2, 3, 4, and 5, respectively). As a primary outcome, the risk of graft loss was investigated. The secondary outcomes were postoperative estimated glomerular filtration rates (eGFRs) and mortality rates of recipients.

RESULTS

Group 4, representing KT between older adult donors and older adult recipients, had the highest graft loss risk and mortality. The eGFRs of the recipients from donors aged 70 to 89 years (groups 4 and 5) were significantly lower than those from donors in the other groups. Although the differences in the eGFR between groups 4 and 5 were not significant, the eGFR of group 4 was lower than that of group 5 at 6 months post-KT.

CONCLUSION

LDKTs from older adult donors to older adult recipients resulted in the worst graft survival and mortality rates.

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.

[Very-old deceased donors in kidney transplantation: How far can we go?]

In order to increase the pool of organ donors, kidney transplantation from very old-donors, notably aged more than 70, is increasing. Compared to the United States, where the use of these grafts does not reach 5%, in France it reaches over 20%. Kidney aging is determined by a progressive glomerusclerosis, interstitial fibrosis, and nephrosclerosis, responsible of a linear decrease of glomerular filtration rate with time. Aging in kidney transplantation goes along also with an increased immunogenicity and risk of ischemia-reperfusion injuries. Hence, the prognosis of these transplantations is worse than those from younger donors, even though it remains better than dialysis. Data is lacking on risk factors of graft loss in this specific population. Hypothermic perfusion machine, pre-implantation kidney biopsy, dual kidney transplantation and immunosuppressive strategies have been evaluated to improve the long-term prognosis of these grafts.

Outcomes with Tacrolimus-Based Immunosuppression After Kidney Transplantation from Standard- and Extended-Criteria Donors - A Post Hoc Analysis of the Prospective OSAKA Study

BACKGROUND This post hoc analysis of data from the prospective OSAKA study evaluated the efficacy and safety of prolonged- and immediate-release tacrolimus in patients who received kidneys from extended-criteria (ECD) and standard-criteria (SCD) donors. MATERIAL AND METHODS Within the ECD and SCD groups, patients were randomized to one of 4 tacrolimus-based regimens (initial dose): Arm 1, immediate-release tacrolimus (0.2 mg/kg/day); Arm 2, prolonged-release tacrolimus (0.2 mg/kg/day); Arm 3, prolonged-release tacrolimus (0.3 mg/kg/day); Arm 4, prolonged-release tacrolimus (0.2 mg/kg/day) plus basiliximab. All patients received mycophenolate mofetil and bolus corticosteroids; Arms 1-3 also received tapered corticosteroids. ECDs met the definition: living/deceased donors aged ≥60 years, or 50-60 years with ≥1 other risk factor, and donation after circulatory death. Primary composite endpoint: graft loss, biopsy-confirmed acute rejection or renal dysfunction by Day 168. Outcomes were compared across treatment arms with the chi-squared or Fisher's exact test. RESULTS A total of 1198 patients were included in the analysis (ECD: n=620 [51.8%], SCD: n=578 [48.2%]). Patients with kidneys from ECDs were older versus SCDs (mean age, 55.7 vs. 44.5 years, p<0.0001). A higher proportion of patients with kidneys from ECDs versus SCDs met the primary composite endpoint (56.8% vs. 32.4%, p<0.0001). However, no statistically significant differences in clinical outcomes or the incidence of treatment-emergent adverse events were seen between treatment arms within each donor group. CONCLUSIONS Worse outcomes were experienced in patients who received kidneys from ECDs versus SCDs. Prolonged-release tacrolimus provided similar graft survival to the immediate-release formulation, with a manageable tolerability profile.

Subclinical Changes in Deceased Donor Kidney Proteomes Are Associated With 12-month Allograft Function Posttransplantation-A Preliminary Study

Background

Cerebral injury during donation after brain death may induce systemic damage affecting long-term kidney function posttransplantation. Conventional evaluation of donor organ quality as a triage for transplantation is of limited utility.

Methods

We compared donor kidneys yielding opposing extremes of the continuum of posttransplantation outcomes by several common kidney biopsy evaluation techniques, including Kidney Donor Profile Index and Remuzzi scoring, and analyzed tissue from a minimal sample cohort using label-free quantitation mass spectrometry. Further assessment of the proteomic results was performed by orthogonal quantitative comparisons of selected key proteins by immunoblotting.

Results

We show that common evaluation techniques of kidney biopsies were not predictive for posttransplantation outcomes. In contrast, despite the limited cohort size, the proteomic analysis was able to clearly differentiate between kidneys yielding extreme posttransplantation outcome differences. Pathway analysis of the proteomic data suggested that outcome-related variance in protein abundance associated with profibrotic, apoptosis, and antioxidant proteins. Immunoblotting confirmation further supported this observation.

Conclusions

We present preliminary data indicating that there is scope for existing evaluation approaches to be supplemented by the analysis of proteomic differences. Furthermore, the observed outcome-related variance in a limited cohort was supported by immunoblotting and is consistent with mechanisms previously implicated in the development of injury and cytoprotection in kidney transplantation.

Proteomic analyses using mass spectrometry and immunoblot of a small cohort of kidneys from brain death donors is superior to predict graft function (estimated glomerular filtration rate at 3 and 12 months) versus clinical and histological standard classifications. Supplemental digital content is available in the text.

Comparison of graft and patient outcomes following kidney transplantation in extended hour and conventional haemodialysis patients

AIM

Differences in early graft function between kidney transplant recipients previously managed with either haemodialysis (HD) or peritoneal dialysis are well described. However, only two single-centre studies have compared graft and patient outcomes between extended hour and conventional HD patients, with conflicting results.

METHODS

This study compared the outcomes of all extended hour (≥24 h/week) and conventional HD patients transplanted in Australia and New Zealand between 2000 and 2014. The primary outcome was delayed graft function (DGF), defined in an ordinal manner as either a spontaneous fall in serum creatinine of less than 10% within 24 h, or the need for dialysis within 72 h following transplantation. Secondary outcomes included the requirement for dialysis within 72 h post-transplant, acute rejection, estimated glomerular filtration rate at 12 months, death-censored graft failure, all-cause and cardiovascular mortality, and a composite of graft failure and mortality.

RESULTS

A total of 4935 HD patients (378 extended hour HD, 4557 conventional HD) received a kidney transplant during the study period. Extended hour HD was associated with an increased likelihood of DGF compared with conventional HD (adjusted proportional odds ratio 1.33; 95% confidence interval 1.06-1.67). There was no significant difference between extended hour and conventional HD in terms of any of the secondary outcomes.

CONCLUSION

Compared to conventional HD, extended hour HD was associated with DGF, although long-term graft and patient outcomes were not different.

Strategies for an Expanded Use of Kidneys From Elderly Donors

The old-for-old allocation policy used for kidney transplantation (KT) has confirmed the survival benefit compared to remaining listed on dialysis. Shortage of standard donors has stimulated the development of strategies aimed to expand acceptance criteria, particularly of kidneys from elderly donors. We have systematically reviewed the literature on those different strategies. In addition to the review of outcomes of expanded criteria donor or advanced age kidneys, we assessed the value of the Kidney Donor Profile Index policy, preimplantation biopsy, dual KT, machine perfusion and special immunosuppressive protocols. Survival and functional outcomes achieved with expanded criteria donor, high Kidney Donor Profile Index or advanced age kidneys are poorer than those with standard ones. Outcomes using advanced age brain-dead or cardiac-dead donor kidneys are similar. Preimplantation biopsies and related scores have been useful to predict function, but their applicability to transplant or refuse a kidney graft has probably been overestimated. Machine perfusion techniques have decreased delayed graft function and could improve graft survival. Investing 2 kidneys in 1 recipient does not make sense when a single KT would be enough, particularly in elderly recipients. Tailored immunosuppression when transplanting an old kidney may be useful, but no formal trials are available.Old donors constitute an enormous source of useful kidneys, but their retrieval in many countries is infrequent. The assumption of limited but precious functional expectancy for an old kidney and substantial reduction of discard rates should be generalized to mitigate these limitations.

Efficacy and Safety Outcomes of Extended Criteria Donor Kidneys by Subtype: Subgroup Analysis of BENEFIT-EXT at 7 Years After Transplant

The phase III Belatacept Evaluation of Nephroprotection and Efficacy as First-Line Immunosuppression Trial-Extended Criteria Donors Trial (BENEFIT-EXT) study compared more or less intensive belatacept-based immunosuppression with cyclosporine (CsA)-based immunosuppression in recipients of extended criteria donor kidneys. In this post hoc analysis, patient outcomes were assessed according to donor kidney subtype. In total, 68.9% of patients received an expanded criteria donor kidney (United Network for Organ Sharing definition), 10.1% received a donation after cardiac death kidney, and 21.0% received a kidney with an anticipated cold ischemic time ≥24 h. Over 7 years, time to death or graft loss was similar between belatacept- and CsA-based immunosuppression, regardless of donor kidney subtype. In all three donor kidney cohorts, estimated mean GFR increased over months 1-84 for belatacept-based treatment but declined for CsA-based treatment. The estimated differences in GFR significantly favored each belatacept-based regimen versus the CsA-based regimen in the three subgroups (p < 0.0001 for overall treatment effect). No differences in the safety profile of belatacept were observed by donor kidney subtype.

Long-Term Outcomes in Belatacept- Versus Cyclosporine-Treated Recipients of Extended Criteria Donor Kidneys: Final Results From BENEFIT-EXT, a Phase III Randomized Study

In the Belatacept Evaluation of Nephroprotection and Efficacy as First-Line Immunosuppression Trial-Extended Criteria Donors (BENEFIT-EXT), extended criteria donor kidney recipients were randomized to receive belatacept-based (more intense [MI] or less intense [LI]) or cyclosporine-based immunosuppression. In prior analyses, belatacept was associated with significantly better renal function compared with cyclosporine. In this prospective analysis of the intent-to-treat population, efficacy and safety were compared across regimens at 7 years after transplant. Overall, 128 of 184 belatacept MI-treated, 138 of 175 belatacept LI-treated and 108 of 184 cyclosporine-treated patients contributed data to these analyses. Hazard ratios (HRs) comparing time to death or graft loss were 0.915 (95% confidence interval [CI] 0.625-1.339; p = 0.65) for belatacept MI versus cyclosporine and 0.927 (95% CI 0.634-1.356; p = 0.70) for belatacept LI versus cyclosporine. Mean estimated GFR (eGFR) plus or minus standard error at 7 years was 53.9 ± 1.9, 54.2 ± 1.9, and 35.3 ± 2.0 mL/min per 1.73 m² for belatacept MI, belatacept LI and cyclosporine, respectively (p < 0.001 for overall treatment effect). HRs comparing freedom from death, graft loss or eGFR <20 mL/min per 1.73 m² were 0.754 (95% CI 0.536-1.061; p = 0.10) for belatacept MI versus cyclosporine and 0.706 (95% CI 0.499-0.998; p = 0.05) for belatacept LI versus cyclosporine. Acute rejection rates and safety profiles of belatacept- and cyclosporine-based treatment were similar. De novo donor-specific antibody incidence was lower for belatacept (p ≤ 0.0001). Relative to cyclosporine, belatacept was associated with similar death and graft loss and improved renal function at 7 years after transplant and had a safety profile consistent with previous reports.

[Deceased donation in renal transplantation]

OBJECTIVES

To review epidemiologic data's and medical results of deceased donation in renal transplantation.

MATERIAL AND METHODS

Relevant publications were identified through Medline (http://www.ncbi.nlm.nih.gov) and Embase (http://www.embase.com) database using the following keywords, alone or in association, "brain death; cardiac arrest; deceased donation; organ procurement; transplantation". Articles were selected according to methods, language of publication and relevance. The reference lists were used to identify additional historical studies of interest. Both prospective and retrospective series, in French and English, as well as review articles and recommendations were selected. In addition, French national transplant and health agencies (http://www.agence-biomedecine.fr and http://www.has-sante.fr) databases were screened using identical keywords. A total of 2498 articles, 8 official reports and 17 newspaper articles were identified; after careful selection 157 publications were eligible for our review.

RESULTS

Deceased donation may involve either brain death or non-heartbeating donors (NHBD). Organ shortage led to the procurement of organs from expanded-criteria donors, with an increased age at donation and extended vascular disease, leading to inferior results after transplantation and underlining the need for careful donor management during brain death or cardiac arrest. Evolution of French legislation covering bioethics allowed procurement from Maastricht categories II and recently III non-heartbeating donors.

CONCLUSION

The increase of organ shortage emphasizes the need for a rigorous surgical technique during procurement to avoid loss of transplants. A history or current neoplasm in deceased-donors, requires attention to increase the pool of organs without putting the recipients at risk for cancer transmission. French NHBD program, especially from Maastricht category III, may stand for a potential source of valuable organs.

The Canadian experience using the expanded criteria donor classification for allocating deceased donor kidneys for transplantation

Background

Although the outcomes of transplantation with expanded criteria donor (ECD) kidneys are inferior to non-ECD transplants in the USA, the impact of the ECD classification on Canadian kidney transplant recipients is not known.

Objectives

The objective of the study was to assess the performance of the US-derived ECD classification among deceased donor kidney transplant recipients in a Canadian setting.

Design

This study was a population-based cohort study.

Setting

The study was conducted in all adult kidney transplant centers in the province of Ontario.

Patients

The patients were incident-deceased donor kidney transplant recipients from January 1, 2005 to March 31, 2011.

Measurements

Study subjects were identified through the Trillium Gift of Life Network and linked to healthcare databases in Ontario. ECD status was based on age, hypertension, kidney function, and stroke-related death. Outcomes of interest included graft loss, death, and delayed graft function.

Methods

The Kaplan-Meier product limit method was used to graphically assess time to graft loss or death. Multivariable Cox proportional hazards models were used to assess graft loss or death as a function of ECD status. Multivariable logistic regression models were fitted for the outcome of delayed graft function.

Results

Of 1422 deceased donor kidney transplants, 325 (23 %) were from ECDs. The median donor age was 63 vs. 42 years for ECD vs. non-ECD, respectively. The 5-year cumulative incidence of total graft loss was 29.2 % in ECD and 20.7 % in non-ECD kidney transplants. The relative hazards for total graft loss (HR 1.48 [95 % CI, 1.10; 2.00]) and death-censored graft loss (HR 1.80 [95 % CI, 1.19, 2.71]) were increased in ECD vs. non-ECD transplants. Increased relative risks were also observed for death and delayed graft function, albeit not statistically significant.

Limitations

Although comprehensive in coverage and outcome ascertainment, the available details on covariate data may be limited in large healthcare databases.

Conclusions

The ECD classification identifies kidneys at increased risk for graft loss in Canadian patients. The performance of more granular measures of donor risk (e.g., Kidney Donor Risk Index) and its impact on organ allocation/utilization in Canadian patients requires further study.

Electronic supplementary material

The online version of this article (doi:10.1186/s40697-016-0106-9) contains supplementary material, which is available to authorized users.

Comparison of survival outcomes between Expanded Criteria Donor and Standard Criteria Donor kidney transplant recipients: a systematic review and meta-analysis

In 2002, the United Network for Organ Sharing proposed increasing the pool of donor kidneys to include Expanded Criteria Donor (ECD). Outside the USA, the ECD definition remains the one used without questioning whether such a graft allocation criterion is valid worldwide. We performed a meta-analysis to quantify the differences between ECD and Standard Criteria Donor (SCD) transplants. We paid particular attention to select studies in which the methodology was appropriate and we took into consideration the geographical area. Thirty-two publications were included. Only five studies, all from the USA, reported confounder-adjusted hazard ratios comparing the survival outcomes between ECD and SCD kidney transplant recipients. These five studies confirmed that ECD recipients seemed to have poorer prognosis. From 29 studies reporting appropriate survival curves, we estimated the 5-year pooled nonadjusted survivals for ECD and SCD recipients. The relative differences between the two groups were lower in Europe than in North America, particularly for death-censored graft failure. It is of primary importance to propose appropriate studies for external validation of the ECD criteria in non-US kidney transplant recipients.

Emotional management and quality of life in mother living versus multi-organ donor renal transplant recipients

The aim of this study was to evaluate psychological differences and quality of life between kidney recipients from living (mother) and multi-organ donor. Overall, 40 patients who had undergone both living (mother) and multi-organ kidney transplantation 3-6 months before were asked to complete four self-report instruments: Toronto Alexithymia Scale, Short Form Health Survey, Regulatory Emotional Self-efficacy, and Attachment Style Questionnaire. A greater difficulty in emotional, social, and mental health functioning was found in recipients receiving kidney from mother living donor. Moreover, in these patients, higher levels of avoidant attachment dimensions were associated with a worse quality of life.

The risk of cancer in recipients of living-donor, standard and expanded criteria deceased donor kidney transplants: a registry analysis

BACKGROUND

Kidneys from expanded criteria deceased donors may elicit a strong inflammatory response, predisposing recipients to an increased risk of cancer after transplantation. We aimed to determine the association between donor types and cancer risk after kidney transplantation.

METHODS

Using the Australian and New Zealand Dialysis and Transplant Registry, we assessed the association between different donor types (living donor, standard, and expanded criteria deceased donors) and the risk of cancer after kidney transplantation using adjusted Cox proportional hazard and competing risk models.

RESULTS

Over a median follow-up period of 4.4 years in 7,040 patients (34,684 patient-years), 468 patients (6.6%) developed cancer. The overall risks for cancer were 1,080, 1,444, and 2,018 per 100,000 patient-years for recipients of living donor, standard, and expanded criteria deceased donor kidneys, respectively. Compared to recipients of living-donor kidneys, recipients of expanded criteria deceased donor kidneys were at an increased risk of cancer (adjusted hazard ratio [HR], 1.52; 95% confidence interval [95% CI], 1.15-2.02; P = 0.004), particularly for genitourinary cancer (adjusted HR, 1.79; 95% CI, 1.03-3.10; P = 0.038) and post-transplant lymphoproliferative disease (adjusted HR, 2.72; 95% CI, 1.38-5.37; P = 0.004).

CONCLUSION

Recipients of expanded criteria deceased donor kidneys are at substantially increased risk of cancer, especially cancers with a viral etiology. Allocation of expanded criteria deceased donor kidneys to potential recipients should balance the harms, such as the excess risk of cancer against the survival gains and quality-of-life benefits associated with transplantation.

Explaining failure through success: a critical analysis of reduction in road and stroke deaths as an explanation for Australia's low deceased organ donation rates

BACKGROUND/AIM

During the past two decades, Australian federal and state governments have funded many initiatives to bolster organ donation. Despite large investments of time, effort and money, Australia's deceased donation rate is in the bottom half of the Organisation for Economic Co-operation and Development countries and has only marginally increased from 11.9 donors per million people (pmp) in 1990 to 14.9 donors pmp in 2011. An often-cited explanation for this situation is that Australia's success in increasing levels of public health and safety through reduced traffic and stroke fatalities has reduced its number of potential deceased organ donors. We refer to this as the 'Failure Because of Success' hypothesis. Although commonly accepted, this hypothesis is largely untested.

METHODS

By analysing data from international donation and transplantation organisations and international public health and safety organisations, we compared historical deceased organ donation rates with traffic and stroke fatality rates in Australia and the seven countries with the world's highest deceased organ donation rates (Spain, Portugal, France, USA, Belgium, Austria and Italy).

RESULTS

Traffic fatality rates across all countries in the study have fallen dramatically during the time period, with Spain having the lowest traffic fatality rates. Stroke fatality rates demonstrate similar reductions, with France showing the lowest cerebral vascular accident mortality rates.

CONCLUSION

When compared with countries with the world's highest deceased donation rates, Australia's improvements to public health and safety through reductions in traffic and stroke fatalities were neither unique nor exemplary and do not provide an adequate explanation for its low organ donor rates.

Bayesian modeling of pretransplant variables accurately predicts kidney graft survival

INTRODUCTION

Machine learning can enable the development of predictive models that incorporate multiple variables for a systems approach to organ allocation. We explored the principle of Bayesian Belief Network (BBN) to determine whether a predictive model of graft survival can be derived using pretransplant variables. Our hypothesis was that pretransplant donor and recipient variables, when considered together as a network, add incremental value to the classification of graft survival.

METHODS

We performed a retrospective analysis of 5,144 randomly selected patients (age ≥18, deceased donor kidney only, first-time recipients) from the United States Renal Data System database between 2000 and 2001. Using this dataset, we developed a machine-learned BBN that functions as a pretransplant organ-matching tool.

RESULTS

A network of 48 clinical variables was constructed and externally validated using an additional 2,204 patients of matching demographic characteristics. This model was able to predict graft failure within the first year or within 3 years (sensitivity 40%; specificity 80%; area under the curve, AUC, 0.63). Recipient BMI, gender, race, and donor age were amongst the pretransplant variables with strongest association to outcome. A 10-fold internal cross-validation showed similar results for 1-year (sensitivity 24%; specificity 80%; AUC 0.59) and 3-year (sensitivity 31%; specificity 80%; AUC 0.60) graft failure.

CONCLUSION

We found recipient BMI, gender, race, and donor age to be influential predictors of outcome, while wait time and human leukocyte antigen matching were much less associated with outcome. BBN enabled us to examine variables from a large database to develop a robust predictive model.

Three-year outcomes from BENEFIT-EXT: a phase III study of belatacept versus cyclosporine in recipients of extended criteria donor kidneys

Recipients of extended-criteria donor (ECD) kidneys have poorer long-term outcomes compared to standard-criteria donor kidney recipients. We report 3-year outcomes from a randomized, phase III study in recipients of de novo ECD kidneys (n = 543) assigned (1:1:1) to either a more intensive (MI) or less intensive (LI) belatacept regimen, or cyclosporine. Three hundred twenty-three patients completed treatment by year 3. Patient survival with a functioning graft was comparable between groups (80% in MI, 82% in LI, 80% in cyclosporine). Mean calculated GFR (cGFR) was 11 mL/min higher in belatacept-treated versus cyclosporine-treated patients (42.7 in MI, 42.2 in LI, 31.5 mL/min in cyclosporine). More cyclosporine-treated patients (44%) progressed to GFR <30 mL/min (chronic kidney disease [CKD] stage 4/5) than belatacept-treated patients (27-30%). Acute rejection rates were similar between groups. Posttransplant lymphoproliferative disorder (PTLD) occurrence was higher in belatacept-treated patients (two in MI, three in LI), most of which occurred during the first 18 months; four additional cases (3 in LI, 1 in cyclosporine) occurred after 3 years. Tuberculosis was reported in two MI, four LI and no cyclosporine patients. In conclusion, at 3 years after transplantation, immunosuppression with belatacept resulted in similar patient survival, graft survival and acute rejection, with better renal function compared with cyclosporine. As previously reported, PTLD and tuberculosis were the principal safety findings associated with belatacept in this study population.

Donor age-specific injury and immune responses

Utilization rates of organs from elderly donors have shown the highest proportional increase during the last decade. Clinical reports support the concept of transplanting older organs. However, the engraftment of such organs has been linked to accelerated immune responses based on ageing changes per se and a proinflammatory environment subsequent to compromised injury and repair mechanism. We analyzed the clinical consequences of transplanting older donor organs and present mechanistic aspects correlating age, injury repair and effects on host immunoresponsiveness.

A review of utility-based allocation strategies to maximize graft years of deceased donor kidneys

With the continuing shortage of deceased donor kidneys coupled with a growing number of older potential recipients, there has been a greater acceptance of using older donor kidneys, including increased utility of expanded criteria donor (ECD) kidneys. In this review, we will look at the impact of using ECD kidneys on graft and patient survival, and to identify modifiable factors that may improve transplant outcomes in recipients receiving ECD kidneys. In addition, we will discuss whether the implementation of utility-based allocation strategies to maximize graft outcomes is an appropriate way forward to provide a better balance between utility and equity in the distribution of deceased donor kidneys.

Donor-recipient age matching improves years of graft function in deceased-donor kidney transplantation

BACKGROUND

Donor and recipient age in kidney transplantation are known to affect graft and patient survival. In deceased-donor (DD) transplantation, donor and recipient age matching are being increasingly accepted as part of the kidney allocation programme. The aims of this study are to evaluate the effect of donor and recipient age on transplant outcomes and to determine the effect of changing existing allocation criteria to allocation based on age matching of donors and recipients on total graft years of function.

METHODS

Using the Australia and New Zealand Dialysis and Transplant Registry, all DD kidney transplant recipients in Australia and New Zealand between 1991 and 2006 were analysed (n = 4616). Outcomes analysed were overall graft failure, death with functioning graft and serum creatinine. We calculated the mean time to graft loss ('years of graft function') for donor and recipient age cut-offs as 60 and 55 years, respectively, over up to 16 years follow-up. We then examined the gain in graft years if all older kidneys were allocated to older recipients.

RESULTS

Older donors were associated with higher risk of overall graft failure [adjusted hazard ratio (HR) = 1.79, 95% confidence interval (95% CI) = 1.45, 2.21 and HR = 1.29, 95% CI = 1.09, 1.53, respectively] at 1-8 years post-transplant and higher serum creatinine at 1 and 5 years post-transplant (mean differences 32.74 micromol/L, 95% CI 27.60, 37.89 and 38.17 micromol/L, 95% CI 27.58, 48.77, respectively). Overall, young and old recipients with young donor kidneys have an additional two to three mean graft years compared to those receiving older donor kidneys.

CONCLUSION

Donor and recipient age matching is an effective method of organ allocation to improve total graft years.