Prospective Swiss cohort study of living-kidney donors: study protocol

Expanding Opportunities for Living Donation: Recommendations From the 2023 Santander Summit to Ensure Donor Protections, Informed Decision Making, and Equitable Access

A strategic vision toward global convergence in transplantation must encourage and remove barriers to living organ donation and transplantation. Here, we discuss deliberations of a working group of the 2023 Santander Summit charged with formulating recommendations for the safe expansion of living donor kidney transplantation and living donor liver transplantation worldwide. Living donor kidney transplantation has grown to be the preferred treatment for advanced kidney failure. Living donor liver transplantation emerged more recently as a strategy to reduce waitlist mortality, with adoption influenced by cultural factors, regional policies, clinical team experience, and the maturity of regional deceased donor transplant systems. Barriers to living donor transplantation span domains of education, infrastructure, risk assessment/risk communication, and financial burden to donors. Paired donor exchange is a growing option for overcoming incompatibilities to transplantation but is variably used across and within countries. Effectively expanding access to living donor transplantation requires multifaceted strategies, including improved education and outreach, and measures to enhance efficiency, transparency, and shared decision making in donor candidate evaluation. Efforts toward global dissemination and vigilant oversight of best practices and international standards for the assessment, informed consent, approval, and monitoring of living donors are needed. Fostering greater participation in paired exchange requires eliminating disincentives and logistical obstacles for transplant programs and patients, and establishing an ethical and legal framework grounded in World Health Organization Guiding Principles. Sharing of best practices from successful countries and programs to jurisdictions with emerging practices is vital to safely expand the practice of living donation worldwide and bring the field together globally.

Living Donation and Pregnancy-Related Complications: State of the Evidence and Call To Action for Improved Risk Assessment

Living kidney donation and living liver donation significantly increases organ supply to make lifesaving transplants possible, offering survival benefits to the recipients and cost savings to society. Of all living donors, 40% are women of childbearing age. However, limited data exist regarding the effect of donation on future pregnancies and of pregnancy-related complications on postdonation outcomes. In February 2023, the American Society of Transplantation Women's Health Community of Practice held a virtual Controversies Conference on reproductive health, contraception, and pregnancy after transplantation and living donation. Experts in the field presented the available data. Smaller breakout sessions were created to discuss findings, identify knowledge gaps, and develop recommendations. We present the conference findings related to living donation. The evidence reviewed shows that gestational hypertension and gestational diabetes mellitus before kidney donation have been associated with an increased risk of developing postdonation hypertension and diabetes mellitus, respectively, without increasing the risk of developing an eGFR <45 ml/min after donation. The risk of preeclampsia in living kidney donors increases to 4%-10%, and low-dose aspirin may help reduce that risk. Little is known about the financial burden for living donors who become pregnant, their risk of postpartum depression, or the optimal time between donation and conception. The data on living liver donors are even scarcer. The creation of a registry of donor candidates may help answer many of these questions and, in turn, educate prospective donors so that they can make an informed choice.

Early Complications in Kidney Donors and Course of Health-related Quality of Life 12 mo After Donation: An Analysis of the Swiss Organ Living-Donor Health Registry

Background

Since 1998, the Swiss Organ Living-Donor Health Registry (SOL-DHR) has recorded peri- and postoperative complications of living kidney (LK) donors, as reported by all Swiss transplant centers and has collected follow-up data prospectively.

Methods

We analyzed the early complications of 2379 consecutive individuals who donated a kidney between January 1998 and June 2022 and assessed their health-related quality of life (HRQoL) 1 y after donation.

Results

In total, 447 early complications in 404/2379 LK donors (17.0%) were reported to the SOL-DHR. The frequency of donors with major complications (ie, Dindo-Clavien classification 3/4) was 2.4%. In total, 31 donors needed reoperation, and in 13/31 (42%), donors reoperation was necessary because of bleeding complications. Independent risk factors for major early complications were older donor age (P = 0.005) and type of surgical approach (ie, the laparoscopic retroperitoneal compared with laparoscopic transabdominal surgery; P = 0.01), but not sex. We observed a U-shaped association of body mass index, where very low/high body mass indexes had higher odds of major early complications, without reaching statistical significance. Although HRQoL was affected by kidney donation, 96.5% of donors indicated that they would donate their kidney again. The only independent risk factor for low HRQoL based on mental health scores was worsening EB after living kidney donation (P < 0.0001).

Conclusions

Overall, living kidney donation is a safe procedure, however, donor age and type of surgical approach affect the risk of complications. A decline in emotional bonding with the recipient after donation may worsen the quality of life of the donor.

Factors enabling transplant program participation in the Scientific Registry of Transplant Recipients (SRTR) Living Donor Collective: A national survey

BACKGROUND

The Scientific Registry of Transplant Recipients (SRTR) Living Donor Collective (LDC), the first effort to create a lifetime registry for living donor candidates in the United States, requires transplant programs to register donor candidates while the SRTR conducts follow-up.

METHODS

To better understand facilitators and barriers to program participation, we conducted a brief electronic survey of U.S. transplant program staff from October 26, 2021 to December 17, 2021.

RESULTS

We received 132 responses, with at least one response from 87 living donor programs (46 kidney programs, 33 kidney and liver programs, and eight liver programs alone). We found 86% of program representatives strongly agreed or agreed that funding adequate to cover the cost of data collection would facilitate LDC participation, 92% agreed or strongly agreed with importance of electronic data submission options, and 74% reported that elimination of requirements to submit duplicative pre-operative information to the Organ Procurement and Transplantation Network (OPTN) would be helpful. Other potentially enabling factors include reduction in duration of OPTN postdonation follow-up requirements, ease-of-use, protection from data use for regulation, adequate data security, and equity in data access.

CONCLUSION

This survey identifies potential targets to strengthen participation in the effort to create a national living donor registry in the United States. Collaboration and investment to overcome barriers to LDC participation among transplant programs are vital to generate long-term data on living donation for donor candidates, donors, and patients in need of transplant.

Long-Term Outcomes for Living Kidney Donors With Early Guideline-Concordant Follow-up Care: A Retrospective Cohort Study

Background

Current guidelines recommend that living kidney donors receive lifelong annual follow-up care to monitor kidney health. In the United States, the reporting of complete clinical and laboratory data for kidney donors has been mandated for the first 2 years post-donation; however, the long-term impact of early guideline-concordant care remains unclear.

Objective

The primary objective of this study was to compare long-term post-donation follow-up care and clinical outcomes of living kidney donors with and without early guideline-concordant follow-up care.

Design

Retrospective, population-based cohort study.

Setting

Linked health care databases were used to identify kidney donors in Alberta, Canada.

Patients

Four hundred sixty living kidney donors who underwent nephrectomy between 2002 and 2013.

Measurements

The primary outcome was continued annual follow-up at 5 and 10 years (adjusted odds ratio with 95% confidence interval, _LCLaOR_UCL). Secondary outcomes included mean change in estimated glomerular filtration rate (eGFR) over time and rates of all-cause hospitalization.

Methods

We compared long-term follow-up and clinical outcomes for donors with and without early guideline-concordant care, defined as annual physician visit and serum creatinine and albuminuria measurement for the first 2 years post-donation.

Results

Of the 460 donors included in this study, 187 (41%) had clinical and laboratory evidence of guideline-concordant follow-up care throughout the first 2 years post-donation. The odds of receiving annual follow-up for donors without early guideline-concordant care were 76% lower at 5 years (aOR _0.180.24_0.32) and 68% lower at 10 years (aOR _0.230.32_0.46) compared with donors with early care. The odds of continuing follow-up remained stable over time for both groups. Early guideline-concordant follow-up care did not appear to substantially influence eGFR or hospitalization rates over the longer term.

Limitations

We were unable to confirm whether the lack of physician visits or laboratory data in certain donors was due to physician or patient decisions.

Conclusions

Although policies directed toward improving early donor follow-up may encourage continued follow-up, additional strategies may be necessary to mitigate long-term donor risks.

Differences Between Centers in Psychosocial Evaluations for Living Kidney Donors Do Not Influence Outcome: Results From an Observational Multicenter Study

Rather little is known about how psychosocial evaluations for living kidney donation (LKD) are performed. We aimed to explore whether Swiss transplant centers (STCs) vary regarding the rate of living kidney donors refused for psychosocial reasons, the psychosocial evaluation process, and the characteristics of the donors.

Methods

We investigated 310 consecutive candidates for LKD in 4 of 6 existing STC during mandatory psychosocial evaluations. We registered (i) sociodemographic data, (ii) the type of the decision-making process regarding LKD (ie, snap decision, postponed, deliberate, other), (iii) the evaluator's perception of the donor's emotional bonding and his/her conflicts with the recipient, (iv) the donor's prognosis from a psychosocial perspective, (v) time taken for the psychosocial evaluation, and (vi) its result (eligible, eligible with additional requirements, not eligible).

Results

Centers had comparable proportions of noneligible donors (2.9%-6.0%) but differed significantly in the percentage of donors accepted with additional requirements (3.4%-66%, P < 0.001). Significant differences emerged between centers regarding the time needed for evaluation (75-160 min [interquartile range (IQR) 75-180 min] per single exploration, P < 0.001), the perception of the donor's emotional bonding (visual analogue scale [VAS] 8-9 [IQR 6-10], P < 0.001), his/her conflicts with the recipient (VAS 1.5-2 [IQR 0-3], P = 0.006), the donor's psychosocial prognosis (VAS 8-9 [IQR 7-10], P < 0.001), and the type of decision concerning LKD (59%-82% with snap decision "yes," P = 0.008). However, despite differences in the psychosocial evaluation process, the rates of patients accepted for transplantation (eligible and eligible with additional requirements versus noneligible) were comparable across STC (P = 0.72).

Conclusions

Our results emphasize that it is more important to establish clear guidelines to identify potential psychosocial risks than to stringently standardize the procedure for psychosocial evaluation of living kidney donors.

Managing the Costs of Routine Follow-up Care After Living Kidney Donation: a Review and Survey of Contemporary Experience, Practices, and Challenges

Purpose of Review

While living organ donor follow-up is mandated for 2 years in the USA, formal guidance on recovering associated costs of follow-up care is lacking. In this review, we discuss current billing practices of transplant programs for living kidney donor follow-up, and propose future directions for managing follow-up costs and supporting cost neutrality in donor care.

Recent Findings

Living donors may incur costs and financial risks in the donation process, including travel, lost time from work, and dependent care. In addition, adherence to the Organ Procurement and Transplantation Network (OPTN) mandate for US transplant programs to submit 6-, 12-, and 24-month postdonation follow-up data to the national registry may incur out-of-pocket medical costs for donors. Notably, the Centers for Medicare and Medicaid Services (CMS) has explicitly disallowed transplant programs to bill routine, mandated follow-up costs to the organ acquisition cost center or to the recipient’s Medicare insurance. We conducted a survey of transplant staff in the USA (distributed October 22, 2020–March 15, 2021), which identified that the mechanisms for recovering or covering the costs of mandated routine postdonation follow-up at responding programs commonly include billing recipients’ private insurance (40%), while 41% bill recipients’ Medicare insurance. Many programs reported utilizing institutional allowancing (up to 50%), and some programs billed the organ acquisition cost center (25%). A small percentage (11%) reported billing donors or donors’ insurance.

Summary

To maintain a high level of adherence to living donor follow-up without financially burdening donors, up-to-date resources are needed on handling routine donor follow-up costs in ways that are policy-compliant and effective for donors and programs. Development of a government-supported national living donor follow-up registry like the Living Donor Collective may provide solutions for aspects of postdonation follow-up, but requires transplant program commitment to register donors and donor candidates as well as donor engagement with follow-up outreach contacts after donation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40472-022-00379-w.

Cohort profile: The Swiss Transplant Cohort Study (STCS): A nationwide longitudinal cohort study of all solid organ recipients in Switzerland

PURPOSE

The Swiss Transplant Cohort Study (STCS) is a prospective multicentre cohort study which started to actively enrol study participants in May 2008. It takes advantage of combining data from all transplant programmes in one unique system to perform comprehensive nationwide reporting and to promote translational and clinical post-transplant outcome research in the framework of Swiss transplantation medicine.

PARTICIPANTS

Over 5500 solid organ transplant recipients have been enrolled in all six Swiss transplant centres by end of 2019, around three-quarter of them for kidney and liver transplants. Ninety-three per cent of all transplanted recipients have consented to study participation, almost all of them (99%) contributed to bio-sampling. The STCS genomic data set includes around 3000 patients.

FINDINGS TO DATE

Detailed clinical and laboratory data in high granularity as well as patient-reported outcomes from transplant recipients and activities in Switzerland are available in the last decade. Interdisciplinary contributions in diverse fields of transplantation medicine such as infectious diseases, genomics, oncology, immunology and psychosocial science have resulted in approximately 70 scientific papers getting published in peer-review journals so far.

FUTURE PLANS

The STCS will deepen its efforts in personalised medicine and digital epidemiology, and will also focus on allocation research and the use of causal inference methods to make complex matters in transplant medicine more understandable and transparent.

Living kidney donor and recipient perspectives on their relationship: longitudinal semi-structured interviews

BACKGROUND AND OBJECTIVES

Many donors and recipients report an improved bond posttransplantation; however, unexpected conflicts and tension may also occur. Insights into the lived experiences of the donor-recipient relationship can inform strategies for interventions and support. We aimed to describe donor and recipient expectations and experiences of their relationship before and after living kidney donor transplantation.

DESIGN, SETTING AND PARTICIPANTS

Semistructured interviews were conducted with 16 donor-recipient pairs before the transplant and 11-14 months post-transplant. Transcripts were analysed thematically.

RESULTS

We identified seven themes (with respective subthemes): donation as enacting familial responsibility for care; analytical decision making to mitigate regret (avoiding anticipated regret and maintaining control, removing emotional impulsivity); strengthened interpersonal ties (gaining a deeper appreciation among family members, stronger empathy for each other, improving social participation); instability of relational impacts (anger and aggression threatening dynamics, unanticipated stress and emotional lability, triggering familial tension); renegotiating social roles (unexpected continuation of caregiving responsibilities, inability to relinquish the caregiving role, disappointment with unfulfilled renewal of intimacy, dissatisfaction over discrepant energy levels); guilt over unmet expectations and inevitability of the gift relationship (vague and transient indebtedness, expectation of reciprocity, transferring kidney ownership).

CONCLUSIONS

Donor-recipient relationships may be improved through increased empathy, appreciation, and ability to participate in life together; however, unfulfilled expectations and behavioural and emotional changes in recipients (a side effect related to immunosuppression) remain unresolved consequences of living kidney donor transplantation. Education and counselling to help donors and recipients adjust to potential changes in relationship dynamics may help protect and foster relational stability postdonation.

Follow-up Care of Living Kidney Donors in Alberta, Canada

Background

Previous guidelines recommend that living kidney donors receive lifelong annual follow-up care to assess renal health.

Objective

To determine whether these best practice recommendations are currently being followed.

Design

Retrospective cohort study using linked health care databases.

Setting

Alberta, Canada (2002-2014).

Patients

Living kidney donors.

Measurements

We determined the proportion of donors who had annual outpatient physician visits and laboratory measurements for serum creatinine and albuminuria.

Results

There were 534 living kidney donors with a median follow-up of 7 years (maximum 13 years). The median age at the time of donation was 41 years and 62% were women. Overall, 25% of donors had all 3 markers of care (physician visit, serum creatinine, albuminuria measurement) in each year of follow-up. Adherence to physician visits was higher than serum creatinine or albuminuria measurements (67% vs 31% vs 28% of donors, respectively). Donors with guideline-concordant care were more likely to be older, reside closer to the transplant center, and receive their nephrectomy in more recent years.

Limitations

Our results may not be generalizable to other countries that do not have a similar universal health care system.

Conclusions

These findings suggest significant evidence-practice gaps, in that the majority of donors saw a physician, but the minority had measurements of kidney function or albuminuria. Future interventions should target improving follow-up care for all donors.

Kidney Mass Reduction Leads to l-Arginine Metabolism-Dependent Blood Pressure Increase in Mice

Background

Uninephrectomy (UNX) is performed for various reasons, including kidney cancer or donation. Kidneys being the main site of l‐arginine production in the body, we tested whether UNX mediated kidney mass reduction impacts l‐arginine metabolism and thereby nitric oxide production and blood pressure regulation in mice.

Methods and Results

In a first series of experiments, we observed a significant increase in arterial blood pressure 8 days post‐UNX in female and not in male mice. Further experimental series were performed in female mice, and the blood pressure increase was confirmed by telemetry. l‐citrulline, that is used in the kidney to produce l‐arginine, was elevated post‐UNX as was also asymmetric dimethylarginine, an inhibitor of nitric oxide synthase that competes with l‐arginine and is a marker for renal failure. Interestingly, the UNX‐induced blood pressure increase was prevented by supplementation of the diet with 5% of the l‐arginine precursor, l‐citrulline. Because l‐arginine is metabolized in the kidney and other peripheral tissues by arginase‐2, we tested whether the lack of this metabolic pathway also compensates for decreased l‐arginine production in the kidney and/or for local nitric oxide synthase inhibition and consecutive blood pressure increase. Indeed, upon uninephrectomy, arginase‐2 knockout mice (Arg‐2^−/−) neither displayed an increase in asymmetric dimethylarginine and l‐citrulline plasma levels nor a significant increase in blood pressure.

Conclusions

UNX leads to a small increase in blood pressure that is prevented by l‐citrulline supplementation or arginase deficiency, 2 measures that appear to compensate for the impact of kidney mass reduction on l‐arginine metabolism.

KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

The 2017 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors is intended to assist medical professionals who evaluate living kidney donor candidates and provide care before, during and after donation. The guideline development process followed the Grades of Recommendation Assessment, Development, and Evaluation (GRADE) approach and guideline recommendations are based on systematic reviews of relevant studies that included critical appraisal of the quality of the evidence and the strength of recommendations. However, many recommendations, for which there was no evidence or no systematic search for evidence was undertaken by the Evidence Review Team, were issued as ungraded expert opinion recommendations. The guideline work group concluded that a comprehensive approach to risk assessment should replace decisions based on assessments of single risk factors in isolation. Original data analyses were undertaken to produce a "proof-in-concept" risk-prediction model for kidney failure to support a framework for quantitative risk assessment in the donor candidate evaluation and defensible shared decision making. This framework is grounded in the simultaneous consideration of each candidate's profile of demographic and health characteristics. The processes and framework for the donor candidate evaluation are presented, along with recommendations for optimal care before, during, and after donation. Limitations of the evidence are discussed, especially regarding the lack of definitive prospective studies and clinical outcome trials. Suggestions for future research, including the need for continued refinement of long-term risk prediction and novel approaches to estimating donation-attributable risks, are also provided.In citing this document, the following format should be used: Kidney Disease: Improving Global Outcomes (KDIGO) Living Kidney Donor Work Group. KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors. Transplantation. 2017;101(Suppl 8S):S1-S109.

Investigating kidney donation as a risk factor for hypertension and microalbuminuria: findings from the Swiss prospective follow-up of living kidney donors

OBJECTIVES

To assess the role of nephrectomy as a risk factor for the development of hypertension and microalbuminuria.

DESIGN

Prospective, long-term follow-up study.

SETTING

Swiss Organ Living-Donor Health Registry.

PARTICIPANTS

All living kidney donors in Switzerland between 1993 and 2009.

INTERVENTIONS

Data on health status and renal function before 1 year and biennially after donation were collected.

PRIMARY AND SECONDARY OUTCOME MEASURES

Comparison of 1-year and 5-year occurrences of hypertension among normotensive donors with 1-year and 5-year estimates from the Framingham hypertension risk score. Multivariate random intercept models were used to investigate changes of albumin excretion after donation, correcting for repeated measurements and cofactors such as age, male gender and body mass index.

RESULTS

A total of 1214 donors contributed 3918 data entries with a completed biennial follow-up rate of 74% during a 10-year period. Mean (SD) follow-up of donors was 31.6 months (34.4). Median age at donation was 50.5 years (IQR 42.2-58.8); 806 donors (66.4%) were women. Donation increased the risk of hypertension after 1 year by 3.64 (95% CI 3.52 to 3.76; p<0.001). Those participants remaining normotensive 1 year after donation return to a risk similar to that of the healthy Framingham population. Microalbuminuria before donation was dependent on donor age but not on the presence of hypertension. After nephrectomy, hypertension became the main driver for changes in albumin excretion (OR 1.19; 95% CI 0.13 to 2.25; p=0.03) and donor age had no effect.

CONCLUSIONS

Nephrectomy propagates hypertension and increases susceptibility for the development of hypertension-induced microalbuminuria.

Living donation: the global perspective

Of 195 independent countries in the world, 83 have transplant programs. Some countries (areas) have emphasized living donation; others, decreased donation. As a consequence, rates of living donation vary widely between geographic areas and often between countries within the same geographic area. The major ethical issue in living donation is the risk to the donor. Internationally, numerous guidelines have been developed outlining acceptable donor evaluation and criteria for approval. An ongoing issue is that there remains considerable variation between countries (and programs within a country) in evaluation and in acceptance criteria. A major problem for most countries is the shortage of organs. As a consequence, illegal or quasi-legal unregulated markets have developed in some areas. These markets have not provided protection for either donor or recipient. The transplant community has taken a unified stand against these underground unregulated markets.