Age and the associations of living donor and expanded criteria donor kidneys with kidney transplant outcomes

Benefits of Living Over Deceased Donor Kidney Transplantation in Elderly Recipients. A Propensity Score Matched Analysis of a Large European Registry Cohort

Although kidney transplantation from living donors (LD) offers better long-term results than from deceased donors (DD), elderly recipients are less likely to receive LD transplants than younger ones. We analyzed renal transplant outcomes from LD versus DD in elderly recipients with a propensity-matched score. This retrospective, observational study included the first single kidney transplants in recipients aged ≥65 years from two European registry cohorts (2013-2020, n = 4,257). Recipients of LD (n = 408), brain death donors (BDD, n = 3,072), and controlled cardiocirculatory death donors (cDCD, n = 777) were matched for donor and recipient age, sex, dialysis time and recipient diabetes. Major graft and patient outcomes were investigated. Unmatched analyses showed that LD recipients were more likely to be transplanted preemptively and had shorter dialysis times than any DD type. The propensity score matched Cox's regression analysis between LD and BDD (387-pairs) and LD and cDCD (259-pairs) revealing a higher hazard ratio for graft failure with BDD (2.19 [95% CI: 1.16-4.15], p = 0.016) and cDCD (3.38 [95% CI: 1.79-6.39], p < 0.001). One-year eGFR was higher in LD transplants than in BDD and cDCD recipients. In elderly recipients, LD transplantation offers superior graft survival and renal function compared to BDD or cDCD. This strategy should be further promoted to improve transplant outcomes.

Age-modified risk factors for mortality of non-elderly adult kidney transplant recipients: a retrospective database analysis

PURPOSE

We aimed to investigate the role of the recipient's age strata in modifying the associations between risk factors and mortality in non-elderly adult kidney transplant (KT) recipients (KTR).

METHODS

We stratified 108,695 adult KTRs between 2000 and 2016 with conditional 1-year survival after KT into cohorts based on age at transplant: 18-49 years and 50-64 years. We excluded KTRs aged < 18 years or > / = 65 years. KTRs were observed for 5 years during the 2nd through 6th years post-KT for the outcome, all-cause mortality.

RESULTS

Increasing recipient age strata (18-49-year-old and 50-64-year-old) correlated with decreasing 6-year post-KT survival rates conditional on 1-year survival (79% and 57%, respectively, p < 0.0001). Middle adult age stratum was associated with a higher risk of all-cause mortality than young adult age stratum in KTRs of Hispanic/Latino and other races [HR = 1.23, 95% CI = 1.04-1.45 and HR = 1.51, 95% CI = 1.16-1.97, respectively] and with a primary native renal diagnosis of hypertension or glomerulonephritis [HR = 1.32, 95% CI = 1.12-1.55 and HR = 1.29, 95% CI = 1.10-151, respectively]. When compared with the young adult age stratum, the middle adult age stratum had a mitigating effect on the higher risk of mortality associated with sirolimus-mycophenolate or sirolimus-tacrolimus than the standard calcineurin inhibitor-mycophenolate regimen [HR = 0.75, 95% CI = 0.57-0.99 and HR = 0.71, 95% CI = 0.57-0.89, respectively].

CONCLUSION

Among adult non-elderly KTRs, the age strata, 18-49 years, and 50-64 years, have varying modifying effects on the strength and direction of associations between some specific risk factors and all-cause mortality.

Age Is Just a Number for Older Kidney Transplant Patients

The rise in the mean age of the global population has led to an increase in older kidney transplant (KT) patients. This demographic shift, coupled with the ongoing organ shortage, requires a nuanced understanding of which older adults are most suitable for KT. Recognizing the increased heterogeneity among older adults and the limitations of solely relying on chronological age, there is a need to explore alternative aging metrics beyond chronological age. In this review, we discuss the impact of older age on access to KT and postoperative outcomes. Emphasizing the need for a comprehensive evaluation that extends beyond chronological age, we explore alternative aging metrics such as frailty, sarcopenia, and cognitive function, underscoring their potential role in enhancing the KT evaluation process. Most importantly, we aim to contribute to the ongoing discourse, fostering an optimized approach to KT for the rapidly growing population of older adults.

Evolving Trends in Kidney Transplant Outcomes Among Older Adults: A Comparative Analysis Before and During the COVID-19 Pandemic

Background

Advancements in medical technology, healthcare delivery, and organ allocation resulted in improved patient/graft survival for older (age ≥65) kidney transplant (KT) recipients. However, the recent trends in these post-KT outcomes are uncertain in light of the mounting burden of cardiovascular disease, changing kidney allocation policies, heterogeneity in candidates' risk profile, and the coronavirus disease 2019 pandemic. Thus, we examined secular trends in post-KT outcomes among older and younger KT recipients over the last 3 decades.

Methods

We identified 73 078 older and 378 800 younger adult (aged 18-64) recipients using Scientific Registry of Transplant Recipients (1990-2022). KTs were grouped into 6 prepandemic eras and 1 postpandemic-onset era. Kaplan-Meier and Cox proportional hazards models were used to examine temporal trends in post-KT mortality and death-censored graft failure.

Results

From 1990 to 2022, a 19-fold increase in the proportion of older KT recipients was observed compared to a 2-fold increase in younger adults despite a slight decline in the absolute number of older recipients in 2020. The mortality risk for older recipients between 2015 and March 14, 2020, was 39% (adjusted hazard ratio [aHR] = 0.61, 95% confidence interval [CI], 0.50-0.75) lower compared to 1990-1994, whereas that for younger adults was 47% lower (aHR = 0.53, 95% CI, 0.48-0.59). However, mortality risk during the pandemic was 25% lower (aHR = 0.75, 95% CI, 0.61-0.93) in older adults and 37% lower in younger adults (aHR = 0.63, 95% CI, 0.56-0.70) relative to 1990-1994. For both populations, the risk of graft failure declined over time and was unaffected during the pandemic relative to the preceding period.

Conclusions

The steady improvements in 5-y mortality and graft survival were disrupted during the pandemic, particularly among older adults. Specifically, mortality among older adults reflected rates seen 20 y prior.

Longitudinal estimated glomerular filtration rate (eGFR) modeling in long-term renal function to inform clinical trial design in kidney transplantation

Kidney transplantation is the preferred treatment for individuals with end-stage kidney disease. From a modeling perspective, our understanding of kidney function trajectories after transplantation remains limited. Current modeling of kidney function post-transplantation is focused on linear slopes or percent decline and often excludes the highly variable early timepoints post-transplantation, where kidney function recovers and then stabilizes. Using estimated glomerular filtration rate (eGFR), a well-known biomarker of kidney function, from an aggregated dataset of 4904 kidney transplant patients including both observational studies and clinical trials, we developed a longitudinal model of kidney function trajectories from time of transplant to 6 years post-transplant. Our model is a nonlinear, mixed-effects model built in NONMEM that captured both the recovery phase after kidney transplantation, where the graft recovers function, and the long-term phase of stabilization and slow decline. Model fit was assessed using diagnostic plots and individual fits. Model performance, assessed via visual predictive checks, suggests accurate model predictions of eGFR at the median and lower 95% quantiles of eGFR, ranges which are of critical clinical importance for assessing loss of kidney function. Various clinically relevant covariates were also explored and found to improve the model. For example, transplant recipients of deceased donors recover function more slowly after transplantation and calcineurin inhibitor use promotes faster long-term decay. Our work provides a generalizable, nonlinear model of kidney allograft function that will be useful for estimating eGFR up to 6 years post-transplant in various clinically relevant populations.

The Independent Effects of Kidney Length and Vascular Plaque on Ten-Year Outcomes of Extended Criteria Donor Kidney Transplants

The independent effects of deceased donor kidney length and vascular plaque on long-term graft survival are not established. Utilizing DonorNet attachments from 4,480 expanded criteria donors (ECD) recovered between 2008 and 2012 in the United States with at least one kidney biopsied and transplanted, we analyzed the relationship between kidney length and vascular plaques and 10-year hazard of all-cause graft failure (ACGF) using causal inference methods in a Cox regression framework. The composite plaque score (range 0-4) and the presence of any plaque (yes, no) was also analyzed. Kidney length was modeled both categorically (<10, 10-12, >12 cm) as well as numerically, using a restricted cubic spline to capture nonlinearity. Effects of a novel composite plaque score 4 vs. 0 (HR 1.08; 95% CI: 0.96, 1.23) and the presence of any vascular plaque (HR 1.08; 95% CI: 0.98, 1.20) were attenuated after adjustment. Likewise, we identified a potential nonlinear relationship between kidney length and the 10-year hazard of ACGF, however the strength of the relationship was attenuated after adjusting for other donor factors. The independent effects of vascular plaque and kidney length on long-term ECD graft survival were found to be minimal and should not play a significant role in utilization.

Kidney Transplant Outcomes in Elderly Population: A Systematic Review and Meta-analysis

Context

Owing to population ageing, a growing number of kidney transplants (KTs) in elderly population are being performed. KT is the best treatment for patients with end-stage renal disease (ESRD). However, in older patients, the decision between dialysis and KT can be difficult due to potential inferior outcomes. Few studies have been published addressing this issue, and literature outcomes are controversial.

Objective

To conduct a systematic review and meta-analysis to appraise the evidence about outcomes of KT in elderly patients (>70 yr).

Evidence acquisition

A systematic review and meta-analysis (PROSPERO registration: CRD42022337038) was performed. Search was conducted on PubMed and LILACS databases. Comparative and noncomparative studies addressing outcomes (overall survival [OS], graft survival [GS], complications, delayed graft function [DGF], primary nonfunction, graft loss, estimated glomerular filtrate rate, or acute rejection) of KT in people older than 70 yr were included.

Evidence synthesis

Of the 10 357 yielded articles, 19 met the inclusion criteria (18 observational studies, one prospective multicentre study, and no randomised controlled trials), enrolling a total of 293 501 KT patients. Comparative studies reporting enough quantitative data for target outcomes were combined. There were significant inferior 5-yr OS (relative risk [RR], 1.66; 95% confidence interval [CI], 1.18-2.35) and 5-yr GS in the elderly group (RR, 1.37; 95% CI, 1.14-1.65) to those in the <70-yr group. Short-term GS at 1 and 3 yr was similar between groups, and similar findings occurred with DGF, graft loss, and acute rejection rates. Few data about postoperative complications were reported.

Conclusions

Elderly recipients have worse OS at all time points and long-term GS compared with younger recipients (<70 yr). Postoperative complications were under-reported and could not be assessed. The DGF, acute rejection, death with functioning graft, and graft loss were not inferior in elderly recipients. Geriatric assessment in this setting might be useful for selecting better elderly candidates for KT.

Patient summary

Compared with younger population, kidney transplant in elderly patients has inferior patient and graft survival outcomes in the long term.

Living Donor Kidney Transplantation in Older Individuals: An Ethical Legal and Psychological Aspects of Transplantation (ELPAT) View

Living donor transplantation is the optimal treatment for suitable patients with end-stage kidney disease. There are particular advantages for older individuals in terms of elective surgery, timely transplantation, and early graft function. Yet, despite the superiority of living donor transplantation especially for this cohort, older patients are significantly less likely to access this treatment modality than younger age groups. However, given the changing population demographic in recent decades, there are increasing numbers of older but otherwise healthy individuals with kidney disease who could benefit from living donor transplantation. The complex reasons for this inequity of access are explored, including conscious and unconscious age-related bias by healthcare professionals, concerns relating to older living donors, ethical anxieties related to younger adults donating to aging patients, unwillingness of potential older recipients to consider living donation, and the relevant legislation. There is a legal and moral duty to consider the inequity of access to living donor transplantation, recognising both the potential disparity between chronological and physiological age in older patients, and benefits of this treatment for individuals as well as society.

Older Age is Associated With Lower Utilization of Living Donor Kidney Transplant

Introduction

Older adults (65 years or older) constitute a substantial and increasing proportion of patients with kidney failure, potentially needing kidney replacement therapy. Living donor kidney transplant (LDKT) offers superior outcomes for suitable patients of all ages. However, exploring LDKT and finding a living donor could be challenging for older adults. Here, we assessed the association between age and utilization of LDKT and assessed effect modification of key variables such as ethnicity and language.

Methods

This is a retrospective cohort study of patients with kidney failure referred for kidney transplant (KT) assessment in Toronto between January 2006 and December 2013. The association between age and having a potential living donor identified was assessed using logistic regression and the association between age and the receipt of LDKT was assessed using Cox proportional hazards models.

Results

Of the 1617 participants, 50% were middle-aged (45-64 years old), and 17% were ≥65 years old. In our final multivariable adjusted models, compared to young adults, middle-aged and older adults had lower odds of having a potential living donor identified (odds ratio [OR], 0.47; confidence interval [CI], [0.35-0.63]; OR, 0.30; CI, [0.20-0.43]; P < 0.001, for middle-aged and older adults, respectively), and were less likely to receive LDKT (hazard ratio [HR], 0.79; CI, [0.63-0.99]; P = 0.04; HR, 0.47; CI, [0.30-0.72]; P = 0.001, for middle-aged and older adults, respectively.).

Conclusion

Age is an independent predictor of receiving LDKT. Considering that nearly 90% of patients with kidney failure in Canada are >45 years of age, these results point to important and potentially modifiable age-related barriers to LDKT.

Non-Immunologic Causes of Late Death-Censored Kidney Graft Failure: A Personalized Approach

Despite continuous advances in surgical and immunosuppressive protocols, the long-term survival of transplanted kidneys is still far from being satisfactory. Antibody-mediated rejection, recurrent autoimmune diseases, and death with functioning graft are the most frequent causes of late-kidney allograft failure. However, in addition to these complications, a number of other non-immunologic events may impair the function of transplanted kidneys and directly or indirectly lead to their failure. In this narrative review, we will list and discuss the most important nonimmune causes of late death-censored kidney graft failure, including quality of the donated kidney, adherence to prescriptions, drug toxicities, arterial hypertension, dyslipidemia, new onset diabetes mellitus, hyperuricemia, and lifestyle of the renal transplant recipient. For each of these risk factors, we will report the etiopathogenesis and the potential consequences on graft function, keeping in mind that in many cases, two or more risk factors may negatively interact together.

The Kidney Donor Profile Index (KDPI) Correlates With Histopathologic Findings in Post-reperfusion Baseline Biopsies and Predicts Kidney Transplant Outcome

Background

The increasing organ shortage in kidney transplantation leads to the necessity to use kidneys previously considered unsuitable for transplantation. Numerous studies illustrate the need for a better decision guidance rather than only the classification into kidneys from standard or expanded criteria donors referred to as SCD/ECD-classification. The kidney donor profile index (KDPI) exhibits a score utilizing a much higher number of donor characteristics. Moreover, graft biopsies provide an opportunity to assess organ quality.

Methods

In a single center analysis 383 kidney transplantations (277 after deceased and 106 after living donation) performed between January 1st, 2006, and December 31st, 2016, retrospectively underwent SCD/ECD and KDPI scoring. Thereby, the quality of deceased donor kidneys was assessed by using the KDPI and the living donor kidneys by using the living KDPI, in the further analysis merged as (L)KDPI. Baseline biopsies taken 10 min after the onset of reperfusion were reviewed for chronic and acute lesions. Survival analyses were performed using Kaplan-Meier analysis and Cox proportional hazards analysis within a 5-year follow-up.

Results

The (L)KDPI correlated with glomerulosclerosis (r = 0.30, p < 0.001), arteriosclerosis (r = 0.33, p < 0.001), interstitial fibrosis, and tubular atrophy (r = 0.28, p < 0.001) as well as the extent of acute tubular injury (r = 0.20, p < 0.001). The C-statistic of the (L)KDPI concerning 5-year death censored graft survival was 0.692. Around 48% of ECD-kidneys were classified as (L)KDPI<85%. In a multivariate Cox proportional hazard analysis including (preformed) panel reactive antibodies, cold ischemia time, (L)KDPI, and SCD/ECD-classification, the (L)KDPI was significantly associated with risk of graft loss (hazard ratio per 10% increase in (L)KDPI: 1.185, 95% confidence interval: 1.033–1.360, p = 0.025). Survival analysis revealed decreased death censored (p < 0.001) and non-death censored (p < 0.001) graft survival in kidneys with an increasing (L)KDPI divided into groups of <35, 35–85, and >85%, respectively.

Conclusion

With a higher granularity compared to the SCD/ECD-classification the (L)KDPI is a promising tool to judge graft quality. The correlation with chronic and acute histological lesions in post-reperfusion kidney biopsies underlines the descriptive value of the (L)KDPI. However, its prognostic value is limited and underlines the urgent need for a more precise prognostic tool adopted to European kidney transplant conditions.

A Statistical Prediction Model for Survival After Kidney Transplantation from Deceased Donors

Background

In an environment of limited kidney donation resources, patient recovery and survival after kidney transplantation (KT) are highly important. We used pre-operative data of kidney recipients to build a statistical model for predicting survivability after kidney transplantation.

Material/Methods

A dataset was constructed from a pool of patients who received a first KT in our hospital. For allogeneic transplantation, all donated kidneys were collected from deceased donors. Logistic regression analysis was used to change continuous variables into dichotomous ones through the creation of appropriate cut-off values. A regression model based on the least absolute shrinkage and selection operator (LASSO) algorithm was used for dimensionality reduction, feature selection, and survivability prediction. We used receiver operating characteristic (ROC) analysis, calibration, and decision curve analysis (DCA) to evaluate the performance and clinical impact of the proposed model. Finally, a 10-fold cross-validation scheme was implemented to verify the model robustness.

Results

We identified 22 potential variables from which 30 features were selected as survivability predictors. The model established based on the LASSO regression algorithm had shown discrimination with an area under curve (AUC) value of 0.690 (95% confidence interval: 0.557–0.823) and good calibration result. DCA demonstrated clinical applicability of the prognostic model when the intervention progressed to the possibility threshold of 2%. An average AUC value of 0.691 was obtained on the validation data.

Conclusions

Our results suggest that the proposed model can predict the mortality risk for patients after kidney transplants and could help kidney specialists choose kidney recipients with better prognosis.

Long-Term Results of Kidney Transplantation in the Elderly: Comparison between Different Donor Settings

With scarce organ supply, a selection of suitable elderly candidates for transplant is needed, as well as auditing the long-term outcomes after transplant. We conducted an observational cohort study among our patient cohort >60 years old with a long follow up. (1). Patients and Methods: We used our database to study the results after transplant for 593 patients >60 years old who underwent a transplant between 2000–2017. The outcome was compared between live donor (LD; n = 257) recipients, an old-to-old (OTO, n = 215) group using an extended criteria donor (ECD) kidney, and a young-to-old (YTO, n = 123) group using a standard-criteria donor. The Kaplan−Meir method was used to calculate the patient and graft survival and Cox regression analysis in order to find risk factors associated with death. (2). Results: The 5- and 10-year patient survival was significantly better in the LD group (92.7% and 66.9%) compared with the OTO group (73.3% and 42.8%) and YTO group (70.9% and 40.6%) (p < 0.0001). The 5- and 10-year graft survival rates were 90.3% and 68.5% (LD), 61.7% and 30.9% (OTO), and 64.1% and 39.9%, respectively (YTO group; p < 0.0001 between the LD and the two DD groups). There was no difference in outcome between patients in their 60’s and their 70’s. Factors associated with mortality included: age (HR-1.060), DM (HR-1.773), IHD (HR-1.510), and LD/DD (HR-2.865). (3). Conclusions: Our 17-years of experience seems to justify the rational of an old-to-old allocation policy in the elderly population. Live-donor transplant should be encouraged whenever possible. Each individual decision of elderly candidates for transplant should be based on the patient’s comorbidity and predicted life expectancy.

Multicenter registry analysis comparing survival on home hemodialysis and kidney transplant recipients in Australia and New Zealand

BACKGROUND

In the era of organ shortage, home hemodialysis (HHD) has been identified as the possible preferential bridge to kidney transplantation. Data are conflicting regarding the comparability of HHD and transplantation outcomes. This study aimed to compare patient and treatment survival between HHD patients and kidney transplant recipients.

METHODS

The Australia and New Zealand Dialysis and Transplant Registry was used to include incident HHD patients on Day 90 after initiation of kidney replacement therapy and first kidney-only transplant recipients in Australia and New Zealand from 1997 to 2017. Survival times were analyzed using the Kaplan-Meier product-limit method comparing HHD patients with subtypes of kidney transplant recipients using the log-rank test. Adjusted analyses were performed with multivariable Cox proportional hazards regression models for time to all-cause mortality. Time-to-treatment failure or death was assessed as a composite secondary outcome.

RESULTS

The study compared 1411 HHD patients with 4960 living donor (LD) recipients, 6019 standard criteria donor (SCD) recipients and 2427 expanded criteria donor (ECD) recipients. While LD and SCD recipients had reduced risks of mortality compared with HHD patients [LD adjusted hazard ratio (HR) = 0.57, 95% confidence interval (CI) 0.46-0.71; SCD HR = 0.65 95% CI 0.52-0.79], the risk of mortality was comparable between ECD recipients and HHD patients (HR = 0.90, 95% CI 0.73-1.12). LD, SCD and ECD kidney recipients each experienced superior time-to-treatment failure or death compared with HHD patients.

CONCLUSIONS

This large registry study showed that kidney transplant offers a survival benefit compared with HHD but that this advantage is not significant for ECD recipients.

Effects of Social Deprivation on the Proportion of Preemptive Kidney Transplantation: A Mediation Analysis

Social inequalities in health lead to an increased risk of chronic kidney disease and less access to renal transplantation. The objective of this study was to assess the association between social deprivation estimated by the fifth quintile of the European Deprivation Index (EDI) and preemptive kidney transplantation (PKT) and to explore the potential mediators of this association.

Methods

This retrospective observational multicenter study included 8701 patients who received their first renal transplant in France between 2010 and 2014. Mediation analyses were performed to assess the direct and indirect effects of the EDI on PKT.

Results

Among the 8701 transplant recipients, 32.4% belonged to the most deprived quintile of the EDI (quintile 5) and 16% received a PKT (performed either with a deceased- or living-donor). There was a significant association between quintile 5 of the EDI and PKT (total effect: odds ratio [OR]: 0.64 [95% confidence interval (CI): 0.55-0.73]). Living-donor kidney transplantation was the main mediator of this association (natural indirect effect: OR: 0.92 [0.89-0.95]). To a lesser extent, positive cytomegalovirus and hepatitis C serologies and blood group B were also mediators (respective natural indirect effects: OR: 0.98 [95% CI: 0.95-1.00], OR: 0.99 [95% CI: 0.99-1.00], and OR: 0.99 [95% CI: 0.98-1.00], P < 0.05).

Conclusions

Our study suggests that social deprivation is associated with a decreased proportion of PKT. This association might be mitigated by promoting living-donor transplantation.

[Living donor nephrectomy: The French guidelines from CTAFU]

OBJECTIVE

To propose surgical recommendations for living donor nephrectomy.

METHOD

Following a systematic approach, a review of the literature (Medline) was conducted by the CTAFU regarding functional and anatomical assessment of kidney donors, including which side the kidney should be harvested from. Distinct surgical techniques and approaches were evaluated. References were considered with a predefined process to propose recommendations with the corresponding levels of evidence.

RESULTS

The recommendations clarify the legal and regulatory framework for kidney donation in France. A rigorous assessment of the donor is one of the essential prerequisites for donor safety. The impact of nephrectomy on kidney function needs to be anticipated. In case of modal vascularization of both kidneys without a relative difference in function or urologic abnormality, removal of the left kidney is the preferred choice to favor a longer vein. Mini-invasive approaches for nephrectomy provide faster donor recovery, less donor pain and shorter hospital stay than open surgery.

CONCLUSION

These French recommendations must contribute to improving surgical management of candidates for kidney donation.

Kidney Transplant Outcomes in elderly Recipients: An Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry Study

BACKGROUND

There is an increase in elderly patients receiving kidney transplant internationally. This study describes elderly kidney transplant recipient outcomes in Australia and New Zealand.

METHODS

The study included all adult first kidney transplant recipients in Australia and New Zealand from 2000 to 2015. Survival and graft outcomes were compared between elderly (≥70 years) and younger (18-69 years) recipients using Cox proportional hazards regression.

RESULTS

Overall, 10651 kidney transplant recipients were included, of which 279 (2.6%) were elderly adults. The proportion of elderly recipients increased from 0.6 to 4.4% from 2000 to 2015. Compared with younger recipients, elderly recipients were more likely to receive kidneys from deceased donors, elderly donors, and expanded criteria donors. Elderly recipients experienced poorer patient survival with 1- and 5-year survival ranging from 96% to 97% and 79% to 81%, respectively, compared with 97% to 99% and 90% 95% in younger recipients, respectively. Elderly recipients experienced comparable rates of delayed graft function and, in living donor kidney recipients, lower rates of acute rejection.

CONCLUSIONS

Kidney transplantation in the elderly population is increasing. Although elderly recipients had inferior survival and graft outcomes, elderly recipients generally received poorer quality kidneys. The outcomes achieved in this cohort of elderly adults are encouraging, and improving elderly recipient outcomes should be an important focus for research.

KDIGO Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation

The 2020 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Management of Candidates for Kidney Transplantation is intended to assist health care professionals worldwide who evaluate and manage potential candidates for deceased or living donor kidney transplantation. This guideline addresses general candidacy issues such as access to transplantation, patient demographic and health status factors, and immunological and psychosocial assessment. The roles of various risk factors and comorbid conditions governing an individual's suitability for transplantation such as adherence, tobacco use, diabetes, obesity, perioperative issues, causes of kidney failure, infections, malignancy, pulmonary disease, cardiac and peripheral arterial disease, neurologic disease, gastrointestinal and liver disease, hematologic disease, and bone and mineral disorder are also addressed. This guideline provides recommendations for evaluation of individual aspects of a candidate's profile such that each risk factor and comorbidity are considered separately. The goal is to assist the clinical team to assimilate all data relevant to an individual, consider this within their local health context, and make an overall judgment on candidacy for transplantation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach. Guideline recommendations are primarily based on systematic reviews of relevant studies and our assessment of the quality of that evidence, and the strengths of recommendations are provided. Limitations of the evidence are discussed with differences from previous guidelines noted and suggestions for future research are also provided.

Outcomes of ABO-incompatible kidney transplantation in older patients: a national cohort study

BACKGROUND

Outcomes of ABO-incompatible living donor kidney transplantation (ABOi LDKT) in older individuals have not been established.

METHODS

This multicentric observational study, using data from the Korean Organ Transplantation Registry database, included 634 older patients (≥60 years) undergoing kidney transplantation. We compared clinical outcomes of ABOi LDKT (n = 80) with those of ABO-compatible LDKT (ABOc LDKT, n = 222) and deceased donor kidney transplantation (DDKT, n = 332) in older patients.

RESULTS

Death-censored graft survival was similar between the three groups (P = 0.141). Patient survival after ABOi LDKT was similar to that after ABOc LDKT (P = 0.489) but higher than that after DDKT (P = 0.038). In multivariable analysis, ABOi LDKT was not risk factor (hazard ratio [HR] 1.73, 95% confidence interval [CI] 0.29-10.38, P = 0.548), while DDKT was significant risk factor (HR 3.49, 95% CI 1.01-12.23, P = 0.049) for patient survival. Although ABOi LDKT showed higher biopsy-proven acute rejection than ABOc LDKT, the difference was not significant after adjustment with covariates. However, ABOi LDKT was significant risk factor for infection (HR 1.66, 95% CI 1.12-2.45, P = 0.012).

CONCLUSIONS

In older patients, ABOi LDKT was not inferior to ABOc LDKT and was superior to DDKT for patient survival. ABOi LDKT can be recommended for older patients, rather than waiting for DDKT.

The ageing kidney: Molecular mechanisms and clinical implications

As human life expectancy keeps increasing, ageing populations present a growing challenge for clinical practices. Human ageing is associated with molecular, structural, and functional changes in a variety of organ systems, including the kidney. During the ageing process, the kidney experiences progressive functional decline as well as macroscopic and microscopic histological alterations, which are accentuated by systemic comorbidities like hypertension and diabetes mellitus, or by preexisting or underlying kidney diseases. Although ageing per se does not cause kidney injury, physiologic changes associated with normal ageing processes are likely to impair the reparative capacity of the kidney and thus predispose older people to acute kidney disease, chronic kidney disease and other renal diseases. Mechanistically, cell senescence plays a key role in renal ageing, involving a number of cellular signaling mechanisms, many of which may be harnessed as international targets for slowing or even reversing kidney ageing. This review summarizes the clinical characteristics of renal ageing, highlights the latest progresses in deciphering the role of cell senescence in renal ageing, and envisages potential interventional strategies and novel therapeutic targets for preventing or improving renal ageing in the hope of maintaining long-term kidney health and function across the life course.

Young deceased donor kidneys show a survival benefit over older donor kidneys in transplant recipients aged 20-50 years: a study by the ERA-EDTA Registry

BACKGROUND

Updated survival outcomes of young recipients receiving young or old deceased donor kidneys are required when considering accepting a deceased donor kidney.

METHODS

We examined outcomes in 6448 European kidney allografts donated from younger (≥20-<50 years) and older (≥50-<70 years) deceased donors when transplanted into very young (≥20-<35 years) or young (≥35-<50 years) adult recipients. Outcomes of first kidney transplantations during 2000-13 and followed-up to 2015 were determined via competing risk, restricted mean survival and Cox regression methods.

RESULTS

The 10-year cumulative incidence of graft failure was lowest in very young {22.0% [95% confidence interval (95% CI) 19.1-24.9]} and young [15.3% (95% CI 13.7-16.9)] recipients of younger donor kidneys and highest in very young [36.7% (95% CI 31.9-41.5)] and young [29.2% (95% CI 25.1-33.2)] recipients of older donor kidneys. At the 10-year follow-up, younger donor kidneys had a 1 year (very young) or 9 months (young) longer mean graft survival time compared with older donor kidneys. Graft failure risk in younger donor kidneys was 45% [very young adjusted hazard ratio (aHR) 0.55 (95% CI 0.44-0.68)] and 40% [young aHR 0.60 (95% CI 0.53-0.67)] lower compared with older donor kidneys. A 1-year increase in donor age resulted in a 2% [very young aHR 1.02 (95% CI 1.00-1.04)] or 1% [young aHR 1.01 (95% CI 1.00-1.01)] increase in the 10-year risk of death.

CONCLUSIONS

Younger donor kidneys show survival benefits over older donor kidneys in adult recipients ages 20-50 years. Updated survival outcomes from older deceased donors are necessary due to advances in transplantation medicine and the increasing role these donors play in organ transplantation.

The Impact of Nationwide Allocation System on Kidney Transplantation: A Single-Center Experience

OBJECTIVES

Organ allocation is of decisive importance in the current situation of organ shortage. The aim of this study is to compare the long-term graft outcomes of deceased donor recipients before and after the new nationwide allocation system in Taiwan.

METHODS

From April 1, 2000 to March 31, 2010, 181 deceased kidney transplantations were reviewed retrospectively, and recipients were divided by the enforcement day (April 1, 2005) of nationwide allocation into group 1 (before) and group 2 (after). Baseline demographics were reviewed. Outcomes, including graft survival (GS) and patient survival, at 1-, 3-, 5-, and 10-years after transplantation were analyzed.

RESULTS

The baseline demography was similar between the 2 groups except that group 1 is younger. Group 2 has less HLA-B (P < .001) and HLA mismatches (P = .005). There were significantly more 0-mismatch recipients in group 2 (6 vs 27, P = .001), as well as extended criteria donor (ECD) recipients (0 vs 7). Group 2 has less optimal 1-year GS (95.6% vs 86.8%, Log-Rank P = .037), which becomes nonsignificant at 3-, 5-, and 10-years after transplantation. By excluding ECD recipients, the GS were similar at all time. There was no difference in patient survival between the 2 groups.

CONCLUSION

The new nationwide allocation system provided us more 0-mismatch kidneys. The nationwide scheme remains beneficial to kidney recipients after the acute adverse effects of ECD and aging vanish.

Comparative Analysis of Risk Factors in Declined Kidneys from Donation after Brain Death and Circulatory Death

Background and objectives: Kidneys from donation after circulatory death (DCD) are more likely to be declined for transplantation compared with kidneys from donation after brain death (DBD). The aim of this study was to evaluate characteristics in the biopsies of human DCD and DBD kidneys that were declined for transplantation in order to rescue more DCD kidneys. Materials and Methods: Sixty kidney donors (DCD = 36, DBD = 24) were recruited into the study and assessed using donor demographics. Kidney biopsies taken post cold storage were also evaluated for histological damage, inflammation (myeloperoxidase, MPO), von Willebrand factor (vWF) expression, complement 4d (C4d) deposition and complement 3 (C3) activation using H&E and immunohistochemistry staining, and Western blotting. Results: More DBD donors (16/24) had a history of hypertension compared with DCDs (8/36, p = 0.001). The mean warm ischemic time in the DCD kidneys was 12.9 ± 3.9 min. The mean cold ischemic time was not significantly different between the two groups of kidney donors (DBD 33.3 ± 16.7 vs. DCD 28.6 ± 14.1 h, p > 0.05). The score of histological damage and MPO, as well as the reactivity of vWF, C4d and C3, varied between kidneys, but there was no significant difference between the two donor types (p > 0.05). However, vWF reactivity might be an early indicator for loss of tissue integrity, while C4d deposition and activated C3 might be better predictors for histological damage. Conclusions: Similar characteristics of DCD were shown in comparison with DBD kidneys. Importantly, the additional warm ischemic time in DCD appeared to have no further detectable adverse effects on tissue injury, inflammation and complement activation. vWF, C4d and C3 might be potential biomarkers facilitating the evaluation of donor kidneys.

Usefulness of Kidney Donor Profile Index (KDPI) to predict graft survival in a South Brazilian Cohort

Introduction:

Kidney Donor Profile Index (KDPI) has been incorporated in the United States to improve the kidney transplant allocation system.

Objectives:

To evaluate deceased kidney donors’ profile using KDPI and compare to the previous United Network for Organ Sharing (UNOS) definition of expanded criteria donors (ECD) and assess the KDPI applicability to predict five-year graft survival and renal function in our sample.

Methods:

Retrospective cohort of 589 kidney transplants from deceased donors performed from January 2009 to May 2013 with follow-up until May 2018.

Results:

In 589 kidney transplants, 36.6% of donors were classified as ECD and 28.8% had KDPI ≥ 85%. Mean KDPI was 63.1 (95%CI: 60.8-65.3). There was an overlap of standard and ECD in KDPI between 60 and 95 and a significantly lower death-censored graft survival in KDPI ≥ 85% (78.6%); KDPI 0-20: 89.8%, KDPI 21-59: 91.6%, and KDPI 60-84: 83.0%; p = 0.006. The AUC-ROC was 0.577 (95%CI: 0.514-0.641; p = 0.027). Renal function at 5 years was significantly lower according to the incremental KDPI (p < 0.002). KDPI (HR 1.011; 95%CI 1.001-1.020; p = 0.008), donor-specific antibodies (HR 2.77; 95%CI 1.69-4.54; p < 0.001), acute rejection episode (HR 1.73; 95%CI 1.04-2.86; p = 0.034) were independent and significant risk factors for death-censored graft loss at 5 years.

Conclusion:

In our study, 36.6% were classified as ECD and 28.8% had KDPI ≥ 85%. KDPI score showed a moderate power to predict graft survival at 5 years. Renal function was significantly lower in patients with higher KDPI.

Impact of Pre-Transplant Malignancy on Outcomes After Kidney Transplantation: United Network for Organ Sharing Database Analysis

BACKGROUND

Kidney transplant recipients with a history of a pre-transplant malignancy (pre-TM) have an increased risk of post-transplant malignancies (post-TM) and suspected inferior long-term outcomes. No large database studies have examined modern day trends and outcomes in this patient population compared with those without a pre-TM.

STUDY DESIGN

The United Network for Organ Sharing (UNOS) database was queried for primary adult kidney transplant recipients with pre-TM. Outcomes were compared in patients with and without pre-TM from 2004 to 2016 using multivariable Cox proportional hazard analyses (n = 170,684).

RESULTS

The rate of kidney transplants in patients with pre-TM increased from <1% of all kidney transplants in 1994 (n = 77) to 8.3% in 2016 (n = 1,329). Pre-TM was associated with development of post-TM (hazard ratio [HR] 1.77 CI 1.68, 1.86), all cause (HR 1.22 CI 1.18, 1.27), and death-censored graft failure (HR 1.08 CI 1.02, 1.15) between 2004 and 2016. The 5-year all cause graft failure rate was 28% for pre-TM patients and 22% for non-pre-TM patients. Pre-TM was associated with decreased patient survival (5-year 80% vs 88% and HR 1.23 CI 1.18, 1.28). Of the deceased, more pre-TM patients died of malignancy (19% vs 11%).

CONCLUSIONS

Increasing numbers of patients with pre-TM are undergoing kidney transplantation. This analysis indicates that patients with pre-TM are at increased risk of post-TM, graft loss, and decreased overall survival. The study's limitations highlight the need for collaborative database development between transplant and cancer registries to better define the inter-relationship between a pre-TM and cancer survivorship vs freedom from prolonged dialysis.

Risk Factors for 1-Year Graft Loss After Kidney Transplantation: Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVES

With expansion of the pool of kidney grafts, through the use of higher-risk donors, and increased attention to donor management strategies, the 1-year graft survival rate is subject to change. It is, therefore, useful to elucidate 1-year graft survival rates by dissecting the characteristics of the low-risk and high-risk kidney transplant cases. The objective of our study was to evaluate factors purported to influence the risk of 1-year graft loss in kidney transplant recipients.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We searched bibliographic databases from 2000 to 2017 and included observational studies that measured the association between donor, recipient, the transplant operation, or early postoperative complications, and 1-year death-censored graft loss.

RESULTS

We identified 35 eligible primary studies, with 20 risk factors amenable to meta-analysis. Six factors were associated with graft loss, with moderate to high degree of certainty: donor age (hazard ratio [HR], 1.11 per 10-year increase; 95% confidence interval [95% CI], 1.04 to 1.18), extended criteria donors (HR, 1.35; 95% CI, 1.28 to 1.42), deceased donors (HR, 1.54; 95% CI, 1.32 to 1.82), number of HLA mismatches (HR, 1.08 per one mismatch increase; 95% CI, 1.07 to 1.09), recipient age (HR, 1.17 per 10-year increase; 95% CI, 1.09 to 1.25), and delayed graft function (HR, 1.89; 95% CI, 1.46 to 2.47) as risk factors for 1-year graft loss. Pooled analyses also excluded, with a high degree of certainty, any associations of cold ischemia time, recipient race, pretransplant body mass index, diabetes, and hypertension with 1-year graft loss.

CONCLUSIONS

Recipient age, donor age, standard versus extended criteria donor, living versus deceased donor, HLA mismatch, and delayed graft function all predicted 1-year graft survival. The effect of each risk factor is small.

Fractures and Subsequent Graft Loss and Mortality among Older Kidney Transplant Recipients

OBJECTIVES

Older adults who undergo kidney transplantation (KT) are living longer with a functioning graft and are at risk for age-related adverse events including fractures. Understanding recipient, transplant, and donor factors and the outcomes associated with fractures may help identify older KT recipients at increased risk. We determined incidence of hip, vertebral, and extremity fractures; assessed factors associated with incident fractures; and estimated associations between fractures and subsequent death-censored graft loss (DCGL) and mortality.

DESIGN

This was a prospective cohort study of patients who underwent their first KT between January 1, 1999, and December 31, 2014.

SETTING

We linked data from the Scientific Registry of Transplant Recipients to Medicare claims through the US Renal Data System.

PARTICIPANTS

The analytic population included 47 815 KT recipients aged 55 years or older.

MEASUREMENTS

We assessed the cumulative incidence of and factors associated with post-KT fractures (hip, vertebral, or extremity) using competing risks models. We estimated risk of DCGL and mortality after fracture using adjusted Cox proportional hazards models.

RESULTS

The 5-year incidence of post-KT hip, vertebral, and extremity fracture for those aged 65 to 69 years was 2.2%, 1.0%, and 1.7%, respectively. Increasing age was associated with higher hip (adjusted hazard ratio [aHR] = 1.37 per 5-y increase; 95% confidence interval [CI] = 1.30-1.45) and vertebral (aHR = 1.31; 95% CI = 1.20-1.42) but not extremity (aHR = .97; 95% CI = .91-1.04) fracture risk. DCGL risk was higher after hip (aHR = 1.34; 95% CI = 1.12-1.60) and extremity (aHR = 1.30; 95% CI = 1.08-1.57) fracture. Mortality risk was higher after hip (aHR = 2.31; 95% CI = 2.11-2.52), vertebral (aHR = 2.80; 95% CI = 2.44-3.21), and extremity (aHR = 1.85; 95% CI = 1.64-2.10) fracture.

CONCLUSION

Our findings suggest that older KT recipients are at higher risk for hip and vertebral fracture but not extremity fracture; and those with hip, vertebral, or extremity fracture are more likely to experience subsequent graft loss or mortality. These findings underscore that different fracture types may have different underlying etiologies and risks, and they should be approached accordingly. J Am Geriatr Soc 67:1680-1688, 2019.

Kidney transplant registries: How to optimise their utility?

The scientific Registries (RE) in renal transplantation (Tx) are very useful since they allow us to identify risk factors in this population and facilitate contrasting the information with other national and international registries, contributing to establishing strategies which improve outcomes in terms of survival. They constitute an organised and planned system that uses observational methods and standardised systematic processes, including adjusted risk models, to essentially evaluate survival outcomes. The scientific RE are complemented with clinical trials providing scientific evidence, but inexcusably need adequate statistical analysis to generate reliable clinical data that contribute to optimising the prognosis of the transplant population. In addition, scientific RE provide valuable information on the performance of Tx programmes and help generate prognostic indexes, which could contribute to improving survival. Under these prerequisites, this review will assess the following aspects related to the scientific RE in the Tx: 1) the concept and importance of implementing RE in Tx; 2) the measures that are needed for the correct execution of the scientific RE; 3) the benefits, quality and limitations of RE; 4) the statistical tools for the adequate analysis of survival; and 5) utility of RE in the evaluation of performance, quality and surveillance of transplant programmes and the generation of comorbidity índices.

A Retrospective Cohort Study on Rehospitalization following Expanded Criteria Donor Kidney Transplantation

Background

Expanded criteria donor (ECD) kidneys are commonly used but are associated with increased graft failure. Graft failure is in turn related to rehospitalization within thirty days post transplant. Our goal was to determine whether ECD kidneys independently lead to rehospitalization within 30 days, 1 year, and 2 years after transplant.

Methods

All adult first-time recipients of deceased donor kidneys transplanted from 2003-2012 at our center were reviewed. Models included demographics, medical comorbidities, center for disease control high-risk kidney, ECD kidney, ischemia times, cause of renal failure, immunosuppressive regimen, positive psychiatric screening, alcoholism, surgeon, year the transplant was performed, years on dialysis before transplant, and the number of inpatient hospitalizations within 6 months prior to transplant. We conducted Andersen-Gill modeling and propensity score matching followed by logistic regression. We also used multivariable linear regression to predict average length of stay during rehospitalization.

Results

More ECD patients had a rehospitalization at 1 year (70.3% versus 59%, log-rank test p=0.014). Thirty-day and 2-year time marks were not significant. Andersen-Gill models predicting successive hospitalizations yielded HR of 1.42 (p=0.002) and 1.32 (p=0.015) for ECD patients at 1 and 2 years of after transplantation, respectively. Propensity score matching and logistic regression showed a significant relative risk of 1.630 at one year (p=0.033) and 1.313 at two years (p=0.268). There was no significant association between ECD and subsequent lengths of hospital stay.

Conclusion

Receiving an ECD kidney is independently associated with multiple readmissions within 2 years of transplant but unrelated to length of stay.

Factors Considered by Nephrologists in Excluding Patients from Kidney Transplant Referral

BACKGROUND

Provider perceptions about patient candidacy for kidney transplant (KT) are potentially significant contributors to disparities in KT.

OBJECTIVE

To examine nephrologists' perceptions about factors that are important in excluding patients from KT referral, and to analyze the association between these perceptions and nephrologists' demographic and practice characteristics.Methods: Invitations were sent to 3180 nephrologists. Among those who consented, 822 fulfilled the inclusion criteria, and 250 were randomly invited to complete a questionnaire about perceptions of factors essential in deciding not to refer patients for KT.

RESULTS

Responses from 216 participants with complete responses were analyzed. The 3 most common reasons for excluding patients were "patient's inadequate social support" (44%), "limited understanding of the process due to patient's inadequate education" (32%), and "patient's age above 65" (26%). Nephrologists practicing in rural settings were more likely to consider inadequate support and limited education of patients as reasons not to refer for KT. In multivariate analysis, physicians with 2 or fewer transplant centers within 50 miles were more likely to report inadequate social support (OR: 3.15, 95% CI: 1.59-6.24) and age greater than 65 years (OR: 1.88, 95% CI: 1.01-3.49) as reasons to exclude patients from KT referral. Nephrologists whose practice included patients majority of whom had not completed high school were more likely to consider limited understanding due to inadequate education as an important reason to exclude patients from KT (OR: 3.31, 95% CI: 1.60-6.86).

CONCLUSION

Patient's social support, understanding, and age were the most common factors regarded by nephrologists as important in not referring patients for KT evaluation. Practice location, particularly rural setting, proximity to a transplant center, and the education level of a nephrologist's patient population were important determinants of referral for KT.

Kidney transplantation in older recipients: Preemptive high KDPI kidney vs lower KDPI kidney after varying dialysis vintage

AIM

To evaluate the outcomes of transplanting marginal kidneys preemptively compared to better-quality kidneys after varying dialysis vintage in older recipients.

METHODS

Using OPTN/United Network for Organ Sharing database from 2001-2015, we identified deceased donor kidney (DDK) transplant recipients > 60 years of age who either underwent preemptive transplantation of kidneys with kidney donor profile index (KDPI) ≥ 85% (marginal kidneys) or received kidneys with KDPI of 35%-84% (better quality kidneys that older wait-listed patients would likely receive if waited longer) after being on dialysis for either 1-4 or 4-8 years. Using a multivariate Cox model adjusting for donor, recipient and transplant related factors- overall and death-censored graft failure risks along with patient death risk of preemptive transplant recipients were compared to transplant recipients in the 1-4 and 4-8 year dialysis vintage groups.

RESUTLS

The median follow up for the whole group was 37 mo (interquartile range of 57 mo). A total of 6110 DDK transplant recipients above the age of 60 years identified during the study period were found to be eligible to be included in the analysis. Among these patients 350 received preemptive transplantation of kidneys with KDPI ≥ 85. The remaining patients underwent transplantation of better quality kidneys with KDPI 35-84% after being on maintenance dialysis for either 1-4 years (n = 3300) or 4-8 years (n = 2460). Adjusted overall graft failure risk and death-censored graft failure risk in preemptive high KDPI kidney recipients were similar when compared to group that received lower KDPI kidney after being on maintenance dialysis for either 1-4 years (HR 1.01, 95%CI: 0.90-1.14, P = 0.84 and HR 0.96, 95%CI: 0.79-1.16, P = 0.66 respectively) or 4-8 years (HR 0.82, 95%CI: 0.63-1.07, P = 0.15 and HR 0.81, 95%CI: 0.52-1.25, P = 0.33 respectively). Adjusted patient death risk in preemptive high KDPI kidney recipients were similar when compared to groups that received lower KDPI kidney after being on maintenance dialysis for 1-4 years (HR 0.99, 95%CI: 0.87-1.12, P = 0.89) but lower compared to patients who were on dialysis for 4-8 years (HR 0.74, 95%CI: 0.56-0.98, P = 0.037).

CONCLUSION

In summary, our study supports accepting a “marginal” quality high KDPI kidney preemptively in older wait-listed patients thus avoiding dialysis exposure.

Experiences With Expanded Criteria Donors: 10-Year Analysis of the Martin, Slovakia Transplant Center

OBJECTIVES

Kidneys from expanded criteria donors with diagnosis of brain death have become a part of the organ transplant program, which have thus increased the number of transplants.

MATERIALS AND METHODS

In this retrospective analysis, we identified the expanded criteria donors in a group of 156 kidney donors at our center. Basic parameters of the donors before kidney recovery were collected. Graft function, graft survival, and patient survival at 1, 3, and 5 years posttransplant were compared in expanded criteria versus standard criteria donors.

RESULTS

Expanded criteria donors were significantly older than standard criteria donors (P < .001), had higher body mass index (P = .006), and had more frequent arterial hypertension (P < .001) and diabetes mellitus (P = .004) in their histories. When we considered the estimated glomerular filtration rate, graft function in the first 6 months after transplant was significantly worse in kidneys from expanded criteria donors (P = .011). In addition, recipients of grafts from expanded criteria donors had significantly worse survival in the first year posttransplant (P = .023); however, no differences in graft survival were observed.

CONCLUSIONS

From the long-term aspect, graft function and graft and patient survival in cases of kidneys from expanded criteria donors were comparable to results with kidneys from standard criteria donors. Expanded use of organs available for transplant is important due to the constantly increasing demands versus limited offers of organs.

Identifying Outcomes that Are Important to Living Kidney Donors: A Nominal Group Technique Study

BACKGROUND AND OBJECTIVES

Living kidney donor candidates accept a range of risks and benefits when they decide to proceed with nephrectomy. Informed consent around this decision assumes they receive reliable data about outcomes they regard as critical to their decision making. We identified the outcomes most important to living kidney donors and described the reasons for their choices.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Previous donors were purposively sampled from three transplant units in Australia (Sydney and Melbourne) and Canada (Vancouver). In focus groups using the nominal group technique, participants identified outcomes of donation, ranked them in order of importance, and discussed the reasons for their preferences. An importance score was calculated for each outcome. Qualitative data were analyzed thematically.

RESULTS

Across 14 groups, 123 donors aged 27-78 years identified 35 outcomes. Across all participants, the ten highest ranked outcomes were kidney function (importance=0.40, scale 0-1), time to recovery (0.27), surgical complications (0.24), effect on family (0.22), donor-recipient relationship (0.21), life satisfaction (0.18), lifestyle restrictions (0.18), kidney failure (0.14), mortality (0.13), and acute pain/discomfort (0.12). Kidney function and kidney failure were more important to Canadian participants, compared with Australian donors. The themes identified included worthwhile sacrifice, insignificance of risks and harms, confidence and empowerment, unfulfilled expectations, and heightened susceptibility.

CONCLUSIONS

Living kidney donors prioritized a range of outcomes, with the most important being kidney health and the surgical, lifestyle, functional, and psychosocial effects of donation. Donors also valued improvements to their family life and donor-recipient relationship. There were clear regional differences in the rankings.

Propensity score-based comparison of the graft failure risk between kidney transplant recipients of standard and expanded criteria donor grafts: Toward increasing the pool of marginal donors

From a prospective and multicentric French cohort, we proposed an external validation study for the expanded criteria donor (ECD), based on 4833 kidney recipients transplanted for the first time between 2000 and 2014. We estimated the subject-specific effect from a multivariable Cox model. We confirmed a 1.75-fold (95% confidence interval [CI] 1.53-2.00, P < .0001) increase in graft failure risk if a given patient received an ECD graft compared to a graft from a donor with standard criteria (standard criteria donor [SCD]). Complementarily, we estimated the population-average effect using propensity scores. We estimated a 1.34-fold (95% CI 1.09-1.64, P = .0049) increase in graft failure risk among ECD patients receiving an ECD graft compared to receiving a SCD graft. With a 10-year follow-up, it corresponded to a decrease of 8 months of the mean time to graft failure due to ECD transplantation (95% CI 2-14 months). The population-average relative risk due to ECD transplantation and the corresponding absolute effect seem finally not so high. Regarding the increase of quality of life in transplantation, our study constitutes an argument to extend the definition of marginality by considering more grafts at high risk and thereby enlarging the pool of kidney grafts.

Access to kidney transplantation in European adults aged 75-84 years and related outcomes: an analysis of the European Renal Association-European Dialysis and Transplant Association Registry

To what extent access to, and allocation of kidney transplants and survival outcomes in patients aged ≥75 years have changed over time in Europe is unclear. We included patients aged ≥75-84 years (termed older adults) receiving renal replacement therapy in thirteen European countries between 2005 and 2014. Country differences and time trends in access to, and allocation of kidney transplants were examined. Survival outcomes were determined by Cox regression analyses. Between 2005 and 2014, 1392 older adult patients received 1406 transplants. Access to kidney transplantation varied from ~0% (Slovenia, Greece and Denmark) to ~4% (Norway and various Spanish regions) of all older adult dialysis patients, and overall increased from 0.3% (2005) to 0.9% (2014). Allocation of kidney transplants to older adults overall increased from 0.8% (2005) to 3.2% (2014). Seven-year unadjusted patient and graft survival probabilities were 49.1% (95% confidence interval, 95% CI: 43.6; 54.4) and 41.7% (95% CI: 36.5; 46.8), respectively, with a temporal trend towards improved survival outcomes. In conclusion, in the European dialysis population aged ≥75-84 years access to kidney transplantation is low, and allocation of kidney transplants remains a rare event. Though both are increasing with time and vary considerably between countries. The trend towards improved survival outcomes is encouraging. This information can aid informed decision-making regarding treatment options.

Mortality in Elderly Waiting-List Patients Versus Age-Matched Kidney Transplant Recipients: Where is the Risk?

The number of elderly patients on the waiting list (WL) for kidney transplantation (KT) has risen significantly in recent years. Because KT offers a better survival than dialysis therapy, even in the elderly, candidates for KT should be selected carefully, particularly in older waitlisted patients. Identification of risk factors for death in WL patients and prediction of both perioperative risk and long-term post-transplant mortality are crucial for the proper allocation of organs and the clinical management of these patients in order to decrease mortality, both while on the WL and after KT. In this review, we examine the clinical results in studies concerning: a) risk factors for mortality in WL patients and KT recipients; 2) the benefits and risks of performing KT in the elderly, comparing survival between patients on the WL and KT recipients; and 3) clinical tools that should be used to assess the perioperative risk of mortality and predict long-term post-transplant survival. The acknowledgment of these concerns could contribute to better management of high-risk patients and prophylactic interventions to prolong survival in this particular population, provided a higher mortality is assumed.

Results of Kidney Transplantation from Expanded Criteria Donors: A Single-Center Experience

BACKGROUND

Collection of kidneys from extended criteria donors (ECD) with diagnosed brain-death forms a part of the collection program that increases the number of transplantations.

OBJECTIVE

To compare the results of ECD with those of standard criteria donors (SCD).

METHODS

In a retrospective analysis in a group of 156 kidney donors, we identified ECD donors. We detected the basic parameters of the donors before kidney collection, and then evaluated the function of the graft, the survival of the graft, and the survival of the patients after 1, 3, and 5 years of transplantation. The results were then compared with the function of the graft from those of SCD donors.

RESULTS

The ECD donors were significantly (p<0.001) older than the SCD donors. They had a higher body mass index (p=0.006) and prevalence of hypertension (p<0.001) and diabetes mellitus (p=0.004) compared to SCD donors. The graft function within the first 6 months and the survival of recipients in the first year of transplantation were significantly worse in ECD than in SCD groups (p=0.01, and 0.023, respectively). No difference in the graft survival was observed between the two groups.

CONCLUSION

The long-term function of the graft and survival of patients and grafts in recipients of kidneys from ECD donors are comparable to SCD donors. Exploitation of the given organs for transplantation is important due to the constantly increasing demand versus limited offer of organs.

Patient and Graft Survival Among Sexagenarian and Septuagenarian Renal Transplant Recipients and Donors: The Context for Older Recipients

Due to the increasing number of patients with end-stage renal disease, there is a growing demand for transplants for recipients and donors aged 60 years and older. Using data from the Scientific Registry of Transplant Recipients, we performed survival analyses and multivariate logistic regression to help guide transplant professional decisions regarding the selection of graft type (living vs deceased) and donor age (60-69 vs 70+ years) for recipients aged 60 years and older.

[Focusing on kidney transplantation in the elderly]

Due to the increase in life expectancy and the ageing of end-stage renal disease patients, the number of patients older than 65 years receiving a kidney transplant has been continuously growing over the last fifteen years. The benefits of renal transplantation compared to dialysis in terms of survival and quality of life have been shown in selected recipients over 65, or 70 years. However, the age remains the main limiting factor for the access to the waiting list, and the reluctance of the clinicians can be explained by the multiple comorbidities of these candidates, their limited life expectancy or the shortage of grafts. The challenge is to select the candidates who can benefit from renal transplantation, thanks to rigorous cardiovascular and neoplastic evaluation before enrolment and by taking into account the specific characteristics of elderly patients. The living donor appears to be the ideal option for elderly recipients, the alternative being the extended criteria donor, allowing waiting times to be limited. The choice of immunosuppressive therapy is also crucial in these patients at high risk of infectious and cardiovascular complications in whom the occurrence of acute rejection can have severe consequences. There are currently no specific recommendations for immunosuppression in elderly recipients, and we would need large-scale randomized studies to improve the prognosis of renal transplantation in this population.

Reversal of Arterial Stiffness and Maladaptative Arterial Remodeling After Kidney Transplantation

BACKGROUND

Chronic kidney disease is characterized by stiffening, thinning, dilatation, and increased circumferential wall stress of large arteries, associated with increased cardiovascular risk. Kidney transplantation (KT) reverses many pathological features of chronic kidney disease and improves life expectancy; however, longitudinal studies exploring the impact of KT on recipient large arteries are scarce.

METHODS AND RESULTS

This study was designed to appraise arterial changes following KT. Carotid-femoral pulse wave velocity, carotid remodeling (circumferential wall stress and carotid internal diameter), and stiffness were measured in 161 consecutive recipients receiving either a living (n=49) or a deceased (n=112) donor allograft, at 3 and 12 months after transplantation. Mean pulse wave velocity decreased from 10.8 m/s (95% confidence interval, 10.5-11.2 m/s) (at month 3) to 10.1 m/s (95% confidence interval, 9.8-10.5 m/s) (at month 12) (P<0.001). After multivariate adjustment, pulse wave velocity reduction from month 3 to month 12 was significantly larger in the living donor allograft KT (P<0.001). Circumferential wall stress decreased, 70 kPa (95% confidence interval, 68-72 kPa) to 64 kPa (95% confidence interval, 62-67 kPa), as well as carotid internal diameter and carotid stiffness (P<0.001 for all). Reductions in circumferential wall stress, diameter, and stiffness were significantly larger in the living donor allograft KT (P<0.001). When deceased donor allograft patients were classified into standard and expanded criteria donors, changes in both pulse wave velocity and circumferential wall stress were blunted in expanded criteria donors. Changes were independent of graft function and blood pressure changes.

CONCLUSIONS

Large-artery stiffness and maladaptive carotid artery remodeling of chronic kidney disease is partially reversed within 12 months of KT and appears unrelated to renal function. Improvements were independently associated with live organ donation. Our data suggest that expanded criteria donors may hamper vascular recovery.

Predictive Score for Posttransplantation Outcomes

BACKGROUND

Most current scoring tools to predict allograft and patient survival upon kidney transplantion are based on variables collected posttransplantation. We developed a novel score to predict posttransplant outcomes using pretransplant information including routine laboratory data available before or at the time of transplantation.

METHODS

Linking the 5-year patient data of a large dialysis organization to the Scientific Registry of Transplant Recipients, we identified 15 125 hemodialysis patients who underwent first deceased transplantion. Prediction models were developed using Cox models for (a) mortality, (b) allograft loss (death censored), and (c) combined death or transplant failure. The cohort was randomly divided into a two thirds set (Nd = 10 083) for model development and a one third set (Nv = 5042) for validation. Model predictive discrimination was assessed using the index of concordance, or C statistic, which accounts for censoring in time-to-event models (a-c). We used the bootstrap method to assess model overfitting and calibration using the development dataset.

RESULTS

Patients were 50 ± 13 years of age and included 39% women, 15% African Americans, and 36% persons with diabetes. For prediction of posttransplant mortality and graft loss, 10 predictors were used (recipients' age, cause and length of end-stage renal disease, hemoglobin, albumin, selected comorbidities, race and type of insurance as well as donor age, diabetes status, extended criterion donor kidney, and number of HLA mismatches). The new model (www.TransplantScore.com) showed the overall best discrimination (C-statistics, 0.70; 95% confidence interval [95% CI], 0.67-0.73 for mortality; 0.63; 95% CI, 0.60-0.66 for graft failure; 0.63; 95% CI, 0.61-0.66 for combined outcome).

CONCLUSIONS

The new prediction tool, using data available before the time of transplantation, predicts relevant clinical outcomes and may perform better to predict patients' graft survival than currently used tools.

Design and approach of the Living Organ Video Educated Donors (LOVED) program to promote living kidney donation in African Americans

PURPOSE

To describe the rationale, methodology, design, and interventional approach of a mobile health education program designed for African Americans with end stage renal disease (ESRD) to increase knowledge and self-efficacy to approach others about their need for a living donor kidney transplant (LDKT).

METHODS

The Living Organ Video Educated Donors (LOVED) program is a theory-guided iterative designed, mixed methods study incorporating three phases: 1) a formative evaluation using focus groups to develop program content and approach; 2) a 2-month proof of concept trial (n=27) to primarily investigate acceptability, tolerability and investigate increases of LDKT knowledge and self-efficacy; and 3) a 6-month, 2-arm, 60-person feasibility randomized control trial (RCT) to primarily investigate increases in LDKT knowledge and self-efficacy, and secondarily, to increase the number of living donor inquiries, medical evaluations, and LDKTs. The 8-week LOVED program includes an interactive web-based app delivered on 10″ tablet computer incorporating weekly interactive video education modules, weekly group video chat sessions with an African American navigator who has had LDKT and other group interactions for support and improve strategies to promote their need for a kidney.

RESULTS

Phase 1 and 2 have been completed and the program is currently enrolling for the feasibility RCT. Phase 2 experienced 100% retention rates with 91% adherence completing the video modules and 88% minimum adherence to the video chat sessions.

CONCLUSIONS

We are in the early stages of an RCT to evaluate the LOVED program; to date, we have found high tolerability reported from Phase 2.