Recipient Outcomes Following Transplantation of Allografts From Live Kidney Donors Who Subsequently Developed End-Stage Renal Disease

Clinical relevance of the living kidney donor profile index in Korean kidney transplant recipients

BACKGROUND

The Living Kidney Donor Profile Index (LKDPI) was developed in the United States to predict graft outcomes based on donor characteristics. However, there are significant differences in donor demographics, access to transplantation, proportion of ABO incompatibility, and posttransplant mortality in Asian countries compared with the United States.

METHODS

We evaluated the clinical relevance of the LKDPI score in a Korean kidney transplant cohort by analyzing 1860 patients who underwent kidney transplantation between 2000 and 2019. Patients were divided into three groups according to LKDPI score: <0, 1-19.9, and ≥20.

RESULTS

During a median follow-up of 119 months, 232 recipients (12.5%) experienced death-censored graft loss, and 98 recipients (5.3%) died. High LKDPI scores were significantly associated with increased risk of death-censored graft loss independent of recipient characteristics (LKDPI 1-19.9: HR 1.389, 95% CI 1.036-1.863; LKDPI ≥20: HR 2.121, 95% CI 1.50-2.998). High LKDPI score was also significantly associated with increased risk of biopsy-proven acute rejection and impaired graft renal function. By contrast, overall patient survival rates were comparable among the LKDPI groups.

CONCLUSION

High LKDPI scores were associated with an increased risk of death-censored graft loss, biopsy-proven acute rejection, and impaired graft renal function among a Korean kidney transplant cohort.

Recommendations for living donor kidney transplantation

This Guide for Living Donor Kidney Transplantation (LDKT) has been prepared with the sponsorship of the Spanish Society of Nephrology (SEN), the Spanish Transplant Society (SET), and the Spanish National Transplant Organization (ONT). It updates evidence to offer the best chronic renal failure treatment when a potential living donor is available. The core aim of this Guide is to supply clinicians who evaluate living donors and transplant recipients with the best decision-making tools, to optimise their outcomes. Moreover, the role of living donors in the current KT context should recover the level of importance it had until recently. To this end the new forms of incompatible HLA and/or ABO donation, as well as the paired donation which is possible in several hospitals with experience in LDKT, offer additional ways to treat renal patients with an incompatible donor. Good results in terms of patient and graft survival have expanded the range of circumstances under which living renal donors are accepted. Older donors are now accepted, as are others with factors that affect the decision, such as a borderline clinical history or alterations, which when evaluated may lead to an additional number of transplantations. This Guide does not forget that LDKT may lead to risk for the donor. Pre-donation evaluation has to centre on the problems which may arise over the short or long-term, and these have to be described to the potential donor so that they are able take them into account. Experience over recent years has led to progress in risk analysis, to protect donors' health. This aspect always has to be taken into account by LDKT programmes when evaluating potential donors. Finally, this Guide has been designed to aid decision-making, with recommendations and suggestions when uncertainties arise in pre-donation studies. Its overarching aim is to ensure that informed consent is based on high quality studies and information supplied to donors and recipients, offering the strongest possible guarantees.

Long-term kidney function and survival in recipients of allografts from living kidney donors with hypertension: a national cohort study

Allografts from living kidney donors with hypertension may carry subclinical kidney disease from the donor to the recipient and, thus, lead to adverse recipient outcomes. We examined eGFR trajectories and all-cause allograft failure in recipients from donors with versus without hypertension, using mixed-linear and Cox regression models stratified by donor age. We studied a US cohort from 1/1/2005 to 6/30/2017; 49 990 recipients of allografts from younger (<50 years old) donors including 597 with donor hypertension and 21 130 recipients of allografts from older (≥50 years old) donors including 1441 with donor hypertension. Donor hypertension was defined as documented predonation use of antihypertensive therapy. Among recipients from younger donors with versus without hypertension, the annual eGFR decline was -1.03 versus -0.53 ml/min/m² (P = 0.002); 13-year allograft survival was 49.7% vs. 59.0% (adjusted allograft failure hazard ratio [aHR] 1.23; 95% CI 1.05-1.43; P = 0.009). Among recipients from older donors with versus without hypertension, the annual eGFR decline was -0.67 versus -0.66 ml/min/m² (P = 0.9); 13-year allograft survival was 48.6% versus 52.6% (aHR 1.05; 95% CI 0.94-1.17; P = 0.4). In secondary analyses, our inferences remained similar for risk of death-censored allograft failure and mortality. Hypertension in younger, but not older, living kidney donors is associated with worse recipient outcomes.

Extended Criteria Donors in Living Kidney Transplantation Including Donor Age, Smoking, Hypertension and BMI

Purpose

An expansion of selection criteria for deceased organ transplantation already exists to manage the current donor shortage. Comparable evaluation of risk factors for living donors should be investigated to improve this issue.

Patients and Methods

Our retrospective single-centre study analysed 158 patients with living kidney transplants performed between February 2006 and June 2012. We investigated the influence of donor risk factors (RF) including body mass index over 30 kg/m², age >60 years, active nicotine abuse and arterial hypertension on postoperative kidney function with focus on the recipients. This was measured for long-term survival and glomerular filtration rate (GFR) in a 5-year follow-up.

Results

Overall, out of 158 living donors, 84 donors were identified to have no risk factors, whereas 74 donors had at least one risk factor. We noted a significant higher delayed graft function (p=0.042) in the first 7 days after transplantation, as well as lower GFR of recipients of allografts with risk factors in the first-year after transplantation. In our long-term results, there was no significant difference in the functional outcome (graft function, recipient and graft survival) between recipients receiving kidneys from donors with no and at least one risk factors. In the adjusted analysis of subgroups of different risk factors, recipients of donors with “age over 60 years” at time of transplantation had a decreased transplant survival (p=0.014).

Conclusion

Thus, a careful expansion for selection criteria for living donors with critical evaluation could be possible, but especially the age of the donors could be a limited risk factor.

Association Between Living Kidney Donor Postdonation Hypertension and Recipient Graft Failure

BACKGROUND

Recipients of kidneys from living donors who subsequently develop end-stage renal disease (ESRD) also have higher graft failure, suggesting the 2 donor kidneys share risk factors that could inform recipient outcomes. Given that donor ESRD is rare, an earlier and more common postdonation outcome could serve as a surrogate to individualize counseling and management for recipients. Hypertension is a frequent event before donor ESRD; thus, early postdonation hypertension might indicate higher risk of graft failure.

METHODS

We studied Scientific Registry of Transplant Recipients data to quantify the association between early postdonation hypertension and recipient graft failure using propensity score-weighted Cox proportional hazards regression. We also examined the association between postdonation systolic blood pressure and graft failure.

RESULTS

Of 37 901 recipients, 2.4% had a donor who developed hypertension within 2 years postdonation. Controlling for donor and recipient characteristics, recipients whose donors developed hypertension had no higher risk for graft failure (adjusted hazard ratio [aHR] 1.03, 95% confidence interval [CI] 0.85-1.25, P = 0.72). This was consistent among subgroups of recipients at higher risk for adverse outcomes due to hyperfiltration: African American recipients (aHR 1.10, 95% CI 0.70-1.73, P = 0.68) and those with ESRD caused by hypertension (aHR 1.10, 95% CI 0.65-1.85, P = 0.73) or diabetes (aHR 0.80, 95% CI 0.56-1.13, P = 0.20). However, graft failure was associated with postdonation systolic blood pressure (per 10 mm Hg, aHR 1.05, 95% CI 1.03-1.08, P < 0.001).

CONCLUSIONS

Although postdonation systolic blood pressure is associated with graft failure, the reported diagnosis of hypertension as determined by the requirement for blood pressure treatment early postdonation did not portend a higher risk of recipient graft failure in the same way as eventual postdonation ESRD.

Bariatric surgery for prospective living kidney donors with obesity?

The obesity epidemic has gripped the transplant community. With nearly 40% of adults in the United States being obese (BMI ≥30 kg/m² ) and 20% being morbidly obese (BMI ≥35 kg/m² ), the implications for both donors and recipients of solid organs continue to grow.¹ Nowhere is this more impactful than the candidacy of living kidney donors (LKDs). As increasing numbers of obese adults present for LKD consideration and evidence of inferior outcomes among obese LKDs grows, transplant surgeons will become progressively challenged by how to manage these patients in the clinic. Therefore, we offer this Personal Viewpoint to the transplant surgery community in order to review the current impact of obesity on living kidney donation, highlight what weight-loss interventions have already been attempted, and discuss the role that referral for weight-loss interventions including bariatric surgery might have going forward.

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 Effect of Donors' Demographic Characteristics in Renal Function Post-Living Kidney Donation. Analysis of a UK Single Centre Cohort

Introduction: There is a great need to increase the organ donor pool, particularly for living donors. This study analyses the difference in post-living donation kidney function according to pre-donation characteristics of age, genetic relationship with the recipient, sex, ethnicity, and Body Mass Index (BMI). Methods: Retrospective single centre analysis of the trajectory of estimated Glomerular Filtration Rate (eGFR) post-living kidney donation, as a measure of kidney function. Mean eGFR of the different groups was compared at 6 months and during the 60 months follow up. Results: Mean age was 46 ± 13 years, 57% were female, and 60% Caucasian. Mean BMI was 27 ± 5 kg/m², with more than a quarter of the cohort having a BMI > 30 (26%), and the majority of the donors genetically related to their recipients (56%). The higher decline rate in eGFR was at 6 months after donation, with female sex, non-Caucasian ethnicity, and age lower than 60 years being independently associated with higher recovery in kidney function (p < 0.05). In the 60 months follow up, older age, genetic relationship with the recipient, and male sex led to higher percentual difference in eGFR post-donation. Conclusion: In this study, with a high proportion of high BMI living kidney donors, female sex, age lower than 60 years, and non-genetic relationship with recipient were persistently associated with higher increase in post-donation kidney function. Ethnicity and BMI, per se, should not be a barrier to increasing the living donor kidney pool.

Living donor postnephrectomy kidney function and recipient graft loss: A dose-response relationship

Development of end-stage renal disease (ESRD) in living kidney donors is associated with increased graft loss in the recipients of their kidneys. Our goal was to investigate if this relationship was reflected at an earlier stage postdonation, possibly early enough for recipient risk prediction based on donor response to nephrectomy. Using national registry data, we studied 29 464 recipients and their donors from 2008-2016 to determine the association between donor 6-month postnephrectomy estimated GFR (eGFR) and recipient death-censored graft failure (DCGF). We explored donor BMI as an effect modifier, given the association between obesity and hyperfiltration. On average, risk of DCGF increased with each 10 mL/min decrement in postdonation eGFR (adjusted hazard ratio [aHR] 1.06, 95% confidence interval [CI] 1.02-1.10, P = .007). The association was attenuated with higher donor BMI (interaction P = .049): recipients from donors with BMI = 20 (aHR 1.12, 95% CI 1.04-1.19, P = .002) and BMI = 25 (aHR 1.07, 95% CI 1.03-1.12, P = .001) had a higher risk of DCGF with each 10 mL/min decrement in postdonation eGFR, whereas recipients from donors with BMI = 30 and BMI = 35 did not have a higher risk. The relationship between postdonation eGFR, donor BMI, and recipient graft loss can inform counseling and management of living donor kidney transplant recipients.

Inferior long-term allograft and patient outcomes among recipients of offspring living donor kidneys

While offspring-to-parent living donor kidney transplantations may represent an ideal donor-recipient combination to optimize long-term transplantation outcomes, the sex-specific long-term success of these transplantations remains unclear. We hypothesize that allograft and recipient survivals in offspring-to-parent living donor kidney transplantation differ between men and women due to donor-specific alloimmunization during pregnancy. We retrospectively analyzed long-term allograft and patient survival among men and women who received an offspring living donor kidney compared with those who received other haplotype-matched living donor kidneys. Based on multivariable Cox proportional hazards modeling of Organ Procurement and Transplantation Network data from 2001 to 2015, we found that both men and women who received offspring living donor kidneys had significantly increased mortality compared with recipients who received nonoffspring living donor kidneys. While male recipients of any living donor kidney had greater risk of mortality and allograft failure than female recipients, there was no significant difference in all-cause allograft failure or mortality in male versus female recipients of offspring living donor kidney transplantations. Our analysis demonstrated no significant interaction between recipient sex and donor offspring status. We conclude that nonoffspring living donors should be considered whenever feasible for both men and women with multiple donor options.

A Case-Based Analysis of Whether Living Related Donors Listed for Transplant Share ESRD Causes with Their Recipients

BACKGROUND AND OBJECTIVES

Two recent studies reported increased risk of ESRD after kidney donation. In both, the majority of ESRD was seen in those donating to a relative. Confounding this observation is that, in the absence of donation, relatives of those with ESRD are at increased risk for ESRD. Understanding the pathogenesis and risk factors for postdonation ESRD is critical for both donor selection and counseling.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We hypothesized that if familial relationship was an important consideration in pathogenesis, the donor and linked recipient would share ESRD etiology. We obtained information from the Organ Procurement and Transplantation Network (OPTN) on all living kidney donors subsequently waitlisted for a kidney transplant in the United States between January 1, 1996 and November 30, 2015, to determine (1) the donor-recipient relationship and (2) whether related donor-recipient pairs had similar causes of ESRD.

RESULTS

We found that a significant amount of information, potentially available at the time of listing, was not reported to the OPTN. Of 441 kidney donors listed for transplant, only 169 had information allowing determination of interval from donation to listing, and only 99 (22% of the total) had information on the donor-recipient relationship and ESRD etiology. Of the 99 donors, 87 were related to their recipient. Strikingly, of the 87, only a minority (23%) of donor-recipient pairs shared ESRD etiology. Excluding hypertension, only 8% shared etiology.

CONCLUSIONS

A better understanding of ESRD in donors requires complete and detailed data collection, as well as a method to capture all ESRD end points. This study highlights the absence of critical information that is urgently needed to provide a meaningful understanding of ESRD after kidney donation. We found that of living related donors listed for transplant, where both donor and recipient cause of ESRD is recorded, only a minority share ESRD etiology with their recipient.

Death of recipients after kidney living donation triples donors' risk of dropping out from follow-up: a retrospective study

Although kidney transplantation from the donation of a living donor is a safe treatment for end-stage renal disease, inferences about safety of living kidney donors might be biased by an informative censoring caused by the noninclusion of a substantial percentage of donors lost to follow-up. With the aim of assessing the presence of a potential informative censoring in living kidney donation outcomes of Catalan donors for a period of 12 years, 573 donors followed and lost to follow-up were compared. Losses of follow-up over time were also assessed by univariate and multivariate survival analysis, along with Cox regression. Younger and older ages, and the death of their recipient differentiated those donors who were lost to follow-up over time. The risk of dropping out from follow-up was more than twofold for the youngest and oldest donors, and almost threefold for those donors whose recipient died. Results of studies on postdonation outcomes of Catalan living kidney donors might have overlooked older and younger cases, and, remarkably, a percentage of donors whose recipient died. If these donors showed a higher incidence of psychological problems, conclusions about living donors' safety might be compromised thus emphasizing the necessity of sustained surveillance of donors and prompt identification of these cases.