Risk Factors for Early Graft Failure and Death After Kidney Transplantation in Recipients Older Than 70 Years

Longitudinal non-targeted metabolomic profiling of urine samples for monitoring of kidney transplantation patients

The assessment of kidney function within the first year following transplantation is crucial for predicting long-term graft survival. This study aimed to develop a robust and accurate model using metabolite profiles to predict early long-term outcomes in patient groups at the highest risk of early graft loss. A group of 61 kidney transplant recipients underwent thorough monitoring during a one-year follow-up period, which included a one-week hospital stay and follow-up assessments at three and six months. Based on their 12-month follow-up serum creatinine levels: Group 2 had levels exceeding 1.5 mg/dl, while Group 1 had levels below 1.5 mg/dl. Metabolites were detected by mass spectrometer and first pre-processed. Univariate and multivariate statistical analyses were employed to identify significant differences between the two groups. Nineteen metabolites were found to differ significantly in the 1st week, and seventeen metabolites in the 3rd month (adjusted p-value < 0.05, quality control (QC) < 30, a fold change (FC) > 1.1 or a FC < 0.91, Variable Influence on Projection (VIP) > 1). However, no significant differences were observed in the 6th month. These distinctive metabolites mainly belonged to lipid, fatty acid, and amino acid categories. Ten models were constructed using a backward conditional approach, with the best performance seen in model 5 for Group 2 at the 1st-week mark (AUC 0.900) and model 3 at the 3rd-month mark (AUC 0.924). In conclusion, the models developed in the early stages may offer potential benefits in the management of kidney transplant patients.

ACEI/ARB Use within One Year of Kidney Transplant is Associated with Less AKI and Graft Loss in Elderly Recipients

BACKGROUND

Optimizing long-term graft survival remains a major focus in transplant. Elderly kidney transplant recipients are vulnerable to acute kidney injury (AKI) and graft loss. This study assessed the safety and efficacy of ACEI/ARB in elderly kidney transplant recipients and impact on graft outcomes.

METHODS

Retrospective, longitudinal, cohort study of 500 patients age ≥60 years, who underwent kidney transplantation between 2005-2015. Demographic, transplant, and outcomes data were collected. Manual chart abstraction was conducted to determine medication use at discharge, one, three, and five years post-transplant. Univariate and multivariable Cox regression modeling were used to analyze outcomes.

RESULTS

Mean age of subjects was 66 years (range 60-81). 59% were males and 50% were African-American. 49% had chronic kidney disease (CKD) due to diabetes mellitus (DM). A total of 38, 134, 167, and 112 elderly kidney transplant recipients were on ACEI/ARB at discharge, one, three, and five years post-transplant respectively. ACEI/ARB initiated within one year of transplant was associated with lower risk of graft loss (HR=0.62, CI 0.38-0.99, p=0.047). This was driven mainly by a lower risk of death (HR=0.41, CI 0.24-0.71, p=0.002). ACEI/ARB use was associated with lower risk of AKI after 1 year (HR 0.70, CI 0.52-0.95, p=0.02). ACEI/ARB was not associated with increased risk of acute rejection or hospitalization.

CONCLUSION

Initiation of ACEI/ARB within one year of transplant is associated with lower risk of AKI and graft loss, driven by lower risk of death in elderly kidney transplant recipients. Clinicians should maximize ACEI/ARB therapy early on after kidney transplant.

Design, cohort profile and comparison of the KTD-Innov study: a prospective multidimensional biomarker validation study in kidney allograft rejection

There is an unmet need for robust and clinically validated biomarkers of kidney allograft rejection. Here we present the KTD-Innov study (ClinicalTrials.gov, NCT03582436), an unselected deeply phenotyped cohort of kidney transplant recipients with a holistic approach to validate the clinical utility of precision diagnostic biomarkers. In 2018-2019, we prospectively enrolled consecutive adult patients who received a kidney allograft at seven French centers and followed them for a year. We performed multimodal phenotyping at follow-up visits, by collecting clinical, biological, immunological, and histological parameters, and analyzing a panel of 147 blood, urinary and kidney tissue biomarkers. The primary outcome was allograft rejection, assessed at each visit according to the international Banff 2019 classification. We evaluated the representativeness of participants by comparing them with patients from French, European, and American transplant programs transplanted during the same period. A total of 733 kidney transplant recipients (64.1% male and 35.9% female) were included during the study. The median follow-up after transplantation was 12.3 months (interquartile range, 11.9-13.1 months). The cumulative incidence of rejection was 9.7% at one year post-transplant. We developed a distributed and secured data repository in compliance with the general data protection regulation. We established a multimodal biomarker biobank of 16,736 samples, including 9331 blood, 4425 urinary and 2980 kidney tissue samples, managed and secured in a collaborative network involving 7 clinical centers, 4 analytical platforms and 2 industrial partners. Patients' characteristics, immune profiles and treatments closely resembled those of 41,238 French, European and American kidney transplant recipients. The KTD-Innov study is a unique holistic and multidimensional biomarker validation cohort of kidney transplant recipients representative of the real-world transplant population. Future findings from this cohort are likely to be robust and generalizable.

Transplant Candidates of 70+ Years Have Superior Survival If Receiving Pre-Emptively a Living Donor Kidney

Background: The number of kidney transplant recipients over 70 years of age is increasing but detailed data on patient and graft survival in the modern era of immune suppression are few. Methods: A single-center cohort of patients of 70 years and older (n = 349) at time of kidney transplantation from 2010-2020 were followed until January 2023. Results: The median age was 73 years with a median follow-up of 4.3 years. Fifty percent of recipients of a living donor kidney (LDK, n = 143) received their graft pre-emptively. Cumulative death-censored graft survival was excellent in the LDK group and reached 98% at 5 years vs. 85% in the deceased donor kidney (DDK) group. Primary non-function (38%) and rejection (43%) were the major causes of graft loss in the first year after DDK transplantation. Rejection-related graft loss was 4.6% during follow-up. Median recipient survival was superior in the subgroup of pre-emptively transplanted LDK patients compared to non-pre-emptively LDK transplanted patients (11.1 versus 6.2 years). Non-pre-emptively transplanted patients had a significantly increased incidence of infection (HR 3.81, 1.46-9.96) and cardiovascular-related causes of death (HR 3.35, 1.16-9.71). Pre-emptive transplantation was also associated with a significantly improved graft survival in the DDK recipients but this result was confounded by significantly better HLA matching and younger donor age in this group. Conclusions: Pre-emptive LDK transplantation in patients of 70 years or older confers superior graft and recipient survival.

Impact of Immunosenescence in Older Kidney Transplant Recipients: Associated Clinical Outcomes and Possible Risk Stratification for Immunosuppression Reduction

The number of older individuals receiving a kidney transplant as replacement therapy has significantly increased in the past decades and this increase is expected to continue. Older patients have a lower rate of acute rejection but an increased incidence of death with a functioning graft. Several factors, including an increased incidence of infections, post-transplant malignancy and cardiovascular comorbidity and mortality, contribute to this increased risk. Notwithstanding, kidney transplantation is still the best form of kidney replacement therapy in all patients with chronic kidney disease, including in older individuals. The best form of immunosuppression and the optimal dose of these medications in older recipients remains a topic of discussion. Pharmacological studies have usually excluded older patients and when included, patients were highly selected and their numbers insignificant to draw a reasonable conclusion. The reduced incidence of acute rejection in older recipients has largely been attributed to immunosenescence. Immunosenescence refers to the aging of the innate and adaptive immunity, accumulating in phenotypic and functional changes. These changes influences the response of the immune system to new challenges. In older individuals, immunosenescence is associated with increased susceptibility to infectious pathogens, a decreased response after vaccinations, increased risk of malignancies and cardiovascular morbidity and mortality. Chronic kidney disease is associated with premature immunosenescent changes, and these are independent of aging. The immunosenescent state is associated with low-grade sterile inflammation termed inflammaging. This chronic low-grade inflammation triggers a compensatory immunosuppressive state to avoid further tissue damage, leaving older individuals with chronic kidney disease in an immune-impaired state before kidney transplantation. Immunosuppression after transplantation may further enhance progression of this immunosenescent state. This review covers the role of immunosenescence in older kidney transplant recipients and it details present knowledge of the changes in chronic kidney disease and after transplantation. The impact of immunosuppression on the progression and complications of an immunosenescent state are discussed, and the future direction of a possible clinical implementation of immunosenescence to individualize/reduce immunosuppression in older recipients is laid out.

Impact of Early Rejection Treatment on Infection Development in Kidney Transplant Recipients: A Propensity Analysis

Introduction

The impact of renal allograft rejection treatment on infection development has not been formally defined in the literature.

Methods

We conducted a retrospective cohort study of 185 rejection (case) and 185 nonrejection (control) kidney transplant patients treated at our institution from 2014 to 2020 to understand the impact of rejection on infection development. Propensity scoring was used to match cohorts. We collected data for infections within 6 months of rejection for the cases and 18 months posttransplant for controls.

Results

In 370 patients, we identified 466 infections, 297 in the controls, and 169 in the cases. Urinary tract infections (38.9%) and cytomegalovirus viremia (13.7%) were most common. Cumulative incidence of infection between the case and controls was 2.17 (CI 1.54-3.05); p < 0.001. There was no difference in overall survival (HR 0.90, CI 0.49-1.66) or graft survival (HR 1.27, CI 0.74-2.20) between the groups. There was a significant difference in overall survival (HR 2.28, CI 1.14-4.55; p = 0.019) and graft survival (HR 1.98, CI 1.10-3.56; p = 0.023) when patients with infection were compared to those without.

Conclusions

As previously understood, rejection treatment is a risk factor for subsequent infection development. Our data have defined this relationship more clearly. This study is unique, however, in that we found that infections, but not rejection, negatively impacted both overall patient survival and allograft survival, likely due to our institution's robust post-rejection protocols. Clinicians should monitor patients closely for infections in the post-rejection period and have a low threshold to treat these infections while also restarting appropriate prophylaxis.

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.

Influence of Surgical Complications on Outcomes in Kidney Transplantation Patients

BACKGROUND/AIM

With the increasing use of marginal donors, it is important to identify factors for outcomes in kidney transplantation. The aim of the present study was to evaluate the influence of surgical complications for graft survival after kidney transplantation and identify risk factors for surgical complications.

PATIENTS AND METHODS

We performed a retrospective cohort study by chart review of patients who underwent kidney transplantation at the Taichung Veterans General Hospital in the period from 2007 to 2018.

RESULTS

Of the 433 patients who underwent kidney transplantation, 57 experienced surgical complications with an occurrence rate of 13.2%. The most common complications were vascular complications (n=31; 7.2%), followed by urologic (n=9; 2%) and wound (n=9; 2%) complications. From univariate analyses, risk factors for surgical complications were cold ischemia time, blood loss, operation time, number of vascular anastomoses and year of operation. From univariate and multivariate analyses, operation time was associated to surgical complications. Patients with surgical complications experienced worse both one-year and five-year death-censored graft and patient survival.

CONCLUSION

Surgical complications were associated with higher risk of death-censored graft failure and mortality. Cold ischemia time, blood loss, operation time, number of vascular anastomoses and year of operation were risk factors for surgical complications. Efforts should aim to minimize surgical complications to improve both graft and patient survival.

Survival after kidney transplantation compared with ongoing dialysis for people over 70 years of age: A matched-pair analysis

Kidney transplantation offers improved survival and quality of life compared to dialysis for most recipients; however, benefits for elderly patients (>70 years) remain uncertain. Using the Australia and New Zealand Dialysis and Transplant Registry (2009-2019), elderly transplant recipients were matched to a waitlisted dialysis patient by age, cause of end-stage kidney disease, and dialysis duration (paired controls). We censored dialysis patients at the time of transplant. Survival was compared using stratified Cox regression. Elderly transplant recipients (KTRs) (n = 465) were matched to waitlisted pairs. Transplant group mortality initially exceeded dialysis due to excess infection-related deaths (1.9 transplant versus 0.3 dialysis/100 patient-years, P = .03). Beyond month 9, a progressive survival benefit in favor of transplantation was apparent. Over a median follow-up of 1.7 years, mortality was 38% lower for KTRs (95% confidence interval 0.41-0.94, P = .02), and 5-year survival was 80% KTRs vs 53% dialysis (P < .001). Recipients of living and standard criteria donor kidneys acquired immediate survival advantage compared with dialysis, while recipients of expanded criteria donor's kidneys experienced elevated risk of death for the first 17 months. Compared with remaining on dialysis, elderly KTRs incur an increased risk of early posttransplant mortality but thereafter may anticipate progressively superior survival rates.

A paired-kidney allocation study found superior survival with HLA-DR compatible kidney transplants in the Eurotransplant Senior Program

The Eurotransplant Senior Program (ESP) has expedited the chance for elderly patients with kidney failure to receive a timely transplant. This current study evaluated survival parameters of kidneys donated after brain death with or without matching for HLA-DR antigens. This cohort study evaluated the period within ESP with paired allocation of 675 kidneys from donors 65 years and older to transplant candidates 65 years and older, the first kidney to 341 patients within the Eurotransplant Senior DR-compatible Program and 334 contralateral kidneys without (ESP) HLA-DR antigen matching. We used Kaplan-Meier estimates and competing risk analysis to assess all cause mortality and kidney graft failure, respectively. The log-rank test and Cox proportional hazards regression were used for comparisons. Within ESP, matching for HLA-DR antigens was associated with a significantly lower five-year risk of mortality (hazard ratio 0.71; 95% confidence interval 0.53-0.95) and significantly lower cause-specific hazards for kidney graft failure and return to dialysis at one year (0.55; 0.35-0.87) and five years (0.73; 0.53-0.99) post-transplant. Allocation based on HLA-DR matching resulted in longer cold ischemia (mean difference 1.00 hours; 95% confidence interval: 0.32-1.68) and kidney offers with a significantly shorter median dialysis vintage of 2.4 versus 4.1 yrs. in ESP without matching. Thus, our allocation based on HLA-DR matching improved five-year patient and kidney allograft survival. Hence, our paired allocation study suggests a superior outcome of HLA-DR matching in the context of old-for-old kidney transplantation.

Multiview Clustering to Identify Novel Kidney Donor Phenotypes for Assessing Graft Survival in Older Transplant Recipients

Key Points

An unsupervised machine learning clustering algorithm identified distinct deceased kidney donor phenotypes among older recipients. Recipients of certain donor phenotypes were at a relatively higher risk of all-cause graft loss even after accounting for recipient factors. The use of unsupervised clustering to support kidney allocation systems may be an important area for future study.

Background

Older transplant recipients are at a relatively increased risk of graft failure after transplantation, and some of this risk may relate to donor characteristics. Unsupervised clustering using machine learning may be a novel approach to identify donor phenotypes that may then be used to evaluate outcomes for older recipients. Using a cohort of older recipients, the purpose of this study was to (1 ) use unsupervised clustering to identify donor phenotypes and (2 ) determine the risk of death/graft failure for recipients of each donor phenotype.

Methods

We analyzed a nationally representative cohort of kidney transplant recipients aged 65 years or older captured using the Scientific Registry of Transplant Recipients between 2000 and 2017. Unsupervised clustering was used to generate phenotypes using donor characteristics inclusive of variables in the kidney donor risk index (KDRI). Cluster assignment was internally validated. Outcomes included all-cause graft failure (including mortality) and delayed graft function. Differences in the distribution of KDRI scores were also compared across the clusters. All-cause graft failure was compared for recipients of donor kidneys from each cluster using a multivariable Cox survival analysis.

Results

Overall, 23,558 donors were separated into five clusters. The area under the curve for internal validation of cluster assignment was 0.89. Recipients of donor kidneys from two clusters were found to be at high risk of all-cause graft failure relative to the lowest risk cluster (adjusted hazards ratio, 1.86; 95% confidence interval, 1.69 to 2.05 and 1.73; 95% confidence interval, 1.61 to 1.87). Only one of these high-risk clusters had high proportions of donors with established risk factors (i.e. , hypertension, diabetes). KDRI scores were similar for the highest and lowest risk clusters (1.40 [1.18–1.67] and 1.37 [1.15–1.65], respectively).

Conclusions

Unsupervised clustering can identify novel donor phenotypes comprising established donor characteristics that, in turn, may be associated with different risks of graft loss for older transplant recipients.

Factors Influencing Short-Term Patient Survival in Elderly Kidney Transplant Recipients

BACKGROUND

For the average patient with end-stage renal disease, kidney transplantation improves quality of life and prolongs survival compared with patients on the transplant waiting list who remain on dialysis. Patients ≥65 years of age represent an increasing proportion of adults with end-stage renal disease, and kidney transplantation outcomes remain controversial in this population. The aim of this study was to evaluate factors that may increase 1-year mortality after renal transplantation in older recipients.

METHODS

A retrospective study that included 147 patients (75.5% men) ≥65 years old (mean age 67.5 ± 2 years) who were transplanted between January 2011 and December 2020. The mean follow-up was 52.6 ± 27.2 months.

RESULTS

Rehospitalization (<1 year) occurred in 39.5% of patients. Infectious complications were present in 18.4% of patients. The overall mortality rate was 23.1%, and 1-year mortality was 6.8%. As 1-year mortality predictors, we found a positive correlation with factors related to kidney transplant, such as cold ischemia time (P = .003), increasing donor age (P = .001); and factors related to the receptor such as pretransplantation dialysis modality as peritoneal dialysis (P = .04), cardiovascular disease (P = .004), delayed graft function (P = .002), early cardiovascular complications after kidney transplant (P < .001), and early rehospitalizations (P < .001). No correlation was found between 1-year mortality and age, sex, race, body mass index, and type of kidney transplant.

CONCLUSION

A more rigorous pretransplant evaluation, focusing on cardiovascular disease and strict exclusion criteria, is recommended for patients ≥65 years old.

Imlifidase for Kidney Transplantation of Highly Sensitized Patients With a Positive Crossmatch: The French Consensus Guidelines

Imlifidase recently received early access authorization for highly sensitized adult kidney transplant candidates with a positive crossmatch against an ABO-compatible deceased donor. These French consensus guidelines have been generated by an expert working group, in order to homogenize patient selection, associated treatments and follow-up. This initiative is part of an international effort to analyze properly the benefits and tolerance of this new costly treatment in real-life. Eligible patients must meet the following screening criteria: cPRA ≥ 98%, ≤ 65-year of age, ≥ 3 years on the waiting list, and a low risk of biopsy-related complications. The final decision to use Imlifidase will be based on the two following criteria. First, the results of a virtual crossmatch on recent serum, which shall show a MFI for the immunodominant donor-specific antibodies (DSA) > 6,000 but the value of which does not exceed 5,000 after 1:10 dilution. Second, the post-Imlifidase complement-dependent cytotoxicity crossmatch must be negative. Patients treated with Imlifidase will receive an immunosuppressive regimen based on steroids, rATG, high dose IVIg, rituximab, tacrolimus and mycophenolic acid. Frequent post-transplant testing for DSA and systematic surveillance kidney biopsies are highly recommended to monitor post-transplant DSA rebound and subclinical rejection.

Incidence and Causes of Early Hospital Readmissions After Living-Donor Renal Transplant at King Abdulaziz Medical City, Riyadh

BACKGROUND

 Living-donor organ transplant has a higher long-term survival rate compared to deceased-donor organ transplant, with kidney transplantation being the optimal treatment for most kidney failure patients. However, early hospital readmission within 30 days of discharge can occur due to various factors and can negatively affect long-term outcomes. Effective communication with patients pre-and post-transplant is crucial for a better quality of life and for reducing readmissions. Chronic kidney disease and co-morbid conditions must also be addressed for better long-term outcomes. The incidence and causes of early hospital readmission vary depending on local characteristics and other factors.

METHODS

 A retrospective cohort study of outcomes in patients who underwent living-donor renal transplantation at King Abdulaziz Medical City (KAMC) between 2015 and 2022. Data were collected by chart review using the BestCare system. The data collected included patients' demographics, comorbidities, surgery-related data, and the outcome of transplantation. The categorical data were presented using percentages and frequencies, while the numerical data were presented as mean and standard deviation. The Chi-square test was used for inferential statistics to find the association between categorical variables.

RESULTS

 Regarding sociodemographic characteristics, the majority of patients were male, aged 19-50 years, and either overweight or had obesity class 1. The incidence of complications, graft failure, and mortality after renal transplant was low, with only a small percentage of patients experiencing these outcomes within one year of transplant. There is no significant association between gender, age, BMI, and the likelihood of readmission after renal transplantation. Patients with comorbidities such as hypertension, diabetes, and coronary artery disease had a higher likelihood of readmission after renal transplantation. The study provides an association between readmission after renal transplantation and various factors such as surgical complications, previous transplant, age at transplant, graft failure, and mortality. Out of the 107 readmitted patients, 2.8% had surgical complications, and 5.6% had a previous transplant, but the association was not statistically significant.

CONCLUSION

 Early hospital readmission within 30 days of discharge can be a concern for patients undergoing renal transplants. While the incidence of complications, graft failure, and mortality after renal transplant was low, patients with comorbidities such as hypertension, diabetes, and coronary artery disease had a higher likelihood of readmission after renal transplantation. Although the association between surgical complications and readmission was not statistically significant, it is important to continue monitoring this factor in future studies. Effective communication with patients pre-and post-transplant can play a crucial role in reducing readmissions and improving long-term outcomes.

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.

Maximizing opportunities for kidney transplantation in older adults

PURPOSE OF REVIEW

To summarize the current state of evidence related to the outcomes of older adults who need and receive kidney transplants, and strategies to facilitate appropriate transplant access in this at-risk group.

RECENT FINDINGS

Older adults are a rapidly growing subgroup of the kidney transplant waitlist. Compared to younger adults, older kidney transplant recipients have increased mortality after kidney transplant and lower death-censored graft survival. In determining suitability for transplantation in older patients, clinicians must balance procedural and immunosuppression-related risk with incremental survival when compared with dialysis. To appropriately increase access to transplantation in this population, clinicians and policy makers consider candidates' chronological age and frailty, as well as the quality of and waiting time for a donated allograft. Given risk of deterioration prior to transplant, candidates should be rapidly evaluated, listed, and transplanted using living donor and or less than ideal deceased donor organs when available.

SUMMARY

Access to transplantation for older adults can be increased through targeted interventions to address frailty and reduce waiting times through optimized organ use. Focused study and educational interventions for patients and providers are needed to improve the outcomes of this vulnerable group.

CYP3A5 Expressor Genotype of the Transplanted Kidney Increases the Risk of Preterm Graft Loss and Acute Rejection

INTRODUCTION

Tacrolimus is metabolized mainly in the liver by the CYP3A enzyme family, with a particularly well-documented role of CYP3A5. CYP3A5 is also expressed in the renal tissue and is present in the transplanted kidney. To date, the association between donor CYP3A5 polymorphisms and transplant outcome remains poorly understood. The aim of this study was to assess the effect of donor CYP3A5 expression on early and long-term transplant outcomes.

METHODS

A retrospective cohort study including 207 patients who received kidney grafts from 110 deceased donors was conducted at a single Central European Center. Tissue samples from all donors were studied for CYP3A5 single-nucleotide polymorphism (rs776746). Death-censored graft loss within 5-year follow-up, acute rejection occurrence, and kidney function, measured using serum creatinine and MDRD eGFR, were compared between groups of patients with allografts from rs776746 carriers (CYP3A5 expressors) and noncarriers (CYP3A5 nonexpressors).

RESULTS

Recipients who received kidneys from CYP3A5 expressors (n = 24) were at significantly higher risk of death-censored graft loss within 5-year follow-up (adjusted HR, 95% CI: 6.82, 2.01-23.12; p = 0.002) and acute rejection within the 1st posttransplant year (adjusted OR, 95% CI: 4.62, 1.67-12.77; p = 0.003) than those who did not (n = 183). The median time to loss of function was 1.93 [IQR; 0.77-3.19] years.

CONCLUSIONS

Donor CYP3A5 expressor status is associated with worse renal graft survival and a higher risk of acute rejection. Determination of donor CYP3A5 genotype is a potentially useful tool that may improve kidney transplant outcomes.

The aging of the immune system and its implications for transplantation

By the last third of life, most mammals, including humans, exhibit a decline in immune cell numbers, immune organ structure, and immune defense of the organism, commonly known as immunosenescence. This decline leads to clinical manifestations of increased susceptibility to infections, particularly those caused by emerging and reemerging microorganisms, which can reach staggering levels-infection with SARS-CoV-2 has been 270-fold more lethal to older adults over 80 years of age, compared to their 18-39-year-old counterparts. However, while this would be expected to be beneficial to situations where hyporeactivity of the immune system may be desirable, this is not always the case. Here, we discuss the cellular and molecular underpinnings of immunosenescence as they pertain to outcomes of solid organ and hematopoietic transplantation.

Seeking Standardized Definitions for HLA-incompatible Kidney Transplants: A Systematic Review

BACKGROUND

There is no standard definition for "HLA incompatible" transplants. For the first time, we systematically assessed how HLA incompatibility was defined in contemporary peer-reviewed publications and its prognostic implication to transplant outcomes.

METHODS

We combined 2 independent searches of MEDLINE, EMBASE, and the Cochrane Library from 2015 to 2019. Content-expert reviewers screened for original research on outcomes of HLA-incompatible transplants (defined as allele or molecular mismatch and solid-phase or cell-based assays). We ascertained the completeness of reporting on a predefined set of variables assessing HLA incompatibility, therapies, and outcomes. Given significant heterogeneity, we conducted narrative synthesis and assessed risk of bias in studies examining the association between death-censored graft failure and HLA incompatibility.

RESULTS

Of 6656 screened articles, 163 evaluated transplant outcomes by HLA incompatibility. Most articles reported on cytotoxic/flow T-cell crossmatches (n = 98). Molecular genotypes were reported for selected loci at the allele-group level. Sixteen articles reported on epitope compatibility. Pretransplant donor-specific HLA antibodies were often considered (n = 143); yet there was heterogeneity in sample handling, assay procedure, and incomplete reporting on donor-specific HLA antibodies assignment. Induction (n = 129) and maintenance immunosuppression (n = 140) were frequently mentioned but less so rejection treatment (n = 72) and desensitization (n = 70). Studies assessing death-censored graft failure risk by HLA incompatibility were vulnerable to bias in the participant, predictor, and analysis domains.

CONCLUSIONS

Optimization of transplant outcomes and personalized care depends on accurate HLA compatibility assessment. Reporting on a standard set of variables will help assess generalizability of research, allow knowledge synthesis, and facilitate international collaboration in clinical trials.

Kidney Transplant Outcomes in Recipients Over the Age of 70

BACKGROUND

Patients older than 70 years are the fastest-growing age group of patients requiring renal replacement therapy. This has resulted in a corresponding increase in the number of elderly transplant recipients. We hypothesized that graft survival in this population would be comparable to that seen in the literature on kidney transplant recipients under 70 years of age.

METHODS

This was a retrospective, single-center review of outcomes of kidney transplant recipients aged ≥70 years. Patients were dichotomized based on whether their allograft originated from a living or deceased donor.

RESULTS

A total of 59 recipients aged ≥70 years underwent kidney transplantation. Of these, five (8.5%) were lost to follow-up within the first year post transplant and excluded from the analysis. History of cerebrovascular accident (p = 0.003), coronary artery disease (p = 0.03), postoperative return to the operating room (p = 0.03), and readmission within one year of transplant were predictive of graft loss (p = 0.003). Overall graft survival in our cohort declined from 92.6% at one year to 53.8% at five years. Death-censored graft survival was 100% at one year and decreased to 80.8% at five years. There were no differences seen in patient, graft, or death-censored graft survival based on donor type.

CONCLUSIONS

Kidney transplant patients over 70 years, as seen in our cohort, had good short-term outcomes. Graft survival is similar to rates seen in younger cohorts but the decline in this rate over time is steeper in the older age group, possibly due to decreased patient survival. These findings could be validated further in larger multi-center studies.

Health Belief Model Constructs Affect Influenza Vaccine Uptake in Kidney Transplant Recipients

This secondary analysis explored how the constructs of the health belief model affect influenza vaccine uptake in kidney transplant recipients (KTRs). In the parent study, a total of 180 KTRs were recruited at an organ transplant center in South Korea. A nonlinear path analysis using generalized structural equation modeling was performed. Previous influenza vaccination had a direct effect on their behavior, while cues to action alone did not directly affect their behavior. Perceived benefits played a key role as a mediator in improving influenza vaccine uptake in KTRs. This study highlights the need for health professionals to assess perceived benefits at the individual level and provide patient-centered interventions based on a consideration of theoretical mechanisms. As cues to action, recommendations for recipients’ first vaccination after kidney transplant should focus on changing patients’ perceptions of benefits by emphasizing the positive aspects of the influenza vaccine for immunosuppressed patients.

Outcomes in older kidney recipients from older donors: A propensity score analysis

Background

The age of patients referred for kidney transplantation has increased progressively. However, the precise influence of age on transplant outcomes is controversial.

Methods

Etrospective study in which graft and recipient survival were assessed in a cohort of ≥75 years old kidney recipients and compared with a contemporary younger one aged 60-65 years through a propensity score analysis.

Results

We included 106 recipients between 60-65 and 57 patients of ≥75 years old with a median follow-up of 31 [13-54] months. Unadjusted one- and five-year recipient survival did not significantly differ between the older (91% and 74%) and the younger group (95% and 82%, P=0.06). In the IPTW weighted Cox regression analysis, recipient age was not associated with an increased risk of death (HR 1.88 95%CI [0.81-4.37], P=0.14). Unadjusted one- and five-year death-censored graft survival did not significantly differ between both groups (96% and 83% for the older and 99% and 89% for the younger group, respectively, P=0.08). After IPTW weighted Cox Regression analysis, recipient age ≥75 years was no associated with an increased risk of graft loss (HR 1.95, 95%CI [0.65-5.82], P=0.23).

Conclusions

These results suggest that recipient age should not be considered itself as an absolute contraindication for kidney transplant.

Preoperative CD52 Level Predicts Graft Survival following Kidney Transplantation

Several factors have been reported to affect graft survival following kidney transplantation. CD52 molecules may increase T cell proliferation and activation, which may contribute to acute graft rejection and graft survival. In the current study, we studied the possible value of preoperative CD52 levels in predicting graft survival following renal transplantation. Ninety-six patients with end-stage renal disease who had kidney transplantation were included in the study from our prospective cohort. Blood samples were taken one day before surgery, and plasma CD52 levels were measured using ELISA (Cloud-Clone Corp., Houston, TX, USA). Acute rejection, acute tubular necrosis, delayed graft function, graft loss, BK infection, cytomegalovirus infection, and graft survival were evaluated. The mean age of recipients was $50.08\pm 12.82\text{years}$ , and 64.6% were male. The incidence of delayed graft function, acute rejection, graft loss ( $p<0.01$ ), BK virus infection, and serum creatinine levels were significantly higher in recipients with high preoperative CD52 levels six months after transplantation ( $p<0.05$ ). Kaplan–Meier analysis revealed that three-year graft survival was significantly higher in patients with low preoperative CD52 levels ( $p<0.0001$ ). Univariate and multivariate Cox regression analyses showed that serum creatinine levels ( $\text{hazard}\text{ratio}\left[\text{HR}\right]=1.7$ , $p<0.05$ ), acute rejection ( $\text{HR}=2.919$ , $p<0.05$ ), and preoperative CD52 levels ( $\text{HR}=3.114$ , $p<0.05$ ) were independent prognostic factors for graft survival after kidney transplantation. We showed that high preoperative CD52 levels are associated with higher rates of acute rejection, delayed graft function, and BK virus infection and lower rates of graft survival after kidney transplantation.

Risk Factors of Rejection in Renal Transplant Recipients: A Narrative Review

Multiple factors influence graft rejection after kidney transplantation. Pre-operative factors affecting graft function and survival include donor and recipient characteristics such as age, gender, race, and immunologic compatibility. In addition, several peri- and post-operative parameters affect graft function and rejection, such as cold and warm ischemia times, and post-operative immunosuppressive treatment. Exposure to non-self-human leucocyte antigens (HLAs) prior to transplantation up-regulates the recipient’s immune system. A higher rate of acute rejection is observed in transplant recipients with a history of pregnancies or significant exposure to blood products because these patients have higher panel reactive antibody (PRA) levels. Identifying these risk factors will help physicians to reduce the risk of allograft rejection, thereby promoting graft survival. In the current review, we summarize the existing literature on donor- and recipient-related risk factors of graft rejection and graft loss following kidney transplantation.

Heart Transplant in Older Adults

Purpose of Review

Older adults with end-stage heart failure may be candidates for heart transplantation (HT) and changing guidelines and institutional policies have increased the availability of HT for septuagenarians. This review explores historical, pre-HT evaluation, and post-HT outcomes for older adult HT recipients.

Recent Findings

Rates of HT in older adults have increased in the past decade and more than 800 septuagenarians have undergone HT. Older adult HT recipients have similar survival, rehospitalization, and graft failure rates when compared to younger patients despite additional comorbidities and higher risk donors.

Summary

HT is feasible in carefully selected older adults. As the number of older adults who are considered for HT increases, additional research into population-specific assessment tools will be needed. Furthermore, age-related immune changes warrant population-specific studies on immunosuppressive regimens.

Maintenance phase of a physical activity intervention in older kidney transplant recipients: A 12-month follow-up

Daily walking activities are associated with improving cardiovascular outcomes in older kidney transplant recipients. However, little is known regarding physical activity adherence outcomes in older kidney recipients. The purpose of this randomized controlled trial 12-month follow-up study was to evaluate the feasibility of the intervention (SystemCHANGE™ + activity tracker) during the maintenance period (7-12 months), compared to an attention-control group (activity tracker only) in older kidney recipients (age 60 and older). The sample included 60 participants (n = 30 IG; n = 30 ACG). Adherence rates for wearing the activity tracker daily were 96.5% in the IG and 80.8% in the ACG. The IG demonstrated within-group improvements for blood pressure at 12 months. Overall, there was a decrease in the average daily steps observed in both groups. These data suggest this intervention is feasible and additional boosters should be considered during the maintenance period to encourage physical activity.

Immunosuppression Regimen Use and Outcomes in Older and Younger Adult Kidney Transplant Recipients: A National Registry Analysis

BACKGROUND

Although the population of older transplant recipients has increased dramatically, there are limited data describing the impact of immunosuppression regimen choice on outcomes in this recipient group.

METHODS

National data for US Medicare-insured adult kidney recipients (N = 67 362; 2005-2016) were examined to determine early immunosuppression regimen and associations with acute rejection, death-censored graft failure, and mortality using multivariable regression analysis in younger (18-64 y) and older (>65 y) adults.

RESULTS

The use of antithymocyte globulin (TMG) or alemtuzumab (ALEM) induction with triple maintenance immunosuppression (reference) was less common in older compared with younger (36.9% versus 47.0%) recipients, as was TMG/ALEM + steroid avoidance (19.2% versus 20.1%) and mammalian target of rapamycin inhibitor (mTORi)-based (6.7% versus 7.7%) treatments. Conversely, older patients were more likely to receive interleukin (IL)-2-receptor antibody (IL2rAb) + triple maintenance (21.1% versus 14.7%), IL2rAb + steroid avoidance (4.1% versus 1.8%), and cyclosporine-based (8.3% versus 6.6%) immunosuppression. Compared with older recipients treated with TMG/ALEM + triple maintenance (reference regimen), those managed with TMG/ALEM + steroid avoidance (adjusted odds ratio [aOR], 0.440.520.61) and IL2rAb + steroid avoidance (aOR, 0.390.550.79) had lower risk of acute rejection. Older patients experienced more death-censored graft failure when managed with Tac + antimetabolite avoidance (adjusted hazard [aHR], 1.411.782.25), mTORi-based (aHR, 1.702.142.71), and cyclosporine-based (aHR, 1.411.782.25) regimens, versus the reference regimen. mTORi-based and cyclosporine-based regimens were associated with increased mortality in both older and younger patients.

CONCLUSIONS

Lower-intensity immunosuppression regimens (eg, steroid-sparing) appear beneficial for older kidney transplant recipients, while mTORi and cyclosporine-based maintenance immunosuppression are associated with higher risk of adverse outcomes.

Kidney and pancreas transplant candidacy

PURPOSE OF REVIEW

Kidney and/or pancreas transplantation candidacy criteria have evolved significantly over time reflecting improved pre and post-transplant management. With improvement in medical care, potential candidates for transplant not only are older but also have complex medical issues. This review focuses on the latest trends regarding candidacy for kidney and/or pancreas transplantation along with advances in pretransplant cardiac testing.

RECENT FINDINGS

More candidates are now eligible for kidney and/or pancreas transplantation owing to less stringent candidacy criteria especially in regards to age, obesity, frailty and history of prior malignancy. Pretransplant cardiovascular assessment has also come a long way with a focus on less invasive strategies to assess for coronary artery disease.

SUMMARY

Criteria for kidney and/or pancreas transplantation are expanding. Patients who in the past might have been declined because of numerous factors are now finding that transplant centers are more open minded to their candidacy, which could lead to better access to organ transplant wait list.

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.

Preoperative Cardiovascular Assessment of the Renal Transplant Recipient: A Narrative Review

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Longitudinal immune profile reveals reduced function of pro-inflammatory monocytes with age following kidney transplantation

Toxicity of immunosuppression, notably the risk of infection, increases with age. However, the dynamic changes in innate immune response following transplantation are unclear. Based on recent observations, we hypothesized that pro-inflammatory capacity would decrease with age. We analyzed approximately 300 PBMC samples collected longitudinally in 45 de novo, adult kidney recipients and performed detailed phenotypic and functional profiling of monocytes and T cell subsets. Inflammatory response to TLR4 stimulation and indirect allostimulation using mismatched HLA peptides were assessed. In patients aged ≥56 years, TNF-α production by intermediate monocytes was similar to that in younger patients early posttransplant, but diminished substantially later. Adjusted analyses suggested that this was not attributable to confounding factors. In contrast, the alloimmune response to HLA peptides measured by IFN-γ in CD4⁺ T cells and TNF-α in monocytes was stable over time, but was low in older recipients. Measurement of CD80-86 surface expression revealed no signal for a lower costimulation capacity of APCs. These results suggest that older recipients have a reduced function of their innate pro-inflammatory immune cells posttransplant while maintaining a stable, low alloimmune response over time. The effect of reduced immunosuppressant doses on preventing this phenomenon needs to be clarified.

Clinical Outcomes of Older Kidney Transplant Recipients

BACKGROUND

Older kidney transplant recipients (OKTR) are vulnerable to infections and AKI, often prompting hospitalization. This study elucidates etiology of hospitalizations, AKI, and outcomes in OKTR.

METHODS

Retrospective study of 500 patients age ≥ 60, who underwent kidney transplantation from 2005-2015. Demographic, transplant, and outcomes data were collected.

RESULTS

OKTR had mean age 66 years; 59% males and 50% African Americans. 62% had at least one hospitalization post-transplant. Predictors of hospitalization were DGF, DM, panel reactive antibodies (PRA), dialysis duration. Hospitalization was mostly due to infection and surgical complications. Average length of stay was 6.4 days. OKTR with at least one hospitalization had 84% higher risk for graft loss (p=0.001). 56% of older kidney transplant recipients had at least one AKI episode post-transplant. Predictors of AKI included DGF, older, African American donor, and tacrolimus variability. The most common etiologies for AKI were infection, dehydration, and GI complications. OKTR with at least one AKI episode had 2.6-fold higher risk for graft loss (p<0.001).

CONCLUSIONS

Post-transplant hospitalization and AKI in OKTR significantly impact graft survival. Addressing comorbidities and risks in the pre-transplant and outpatient setting may help alleviate burden of hospitalization and risk of AKI in OKTR and improve graft outcomes.

Cardiac evaluation of the kidney or liver transplant candidate

PURPOSE OF REVIEW

As the field of transplant has advanced, cardiac events have become the leading cause of morbidity and mortality after liver and kidney transplantation ahead of graft failure and infection. This trend has been bolstered by the transplantation of older and sicker patients who have a higher burden of cardiovascular risk factors, accentuating the need to determine which patients should undergo more extensive cardiac evaluation prior to transplantation.

RECENT FINDINGS

Computed tomography coronary angiography with or without coronary artery calcium scoring is now preferred over stress imaging in most transplant candidates for assessment of coronary artery disease. Assessment of cardiac structure and function using transthoracic echocardiography with tissue doppler imaging and strain imaging is recommended, particularly in liver transplant candidates who are at high risk of cirrhotic cardiomyopathy, for which new diagnostic criteria were recently published in 2019.

SUMMARY

Cardiac evaluation of liver and kidney transplant candidates requires a global assessment for both short and long-term risk for cardiac events. Imaging of cardiac structure and function using transthoracic echocardiography with tissue doppler imaging and strain imaging is recommended. Risk stratification should consider both the anatomic and functional consequences of coronary artery disease in transplant candidates.

VIDEO ABSTRACT

http://links.lww.com/MOT/A27.

Nutrition-Based Management of Inflammaging in CKD and Renal Replacement Therapies

Access to renal transplantation guarantees a substantial improvement in the clinical condition and quality of life (QoL) for end-stage renal disease (ESRD) patients. In recent years, a greater number of older patients starting renal replacement therapies (RRT) have shown the long-term impact of conservative therapies for advanced CKD and the consequences of the uremic milieu, with a frail clinical condition that impacts not only their survival but also limits their access to transplantation. This process, referred to as “inflammaging,” might be reversible with a tailored approach, such as RRT accompanied by specific nutritional support. In this review, we summarize the evidence demonstrating the presence of several proinflammatory substances in the Western diet (WD) and the positive effect of unprocessed food consumption and increased fruit and vegetable intake, suggesting a new approach to reduce inflammaging with the improvement of ESRD clinical status. We conclude that the Mediterranean diet (MD), because of its modulative effects on microbiota and its anti-inflammaging properties, may be a cornerstone in a more precise nutritional support for patients on the waiting list for kidney transplantation.

Factors Influencing Long-Term Patient and Allograft Outcomes in Elderly Kidney Transplant Recipients

Introduction

Individuals aged ≥65 years are increasingly prevalent on the waitlist for kidney transplantation, yet evidence on recipient and donor factors that define optimal outcomes in elderly patients after kidney transplantation is scarce.

Methods

We used multivariable Cox regression modeling to determine the factors associated with all-cause death, death with a functioning graft, and overall and death-censored graft survival, using data from the Australia and New Zealand Dialysis and Transplant (ANZDATA) registry.

Results

A total of 802 kidney transplant recipients aged ≥65 years underwent their first transplantation between June 2006 and December 2016. Median age at transplantation was 68 years (interquartile range = 66−69 years). The 1-year and 5-year overall patient and graft survivals (95% confidence interval [CI]) were 95.1 (93.5−96.7) and 79.0 (75.1−82.9), and 92.9 (91.1−94.7) and 75.4 (71.3−79.5), respectively. Factors associated with higher risks of all-cause death included prevalent coronary artery disease (adjusted hazard ratio [95% confidence interval] = 1.47 [1.03–2.11]), cerebrovascular disease (1.99 [1.26–3.16]), increasing graft ischemic time (1.06 per hour [1.03–1.09]), donor age (1.02 per year [1.01–1.03]), delayed graft function (1.64 [1.13−2.39]), and peritoneal dialysis pretransplantation (1.71 [1.17–2.51]).

Conclusion

Prevalent vascular disease and peritoneal dialysis as a pretransplantation dialysis modality are risk factors associated with poorer outcomes in transplant recipients aged ≥65 years. Careful selection and evaluation of potential candidates may improve graft and patient outcomes in older patients.

Clinical and immunological follow-up of very long-term kidney transplant recipients treated with calcineurin inhibitors indicates dual phenotypes

Operationally tolerant kidney transplant recipients harbor an immunological signature, associated with low rejection risk, and focused on B lymphocytes. Here, we investigated whether patients with long-term transplantation and still on immunosuppressive therapy would present such a signature of low immunological rejection risk, compared to more recently transplanted patients. Of 114 kidney transplant recipients enrolled, 38 with more than 25 years of graft survival and stable graft function under calcineurin inhibitors, were matched with two different groups of transplanted patients (10-15 and 5-7 years after transplantation). Three phenotypes associated with low immunological rejection risk (Tfh, B and regulatory T cells), initially found in operationally tolerant kidney transplant recipients, and the composite score of tolerance (combination of six transcriptomic markers, age at transplantation and age at sampling) were analyzed. We found that very long-term patients were characterized by a significantly lower percentage of total B cells, a significantly higher proportion of CD24^HiCD38^Lo memory B cells, significantly fewer CD24^LoCD38^Lo naive B cells, and a significantly lower proportion of PD1^HiCCR7^Lo Tfh lymphocytes than more recently transplanted patients. This phenotype is associated with a positive composite score of tolerance in patients transplanted for more than 25 years. Thus, our study suggests a dual phenotype in very long-term kidney transplanted patients with an immunological profile associated with low rejection risk.

Kidney transplantation in the extremely elderly from extremely aged deceased donors: a kidney for each age

BACKGROUND

Advances in life expectancy have led to an increase in the number of elderly people with end-stage renal disease (ESRD). Scarce information is available on the outcomes of kidney transplantation (KT) in extremely elderly patients based on an allocation policy prioritizing donor-recipient age matching.

METHODS

We included recipients ≥75 years that underwent KT from similarly aged deceased donors at our institution between 2002 and 2015. Determinants of death-censored graft and patient survival were assessed by Cox regression.

RESULTS

We included 138 recipients with a median follow-up of 38.8 months. Median (interquartile range) age of recipients and donors was 77.5 (76.3-79.7) and 77.0 years (74.7-79.0), with 22.5% of donors ≥80 years. Primary graft non-function occurred in 8.0% (11/138) of patients. Cumulative incidence rates for post-transplant infection and biopsy-proven acute rejection (BPAR) were 70.3% (97/138) and 15.2% (21/138), respectively. One- and 5-year patient survival were 82.1 and 60.1%, respectively, whereas the corresponding rates for death-censored graft survival were 95.6 and 93.1%. Infection was the leading cause of death (46.0% of fatal cases). The occurrence of BPAR was associated with lower 1-year patient survival [hazard ratio (HR) = 4.21, 95% confidence interval (CI) 1.64-10.82; P = 0.003]. Diabetic nephropathy was the only factor predicting 5-year death-censored graft survival (HR = 4.82, 95% CI 1.08-21.56; P = 0.040).

CONCLUSIONS

ESRD patients ≥75 years can access KT and remain dialysis free for their remaining lifespan by using grafts from extremely aged deceased donors, yielding encouraging results in terms of recipient and graft survival.

Long-Term (≥25 Years) Kidney Allograft Survivors: Retrospective Analysis at a Single Center

INTRODUCTION

Despite great improvements in the short-term patient and kidney graft survival, the long-term morbidity and mortality in kidney transplant recipients still remains a significant problem. The aim of the study was to evaluate the impact of both donor and transplant recipient factors, as well as renal function indices on the very long-term (>25 years) kidney allograft survival.

MATERIAL AND METHODS

Retrospective analysis was performed on the data of 41 kidney transplant recipients (KTR), group A: follow-up = 25 years, 20 KTR, 10 male, mean age (mean [M] ± standard deviation [SD]): 34.6 ± 12.6 years, 14 living donors (LD), 6 cadaveric donors (CD); group B: follow-up > 25 years, 21 KTR, 16 male, mean age (M ± SD): 30.86 ± 12.37 years, 14 LD, 7 CD). Kidney graft origin, post-kidney transplantation diabetes mellitus, HLA compatibility, delayed graft function, and acute rejection episodes were also analyzed retrospectively. Statistical analysis with Mann-Whitney test and Kaplan-Meier survival analysis was performed (SPSS 20.0 for Windows).

RESULTS

The mean age of CDs was lower than that of LDs: CD mean age (M ± SD): 23.84 ± 16.26 years vs LD mean age: 52.75 ± 12.42 years (P < .001). Cadaveric kidney graft was associated with better renal allograft function 10, 15, and 25 years post kidney transplant. None of the other factors analyzed reached statistical significance between the 2 groups.

CONCLUSION

The age of the donor and the kidney graft origin are important co-factors of the very long-term kidney allograft survival.

Impact of Combinations of Donor and Recipient Ages and Other Factors on Kidney Graft Outcomes

As the availability of kidneys for transplantation continues to be outpaced by its growing demand, there has been an increasing utilization of older deceased donors in the last decades. Considering that definition of factors that influence deceased donor kidney transplant outcomes is important for allocation policies, as well as for individualization of post-transplant care, the purpose of this study was determine the risks for death censored graft survival and for patient survival conferred by older age of the donor in the context of the age of the recipient and of risk factors for graft and/or patient survival. The investigation was conducted in a single-center cohort of 5,359 consecutive first kidney transplants with adult deceased donors performed on non-prioritized adult recipients from January 1, 2002, to December 31, 2017. Death censored graft survival and patient survival were lower in older donors, whereas graft survival was higher and patient survival was lower in old recipients. The analyses of combinations of donor and recipient ages showed that death censored graft survival was lower in younger recipients in transplants from 18 to 59-year old donors, with standard or extended criteria, but no difference in graft survival was observed between younger and older recipients when the donor was ≥ 60-year old. Patient survival was higher in younger recipients in transplants with younger or older donors. Two to six HLA-A,B,DR mismatches, when compared to 0-1 MM, conferred risk for death-censored graft survival only in transplants from younger donors to younger recipients. Pre-transplant diabetes conferred risk for patient survival only in 50–59-year old recipients, irrespectively, of the age of the donor. Time on dialysis ≥ 10 years was a risk factor for patient survival in transplants with all donor-recipient age combinations, except in recipients with ≥ 60 years that received a kidney from an 18–49-year old donor. In conclusion, the results obtained in this study underline the importance of analyzing the impact of the age of the donor taking into consideration different scenarios.

Transplanting the Elderly: Mandatory Age- and Minimal Histocompatibility Matching

Worldwide over 40% of patients receiving renal replacement therapy (RRT) are aged 65 years or older, a number that is still increasing. Renal transplantation is the preferred RRT, providing substantial survival benefit over those remaining on dialysis, including the elderly. Only 3% of patients aged 65 years or older accepted on the waiting list actually received a kidney transplant offer within the Eurotransplant allocation region. To increase the chance for elderly to receive a timely kidney transplant, the Eurotransplant Senior Program was introduced. The ESP supports local allocation of older kidneys to older donors in order to decrease cold ischemia time, while disregarding former exchange principles based on matching for HLA antigens. As a consequence, more elderly received a kidney transplant and a relative higher incidence of acute rejection resulted in additional courses of high steroids and/or depleting antibody therapy. Since death with a functioning graft due to infections is the dominant reason of graft loss in elderly, more intense clinical immunosuppression to prevent or treat acute rejection is not a very attractive option. Therefore in elderly kidney transplant candidates, we advocate reintroduction of minimal histocompatibility criteria (i.e., HLA-DR matching) followed by age-matching with mandatory local/regional allocation to also facilitate short cold ischemia.