Living kidney donors ages 70 and older: recipient and donor outcomes

Consequences of kidney donation by age in Japanese living kidney donors: a single-center study

BACKGROUND

Elderly living kidney donors (LKDs) are becoming increasingly important in countries with a high prevalence of living-donor kidney transplants and an aging society. This study explored the features of elderly LKDs, focusing on their subsequent outcomes.

METHODS

This single-center, retrospective, observational study included eligible LKDs who donated their kidneys between April 2008 and July 2022. LKDs were categorized into an elderly (≥70 years at donation) or a non-elderly group (<70 years). We examined pre-operative characteristics and post-operative outcomes, such as kidney function, complications, development of end-stage kidney disease (ESKD), and mortality.

RESULTS

Of the 188 LKDs observed for a median of 5.7 years, 31 were in the elderly group (16.5%) and 157 (83.5%) were in the non-elderly group (mean age 72.5 ± 2.7 and 58.2 ± 7.3 years, respectively). No significant differences were observed in hospital stay length or peri-operative complications between groups. Both groups experienced a similar decline in post-donation estimated glomerular filtration rate (eGFR)-approximately 37%. In the elderly group, four LKDs died, and one progressed to ESKD. In the non-elderly group, two LKDs died, and none progressed to ESKD. The cause of death was not strongly suspected to be associated with the donation.

CONCLUSIONS

eGFR was maintained even in elderly LKDs post-donation. Prioritizing LKDs' safety is paramount; however, donations from elderly people would be acceptable, considering their life expectancy. This can expand the pool of living kidney donors and address the growing demand for kidney transplants.

Impact of Age 70 years or Older on Donors for Living-Donor Kidney Transplantation

Introduction

Kidney transplantation (KT) involving elderly living kidney donors (LKDs) is becoming more frequent because of a profound organ shortage. The efficacy of KT involving grafts obtained from LKDs aged 70 years or older has been reported. However, the safety of donor nephrectomy in LKDs aged 70 years or older, including that associated with changes in the estimated glomerular filtration rate (eGFR), has not been investigated. This study investigated the outcomes of LKDs aged 70 years or older after donor nephrectomy.

Methods

This single-center, retrospective cohort study included 1226 LKDs who underwent donor nephrectomy between January 2008 and December 2020. LKDs were stratified into the following age groups: 30 to 49 years (244 LKDs), 50 to 69 years (803 LKDs), and 70 to 89 years (179 LKDs). Surgical outcomes, postoperative eGFR changes, end-stage renal disease (ESRD) rates, and mortality rates were compared among these groups.

Results

No significant difference in surgical outcomes was identified among the groups. LKDs aged 70 to 89 years experienced the lowest eGFR changes at all time points and the lowest eGFR improvement; however, ESRD was not identified in any group during the observation period. Mortality was the highest among LKDs aged 70 to 89 years compared to the other age groups.

Conclusion

Surgical outcomes, eGFR changes, and ESRD incidences can support the safety of donor nephrectomy in LKDs aged 70 years or older. Considering the advanced age, the high mortality rates in LKDs aged 70 years or older could be considered acceptable.

Survival Advantage Comparing Older Living Donor Versus Standard Criteria Donor Kidney Transplants

The aim of this analysis was to explore mortality outcomes for kidney transplant candidates receiving older living donor kidneys (age ≥60 years) versus younger deceased donors or remaining on dialysis. From 2000 to 2019, all patients on dialysis listed for their first kidney-alone transplant were included in a retrospective cohort analysis of UK transplant registry data. The primary outcome was all-cause mortality, with survival analysis conducted by intention-to-treat principle. Time-to-death from listing was modelled using nonproportional hazard Cox regression models with transplantation handled as a time-dependent covariate. A total of 32,978 waitlisted kidney failure patients formed the primary study cohort, of whom 18,796 (58.5%) received a kidney transplant (1,557 older living donor kidneys and 18,062 standard criteria donor kidneys). Older living donor kidney transplantation constituted only 17.0% of all living donor kidney transplant activity (overall cohort; n = 9,140). Recipients of older living donor kidneys had reduced all-cause mortality compared to receiving SCD kidneys (HR 0.904, 95% CI 0.845-0.967, p = 0.003) and much lower all-cause mortality versus remaining on the waiting list (HR 0.160, 95% CI 0.149-0.172, p < 0.001). Older living kidney donors should be actively explored to expand the living donor kidney pool and are an excellent treatment option for waitlisted kidney transplant candidates.

Results in Kidney Transplant Recipients from Living Donors 75 Years of Age or Older

The increasing age of patients receiving renal replacement therapy (RRT) in Turkey, coupled with a shortage of kidney donors, has led to longer waiting times for transplants and an escalation in mortality rates. This retrospective study aimed to assess the effect on transplant outcomes of accepting kidneys from donors ≥70 years of age, given the rising number of older patients in the population. In all, 1400 patients were transplanted with kidneys from donors >50 years, with patient and graft survival as primary endpoints. Our results demonstrated that the most significant risk factors for graft function were recipient age >65 years, male sex, and presence of type 2 diabetes. Moreover, kidneys from donors ≥75 years of age achieved a half-life of 5 years. These findings suggest that donor age does not necessarily correlate with graft failure and that transplantation from older donors could help alleviate the organ shortage. Further research is needed to substantiate these conclusions.

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.

Early clinical and economic outcomes of expanded criteria living kidney donors in the United States

BACKGROUND

The donation of what might be termed expanded criteria kidneys has become an increasingly common practice. This study aimed to assign expanded criteria and non-expanded criteria donation status and examine early clinical and economic outcomes among expanded criteria and non-expanded criteria living kidney donor (LKD) hospitalizations in the US.

METHODS

Healthcare cost and Utilization Project-National (Nationwide) Inpatient Sample (HCUP-NIS) data (Jan 2008-Dec 2019, N = 12,020) were used. Expanded criteria LKDs were identified as admitted patients aged ≥ 60 years, or 50-59 years with any comorbidity that historically precluded donation. The Clavien-Dindo system was applied to classify surgical complications as grade I-IV/V.

RESULTS

The number of LKD admissions decreased by 31% over the study period, although this trend fluctuated over time. Compared to non-expanded criteria LKD admissions, expanded criteria LKD admissions had comparable surgical complication rates in Grade I (aOR 1.0, 0.8-1.3), but significantly higher surgical complication rates in Grade II (aOR 1.5, 1.1-2.2) and Grade III (aOR 1.4, 1.0-2.0). The two groups had comparable hospital length of stay and cost in the adjusted models. Notably, Grade II complications were significantly higher in private, for-profit hospitals (15%) compared to government hospitals (2.9%).

CONCLUSIONS

Expanded criteria LKDs had comparable early outcomes compared to non-expanded criteria LKDs, but the trends evident in LKDs over time and the variation in complication records warrant further research.

The Minnesota attributable risk of kidney donation (MARKD) study: a retrospective cohort study of long-term (> 50 year) outcomes after kidney donation compared to well-matched healthy controls

BACKGROUND

There is uncertainty about the long-term risks of living kidney donation. Well-designed studies with controls well-matched on risk factors for kidney disease are needed to understand the attributable risks of kidney donation.

METHODS

The goal of the Minnesota Attributable Risk of Kidney Donation (MARKD) study is to compare the long-term (> 50 years) outcomes of living donors (LDs) to contemporary and geographically similar controls that are well-matched on health status. University of Minnesota (n = 4022; 1st transplant: 1963) and Mayo Clinic LDs (n = 3035; 1st transplant: 1963) will be matched to Rochester Epidemiology Project (REP) controls (approximately 4 controls to 1 donor) on the basis of age, sex, and race/ethnicity. The REP controls are a well-defined population, with detailed medical record data linked between all providers in Olmsted and surrounding counties, that come from the same geographic region and era (early 1960s to present) as the donors. Controls will be carefully selected to have health status acceptable for donation on the index date (date their matched donor donated). Further refinement of the control group will include confirmed kidney health (e.g., normal serum creatinine and/or no proteinuria) and matching (on index date) of body mass index, smoking history, family history of chronic kidney disease, and blood pressure. Outcomes will be ascertained from national registries (National Death Index and United States Renal Data System) and a new survey administered to both donors and controls; the data will be supplemented by prior surveys and medical record review of donors and REP controls. The outcomes to be compared are all-cause mortality, end-stage kidney disease, cardiovascular disease and mortality, estimated glomerular filtration rate (eGFR) trajectory and chronic kidney disease, pregnancy risks, and development of diseases that frequently lead to chronic kidney disease (e.g. hypertension, diabetes, and obesity). We will additionally evaluate whether the risk of donation differs based on baseline characteristics.

DISCUSSION

Our study will provide a comprehensive assessment of long-term living donor risk to inform candidate living donors, and to inform the follow-up and care of current living donors.

Kidney transplantation from elderly donors (> 70 years): a systematic review

PURPOSE

The incidence of kidney transplants from elderly donors over 70 years of age has increased significantly over the past 10 years to reach 20% of available kidney graft in some European countries. However, there is little data available on the outcomes of transplants from these donors. We performed a systematic review to evaluate the outcomes of transplantation from donors over 70 years of age.

METHODS

A systematic review was performed according to preferred reporting items for systematic reviews and meta-analyses. Medline, Embase, and Cochrane databases were searched to identify all studies reporting outcomes on kidney transplants from donors over 70 years. Due to the heterogeneity of the studies, a meta-analysis could not be performed.

RESULTS

A total of 29,765 patients in 27 studies were included. The mean donors age was 74.79 years, and proportion of kidney graft from women was 53.54%. The estimated 1- and 5-year kidney death-censored graft survivals from donors > 70 years old were, respectively, 85.95 and 80.27%, and the patient survivals were 90.88 and 71.29%. The occurrence of delayed graft function was 41.75%, and primary non-function was 4.67%. Estimated graft function at 1 and 5 years was 36 and 38 mL/min/1.73 m². Paucity data were available on post-operative complications.

CONCLUSIONS

Elderly donors appear to be a reliable source of grafts. However, these transplants are associated with a high rate of delayed graft function without repercussion on long-term graft survival. Allocation strategy to elderly recipients is the main factor of decreased recipient survival.

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.

Long-term Medical Outcomes of Living Kidney Donors

Historically, to minimize risks, living kidney donors have been highly selected and healthy. Operative risks are well-defined, yet concern remains about long-term risks. In the general population, even a mild reduction in glomerular filtration rate (GFR) is associated with cardiovascular disease, chronic kidney disease, and end-stage kidney disease (ESKD). However, reduction in GFR in the general population is due to kidney or systemic disease. Retrospective studies comparing donors with matched general population controls have found no increased donor risk. Prospective studies comparing donors with controls (maximum follow-up, 9 years) have reported that donor GFR is stable or increases slightly, whereas GFR decreases in controls. However, these same studies identified metabolic and vascular donor abnormalities. There are a few retrospective studies comparing donors with controls. Each has limitations in selection of the control group, statistical analyses, and/or length of follow-up. One such study reported increased donor mortality; 2 reported a small increase in absolute risk of ESKD. Risk factors for donor ESKD are similar to those in the general population. Postdonation pregnancies are also associated with increased risk of hypertension and preeclampsia. There is a critical need for long-term follow-up studies comparing donors with controls from the same era, geographic area, and socioeconomic status who are healthy, with normal renal function on the date matching the date of donation, and are matched on demographic characteristics with the donors. These data are needed to optimize donor candidate counseling and informed consent.

Rethinking Chronic Kidney Disease in the Aging Population

The process of aging population will inevitably increase age-related comorbidities including chronic kidney disease (CKD). In light of this demographic transition, the lack of an age-adjusted CKD classification may enormously increase the number of new diagnoses of CKD in old subjects with an indolent decline in kidney function. Overdiagnosis of CKD will inevitably lead to important clinical consequences and pronounced negative effects on the health-related quality of life of these patients. Based on these data, an appropriate workup for the diagnosis of CKD is critical in reducing the burden of CKD worldwide. Optimal management of CKD should be based on prevention and reduction of risk factors associated with kidney injury. Once the diagnosis of CKD has been made, an appropriate staging of kidney disease and timely prescriptions of promising nephroprotective drugs (e.g., RAAS, SGLT-2 inhibitors, finerenone) appear crucial to slow down the progression toward end-stage kidney disease (ESKD). The management of elderly, comorbid and frail patients also opens new questions on the appropriate renal replacement therapy for this subset of the population. The non-dialytic management of CKD in old subjects with short life expectancy features as a valid option in patient-centered care programs. Considering the multiple implications of CKD for global public health, this review examines the prevalence, diagnosis and principles of treatment of kidney disease in the aging population.

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.

Donor‐reported barriers to living kidney donor follow‐up

BACKGROUND

Despite regulations mandating follow-up laboratory testing for living kidney donors, less than half of transplant centers are in compliance. We sought to understand barriers to follow-up testing from the donors' perspective.

METHODS

We surveyed our center's living kidney donors. Binary logistic regression was used to assess factors associated with follow-up testing completion.

RESULTS

Of 185 living kidney donors, 110 (59.4%) participated. Among them, 82 (74.5%) completed 6-month laboratory testing, 76 (69.1%) completed 12-month testing, 68 (61.8%) completed both, and 21 (19.0%) completed neither. Six-month testing completion was strongly associated with 12-month testing completion (OR 9.74, 95%CI: 2.23-42.50; p = .002). Those who disagreed with the statements, "Getting labs checked wasn't a priority for me," (OR for completing 6-month testing: 15.05, 95%CI: 3.70-61.18; p < .001; OR for completing 12-month testing: 5.85, 95%CI: 1.94-17.63; p = .002); and, "I forgot to get labs drawn [until I was reminded]" (OR for completing 6-month testing: 6.93, 95%CI: 1.59-30.08; p = .01; OR for completing 12-month testing: 6.55, 95%CI: 1.98-21.63; p = .002) were more likely to complete testing.

CONCLUSIONS

To our knowledge, this is the only study providing perspective on donor insights regarding the need for follow-up testing post donation. Interventions to influence living donor attitudes toward follow-up testing may improve follow-up.

Assessment of Physiological Rat Kidney Ageing—Implications for the Evaluation of Allograft Quality Prior to Renal Transplantation

Due to organ shortage and rising life expectancy the age of organ donors and recipients is increasing. Reliable biomarkers of organ quality that predict successful long-term transplantation outcomes are poorly defined. The aim of this study was the identification of age-related markers of kidney function that might accurately reflect donor organ quality. Histomorphometric, biochemical and molecular parameters were measured in young (3-month-old) and old (24-month-old) male Sprague Dawley rats. In addition to conventional methods, we used urine metabolomics by NMR spectroscopy and gene expression analysis by quantitative RT-PCR to identify markers of ageing relevant to allograft survival. Beside known markers of kidney ageing like albuminuria, changes in the concentration of urine metabolites such as trimethylamine-N-oxide, trigonelline, 2-oxoglutarate, citrate, hippurate, glutamine, acetoacetate, valine and 1-methyl-histidine were identified in association with ageing. In addition, expression of several genes of the toll-like receptor (TLR) pathway, known for their implication in inflammaging, were upregulated in the kidneys of old rats. This study led to the identification of age-related markers of biological allograft age potentially relevant for allograft survival in the future. Among those, urine metabolites and markers of immunity and inflammation, which are highly relevant to immunosuppression in transplant recipients, are promising and deserve further investigation in humans.

Risk for subsequent hypertension and cardiovascular disease after living kidney donation: is it clinically relevant?

The first successful live donor kidney transplant was performed in 1954. Receiving a kidney transplant from a live kidney donor remains the best option for increasing both life expectancy and quality of life in patients with end-stage kidney disease. However, ever since 1954, there have been multiple questions raised on the ethics of live kidney donation in terms of negative impacts on donor life expectancy. Given the close relationship between reduced kidney function in patients with chronic kidney disease (CKD) and hypertension, cardiovascular disease and cardiovascular mortality, information on the impact of kidney donation on these is particularly relevant. In this article, we review the existing evidence, focusing on the more recent studies on the impact of kidney donation on all-cause mortality, cardiovascular mortality, cardiovascular disease and hypertension, as well as markers of cardiovascular damage including arterial stiffness and uraemic cardiomyopathy. We also discuss the similarities and differences between the pathological reduction in renal function that occurs in CKD, and the reduction in renal function that occurs because of a donor nephrectomy. Kidney donors perform an altruistic act that benefits individual patients as well as the wider society. They deserve to have high-quality evidence on which to make informed decisions.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

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.

Surgical site complications in kidney transplant recipients: incidence, risk factors and outcomes in the modern era

BACKGROUND

Surgical site complications (SSCs) are an important source of morbidity after kidney transplantation. We assessed the incidence, risk factors, outcomes and economic impact of SSCs in a large, diverse population of kidney transplant recipients.

METHODS

We conducted a single-centre, observational cohort study of adult (age ≥ 18 yr) patients who underwent kidney transplantation between Jan. 1, 2005, and Dec. 31, 2015, with a minimum of 1 year of follow-up. Cases of SSC, including infections and wound dehiscence, were determined from patient records. Inpatient and outpatient hospital costs were determined 6 and 12 months after transplantation. We used the Kaplan-Meier product-limit method to determine the cumulative probability of SSCs and other outcomes. We evaluated risk factors and clinical outcomes using Cox proportional hazard ratios. Linear regression models were used to study the effect of SSCs on graft function.

RESULTS

The incidence rate of SSCs within 30 days after transplantation was 4.19 per 100 person-months. The cumulative probability of developing an SSC within 30 days after transplantation was 4.13% (95% confidence interval [CI] 3.23%-5.28%). Increased recipient body mass index (BMI) (hazard ratio [HR] 1.07, 95% CI 1.02-1.11), longer cold ischemic time (HR 1.05, 95% CI 1.01-1.09) and transplantation in 2010-2012 versus 2005-2009 (HR 2.20, 95% CI 1.19-4.04) were risk factors for SSC development. In multivariable stepwise Cox proportional hazard models, SSC was a significant risk factor for death-censored graft failure (HR 3.08, 95% CI 1.60-5.90) and total graft failure (HR 2.09, 95% CI 1.32-3.32). Cumulative median hospital costs were $2238.46 greater for patients with an SSC than for those without.

CONCLUSION

Increased BMI, longer cold ischemic time and the 2010-2012 transplantation period predisposed to SSCs. The development of SSCs was associated with a higher risk of graft failure. Strategies to minimize SSCs may improve outcomes after kidney transplantation and reduce costs.

Long-term mortality of living kidney donors: a systematic review and meta-analysis

BACKGROUND

To date, several studies have reported inconsistent findings regarding the mortality risk faced by living kidney donors and controls. Our study assessed the methodological quality of previous studies and performed an updated meta-analysis of the mortality risk.

METHODS

Comprehensive literature searches were conducted involving the PubMed, Embase, and Cochrane databases through September 2020. The search terms used included 'living donor' and 'kidney transplantation' and 'kidney donor' and 'mortality' or 'death' or 'survival'. We evaluated the risk of bias in such studies using ROBINS-I tool. Mortality risk was analyzed using OR and HR.

RESULTS

The qualitative review involved 18 studies and the meta-analysis included nine studies. We identified 3 studies with an overall risk of bias rated as "Low", 2 studies rated as "Moderate", 8 studies rated as "Serious", and 5 studies rated as "Critical". The pooled overall mortality risk in the meta-analysis was 0.984 (95% CI: 0.743, 1.302). In the subgroup analysis of HR and OR, the summary effect estimates did not reach statistical significance. The meta-regression analysis revealed that the donor group of more than 60,000 (1.836, 95% CI: 0.371, 6.410) carried a significantly high mortality risk compared with the donor group of less than 60,000 (0.810, 95% CI: 0.604, 1.086) (P = 0.007). The number of total patients was associated with slightly elevated mortality risks (0.796 for < 10,000, 0.809 for 10,000-60,000, and 1.852 for > 60,000; P < .054).

CONCLUSIONS

Current evidence based on this systematic review suggests that the methodology of previous studies was inconsistent and also carried a high risk in several aspects. Updated meta-analysis showed that the mortality risk was not significantly different. Future studies with well-designed methodology are necessary.

One size does not fit all: understanding individual living kidney donor risk

Living donor kidney transplantation is the optimal treatment for end-stage kidney disease (ESKD) but confers a risk upon the donor, both in the short term and many years after donation. While perioperative mortality is low and longevity does not appear to be adversely affected, there are small increases in the risk of other important morbidities. The overall risk of ESKD among donors is low but appears to be three- to five-fold higher than among healthy non-donors, and this relative risk is even higher among donors of African ancestry. For these individuals, apolipoprotein L1 genotyping may be helpful. Kidney donors also have an increased risk of developing hypertension post-donation and a modestly increased risk of developing gout. Living kidney donation also increases the risk of gestational hypertension and preeclampsia while not affecting other important pregnancy outcomes. As our understanding of donor risk grows, it is important to counsel prospective donors according to their individual risk and so obtain better informed donor consent. As knowledge advances, it is also important that all clinicians who manage kidney transplant candidates have an up to date understanding of donor risk to inform shared decision making.

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

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

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.

HbA1c and Aortic Calcification Index as Noninvasive Predictors of Pre-Existing Histopathological Damages in Living Donor Kidney Transplantation

We previously reported that allografts from living donors may have pre-existing histopathological damages, defined as the combination of interstitial fibrosis (ci), tubular atrophy (ct), and arteriolar hyalinosis (ah) scores of ≧1, according to the Banff classification. We examined preoperative characteristics to identify whether the degree of these damages was related to metabolic syndrome-related factors of donors. We conducted a single-center cross-sectional analysis including 183 living kidney donors. Donors were divided into two groups: chronic change (ci + ct ≧ 1 &cap; ah ≧ 1, n = 27) and control (n = 156). Preoperative characteristics, including age, sex, blood pressure, hemoglobin A1c (HbA1c), aortic calcification index (ACI), and psoas muscle index (PMI), were analyzed. Comparing the groups, the baseline estimated glomerular filtration rate was not significantly different; however, we observed a significant difference for ACI (p = 0.009). HbA1c (p = 0.016) and ACI (p = 0.006) were independent risk factors to predict pre-existing histopathological damages, whereas PMI was not. HbA1c correlated with ct scores (p = 0.035), and ACI correlated with ci (p = 0.005), ct (p = 0.021), and ah (p = 0.017). HbA1c and ACI may serve as preoperative markers for identifying pre-existing damages on the kidneys of living donors.

Long-term renal function in living kidney donors with simple renal cysts: A retrospective cohort study

Simple (Bosniak I) renal cysts are considered acceptable in living kidney donor selection in terms of cancer risk. However, they tend to increase in number and size over time and might compromise renal function in donors. To clarify their implications for long-term renal function, we characterized the prevalence of renal cysts in 454 individuals who donated at our center from 2000 to 2007. We estimated the association between the presence of cysts in the kidney remaining after nephrectomy (ie, retained cysts) and postdonation eGFR trajectory using mixed-effects linear regression. Donors with retained cysts (N = 86) were older (P < .001) and had slightly lower predonation eGFR (median 94 vs 98 mL/min/1.73 m2 , P < .01) than those without cysts. Over a median 7.8 years, donors with retained cysts had lower baseline eGFR (-8.7 -5.6 -2.3  mL/min/1.73 m2 , P < .01) but similar yearly change in eGFR (-0.4 0.02 0.4  mL/min/1.73 m2 , P = .2) compared to those without retained cysts. Adjusting for predonation characteristics, there was no difference in baseline eGFR (P = .6) or yearly change in eGFR (P > .9). There continued to be no evidence of an association when we considered retained cyst(s) ≥10 mm or multiple retained cysts (all P > .05). These findings reaffirm current practices of accepting candidates with simple renal cysts for donor nephrectomy.

Outcomes With Age Combinations in Living Donor Kidney Transplantation

INTRODUCTION

Reevaluation of donor criteria, including age, is needed to combat organ shortages, lengthy wait times, and anticipated recipient mortality rates. The purpose of this study was to evaluate donor and recipient (D/R) age combinations and patient and graft survival outcomes.

METHODS

Single-organ, living donor kidney transplantations (LDKTs) from 2012 to 2018 were retrospectively reviewed. Donors and recipients were placed into "older" and "younger" age categories of 50 years and above or below age 50, then analyzed with SPSS version 25.

RESULTS

We performed 347 LDKTs. Younger-to-older pairings had significantly higher rates of smoking in recipient (53.6%) and hepatitis C (5.5%), but shorter hospital stays (5.3 days). Older-to-younger pairings had the longest hospital stays (7.4 days) but the shortest cold ischemic time (2.3 hours). Notably, there was no significant variance in delayed graft function (first-week dialysis) between groups. Regarding complication rates, only bleeding within 30 days, highest in older-to-older pairings (7.7%), and renal complications, highest in older-to-younger pairings, significantly varied between groups. Interestingly, though younger-to-older cases had the longest mean graft survival time, older kidneys lasted 537 days longer in older recipients than in younger recipients.

DISCUSSION

These results indicate there is not a one-size-fits-all approach when considering outcomes of donor/recipient age-pairings in LDKT, as significant correlations did not consistently favor one age-pairing over others. Regardless of age-pairing, LDKT provides gold standard treatment and expands the availability of organs. Future research into the impact of age-pairing on specific variables, national or multicenter studies, and protocol development for evaluating donor/recipient age-pairings is needed.

Has the UK living kidney donor population changed over time? A cross-sectional descriptive analysis of the UK living donor registry between 2006 and 2017

BACKGROUND

A living-donor kidney transplant is the best treatment for most people with kidney failure. Population cohort studies have shown that lifetime living kidney donor risk is modified by sex, age, ethnicity, body mass index (BMI), comorbidity and relationship to the recipient.

OBJECTIVES

We investigated whether the UK population of living kidney donors has changed over time, investigating changes in donor demographics.

DESIGN

We undertook a cross-sectional analysis of the UK living kidney donor registry between January 2006 to December 2017. Data were available on living donor sex, age, ethnicity, BMI, hypertension and relationship to recipient.

SETTING

UK living donor registry.

PARTICIPANTS

11 651 consecutive living kidney donors from January 2006 to December 2017.

OUTCOME MEASURES

Living kidney donor demographic characteristics (sex, age, ethnicity, BMI and relationship to the transplant recipient) were compared across years of donation activity. Donor characteristics were also compared across different ethnic groups.

RESULTS

Over the study period, the mean age of donors increased (from 45.8 to 48.7 years, p<0.001), but this change appears to have been limited to the White population of donors. Black donors were younger than White donors, and a greater proportion were siblings of their intended recipient and male. The proportion of non-genetically related non-partner donations increased over the 12-year period of analysis (p value for linear trend=0.002).

CONCLUSIONS

The increasing age of white living kidney donors in the UK has implications for recipient and donor outcomes. Despite an increase in the number of black, Asian and minority ethnic individuals waitlisted for a kidney transplant, there has been no increase in the ethnic diversity of UK living kidney donors. Black donors in the UK may be at a much greater risk of developing kidney failure due to accumulated risks: whether these risks are being communicated needs to be investigated.

Inferior Long-Term Graft Survival of Suboptimal Kidneys After Living Donor Kidney Transplantation

BACKGROUND

In living donors, if both kidneys are considered to be of equal quality, the side with favorable anatomy for transplant is usually selected. A "suboptimal kidney" is a kidney that has a significant abnormality and is chosen to maintain the principle of leaving the better kidney with the donor. We hypothesized that the long-term outcome of suboptimal kidney is inferior to that of the normal kidney.

METHODS

In a retrospective analysis of 1744 living donor kidney transplantations performed between 1999 and 2015 at our institution, 172 allografts were considered as a suboptimal kidney (9.9%). Median length of follow-up after living donor kidney transplantation was 59.5 months (interquartile range 26.3-100.8). This study strictly complied with the Helsinki Congress and the Istanbul Declaration regarding donor source.

RESULTS

The reasons for suboptimal kidneys were cysts or tumors (46.5%), arterial abnormalities (22.7%), inferior size or function (19.8%), and anatomic abnormalities (11.0%). Suboptimal kidneys showed worse long-term overall graft survival regardless of the reasons (5-year: control vs suboptimal kidney; 88.9% vs 79.3%, P = .001 and 10-year: 73.6% vs 63.5%, P = .004). Suboptimal kidneys showed a 1.6-fold higher adjusted hazard ratio (aHR) of all-cause graft loss (95% confidence interval [CI]: 1.1-2.5, P = .025) and had the same impact as older donor age (≥ 54 years old, aHR: 1.6, 95% CI: 1.1-2.4, P = .008).

CONCLUSIONS

The impact of suboptimal kidney should be factored into the donor selection process.

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

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

Long-term Mortality Risks Among Living Kidney Donors in Korea

RATIONALE & OBJECTIVE

Living kidney donors may have a higher risk for death and kidney failure. This study aimed to investigate the long-term mortality experience of living kidney donors compared with members of the general public in Korea who underwent voluntary health examinations.

STUDY DESIGN

Cohort study.

SETTING & PARTICIPANTS

We first calculated standardized mortality ratios for 1,292 Korean living kidney donors who underwent donor nephrectomy between 1982 and 2016 and 72,286 individuals who underwent voluntary health examinations between 1995 and 2016. Next we compared survival between the 1,292 living kidney donors and a subgroup of the health examination population (n=33,805) who had no evident contraindications to living kidney donation at the time of their examinations. Last, a matched comparator group was created from the health examination population without apparent contraindication to donation by matching 4,387 of them to donors (n=1,237) on age, sex, body mass index, estimated glomerular filtration rate, urine dipstick albumin excretion, previously diagnosed hypertension and diabetes, and era.

EXPOSURES

Donor nephrectomy.

OUTCOMES

All-cause mortality and other clinical outcomes after kidney donation.

ANALYTICAL APPROACH

First, standardized mortality ratios were calculated separately for living kidney donors and the health examination population standardized to the general population. Second, we used Cox regression analysis to compare mortality between living kidney donors versus the subgroup of the health examination population without evident donation contraindications. Third, we used Cox regression analysis to compare mortality between living kidney donors and matched comparators from the health examination population without apparent contraindication to donation.

RESULTS

The living kidney donors and health examination population had excellent survival rates compared with the general population. 52 (4.0%) of 1,292 kidney donors died during a mean follow-up of 12.3±8.1 years and 1,072 (3.2%) of 33,805 in the health examiner subgroup without donation contraindications died during a mean follow-up of 11.4±6.1 years. Donor nephrectomy did not elevate the hazard for mortality after multivariable adjustment in kidney donors and the 33,805 comparators (adjusted HR, 1.01; 95% CI, 0.71-1.44; P=0.9). Moreover, living donors showed a similar mortality rate compared with the group of matched healthy comparators.

LIMITATIONS

Donors from a single transplantation center. Residual confounding owing to the observational study design.

CONCLUSIONS

Kidney donors experienced long-term rates of death comparable to nondonor comparators with similar health status.

The changing landscape of live kidney donation in the United States from 2005 to 2017

The number of live kidney donors has declined since 2005. This decline parallels the evolving knowledge of risk for biologically related, black, and younger donors. To responsibly promote donation, we sought to identify declining low-risk donor subgroups that might serve as targets for future interventions. We analyzed a national registry of 77 427 donors and quantified the change in number of donors per 5-year increment from 2005 to 2017 using Poisson regression stratified by donor-recipient relationship and race/ethnicity. Among related donors aged <35, 35 to 49, and ≥50 years, white donors declined by 21%, 29%, and 3%; black donors declined by 30%, 31%, and 12%; Hispanic donors aged <35 and 35 to 49 years declined by 18% and 15%, and those aged ≥50 increased by 10%. Conversely, among unrelated donors aged <35, 35 to 49, and ≥50 years, white donors increased by 12%, 4%, and 24%; black donors aged <35 and 35 to 49 years did not change but those aged ≥50 years increased by 34%; Hispanic donors increased by 16%, 21%, and 46%. Unlike unrelated donors, related donors were less likely to donate in recent years across race/ethnicity. Although this decline might be understandable for related younger donors, it is less understandable for lower-risk related older donors (≥50 years). Biologically related older individuals are potential targets for interventions to promote donation.

Development and validation of a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation

BACKGROUND

Recently, living-donor kidney transplantation from marginal donors has been increasing. However, a simple prediction model for graft function including preoperative marginal factors is limited. Here, we developed and validated a new prediction model for graft function using preoperative marginal factors in living-donor kidney transplantation.

METHODS

We retrospectively investigated 343 patients who underwent living-donor kidney transplantation at Kyushu University Hospital (derivation cohort). Low graft function was defined as an estimated glomerular filtration rate of < 45 mL/min/1.73 m² at 1 year. A prediction model was developed using a multivariable logistic regression model, and verified using data from 232 patients who underwent living-donor kidney transplantation at Tokyo Women's Medical University Hospital (validation cohort).

RESULTS

In the derivation cohort, 89 patients (25.9%) had low graft function at 1 year. Donor age, donor-estimated glomerular filtration rate, donor hypertension, and donor/recipient body weight ratio were selected as predictive factors. This model demonstrated modest discrimination (c-statistic = 0.77) and calibration (Hosmer-Lemeshow test, P = 0.83). Furthermore, this model demonstrated good discrimination (c-statistic = 0.76) and calibration (Hosmer-Lemeshow test, P = 0.54) in the validation cohort. Furthermore, donor age, donor-estimated glomerular filtration rate, and donor hypertension were strongly associated with glomerulosclerosis and atherosclerotic vascular changes in the "zero-time" biopsy.

CONCLUSIONS

This model using four pre-operative variables will be a simple, but useful guide to estimate graft function at 1 year after kidney transplantation, especially in marginal donors, in the clinical setting.

Non-standard criteria donors in pediatric kidney transplantation

KT remains the treatment of choice for ESRD in children. However, the demand for kidney transplants continues to outstrip supply, even in the pediatric scenario. We reviewed the applicability of nonSCDs for pediatric KT. There is a lack of studies analyzing this modality among pediatric donors and recipients, where most conclusions are based on predictions from adult data. Nevertheless, marginal donors might be a reasonable option in selected cases. For example, the use of older LDs is an acceptable option, with outcomes comparable to SCDs. Organs donated after cardiac death represent another possibility, albeit with logistic, ethical, and legal limitations in some countries. AKI donors also constitute an option in special situations, although there are no pediatric data on these transplants. Likewise, there are no data on the use of expanded criteria donors in pediatric patients, but this appears not to be a good option, considering the compromised long-term survival.

Larger nephron size, low nephron number, and nephrosclerosis on biopsy as predictors of kidney function after donating a kidney

It is unclear whether structural findings in the kidneys of living kidney donors predict postdonation kidney function. We studied living kidney donors who had a kidney biopsy during donation. Nephron size was measured by glomerular volume, cortex volume per glomerulus, and mean cross-sectional tubular area. Age-specific thresholds were defined for low nephron number (calculated from CT and biopsy measures) and nephrosclerosis (global glomerulosclerosis, interstitial fibrosis/tubular atrophy, and arteriosclerosis). These structural measures were assessed as predictors of postdonation measured GFR, 24-hour urine albumin, and hypertension. Analyses were adjusted for baseline age, gender, body mass index, systolic and diastolic blood pressure, hypertension, measured GFR, urine albumin, living related donor status, and time since donation. Of 2673 donors, 1334 returned for a follow-up visit at a median 4.4 months after donation, with measured GFR <60 mL/min/1.73 m² in 34%, urine albumin >5 mg/24 h in 13%, and hypertension in 5.3%. Larger glomerular volume and interstitial fibrosis/tubular atrophy predicted follow-up measured GFR <60 mL/min/1.73 m² . Larger cortex volume per glomerulus and low nephron number predicted follow-up urine albumin >5 mg/24 h. Arteriosclerosis predicted hypertension. Microstructural findings predict GFR <60 mL/min/1.73 m² , modest increases in urine albumin, and hypertension shortly after kidney donation.

Risk of ESKD in Older Live Kidney Donors with Hypertension

BACKGROUND AND OBJECTIVES

Hypertension in older kidney donor candidates is viewed as safe. However, hypertension guidelines have evolved and long-term outcomes have not been explored. We sought to quantify the 15-year risk of ESKD and mortality in older donors (≥50 years old) with versus those without hypertension.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

A United States cohort of 24,533 older donors from 1999 to 2016, including 2265 with predonation hypertension, were linked to Centers for Medicare and Medicaid Services data and the Social Security Death Master File to ascertain ESKD development and mortality. The exposure of interest was predonation hypertension. From 2004 to 2016, hypertension was defined as documented predonation use of antihypertensive therapy, regardless of systolic BP or diastolic BP; from 1999 to 2003, when there was no documentation of antihypertensive therapy, hypertension was defined as predonation systolic BP ≥140 or diastolic BP ≥90 mm Hg.

RESULTS

Older donors were 82% white, 6% black, 7% Hispanic, and 3% Asian. The median follow-up was 7.1 years (interquartile range, 3.4-11.1; maximum, 18). There were 24 ESKD and 252 death events during the study period. The 15-year risk of ESKD was 0.8% (95% confidence interval [95% CI], 0.4 to 1.6) for donors with hypertension (mean systolic BP, 138 mm Hg) versus 0.2% (95% CI, 0.1 to 0.4) for donors without hypertension (mean systolic BP, 123 mm Hg; adjusted hazard ratio, 3.04; 95% CI, 1.28 to 7.22; P=0.01). When predonation antihypertensive therapy was available, the risk of ESKD was 6.21-fold higher (95% CI, 1.20 to 32.17; P=0.03) for donors using antihypertensive therapy (mean systolic BP, 132 mm Hg) versus those not using antihypertensive therapy (mean systolic BP, 124 mm Hg). There was no significant association between donor hypertension and 15-year mortality (hazard ratio, 1.18; 95% CI, 0.84 to 1.66; P=0.34).

CONCLUSIONS

Compared with older donors without hypertension, older donors with hypertension had higher risk of ESKD, but not mortality, for 15 years postdonation. However, the absolute risk of ESKD was small.

The 6-year clinical outcomes for patients registered in a multiregional United States Kidney Paired Donation program - a retrospective study

We examined what happened during a 6-year period to 1121 end-stage renal disease patients who registered with their willing/incompatible living donors for kidney exchanges with the Alliance for Paired Donation (APD). Of all patients, 65% were transplanted: 37% in kidney paired donation (APD-KPD, APD-other-KPD); 10% with compatible live donors (APD-LD); and 18% with deceased donors (APD-DD). The remaining patients were withdrawn (sick/died/others; 15%), or were still waiting (20%). For those patients with a cPRA 0-94%, 72% received a transplant. In contrast, only 49% of very highly sensitized (VHS; cPRA 95-100%) were transplanted. Of the VHS patients, 50% were transplanted by KPD/APD-LD while 50% benefited through prioritization of deceased donors in the modified kidney allocation system (KAS introduced in 2014). All APD transplanted groups had similar death-censored 4-year graft survivals as their relevant Organ Procurement and Transplantation Network (OPTN) groups. It is noteworthy that VHS graft and patient survival results were comparable to less sensitized and nonsensitized patients. All patients should be encouraged to search for compatible donors through different options. Expanding the donor pool through KPD and the new KAS of the OPTN increases the likelihood of transplantation for VHS patients.

Short- and Long-Term Outcomes of Live Donor Renal Allografts From Older and Younger Donors

BACKGROUND

The rising demand for living renal donors has led to the recruitment of older donors. Findings vary, but these grafts appear to survive as long as grafts from standard criteria deceased and expanded criteria deceased donors. We investigated the effects of donor age ≥65 years and the presence or absence of donor antihypertensive therapy on patient condition 1 year after transplantation, and retrospectively examined 1-year (273 patients), 3-year (217 patients), and 5-year (140 patients) patient and graft survival.

METHODS

We divided 273 donor-recipient pairs into Group Y (donor age <65 years, n = 224) and Group O (donor age ≥65 years, n = 49). Group O was subdivided into donors receiving treatment for hypertension (subgroup O-1, n = 16) and those not receiving treatment for hypertension (subgroup O-2, n = 33). We compared results of 1 hour post-transplant biopsies and looked at a small number of 1 year post-transplant biopsies.

RESULTS

Although a significantly larger percentage of recipients from younger donors were undergoing preemptive transplantation, and the incidence of arteriosclerosis was significantly higher in the Group O kidneys, there were no significant differences between the 2 groups in terms of patient or graft survival at 1, 3, or 5 years; serum creatinine levels; or number of episodes of acute rejection. The presence or absence of donor antihypertensive treatment had no effect.

CONCLUSIONS

We found that donor age ≥65, with or without antihypertensive treatment, had no effect on graft or patient survival.

Comparison of accepted and unaccepted living kidney donors: one-center experience

BACKGROUND

Kidney transplantation from living donors (LD) has stagnated in many countries. This study aimed to check whether correction of LD selection practice could increase the number of kidney transplantations.

METHODS

From January 2003 to December 2012, 241 potential adult LD were evaluated in our hospital. Outcome (mortality and end-stage renal disease-ESRD) of accepted LD (182) was compared with unaccepted (59) donors.

RESULTS

Mortality of LD was comparable with that for the standardized Serbian population (SMR = 1.104; 95% CI (0.730-1.606). Among evaluated potential LD, almost every fourth had been unaccepted, but reasons were modifiable in 42.4% of them. In pre-donation period unaccepted donors were significantly older, measured glomerular filtration rate was lower, with higher 15-year and lifelong projected ESRD risks than accepted donors. Despite this, ten years outcome of both groups LD was similar: none of LD developed ESRD, 9.8% of accepted and 11.8% of unaccepted LD died (p = .803).

CONCLUSIONS

During an average of 101 months of follow-up mortality of accepted LD did not differ significantly as compared to the age standardized Serbian population and none of them developed ESRD. In examination of potential LD, the use of accurate and precise methods for kidney function estimation and the evaluation of risk for ESRD and mortality as well as treatment of modifiable contraindications for kidney donation are necessary.

Safety of Elderly Living Kidney Donors: 2 Cases of Donors Older Than 80 Years: A Case Report

Much controversy exists over the performance of elderly living donor kidney transplantation. We report the safety of 2 cases of elderly living kidney donations in our hospital. CASE 1: An 82-year-old man was a living kidney donor for his 56-year-old son. The donor suffered from hypertension, but has successfully managed his blood pressure with only one medication. His serum creatinine was 0.7 mg/dL and inulin clearance was 122.5 mL/min, which met the usual criteria for living kidney donors. This was his son's secondary kidney transplantation, and no other donors existed. CASE 2: An 80-year-old woman was a living kidney donor for her 45-year-old son. Her serum creatinine was 0.61 mg/dL and inulin clearance was 71.7 mL/min, which met the marginal kidney donor criteria. In both cases, we determined that the donor kidney function was acceptable. Though we explained the risks of the transplantation thoroughly, the patients' strong will to offer a kidney to their family member did not change. We decided to carry out the transplantation. At the time of publication, nearly 2 years have passed since the transplantation, but both donors and recipients are doing well. In the future, it seems more likely that the number of elderly living donor kidney transplantation will rise. On one hand, there is no absolute contraindication for elderly donors, while on the other hand, the criteria for a living kidney donor must be strictly examined. Furthermore, careful observation of both donors and recipients after transplantation is required.

Long-Term Consequences of Complex Living Renal Donation: Is It Safe?

INTRODUCTION

As there is a paucity of literature regarding the long-term outcomes of complex living donors, we conducted this study to assess the effect of kidney donation on the complex living kidney donor.

MATERIALS AND METHODS

This retrospective study was conducted in Narayan Health Hospital, Kolkata, Eastern India. The cohort consisted of complex living kidney donors who donated kidneys between the years 2007 and 2012. All donors were 60 years old or older, or were younger than 60 years and had comorbidities like hypertension and obesity. After a minimum follow-up of 5 years, all donors underwent evaluation. Data pertaining to hypertension, new-onset diabetes, body mass index (BMI), estimated glomerular filtration rate (eGFR) and albuminuria, and cardiac events were compared from the time of donation till 5 years post-transplant.

RESULTS AND DISCUSSION

We found a statistically significant increase in blood pressure, number of antihypertensives used, and mean BMI at follow-up. Diabetes mellitus was developed in 22.3% of donors. The mean GFR also decreased significantly at follow-up. There were 42 elderly donors (≥60 years) and 23 ≤ 59 years of age. There was a significant fall of eGFR in both groups, but the percentage fall was similar in both groups. A significant percentage of donors developed proteinuria, the majority being hypertensives.

CONCLUSION

Procurement of kidneys from marginal donors should be done cautiously, and donors should be assessed for morbidity and mortality in the future, as we found a statistically significant deterioration in renal function, blood pressure, and BMI over long-term follow-up.