The medical evaluation of living kidney donors: a survey of US transplant centers

The psychology, legality, ethics and medical aspects of organ donation by minors

Any individual who has not attained the chronological age of legal majority as per national law is termed a minor. The concept of living donation (LD) has always been a subject of ethical debate and further compounding the controversy is the question of LD by minors. The decision for a minor to donate poses a special challenge as it involves a close family unit of parent-child relationship. Such an emotionally loaded situation wherein questions of attachment, perceived duties, moral obligation are likely to cloud a truly informed consent on the part of the minor to donation, who may find themselves in a vulnerable position. Furthermore, a minor's cognitive ability to comprehend the gravity of LD and when required defy parental coercion need to be elucidates before a minor is accepted for LD. Experts have set out stringent conditions which need to be met prior to the exceptional circumstance that a minor is considered for organ donation. Such donations should require parental permission, child's assent and the involvement of a paediatric-trained donor advocacy team. This article debates the question of minors acting as live donors from ethical, medical, psychosocial and legal viewpoints with an aim to present internationally defined circumstances when a minor may morally participate as a LD, thereby laying the foundation for future deliberations in this regard using traditional metrics to juxtapose divergent courses of action.

Analysis of sexual dysfunction development among male and female living kidney donors

INTRODUCTION

Living kidney donations (LKDs) face a persistent demand for patients with end-stage renal disease, emphasizing the importance of LKDs' growth and success. Although living kidney donors generally exhibit excellent survival rates, little research has explored the development of long-term sexual dysfunction following LKD.

OBJECTIVES

This study aimed to analyze differences in 5-year sexual dysfunction outcomes between male and female living kidney donors, utilizing the TriNetX database, a federated network of electronic medical records from multiple U.S. healthcare organizations.

METHODS

A propensity score-matched cohort study compared 45-year sexual dysfunction outcomes in adult male and female living kidney donors from December 2013 to December 2022. Cohorts were matched on age; sex; race and ethnicity; diabetes, cardiovascular, genitourinary, and psychiatric comorbidities; lifestyle-related factors; and medications that may impact normal sexual functioning. Primary outcomes included hazard ratio (HR) for decreased libido, sexual dysfunction (composite of male erectile dysfunction, ejaculatory disorders, vaginismus/dyspareunia, infertility, orgasmic disorders, arousal/desire disorders), and sexually transmitted diseases. Secondary outcomes assessed sex counseling and interpersonal relationship issues with spouses or partners.

RESULTS

The matched cohorts included 2315 patients each (male, female), and the mean age was 42.3 ± 12.5 years. At 5 years, male donors had a significantly higher HR for sexual dysfunction (HR, 3.768; 95% confidence interval, 1.929-7.358). Erectile dysfunction occurred in 1% of male patients, while vaginismus/dyspareunia affected <1% of female patients. Other sexual disorders, decreased libido, sexually transmitted diseases, and incidences of sexual and interspousal counseling were not significantly different.

CONCLUSION

Male living kidney donors faced a higher risk of developing sexual dysfunction 5 years after donation. While LKD remains a safe and viable alternative, clinicians and donors should be mindful of the potential association with sexual dysfunction postdonation. Further research may enhance support for the well-being of living kidney donors.

Patient-Level and Center-Level Factors Associated with Required Predonation Weight Loss among Obese Living Kidney Donors

Key Points

Among obese living kidney donors, year of donation, preoperative body mass index, hypertension, and center percent of living kidney donor transplants were associated with required predonation weight loss. There were no significant differences in the likelihood of predonation weight loss requirement by race, sex, or age or by markers of preoperative metabolic dysfunction.

Background

The proportion of overweight/mildly obese living kidney donors (OLKDs) has increased in the past few decades, with significant center variation in the body mass index (BMI) of LKDs. The purpose of this study was to examine factors associated with required predonation weight loss among OLKDs (BMI, ≥30 kg/m2).

Methods

This retrospective cohort study surveyed 1097 OLKDs (1979–2020) (mean BMI, 33 kg/m2) about their donation experience. Bivariate analyses compared donor demographic and center characteristics by whether the donor reported predonation weight loss requirement. Generalized estimating equations with logit link were used to estimate marginal effects of patient-level and center-level factors. Multiple imputation using chained equations was implemented to account for missing values.

Results

Of 1097 OLKDs surveyed, 340 (31.0%) reported predonation weight loss requirement. Donors with a predonation weight loss requirement had slightly higher predonation BMIs and donated in more recent years at centers performing a lower percentage of living donor nephrectomies and with a lower median BMI. In multivariable logistic regression analysis, we observed transplant year (odds ratio [OR], 1.04 per year donation; 95% confidence interval [CI], 1.01 to 1.07; P = 0.005), preoperative BMI (OR, 1.16; 95% CI, 1.05 to 1.28; P < 0.01), preoperative hypertension (OR, 1.61; 95% CI, 1.08 to 2.40; P = 0.02), and center percentage of living donor kidney transplants (OR, 0.99; 95% CI, 0.98 to 1.00; P = 0.02) as significantly associated with a predonation weight loss requirement. The study found no differences in the likelihood of predonation weight loss requirement by race, sex, age, preoperative creatinine, preoperative metabolic dysfunction, or center-level median BMI of living donors.

Conclusions

These results suggest that both center-level and patient-level factors influence whether OLKDs are required to lose weight before donation. Future study is needed to determine whether predonation weight loss is associated with improved long-term postdonation outcomes.

The Current State of Nuclear Nephrology in Modern Medicine

Glomerular filtration rate (GFR) is the most reliable parameter of renal function. Regarding the complexity of the gold standard inulin clearance, different estimating equations have been developed with CKD-EPI creatinine equation recommended as the most reliable one. In some clinical situations where creatinine based equations might not be valid, alternative methods are needed. Nuclear medicine methods for measuring GFR with 51Cr EDTA and 99mTc DTPA have been widely used for decades. There are different methodologies for the measurement of kidney function with radiopharmaceuticals: urinary clearance, plasma clearance, multiple plasma sampling, slope intercept, single sample plasma equation, slope only, and the gamma camera-based method. Greater precision of measuring GFR is needed in certain clinical situations. The most common are diagnosis and follow up of chronic kidney disease and definition of the beginning of replacement therapy. The assessment of renal function is also important for potential kidney donors. In recent years, with the introduction of new chemotherapeutic drugs and targeted therapy, oncologic patients treated with nephrotoxic drugs have become more commonly referred for measuring GFR. The monitoring of renal function is important during treatment in order to detect the transformation from reversible acute kidney injury to irreversible chronic kidney disease as well as in the cases of renal insufficiency reduce the dosage and prevent accumulation of the drug and avoid dosage related toxic effects. Assessment of kidney function using measured mGFR will be an important milestone in the creation of more accurate and expanding personalized medicine principle in current onconephrology practice.

Breaking Barriers and Bridging Gaps: Advancing Diversity, Equity, and Inclusion in Kidney Transplant Care for Black and Hispanic Patients in the United States

Kidney transplantation offers better mortality and quality of life outcomes to patients with end-stage renal failure compared to dialysis. Specifically, living donor kidney transplantation is the best treatment for end-stage renal disease, since it offers the greatest survival benefit compared to deceased donor kidney transplant or dialysis. However, not all patients from all racial/ethnic backgrounds enjoy these benefits. While black and Hispanic patients bear the predominant disease burden within the United States, they represent less than half of all kidney transplants in the country. Other factors such as cultural barriers that proliferate myths about transplant, financial costs that impede altruistic donation, and even biological predispositions create a complex maze and can also perpetuate care inaccessibility. Therefore, blanket efforts to increase the overall donation pool may not extend access to vulnerable populations, who may require more targeted attention and interventions. This review uses US kidney transplantation data to substantiate accessibility differences amongst racial minorities as well as provides examples of successful institutional and national systemic level changes that have improved transplantation outcomes for all.

Bariatric Surgery in Severely Obese Kidney Donors Before Kidney Transplantation: A Retrospective Study

BACKGROUND

Bariatric surgery (BS) is the optimal approach for sustained weight loss and may alter donation candidacy in potential donors with obesity. We evaluated the long-term effects of nephrectomy after BS on metabolic profile, including body mass index, serum lipids and diabetes, and kidney function of donors.

METHODS

This was a single-center retrospective study. Live kidney donors who underwent BS before nephrectomy were matched for age, gender, and body mass index with patients who underwent BS alone and with donors who underwent nephrectomy alone. Estimated glomerular filtration rate (eGFR) was calculated according to Chronic Kidney Disease Epidemiology Collaboration and adjusted to individual body surface area to create absolute eGFR.

RESULTS

Twenty-three patients who underwent BS before kidney donation were matched to 46 controls who underwent BS alone. At the last follow-up, the study group showed significantly worse lipid profile with low-density lipoprotein of 115 ± 25 mg/dL versus the control group with low-density lipoprotein of 99 ± 29 mg/dL ( P  = 0.036) and mean total cholesterol of 191 ± 32 versus 174 ± 33 mg/dL ( P  = 0.046). The second control group of matched nonobese kidney donors (n = 72) had similar serum creatinine, eGFR, and absolute eGFR as the study group before nephrectomy and 1 y after the procedure. At the end of follow-up, the study group had significantly higher absolute eGFR compared with the control group (86 ± 21 versus 76 ± 18 mL/min; P  = 0.02) and similar serum creatinine and eGFR.

CONCLUSIONS

BS before live kidney donation is a safe procedure that could increase the donor pool and improve their health in the long run. Donors should be encouraged to maintain their weight and avoid adverse lipid profile and hyperfiltration.

The strategy of diminishing age gap effect on different donor-recipient combinations in living donor kidney transplantation

BACKGROUND

The disparity between kidney donation and the number of uremic patients on the waiting list has increased the demand for older live-donor kidneys (OLK). However, the donor-recipient age gap may have an impact on the recipient's outcome.

METHODS

Patients who underwent living donor kidney transplantation at our institute between 2005 and 2019 were enrolled and categorized into four donor-recipient groups according to age (≥50 years and <50 years). The Estimated Post-Transplant Survival (EPTS) score was used to quantify the recipient's condition. Adjusted models analyzed recipient outcomes and related risks among the four groups.

RESULTS

Of the 154 pairs of live donors and recipients, OLK did not influence overall or death-censored graft survival. The four donor-recipient combinations had similar recipient outcomes, except it slightly worsened in the "old donor to young recipient" group. The EPTS score (adjusted HR, 1.02; 95% CI, 1.01-1.04; p = 0.014) and rejection (adjusted HR, 4.26; 95% CI, 1.36-13.37; p = 0.013) were significant risk factors for overall and death-censored graft survival, respectively. Recipients with pretransplant diabetes or prior solid organ transplantation could have amplified risk effects. The main causes of graft loss were death in older recipients and chronic rejection in younger recipients.

CONCLUSION

OLK is safe for young recipients. Nevertheless, adequate immunosuppression should be maintained to prevent rejection and subsequent graft loss, especially for those receiving second kidney transplantation. In contrast, older recipients should avoid overt immunosuppression and control their comorbidities, such as diabetes-related complications to improve their long-term outcomes.

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.

Pregnancy after living kidney donation, a systematic review of the available evidence, and a review of the current guidance

Understanding and communicating the risk of pregnancy complications post-living kidney donation is imperative as the majority of living kidney donors (LKD) are women of childbearing age. We aimed to identify all original research articles examining complications in post-donation pregnancies and compared the quality and consistency of related guidelines. We searched Embase, MEDLINE, PubMed, society webpages, and guideline registries for English-language publications published up until December 18, 2020. Ninety-three articles were screened from which 16 studies were identified, with a total of 1399 post-donation pregnancies. The outcome of interest, post-donation pregnancy complications, was not calculable, and only a narrative synthesis of the evidence was possible. The absolute risk of pre-eclampsia increased from ~1%-3% pre-donation (lower than the general population) to ~4%-10% post-donation (comparable to the general population). The risks of adverse fetal and neonatal outcomes were no different between post-donation and pre-donation pregnancies. Guidelines and consensus statements were consistent in stating the need to inform LKDs of their post-donation pregnancy risk, however, the depth and scope of this guidance were variable. While the absolute risk of pregnancy complications remains low post-donation, a concerted effort is required to better identify and individualize risk in these women, such that consent to donation is truly informed.

Practices and Perceptions of Living Donor Liver Transplantation, Nondirected Donation, and Liver Paired Exchange: A National Survey

Living donor liver transplantation (LDLT) remains underutilized in the United States. Barriers to LDLT and acceptance of nondirected living liver donation (ND-LLD) and liver paired exchange (LPE) are unclear. The medical and surgical directors of 99 unique transplantation programs (56 LDLT programs and 43 non-LDLT programs) were surveyed to gain insight into perceptions and practices of LDLT and types of donors utilized. The response rate was 84%. Most LDLT programs (65%) reported performing ND-LLD, though opinions regarding allocation and the need for additional evaluation of these donors were mixed. Only a minority of LDLT programs reported performing LPE (12%), but most programs (78%) would be open to cross-institutional LPE barring logistical barriers. There were significant differences between LDLT and non-LDLT programs with regard to perceived barriers to LDLT, with LDLT programs reporting mainly donor and recipient factors and non-LDLT programs reporting institutional factors (P < 0.001). Understanding perceptions and practices of LDLT, ND-LLD, and LPE is important to aid in the growth of LDLT.

Outcomes of Kidney Donors with Sickle Cell Trait: A Preliminary Analysis

Most transplant centers do not screen kidney donor candidates for sickle cell trait (SCT) and many decline candidates with SCT since it may associate with kidney disease. We compared 17 kidney donors with SCT to propensity score matched donor controls on mortality, reduced eGFR, proteinuria and kidney failure. The prevalence of SCT in African American (AA) donors was 11 per 1000 compared to 73 per 1000 in non-donor AA. Donors with SCT were younger; 33 vs. 35 years in controls, 9 were AA, 6 were White and 2 were listed as other or unknown ethnicities. After a follow-up period of 18.2 ± 10.5 years, the proportions of donors with SCT and controls who were alive, developed hypertension or cardiovascular disease were similar. No donor with SCT developed an eGFR <30 ml/min/1.73m² or kidney failure. SCT was, however, associated with increased risk of proteinuria; RR 5.71 (95% CI 5.7 - 22.7), p = 0.01. This small and preliminary case series suggest that donors with SCT should perhaps be considered more often provided they were aware of the lack of evidence to support liberal acceptance and that these outcomes reported here likely represent a healthy cohort of donors with SCT. This article is protected by copyright. All rights reserved.

Assessing Renal Function for Kidney Donation. How Low Is Too Low?

Kidney transplantation (KT) is the treatment of choice for patients with end-stage kidney disease (ESKD) with decreased morbi-mortality, improved life quality, and reduced cost. However, the shortage of organs from deceased donors led to an increase in KT from living donors. Some stipulate that living donors have a higher risk of ESKD after donation compared with healthy non-donors. The reason for this is not clear. It is possible that ESKD is due to the nephrectomy-related reduction in glomerular filtration rate (GFR), followed by an age-related decline that may be more rapid in related donors. It is essential to assess donors properly to avoid rejecting suitable ones and not accepting those with a higher risk of ESKD. GFR is a central aspect of the evaluation of potential donors since there is an association between low GFR and ESKD. The methods for assessing GFR are in continuous debate, and the kidney function thresholds for accepting a donor may vary according to the guidelines. While direct measurements of GFR (mGFR) provide the most accurate evaluation of kidney function, guidelines do not systematically use this measurement as a reference. Also, some studies have shown that the GFR decreases with age and may vary with gender and race, therefore, the lower limit of GFR in patients eligible to donate may vary based on these demographic factors. Finally, it is known that CrCl overestimates mGFR while eGFR underestimates it, therefore, another way to have a reliable GFR could be the combination of two measurement methods.

Outcomes of Kidney Donors With Impaired Fasting Glucose

BACKGROUND

Many kidney donor candidates with impaired fasting glucose (IFG) and all candidates with diabetes are currently excluded from kidney donation, fearing the development of an accelerated course of diabetic kidney disease in the remaining kidney.

METHODS

We studied mortality, proteinuria, and end-stage kidney disease (ESKD) in 8280 donors who donated between 1963 and 2007 according to donation fasting plasma glucose (FPG): <100 mg/dL (n = 6204), 100-125 mg/dL (n = 1826), and ≥126 mg/dL (n = 250).

RESULTS

Donors with IFG and those with FPG ≥126 mg/dL were older, less likely to be non-Hispanic White, had a higher body mass index, and were more likely to be related to their recipient. After 15.7 ± 10.5 y from donation to study close, 4.4% died, 29.4% developed hypertension, 13.8% developed proteinuria, and 41 (0.5%) developed ESKD. In both the logistic and Cox models, IFG was associated with a higher diabetes risk (adjusted hazard ratio [aHR], 1.65; 95% confidence interval [CI], 1.18-2.30) and hypertension (aHR, 1.35; 95% CI, 1.10-1.65; P = 0.003 for both), but not higher risk of proteinuria or ESKD. The multivariable risk of mortality in donors with ≥126 mg/dL was higher than the 2 other groups, but risks of proteinuria, cardiovascular disease, and reduced estimated glomerular filtration rate were similar to those with FPG <126 mg/dL. Three cases of ESKD developed in the 250 donors with FPG ≥126 mg/dL at 18.6 ± 10.3 y after donation (aHR, 5.36; 95% CI, 1.0-27.01; P = 0.04).

CONCLUSIONS

Donors with IFG and the majority of donors with ≥126 mg/dL do well and perhaps should not be routinely excluded from donation.

Clinical and Kidney Structural Characteristics of Living Kidney Donors With Nephrolithiasis and Their Long-term Outcomes

Nephrolithiasis in living kidney donors is concerning due to the potential impact on long-term postdonation kidney function.

Practice Patterns in the Acceptance of Medically Complex Living Kidney Donors with Obesity, Hypertension, Family History of Kidney Disease, or Donor-Recipient Age Discrepancy

Background  To assess the practice patterns of the acceptance of medically complex living kidney donors (MCLKDs).

Methods  We distributed a survey to nephrologists and transplant surgeons (TS) across the world through major international transplant societies. The survey contained questions regarding obesity, abnormal blood glucose profile, mild hypertension, donor-recipient age discrepancy, or family history of kidney disease of unknown etiology.

Results  In total, 239 respondents from 29 countries (42% were nephrologists and 58% were TS).

Most respondents would allow donations from obese donors, especially if they intended to lose weight but would be cautious if these donors had abnormal blood glucose or family history of diabetes mellitus. In hypertensive donors, future pregnancy plans mattered in decisions regarding the acceptance of female donors. Most respondents would allow young donors but would be more cautious if they had a future risk of hypertension or a family history of kidney disease of unknown etiology. They would also allow donations from an older person if prolonged waiting time was anticipated. We found multiple areas of consensus of practice among the diverse members of international transplant societies, with some interesting variations among nephrologists and TS.

Conclusions  This survey highlights the practice patterns of the acceptance of MCLKDs among the international community. In the absence of clear guidelines, this survey provides additional information to counsel kidney donors with these conditions.

CT-measured Cortical Volume Ratio Is an Accurate Alternative to Nuclear Medicine Split Scan Ratio Among Living Kidney Donors

BACKGROUND

The 125I-iothalamate clearance and 99mTc diethylenetriamine-pentaacetic acid (99mTc-DTPA) split scan nuclear medicine studies are used among living kidney donor candidates to determine measured glomerular filtration rate (mGFR) and split scan ratio (SSR). The computerized tomography-derived cortical volume ratio (CVR) is a novel measurement of split kidney function and can be combined with predonation estimated GFR (eGFR) or mGFR to predict postdonation kidney function. Whether predonation SSR predicts postdonation kidney function better than predonation CVR and whether predonation mGFR provides additional information beyond predonation eGFR are unknown.

METHODS

We performed a single-center retrospective analysis of 204 patients who underwent kidney donation between June 2015 and March 2019. The primary outcome was 1-y postdonation eGFR. Model bases were created from a measure of predonation kidney function (mGFR or eGFR) multiplied by the proportion that each nondonated kidney contributed to predonation kidney function (SSR or CVR). Multivariable elastic net regression with 1000 repetitions was used to determine the mean and 95% confidence interval of R2, root mean square error (RMSE), and proportion overprediction ≥15 mL/min/1.73 m2 between models.

RESULTS

In validation cohorts, eGFR-CVR models performed best (R2, 0.547; RMSE, 9.2 mL/min/1.73 m2, proportion overprediction 3.1%), whereas mGFR-SSR models performed worst (R2, 0.360; RMSE, 10.9 mL/min/1.73 m2, proportion overprediction 7.2%) (P < 0.001 for all comparisons).

CONCLUSIONS

These findings suggest that predonation CVR may serve as an acceptable alternative to SSR during donor evaluation and furthermore, that a model based on CVR and predonation eGFR may be superior to other methods.

Intermediate Renal Outcomes, Kidney Failure, and Mortality in Obese Kidney Donors

BACKGROUND

Obesity is associated with the two archetypal kidney disease risk factors: hypertension and diabetes. Concerns that the effects of diabetes and hypertension in obese kidney donors might be magnified in their remaining kidney have led to the exclusion of many obese candidates from kidney donation.

METHODS

We compared mortality, diabetes, hypertension, proteinuria, reduced eGFR and its trajectory, and the development of kidney failure in 8583 kidney donors, according to body mass index (BMI). The study included 6822 individuals with a BMI of <30 kg/m2, 1338 with a BMI of 30-34.9 kg/m2, and 423 with a BMI of ≥35 kg/m2. We used Cox regression models, adjusting for baseline covariates only, and models adjusting for postdonation diabetes, hypertension, and kidney failure as time-varying covariates.

RESULTS

Obese donors were more likely than nonobese donors to develop diabetes, hypertension, and proteinuria. The increase in eGFR in obese versus nonobese donors was significantly higher in the first 10 years (3.5 ml/min per 1.73m2 per year versus 2.4 ml/min per 1.73m2 per year; P<0.001), but comparable thereafter. At a mean±SD follow-up of 19.3±10.3 years after donation, 31 (0.5%) nonobese and 12 (0.7%) obese donors developed ESKD. Of the 12 patients with ESKD in obese donors, 10 occurred in 1445 White donors who were related to the recipient (0.9%). Risk of death in obese donors was not significantly increased compared with nonobese donors.

CONCLUSIONS

Obesity in kidney donors, as in nondonors, is associated with increased risk of developing diabetes and hypertension. The absolute risk of ESKD is small and the risk of death is comparable to that of nonobese donors.

Transplant Clinician Opinions on Use of Race in the Estimation of Glomerular Filtration Rate

BACKGROUND AND OBJECTIVES

Current race-based eGFR calculators assign a higher eGFR value to Black patients, which could affect the care of kidney transplant candidates and potential living donors.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We conducted a survey of staff at adult kidney transplant centers in the United States (December 17, 2020 to February 28, 2021) to assess opinions on use of race-based eGFR equations for waitlisting and living donor candidate evaluation, availability of serum cystatin C testing and measured GFR, and related practices.

RESULTS

Respondents represented 57% (124 of 218) of adult kidney transplant programs, and the responding centers conducted 70% of recent kidney transplant volume. Most (93%) programs use serum creatinine-based eGFR for listing candidates. However, only 6% of respondents felt that current race-based eGFR calculators are appropriate, with desire for change grounded in concerns for promotion of health care disparities by current equations and inaccuracies in reporting of race. Most respondents (70%) believed that elimination of race would allow more preemptive waitlisting for Black patients, but a majority (79%) also raised concerns that such an approach could incur harms. More than one third of the responding programs lacked or were unsure of availability of testing for cystatin C or measured GFR. At this time, 40% of represented centers did not plan to remove race from eGFR calculators, 46% were planning to remove, and 15% had already done so. There was substantial variability in eGFR reporting and listing of multiracial patients with some Black ancestry. There was no difference in GFR acceptance thresholds for Black versus non-Black living donors.

CONCLUSIONS

This national survey highlights a broad consensus that extant approaches to GFR estimation are unsatisfactory, but it also identified a range of current opinions.

Operational challenges in the COVID era: Asymptomatic infections and vaccination timing

The coronavirus disease 2019 (COVID‐19) pandemic has created unprecedented challenges for solid organ transplant programs. While transplant activity has largely recovered, appropriate management of deceased donor candidates who are asymptomatic but have positive nucleic acid testing (NAT) for SARS‐CoV‐2 is unclear, as this result may reflect active infection or prolonged viral shedding. Furthermore, candidates who are unvaccinated or partially vaccinated continue to receive donor offers. In the absence of robust outcomes data, transplant professionals at US adult kidney transplant centers were surveyed (February 13, 2021 to April 29, 2021) to determine community practice (N: 92 centers, capturing 41% of centers and 57% of transplants performed). The majority (97%) of responding centers declined organs for asymptomatic NAT+ patients without documented prior infection. However, 32% of centers proceed with kidney transplant in NAT+ patients who were at least 30 days from initial diagnosis with negative chest imaging. Less than 7% of programs reported inactivating patients who were unvaccinated or partially vaccinated. In conclusion, despite national recommendations to wait for negative testing, many centers are proceeding with kidney transplant in patients with positive SARS‐CoV‐2 NAT results due to presumed viral shedding. Furthermore, few centers are requiring COVID‐19 vaccination prior to transplantation at this time.

Contrast-enhanced MRI for simultaneous evaluation of renal morphology and split renal function in living kidney donor candidates

PURPOSE

The evaluation process of potential living kidney donors focusses on renal anatomy and split renal function. This study aimed to evaluate a magnetic resonance imaging (MRI)-based approach for simultaneous evaluation of both and its impact on clinical decision making.

METHOD

Over a 3-year period, 65 potential living kidney donors were consecutively enrolled. The MRI protocol was extended by MR-nephrography to measure split renal function. Standard DTPA-scintigraphy was used for functional comparison.

RESULTS

Split renal function showed no systematic bias between the two methods (mean difference 0.3%, p = 0.08). Both methods would have yielded the same clinical decision for donor nephrectomy in 75% of the patients. In 25 % of the patients, one method indicated a relevant side difference while the other did not, and a different clinical decision could have been made based on split renal function alone.

CONCLUSIONS

MRI proved eligible for comprehensive living kidney donor evaluation and non-inferior to scintigraphy for determining split renal function. In clinical decision making, these two methods would have resulted in the same side for donor nephrectomy in a large proportion of potential donors. Whether MRN will be implemented in clinical practice depends on transplant centre infrastructure and policy.

Is Bigger Better? Living Donor Kidney Volume as Measured by the Donor CT Angiogram in Predicting Donor and Recipient eGFR after Living Donor Kidney Transplantation

BACKGROUND

The role of kidney volume measurement in predicting the donor and recipient kidney function is not clear.

METHODS

We measured kidney volume bilaterally in living kidney donors using CT angiography and assessed the association with the donor remaining kidney and recipient kidney (donated kidney) function at 1 year after kidney transplantation. Donor volume was categorized into tertiles based on lowest, middle, and highest volume.

RESULTS

There were 166 living donor and recipient pairs. The mean donor age was 44.8 years (SD ± 10.8), and donor mean BMI was 25.5 (SD ± 2.9). The recipients of living donor kidneys were 64% male and had a mean age of 43.5 years (SD ± 13.3). Six percent of patients experienced an episode of cellular rejection and were maintained on dialysis for a mean of 18 months (13-32) prior to transplant. Kidney volume was divided into tertiles based on lowest, middle, and highest volume. Kidney volume median (range) in tertiles 1, 2, and 3 was 124 (89-135 ml), 155 (136-164 ml), and 184 (165-240 ml) with donor eGFR ml/min (adjusted for body surface area expressed as ml/min/1.73 m2) at the time of donation in each tertile, 109 (93-129), 110 (92-132), and 101 ml/min (84-117). The median (IQR) eGFR in tertiles 1 to 3 in kidney recipients at 1 year after donation was 54 (44-67), 62 (50-75), and 63 ml/min (58-79), respectively. The median (IQR) eGFR in tertiles 1 to 3 in the remaining kidney of donors at 1 year after donation was 59 (53-66), 65 (57-72), and 65 ml/min (56-73), respectively.

CONCLUSION

Bigger kidney volume was associated with better eGFR at 1 year after transplant in the recipient and marginally in the donor remaining kidney.

The Evaluation of Kidney Function in Living Kidney Donor Candidates

Living kidney donors incur a small increased risk of ESKD, of which predonation GFR is an important determinant. As a result, kidney function assessment is central to the donor candidate evaluation and selection process. This article reviews the different methods of GFR assessment, including eGFR, creatinine clearance, and measured GFR, and the current guidelines on GFR thresholds for donor acceptance. eGFR obtained using the 2009 CKD Epidemiology Collaboration equation that, although the best of estimating estimations, tends to underestimate levels and has limited accuracy, especially near-normal GFR values. In the United States, the Organ Procurement and Transplantation Network policy on living donation mandates either measured GFR or creatinine clearance as part of the evaluation. Measured GFR is considered the gold standard, although there is some variation in performance characteristics, depending on the marker and technique used. Major limitations of creatinine clearance are dependency on accuracy of timed collection, and overestimation as a result of distal tubular creatinine secretion. GFR declines with healthy aging, and most international guidelines recommend use of age-adapted selection criteria. The 2017 Kidney Disease: Improving Global Outcomes Guideline for the Evaluation and Care of Living Kidney Donors diverges from other guidelines and recommends using absolute cutoff of <60 ml/min per 1.73m² for exclusion and ≥90 ml/min per 1.73m² for acceptance, and determination of candidacy with intermediate GFR on the basis of long-term ESKD risk. However, several concerns exist for this strategy, including inappropriate acceptance of younger candidates due to underestimation of risk, and exclusion of older candidates whose kidney function is in fact appropriate for age. The role of cystatin C and other newer biomarkers, and data on the effect of predonation GFR on not just ESKD risk, but also advanced CKD risk and cardiovascular outcomes are needed.

Hypertension and obesity in living kidney donors

Over the past few decades, the shortage in the kidney donor pool as compared to the increasing number of candidates on the kidney transplant waitlist led to loosening of kidney donors’ acceptance criteria. Hypertension and obesity represent risk factors for chronic kidney disease, both in native kidneys and those in kidney transplant recipients. While great progress has been made in kidney transplantation from living donors to benefit the recipient survival and quality of life, progress has been slow to fully risk-characterize the donors. This review critically reassesses the current state of understanding regarding the risk of end-stage kidney disease in those donors with obesity, hypertension or both. Accurate risk assessment tools need to be developed urgently to fully understand the risk glomerular filtration rate compensation failure in the remaining kidney of the donors.

The relationship between serum uric acid levels and development of obesity in living kidney donors after donor nephrectomy

BACKGROUND

Hyperuricaemia plays a role in the pathogenesis of obesity and related metabolic disorders. The aim of this study to investigate the relationship between pre-donation serum uric acid (SUA) level and obesity development after nephrectomy in living kidney donors.

METHODS

Living donors of kidney transplants between 1998 and 2019 were evaluated. Donors with less than 1 year of follow-up were excluded from the study. The participants were divided into two groups according to last control body mass index (BMI) (obese; ≥ 30 kg/m² and nonobese; <30 kg/m² ) and median baseline SUA level (<4.6 mg/dL and ≥4.6 mg/dL).

RESULTS

In the included 240 donors, the mean follow-up was 50 ± 44 (12-216) months. The mean age was 47 ± 11 (19-82) years, and 46.6% of donors were male. At last control, the percentage of obese donors had increased significantly compared to pre-donation time (22.5% vs 33.8%; P < .001) and last control obese donors had both higher baseline SUA (5.1 ± 1.4 vs 4.5 ± 1.2; P < .01) and BMI (30.7 ± 2.6 vs 24.8 ± 3.0; P < .001). Cox regression analysis showed that there is an independent relationship between the baseline SUA level and development of obesity (odds ratio: 1.30 [CI; 1.12-1.50]; P < .001). In Kaplan-Meier analysis, the development of obesity was significantly higher in kidney donors with high SUA level.

CONCLUSION

Living kidney donors (LKD) have a tendency to obesity after nephrectomy. Preoperative serum uric acid level gives important information in LKDs that it could foresee the development of obesity after donation.

Outcomes of Hypertensive Kidney Donors Using Current and Past Hypertension Definitions

Introduction

As many as 50% of U.S. transplant centers do not accept kidney donor candidates with hypertension, citing the link between hypertension, kidney disease, and cardiovascular disease (CVD).

Methods

We ascertained mortality, CVD, proteinuria, estimated glomerular filtration rate (eGFR) trajectory, reduced eGFR, and end-stage kidney disease (ESKD) in 904 hypertensive donors (blood pressure [BP] ≥140/90 mm Hg or receiving treatment) versus 7817 donors with BP <140/90 mm Hg.

Results

Hypertensive donors were older, 58.1% were <50 years of age, and they had a lower eGFR. The majority were white and related to their recipient. At the end of follow-up, 14.3 ± 10.1 years (range 4-48 years) from donation, hypertensive and nonhypertensive donors had a similar prevalence of cardiovascular disease and renal outcomes. The multivariable risk of mortality, CVD, and proteinuria were also comparable in normotensive and hypertensive donors. eGFR slope over time was similar in hypertensive and nonhypertensive donors, and in total 5 hypertensive and 39 normotensive donors developed ESKD 19.2 ± 10.3 years after donation (adjusted hazard ratio 1.14 [95% confidence interval 0.62-2.12], P = 0.67). Sensitivity analysis using the new definition of hypertension (≥130/80 mm Hg or requiring treatment) yielded similar results for renal outcomes, but hypertensive donors were more likely to develop CVD and diabetes.

Conclusions

Kidney donors with hypertension defined by past criteria do not appear to incur higher mortality, CVD, or ESKD. Donors with current definition of hypertension enjoyed similar renal outcomes but were more likely to develop CVD.

The Association between Body Composition Measurements and Surgical Complications after Living Kidney Donation

Obesity is considered a risk factor for peri- and postoperative complications. Little is known about this risk in overweight living kidney donors. The aim of this study was to assess if anthropometric body measures and/or surgical determinants are associated with an increased incidence of peri- and postoperative complications after nephrectomy. We included 776 living kidney donors who donated between 2008 and 2018 at the University Medical Center Groningen. Prenephrectomy measures of body composition were body mass index (BMI), body surface area (BSA), waist circumference, weight, and waist–hip ratio. Incidence and severity of peri- and postoperative complications were assessed using the Comprehensive Complication Index. Mean donor age was 53 ± 11 years; 382 (49%) were male, and mean BMI at donor screening was 26.2 ± 3.41 kg/m². In total, 77 donors (10%) experienced peri- and postoperative complications following donor nephrectomy. Male sex was significantly associated with fewer surgical complications (OR 0.59, 0.37–0.96 95%CI, p = 0.03) in binomial logistic regression analyses. Older age (OR: 1.03, 1.01–1.05 95%CI, p = 0.02) and a longer duration of surgery (OR: 1.01, 1.00–1.01 95%CI, p = 0.02) were significantly associated with more surgical complications in binomial logistic regression analyses. Multinomial logistic regression analyses did not identify any prenephrectomy measure of body composition associated with a higher risk of surgical complications. This study shows that higher prenephrectomy BMI and other anthropometric measures of body composition are not significantly associated with peri- and postoperative complications following living donor nephrectomy.

Outcomes of kidney donors with pre- and post-donation kidney stones

Roughly 25% of US transplant centers exclude donor candidates with kidney stones fearing future obstructive consequences and the possible association between stones and CKD. We compared the development of hypertension, proteinuria, and reduced eGFR in 227 kidney donors with kidney stones to 908 propensity score-matched donor controls without kidney stones using data from The Renal and Lung Donor Evaluation (RELIVE) Study which studied intermediate and long-term outcomes of 8922 donors who donated between 1963 and 2007. 200 donors had kidney stones prior to donation, 21 had post-donation stones, and 6 had pre- and post-donation stones. Donors with stones were older, more likely to be Caucasian, less likely to be related to the recipient and had a higher fasting glucose. After 16.5 ± 10.9 years (range 0-44 years) from donation to study close, no ESKD occurred in donors with stones. The multivariable risks of hypertension, proteinuria, and reduced GFR were similar in donors with and without kidney stones. We could not demonstrate an association between stones and adverse renal outcomes in kidney donors, and the occurrence of post-donation stones was distinctly rare. These data may provide a rationale for possibly a wider acceptance of donor candidates with low kidney stones burden.

An International survey on living kidney donation and transplant practices during the COVID-19 pandemic

The scope of the impact of the Coronavirus disease 19 (COVID‐19) pandemic on living donor kidney transplantation (LDKT) practices across the world is not well‐defined. We received survey responses from 204 transplant centers internationally from May to June 2020 regarding the impact of the COVID‐19 pandemic on LDKT practices. Respondents represented 16 countries on five continents. Overall, 75% of responding centers reported that LDKT surgery was on hold (from 67% of North American centers to 91% of European centers). The majority (59%) of centers reported that new donor evaluations were stopped (from 46% of North American centers to 86% of European centers), with additional 23% of centers reporting important decrease in evaluations. Only 10% of centers reported slight variations on their evaluations. For the centers that continued donor evaluations, 40% performed in‐person visits, 68% by video, and 42% by telephone. Center concerns for donor (82%) and recipient (76%) safety were the leading barriers to LDKT during the pandemic, followed by patients concerns (48%), and government restrictions (46%). European centers reported more barriers related to staff limitations while North and Latin American centers were more concerned with testing capacity and insufficient resources including protective equipment. As LDKT resumes, 96% of the programs intend to screen donor and recipient pairs for coronavirus infection, most of them with polymerase chain reaction testing of nasopharyngeal swab samples. The COVID‐19 pandemic has had broad impact on all aspects of LDKT practice. Ongoing research and consensus‐building are needed to guide safe reopening of LDKT programs.

The kidney evaluation of living kidney donor candidates: US practices in 2017

We surveyed US transplant programs to assess practices used to assess kidney health in living kidney donor candidates in 2017; the response rate was 31%. In this report, we focus on the kidney; a companion piece focuses on the metabolic and cardiovascular aspects of candidate evaluation. Compared to 2005, programs have become more stringent in accepting younger candidates and less stringent in accepting older candidates. The 24-hour creatinine clearance remains the mainstay for kidney function assessment, with 74% continuing to use a value below 80 mL/min/1.73 m² for exclusion and 22% using age-based criteria. ApoL1 genotyping is obtained routinely or selectively by 45%, half of which use the high-risk genotype as an absolute exclusion criterion. For history of symptomatic stones, 49% accept if there is no current radiographic evidence of stones and urine profile is low risk, 80%-95% consider candidates with unilateral asymptomatic stones, but only 33%-48% consider if stones are bilateral. In addition, 14% use the risk assessment tool developed by Grams et al routinely for decision-making, and 42% use it sometimes. Also, 57% reported not having yet determined a risk threshold for acceptable postdonation risk above which candidates are excluded. Contemporary practice variation underscores the need for better evidence to guide the donor selection process.

Metabolic, cardiovascular, and substance use evaluation of living kidney donor candidates: US practices in 2017

We surveyed US transplant centers to assess practices regarding the evaluation and selection of living kidney donors based on metabolic, cardiovascular, and substance use risk factors. Our companion article describes renal aspects of the evaluation. Response rate was 31%. Compared with 2005, programs have become more accepting of hypertensive candidates: 65% in 2017% vs 41% in 2005 consider candidates with hypertension well controlled with 1 medication. One notable exception is black hypertensive candidates, who are frequently excluded regardless of severity. The most common body mass index (BMI) cutoff remains 35 kg/m² , and fewer programs now consider candidates with BMI >40 kg/m² . A 2-hour oral glucose tolerance test of ≥140 mg/dL remains the most common criterion for exclusion of prediabetic candidates. One quarter to one third of programs exclude based on isolated cardiac abnormalities, such as mild aortic stenosis; a similar proportion consider these candidates only if older than 50 years. Cigarette or marijuana smoking are infrequently criteria for exclusion, although 45% and 37% programs, respectively, require cessation 4 weeks prior to surgery. In addition to providing an overview of current practices in living kidney donor evaluation, our study highlights the importance of research evaluating outcomes with various comorbidities to guide practice.

Survey of Clinician Opinions on Kidney Transplantation from Hepatitis C Virus Positive Donors: Identifying and Overcoming Barriers

Background

Transplant practices related to use of organs from Hepatitis C virus infected donors (DHCV+) is evolving rapidly.

Methods

We surveyed U.S. kidney transplant programs by email and professional society listserv postings between 7/19-1/20 to assess attitudes, management strategies, and barriers related to use of viremic (nucleic acid testing (NAT)+) donor organs in HCV uninfected recipients.

Results

Staff at 112 unique programs responded, representing 54% of U.S. adult kidney transplant programs and 69% of adult deceased donor kidney transplant volume in 2019. Most survey respondents were transplant nephrologists (46%) or surgeons (43%). Among responding programs, 67% currently transplant DHCV antibody+/NAT- organs under a clinical protocol or as standard of care. By comparison, only 58% offer DHCV NAT+ kidney transplant to HCV- recipients, including 35% under clinical protocols, 14% as standard of care, and 9% under research protocols. Following transplant of DHCV NAT+ organs to uninfected recipients, 53% start direct acting antiviral agent (DAA) therapy after discharge and documented viremia. Viral monitoring protocols after DHCV NAT+ to HCV uninfected recipient kidney transplantation varied substantially. 56% of programs performing these transplants report having an institutional plan to provide DAA treatment if declined by the recipient's insurance. Respondents felt a mean decrease in waiting time of ≥18 months (range 0-60) justifies the practice. Program concerns related to use of DHCV NAT+ kidneys include insurance coverage concerns (72%), cost (60%), and perceived risk of transmitting resistant infection (44%).

Conclusions

Addressing knowledge about safety and logistical/financial barriers related to use of DHCV NAT+ kidney transplantation for HCV uninfected recipients may help reduced discards and expand the organ supply.

Survey of US Living Kidney Donation and Transplantation Practices in the COVID-19 Era

INTRODUCTION

The scope of the impact of the coronavirus disease 2019 (COVID-19) pandemic on living donor kidney transplantation (LDKT) practices is not well defined.

METHODS

We surveyed US transplant programs to assess practices, strategies, and barriers to living LDKT during the COVID-19 pandemic. After institutional review board approval, the survey was distributed from 9 May 2020 to 30 May 2020 by e-mail and postings to professional society list-servs. Responses were stratified based on state COVID-19 cumulative incidence levels.

RESULTS

Staff at 118 unique centers responded, representing 61% of US living donor recovery programs and 75% of LKDT volume in the prepandemic year. Overall, 66% reported that LDKT surgery was on hold (81% in "high" vs. 49% in "low" COVID-19 cumulative incidence states). A total of 36% reported that evaluation of new donor candidates had paused, 27% reported that evaluations were very much decreased (>0% to <25% typical), and 23% reported that evaluations were moderately decreased (25% to <50% typical). Barriers to LDKT surgery included program concerns for donor (85%) and recipient (75%) safety, patient concerns (56%), elective case restrictions (47%), and hospital administrative restrictions (48%). Programs with higher local COVID-19 cumulative incidence reported more barriers related to staff and resource diversion. Most centers continuing donor evaluations used remote strategies (video, 82%; telephone, 43%). As LDKT resumes, all programs will screen for COVID-19, although timeframe and modalities will vary. Recommendations for presurgical self-quarantine are also variable.

CONCLUSION

The COVID-19 pandemic has had broad impacts on LDKT practice. Ongoing research and consensus building are needed to reduce barriers, to guide optimal practices, and to support safe restoration of LDKT across centers.

Care of international living kidney donor candidates in the United States: A survey of contemporary experience, practice, and challenges

The evaluation and care of non-US citizen, non-US residents who wish to come to the United States to serve as international living kidney donors (ILKDs) can pose unique challenges. We surveyed US transplant programs to better understand practices related to ILKD care. We distributed the survey by email and professional society list-servs (Fall 2018, assessing 2017 experience). Eighty-five programs responded (36.8% program response rate), of which 80 considered ILKD candidates. Only 18 programs had written protocols for ILKD evaluation. Programs had a median of 3 (range: 0,75) ILKD candidates who initiated contact during the year, from origin countries spanning 6 continents. Fewer (median: 1, range: 0,25) were approved for donation. Program-reported reasons for not completing ILKD evaluations included visa barriers (58.6%), inability to complete evaluation (34.3%), concerns regarding follow-up (31.4%) or other healthcare access (28.6%), and financial impacts (21.4%). Programs that did not evaluate ILKDs reported similar concerns. Staff time required to evaluate ILKDs was estimated as 1.5-to-3-times (47.9%) or >3-times (32.9%) that needed for domestic candidates. Among programs accepting ILKDs, on average 55% reported successful completion of 1-year follow-up. ILKD evaluation is a resource-intensive process with variable outcomes. Planning and commitment are necessary to care for this unique candidate group.

Racial and Ethnic Disparities in Kidney Transplant Access Within a Theoretical Context of Medical Eligibility

BACKGROUND

Non-Hispanic black (NHB) and Hispanic patients have lower access to kidney transplantation compared to non-Hispanic whites (NHWs). We examined whether differences in the prevalence of comorbidities that affect eligibility for transplant contribute to disparities in receipt of transplantation.

METHODS

We performed a retrospective study of 986 019 adults who started dialysis between 2005 and 2014, according to the United States Renal Data System. We compared prevalence of comorbidities that could influence transplant eligibility by race/ethnicity. We examined time to first transplant by race/ethnicity in this overall cohort and in a very healthy sub-cohort without conditions that could be contraindications to transplantation.

RESULTS

During 2.3 years of mean follow-up, 64 892 transplants occurred. NHBs and Hispanics had a lower prevalence of medical barriers to transplantation at the time of dialysis initiation than NHWs, including age >70 years (26% in NHB versus 47% in NHW) and malignancy (4% in Hispanics versus 10% in NHWs). Access to transplant was 65% lower (95% CI, 0.33-0.37) in NHBs and 43% lower (95% CI, 0.54-0.62) in Hispanics (versus NHWs) in the first year after end-stage renal disease, but by Year 4, access to transplantation was not statistically significantly different between Hispanics or NHBs (versus NHWs). In our very healthy cohort, racial and ethnic disparities in access to transplantation persisted up to Year 5 in NHBs and Year 4 in Hispanics after end-stage renal disease onset.

CONCLUSIONS

Differences in medical eligibility do not appear to explain racial/ethnic disparities in receipt of kidney transplantation and may mask the actual magnitude of the inequities that are present.

Performance of Creatinine Clearance and Estimated GFR in Assessing Kidney Function in Living Donor Candidates

BACKGROUND

Glomerular filtration rate (GFR) assessment is a key aspect in the evaluation of living kidney donor candidates; however, data on performance of commonly used methods are limited.

METHODS

We examined 769 living kidney donor candidates with 24-hour urine collections assessed as accurate by comparing measured creatinine excretion rate (CER) to CER estimated using a 4-variable equation previously developed and validated using robust methodology.

RESULTS

Of all collections, 42.6% would have been deemed inaccurate, mostly under-collections, using the conventional weight- and gender-based CER estimation. Creatinine clearance (CrCl) overestimated I-iothalamate GFR (iGFR), estimated GFR (eGFR), underestimated iGFR, and their average [Avg (CrCl and eGFR)] essentially eliminated the GFR bias (median bias = +2.2, -5.4, and -1.0 mL/min/1.73 m, respectively; P < 0.001). This held true for all subgroups except blacks, where all 3 measures overestimated iGFR. Avg (CrCl and eGFR) also offered modestly improved accuracy compared with CrCl alone, as measured by the proportion of values falling within 10% (50.7% versus 45.3%; P = 0.009) and 30% of iGFR (94.5% versus 89.3%; P < 0.001).

CONCLUSIONS

When measured GFR is unavailable, the Avg (CrCl and eGFR) provides a better estimate of kidney function in kidney donor candidates than either measure alone, although in blacks the estimates are neither better nor worse.

Why Living Kidney Donor Candidates Are Turned Down? A Single-Center Cohort Study

Introduction Living donor kidney transplantation is the best replacement therapy for patients with end-stage renal disease. It offers more benefits than deceased donor transplantation. However, living kidney donors (LKDs) undergo an extensive evaluation to ensure their suitability for donation, and this can result in rejection of many potential donors. Aim The aim of this study was to recognize the reasons for declining LKDs in our Organ Transplant Center at King Abdulaziz Medical City. Settings and Design This was a retrospective study to determine the various reasons to reject an LKD at the Organ Transplant Center. Methods and Material All the LKDs from January 2016 to December 2019 were included. Declined donors were reviewed and data were obtained from the electronic database and transplant nephrology shared files. Statistical analysis We performed data analysis using SPSS version 24.0 (IBM Corp., Armonk, NY, USA). Data for continuous variables were presented as mean ± standard deviation and were compared using t-test. Categorical variables were presented as frequencies and percentages; chi-square test was used to test for main association and then Bonferroni adjustment was used for post-hoc testing. Statistical significance was considered if a two-tailed p-value of <0.05 was achieved. Results A total of 410 potential LKDs were evaluated, of whom 241 (58.8%) successfully underwent donor nephrectomy and 169 (41.2%) were unable to proceed for kidney donation. The most common reasons for rejection of LKDs were medical (47.9%) followed by immunological reasons mainly blood group incompatibility (19.5%). Other reasons were donor withdrawal (15.4%), recipient-related reasons (7.1%), surgically unfit to proceed for nephrectomy (4.7%), or psychological reasons (2.3%). Conclusions A significant proportion of potential LKDs did not complete the kidney donation process due to medical, immunological, and surgical reasons. In addition, a proportion of LKDs decided to withdraw at some point during the evaluation process. Investing in donors' educational programs and implementing a standardized evaluation process are essential to increase LKDs pool.

Incidence and Risk Factors of Obesity in Childhood Solid-Organ Transplant Recipients

BACKGROUND

Obesity is a significant public health concern; however, the incidence post solid-organ transplantation is not well reported.

METHODS

This study determined the incidence and risk factors of obesity among pediatric solid-organ transplant recipients (heart, lung, liver, kidney, multiorgan) at The Hospital for Sick Children (2002-2011), excluding prevalent obesity. Follow-up occurred from transplantation until development of obesity, last follow-up, or end of study. Incidence of obesity was determined overall, by baseline body mass index, and organ group. Risk factors were assessed using Cox proportional-hazards regression.

RESULTS

Among 410 (55% male) children, median transplant age was 8.9 (interquartile range [IQR]: 1.0-14.5) years. Median follow-up time was 3.6 (IQR: 1.5-6.4) years. Incidence of obesity was 65.2 (95% confidence interval [CI]: 52.7-80.4) per 1000 person-years. Overweight recipients had a higher incidence, 190.4 (95% CI: 114.8-315.8) per 1000 person-years, than nonoverweight recipients, 56.1 (95% CI: 44.3-71.1). Cumulative incidence of obesity 5-years posttransplant was 24.1%. Kidney relative to heart recipients had the highest risk (3.13 adjusted hazard ratio [aHR]; 95% CI: 1.53-6.40) for obesity. Lung and liver recipients had similar rates to heart recipients. Those with higher baseline body mass index (z-score; 1.72 aHR; 95% CI: 1.39-2.14), overweight status (2.63 HR; 95% CI: 1.71-4.04), and younger transplant age (y; 1.18 aHR; 95% CI: 1.12-1.25) were at highest risk of obesity. Higher cumulative steroid dosage (per 10 mg/kg) was associated with increased risk of obesity after adjustment.

CONCLUSIONS

Among all transplanted children at The Hospital for Sick Children, 25% developed obesity within 5-years posttransplant. Kidney recipients, younger children, those overweight at transplant, and those with higher cumulative steroid use (per 10 mg/kg) were at greatest risk. Early screening and intervention for obesity are important preventative strategies.

Robotic Assisted Living Donor Nephrectomies: A Safe Alternative to Laparoscopic Technique for Kidney Transplant Donation

OBJECTIVE

To review outcomes after laparoscopic, robotic-assisted living donor nephrectomy (RLDN) in the first, and largest series reported to date.

SUMMARY OF BACKGROUND DATA

Introduction of minimal invasive, laparoscopic donor nephrectomy has increased live kidney donation, paving the way for further innovation to expand the donor pool with RLDN.

METHODS

Retrospective chart review of 1084 consecutive RLDNs performed between 2000 and 2017. Patient demographics, surgical data, and complications were collected.

RESULTS

Six patients underwent conversion to open procedures between 2002 and 2005, whereas the remainder were successfully completed robotically. Median donor age was 35.7 (17.4) years, with a median BMI of 28.6 (7.7) kg/m. Nephrectomies were preferentially performed on the left side (95.2%). Multiple renal arteries were present in 24.1%. Median operative time was 159 (54) minutes, warm ischemia time 180 (90) seconds, estimated blood loss 50 (32) mL, and length of stay 3 (1) days. The median follow-up was 15 (28) months. Complications were reported in 216 patients (19.9%), of which 176 patients (81.5%) were minor (Clavien-Dindo class I and II). Duration of surgery, warm ischemia time, operative blood loss, conversion, and complication rates were not associated with increase in body mass index.

CONCLUSION

RLDN is a safe technique and offers a reasonable alternative to conventional laparoscopic surgery, in particular in donors with higher body mass index and multiple arteries. It offers transplant surgeons a platform to develop skills in robotic-assisted surgery needed in the more advanced setting of minimal invasive recipient operations.

KDOQI US Commentary on the 2017 KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

Living kidney donation is widely practiced throughout the world. During the past 2 decades, various groups have provided guidance about the evaluation and care of living donors. However, during this time, our knowledge in the field has advanced substantially and many agreed on the need for a comprehensive, unifying document. KDIGO (Kidney Disease: Improving Global Outcomes) addressed this issue at an international level with the publication of its clinical practice guideline on the evaluation and care of living kidney donors. The KDIGO work group extensively reviewed the available literature and wrote a series of guideline recommendations using various degrees of evidence when available. As has become recent practice, NKF-KDOQI (National Kidney Foundation-Kidney Disease Outcomes Quality Initiative) convened a work group to provide a commentary on the KDIGO guideline, with a focus on how these recommendations apply in the context of the United States. In the United States, the United Network for Organ Sharing (UNOS) guides and regulates the practice of living kidney donation. While the KDIGO guideline for the care of living kidney donors and UNOS policy are similar in most aspects of the care of living kidney donors, several important areas are not consistent or do not align with common practice by US transplantation programs in areas in which UNOS has not set specific policy. For the time being, and recognizing the value of the KDIGO guidelines, US transplantation programs should continue to follow UNOS policy.

Differences in national and international guidelines regarding use of kidney stone formers as living kidney donors

PURPOSE OF REVIEW

Traditionally, nephrolithiasis was considered a relative contraindication to kidney donation because of a risk of recurrent stones in donors and adverse stone-related outcomes in recipients. However, the scarcity of organs has driven the transplant community to re-examine and broaden selection criteria for living donors with stones. In this review, we summarize and contrast the guidelines published by various prominent national and international societies on this topic.

RECENT FINDINGS

Although recent iterations of living donor guidelines are less stringent with respect to nephrolithiasis than those published in the 1990s, there is little consensus among national and international transplant society guidelines regarding selection criteria for potential kidney donors with nephrolithiasis.

SUMMARY

The lack of evidence-based guidelines deters transplant centers from implementing selection criteria to accept donors with nephrolithiasis and discourages studies of outcomes in donors with nephrolithiasis and their recipients. In addition to drawing attention to the disparities in prevailing guidelines, we put forth several questions that must be answered before generalizable criteria for selection of donor with nephrolithiasis can be developed.

Policies to promote timely referral for kidney transplantation

There are numerous patient, provider, and health system barriers to accessing kidney transplantation. Patient barriers such as sociocultural and clinical characteristics and provider factors such as provider knowledge and awareness of transplantation play important roles in facilitating transplant. Health system factors like misaligned incentives and quality metrics for dialysis facilities and transplant centers also influence transplant access. While numerous studies have documented the impact of these barriers on wait-listing and transplant, few studies have examined referral from a dialysis facility to a transplant center and start of the transplant evaluation process. While the Centers for Medicare and Medicaid Services (CMS) require that dialysis facilities educate patients about transplant, there are no guidelines for the content and objectives for this education. In addition, policies to require timely referral for transplantation have been considered by CMS but are difficult to implement without national data on referral. Federal policies should be amended to mandate transplant center submission of referral data-while decreasing the unfunded mandate to collect other unusable data currently collected as part of regulatory monitoring of transplant centers-to promote timely access to transplant, increased transplant rates, and to better understand the multilevel barriers and facilitators to transplant referral.

Donor-Recipient Relationship and Risk of ESKD in Live Kidney Donors of Varied Racial Groups

RATIONALE & OBJECTIVE

Risk factors for kidney failure are the basis of live kidney donor candidate evaluation. We quantified risk for end-stage kidney disease (ESKD) by the biological relationship of the donor to the recipient, a risk factor that is not addressed by current clinical practice guidelines.

STUDY DESIGN

Retrospective cohort study.

SETTING & PARTICIPANTS

A cohort of 143,750 US kidney donors between 1987 and 2017.

EXPOSURE

Biological relationship of donor and recipient.

OUTCOME

ESKD. Donors' records were linked to national dialysis and transplantation registries to ascertain development of the outcome.

ANALYTIC APPROACH

Donors were observed over a median of 12 (interquartile range, 6-18; maximum, 30) years. Survival analysis methods that account for the competing risk for death were used.

RESULTS

Risk for ESKD varied by orders of magnitude across donor-recipient relationship categories. For Asian donors, risks compared with unrelated donors were 259.4-fold greater for identical twins (95% CI, 19.5-3445.6), 4.7-fold greater for full siblings (95% CI, 0.5-41.0), 3.5-fold greater for offspring (95% CI, 0.6-39.5), 1.0 for parents, and 1.0 for half-sibling or other biological relatives. For black donors, risks were 22.5-fold greater for identical twin donors (95% CI, 4.7-107.0), 4.1-fold for full siblings (95% CI, 2.1-7.8), 2.7-fold for offspring (95% CI, 1.4-5.4), 3.1-fold for parents (95% CI, 1.4-6.8), and 1.3-fold for half-sibling or other biological relatives (95% CI, 0.5-3.3). For white donors, risks were 3.5-fold greater for identical twin donors (95% CI, 0.5-25.3), 2.0-fold for full siblings (95% CI, 1.4-2.8), 1.4-fold for offspring (95% CI, 0.9-2.3), 2.9-fold for parents (95% CI, 2.0-4.1), and 0.8-fold for half-sibling or other biological relatives (95% CI, 0.3-1.6).

LIMITATIONS

Insufficient sample size in some race and relationship groups. Absence of data for family history of kidney disease for donors biologically unrelated to their recipients.

CONCLUSIONS

Marked differences in risk for ESKD across types of donor-recipient relationship were observed for Asian, black, and white donors. These findings warrant further validation with more robust data to better inform clinical practice guidelines.

Should minors and young adults qualify as potential live kidney donors? The views of international transplant professionals

Although live kidney donation (LD) has become an increasingly common procedure, European and US transplant centres disagree as to whether minors and young adults should qualify as donor candidates. Therefore, we aimed to better understand the attitudes and viewpoints of transplant professionals. We conducted fourteen in-depth interviews with a purposive sample of international transplant professionals from various professional backgrounds. Data analysis was guided by QUAGOL, a systematic approach based on the constant-comparative method. Professionals expressed a cautionary view, worrying about the uncertain long-term medical and psychosocial consequences of LD at a young age. They also worried that young individuals' decisions are more likely to be influenced by their psychosocial developmental stage or family pressure. As these concerns were more significant for minors as compared to young adults, minors were deemed ineligible for LD except for in highly exceptional circumstances. Professionals' attitudes were also influenced by the expected benefits for the recipient and the availability of therapeutic alternatives, as well as the strength of the donor-recipient relationship. More prospective research on the long-term medical and psychological outcomes in young adult donors is likely to shed more light on the acceptability of LD by adolescents and young adults.

Prevalence and risk factors of hypertension following nephrectomy in living kidney donors

Living donor kidney transplantation is the treatment of choice for the patients with end-stage renal disease, especially where deceased donor programs are limited. There are limited data on the outcomes of living kidney donors (LKD) from developing countries, especially from North Africa. The aim of this study is to evaluate the prevalence of hypertension (HTN) in LKD and to analyze its risk factors. This is a longitudinal monocentric study, and the donors who underwent nephrectomy for donation between 2006 and 2015 were included. Ninety-two donors were assessed. The mean age at the time of nephrectomy was 42.8 ± 10 years (21-68 years). The sex ratio was 0.6. At the time of donation, the median systolic blood pressure was 120 mm Hg and the median diastolic blood pressure was 70 mm Hg. HTN was noted in 4% of donors. The median follow-up duration was 26 months. Two years after donation, the prevalence of HTN was 28% in the study group (8% male and 20% female). The mean time to development of HTN was 16 months. Associations between HTN after donation and the cardiovascular family history, age >40 years, HTN, obesity, android obesity, glomerular filtration rate GFR <90 mL/min/1.73 m², perioperative HTN, and dyslipidemia were noted. The multivariate analysis showed that obesity at the time of donation was a risk factor for HTN (odds ratio = 4.8; P = 0.04). Obese donor [body mass index (BMI) ≥30)] has higher risk of HTN after nephrectomy than nonobese donor.