Proteinuria and reduced kidney function in living kidney donors: A systematic review, meta-analysis, and meta-regression

Long-term risks after kidney donation: how do we inform potential donors? A survey from DESCARTES and EKITA transplantation working groups

Background

Publications from the last decade have increased knowledge regarding long-term risks after kidney donation. We wanted to perform a survey to assess how transplant professionals in Europe inform potential kidney donors regarding long-term risks. The objectives of the survey were to determine how they inform donors and to what extent, and to evaluate the degree of variation.

Methods

All transplant professionals involved in the evaluation process were considered eligible, regardless of the type of profession. The survey was dispatched as a link to a web-based survey. The subjects included questions on demographics, the information policy of the respondent and the use of risk calculators, including the difference of relative and absolute risks and how the respondents themselves understood these risks.

Results

The main finding was a large variation in how often different long-term risks were discussed with the potential donors, i.e. from always to never. Eighty percent of respondents stated that they always discuss the risk of end-stage renal disease, while 56% of respondents stated that they always discuss the risk of preeclampsia. Twenty percent of respondents answered correctly regarding the relationship between absolute and relative risks for rare outcomes.

Conclusions

The use of written information and checklists should be encouraged. This may improve standardization regarding the information provided to potential living kidney donors in Europe. There is a need for information and education among European transplant professionals regarding long-term risks after kidney donation and how to interpret and present these risks.

Factors Associated With Residual Kidney Function and Proteinuria After Living Kidney Donation in the United States

BACKGROUND

Living kidney donors are carefully screened, but despite overall good health, long-term donor outcomes have been shown to vary by predonation demographics. Since 2013, the United Network for Organ Sharing has mandated 2-year postdonation follow-up with measurements of kidney function and proteinuria.

METHODS

Using data from the Scientific Registry of Transplant Recipients, we sought to analyze donor factors associated with the percent change of kidney function from baseline (predonation) to 2-year postdonation, along with incidence of proteinuria reported within the same follow-up period.

RESULTS

Older donor age, male gender, black race, and body mass index >25 kg/m2 were independently associated with a greater percent decline in estimated glomerular filtration rate (eGFR). Male gender, black race, and higher body mass index were also independently associated with incident proteinuria. In contrast, younger donor age was associated with proteinuria, but proteinuria did not correlate with greater decline in eGFR in the overall cohort.

CONCLUSIONS

Donor factors associated with lower eGFR at 2-year postdonation were similar to those previously found to be associated with long-term risk for end-stage renal disease. Early postdonation assessment of kidney function and proteinuria may help to identify donors who are at greater risk of end-stage renal disease and who may benefit from more intense long-term monitoring.

Kidney Microstructural Features at the Time of Donation Predict Long-term Risk of Chronic Kidney Disease in Living Kidney Donors

OBJECTIVE

To determine whether microstructural features on a kidney biopsy specimen obtained during kidney transplant surgery predict long-term risk of chronic kidney disease in the donor.

PATIENTS AND METHODS

We studied kidney donors from May 1, 1999, through December 31, 2018, with a follow-up survey for the results of recent blood pressure and kidney function tests (estimated glomerular filtration rate [eGFR] and proteinuria). If not recently available, blood pressure and eGFRs were requested from a local clinic. Microstructural features on kidney biopsy at the time of donation were assessed as predictors of hypertension and kidney function after adjusting for years of follow-up, baseline age, sex, and clinical predictors.

RESULTS

There were 807 donors surveyed a mean 10.5 years after donation. An eGFR less than 45 mL/min/1.73 m2 in 6.4% (43/673) of donors was predicted by larger glomerular volume per standard deviation (odds ratio [OR], 1.48; 95% CI, 1.08 to 2.04) and nephron number below the age-specific 5th percentile (OR, 3.38; 95% CI, 1.31 to 8.72). An eGFR less than 60 mL/min/1.73 m2 in 42.5% (286/673) of donors was not predicted by any microstructural feature. Residual eGFR (postdonation/predonation eGFR) was predicted by nephron number below the age-specific 5th percentile (difference, -6.07%; 95% CI, -10.24% to -1.89%). Self-reported proteinuria in 5.1% (40/786) of donors was predicted by larger glomerular volume (OR, 1.42; 95% CI, 1.08 to 1.86). Incident hypertension in 18.8% (119/633) of donors was not predicted by any microstructural features.

CONCLUSION

Low nephron number for age and larger glomeruli are important microstructural predictors for long-term risk of chronic kidney disease after living kidney donation.

Study of Glomerulopathy in Donors after Kidney Transplantation

INTRODUCTION

Living kidney donation improves the lives of individuals with kidney failure; however, recent studies have suggested that living kidney donors may be at a relatively higher risk of reduced renal function than healthy non-donors. We therefore aimed to evaluate the clinical and pathological findings in living kidney donors who developed kidney disease.

METHODS

From January 1991 to May 2019, 1,625 live kidney donations were performed at our hospital. Among the donors, 7 developed kidney disease after donation and underwent open renal biopsy. We studied the clinical and pathological findings of these patients from their clinical records.

RESULTS

There were 3 patients with immunoglobulin A (IgA) nephropathy, 2 with membranous nephropathy, 1 with anti-neutrophil cytoplasmic antibody (ANCA)-associated glomerulonephritis, and 1 with secondary focal segmental glomerulosclerosis (FSGS). All patients with IgA nephropathy had latent IgA deposition on their baseline biopsy. One patient with membranous nephropathy demonstrated findings of membranous nephropathy on the baseline biopsy, despite being asymptomatic. All patients, except for those with ANCA-associated nephropathy and secondary FSGS, recovered from the nephritis or maintained an adequate renal function after treatment.

DISCUSSION/CONCLUSION

Baseline biopsy is necessary for assessing the renal condition of kidney donors, and these donors require long-term follow-up based on their baseline biopsy findings. If donors develop kidney disease, appropriate diagnosis and treatment are essential.

How Does the Remaining Single Kidney Cope After Contralateral Nephrectomy of the Kidney Donor? A Single-Center Cohort Study

Introduction

Immediately after kidney donation, the remaining kidney will undergo hyperfiltration and work at a higher level to compensate for the other kidney's loss. It is estimated that 70% of the baseline renal function before the donation is recovered post-donation. However, factors that determine the post-donation renal compensation are not well understood.

Methods

We conducted a retrospective study of 190 consecutive kidney donors who completed a one-year follow-up in order to predict the factors affecting the function of the remaining kidney post-contralateral nephrectomy.

Results

We enrolled 190 living kidney donors who had completed at least one year of follow-up after nephrectomy. Among the participants, 149 (78.4%) were males and 41 (21.6%) were females. The mean age of the participants was 31.33 ±7.9 years and the mean body mass index (BMI) was 25.6 ±3.9 kg/m². Before kidney donation, the mean estimated glomerular filtration rate (eGFR) and serum creatinine were 114.31 ±15.94 ml/min/1.73 m² and 71.60 ±10.62 mmol/min, respectively. At the one-year follow-up, the mean eGFR was 77.97 ±14.44 ml/min/1.73 m² and serum creatinine was 100.84 ±20.15 mmol/min. The female gender [odds ratio (OR): 20.6, 95% CI: 3.9-107.7, p: <0.001] and having a higher baseline eGFR (OR: 8.8, 95% CI: 1.6-45.8, p = 0.01) were found to be significant predictors of having a better eGFR at one year post-nephrectomy.

Conclusions

Female gender and pre-donation low serum creatinine and high eGFR were the significant predictors of better kidney function at one year post-contralateral nephrectomy. However, further studies with longer follow-up durations are needed to better assess the factors that could predict renal compensation and the renal compensation rate's suitability as a prognostic measure for long-term renal outcomes.

Pediatric Donor Glomerulopathy Is a Possible Cause of Abnormal Urinalysis in Adults Receiving Small Pediatric Donor Kidneys

Background.

Reports about prognosis of adults receiving small pediatric-donor kidneys (PDK) as compared to those receiving elder pediatric or adult donor kidneys (ADKs) are controversial. This study aimed to examine the outcomes of adults receiving small PDK and possible prognostic factors.

Methods.

The records of adults who received kidneys from donors < 10 years old at our center from July 1, 2011 to June 30, 2018 were reviewed.

Results.

A total of 121 adults were small PDK recipients. Twenty-three patients received 29 biopsies or nephrectomy between 6 and 896 days posttransplantation days. Seven patients (30.4%) had pediatric donor glomerulopathy (PDG), which developed from 113 to 615 days posttransplantation. The incidence of proteinuria and hematuria was significantly higher in the PDG group. The characteristic pathological finding in PDG was irregular lamination and splintering of the glomerular basement membrane (GBM). Donor age, donor weight, and donor kidney volume were significantly less in PDG cases compared with the non-PDG cases. For the risk factors of PDG, increasing urinary RBC count during follow-up was an independent predictor, while increasing donor age and body weight were protective factors. PDG was not a significant risk factor for Scr increasing of PDKs.

Conclusions.

PDG is a potential cause of abnormal urinalysis in adults receiving small PDKs. The pathological characteristic change of PDG is splitting and lamination of GBM. Persistent hematuria after transplantation in recipients of PDK is a predictor of PDG development.

Safe Long-Term Outcome After Kidney Donation in Older Donors: A Single-Center Experience

Background

Declining numbers of deceased donors and prolonged waiting time emphasize the importance of living kidney donation. Furthermore, because of the changing age structures with increasingly older recipients, the question of acceptance of older donors is becoming more relevant. However, sufficient long-term outcome data, especially for older donors – including histopathological analysis – are lacking. The aim of this study was to analyze the Regensburg Living Donor Cohort with regard to age <65 and ≥65 years, with a 10-year follow-up to identify attributable risk factors.

Material/Methods

All donors were analyzed for renal, cardiovascular, and pre-existing conditions at baseline and at follow-up. They were studied for predefined renal and additional end-points, eg cardiovascular ones and various stratifications such as estimated glomerular filtration rate (eGFR). Additionally, as a unique feature in such an analysis, a histopathological workup of pre-existing chronic lesions of the donated kidneys was added.

Results

On average, donors in the group <65 years were 50 years old at the time of donation compared with 68 years in the older group. Creatinine at baseline was 0.8 mg/dl in both groups, corresponding to an eGFR of 96.8±12.8 ml/min (Chronic Kidney Disease Epidemiology Collaboration [CKD-EPI]) and 83.7±10.3 ml/min (CKD-EPI). In the follow-up, donors ≥65 years showed a statistically significantly worse eGFR and a greater eGFR decline, being accompanied by more pronounced chronic histopathological lesions, eg glomerulopathy, than the control group. However, this was largely constant over the entire observation period and no donor developed an end-stage renal disease or an eGFR below 30 ml/min.

Conclusions

To summarize, living kidney donation after an intensive screening is safe even for older donors; however, a precise aftercare to ensure balanced risk profile for living donors is mandatory.

The Alteration of Pro-inflammatory Cytokines and Oxidative Stress Markers at Six-Month Post-living Kidney Donation

Donors have a higher risk of developing chronic kidney disease than the general population. Some mechanisms mediated by pro-inflammatory cytokines and oxidative stress may be involved as risk factors. The objective of the study was to evaluate the behavior of pro-inflammatory cytokines and oxidative stress markers in living renal donors with a 6-month follow-up. A single prospective cohort was performed in 88 renal donors. At the end of the follow-up, the levels of lipoperoxides, 6.52 ± 1.12 mM, and 8-isoprostanes, 63.75 ± 13.28 pg/mL, were lower than before donation, 10.20 ± 3.95 mM (p < 0.001) and 67.54 ± 9.64 pg/mL (p = 0.026), respectively. Initial levels of nitric oxide (NO), 356.09 ± 59.38 μM increased at the end of the follow-up, 467.08 ± 38.74 μM (p < 0.001). It was observed in the final determination of donors decreased activity of antioxidant enzymes superoxide dismutase (SOD), 0.74 ± 0.57 U/L and glutathione peroxidase (GPx), 556.41 ± 80.37 nmol, in comparison with the levels obtained in the initial determination, 1.05 ± 0.57 U/L (p < 0.001) and 827.93 ± 162.78 nmol (p < 0.001), respectively. The pro-inflammatory cytokines, Tumor necrosis factor alpha and interleukin-6 showed no differences at 6 months after donation. The enzyme oxoguanine glycosylase (hOGG1) responsible for repairing oxidative damage to DNA, showed a decrease in its concentration at the end of the study in donor men, 0.40 ± 0.21 ng/mL compared to the initial levels, 0.55 ± 0.32 ng/mL (p = 0.025). The marker, 8-hydroxy-2-deoxyguanosine (8-OHdG) exhibited an increase in donor men at the final determination 2.28 ± 1.99 ng/mL, compared to the concentration before donation, 1.72 ± 1.96 ng/mL (p < 0.001). We found significant changes in the markers of the oxidative state with increased NO and 8-OHdG, as well as a significant decrease in the antioxidant defenses SOD, GPx, and in the DNA repair enzyme in living renal donors after 6 months of follow-up.

Long-term compensation of renal function after donor nephrectomy

Background

Living donors are the major source of kidneys in countries with a shortage of deceased donors. Kidney donation after careful donor selection is generally accepted as a safe procedure, but the physiologic consequences after donor nephrectomy are not fully verified. In this study we retrospectively reviewed the renal function of the residual kidney in living donors.

Methods

Post-nephrectomy laboratory data of 1,175 living donors (60.7%) from 1,933 living donors who received uninephrectomy from January 1999 to December 2017 at Yonsei University, Severance Hospital, Korea were retrospectively collected. Post-nephrectomy renal function was monitored by the relative ratio of estimated glomerular filtration rate (e-GFR; pre-nephrectomy e-GFR ratio vs. post-nephrectomy e-GFR) that was calculated by the Modification of Diet in Renal Disease formula.

Results

During 36.3±37.6 months of mean follow-up, two cases (0.17%, 2/1,175) of renal failure developed. The mean e-GFR decreased to 64.3±14.2 mL/min/1.73 m2 immediately after nephrectomy from 99.2±19.9 mL/min/1.73 m2 of the pre-nephrectomy e-GFR. Early decrement of e-GFR was prominent in male and obese donors (body mass index >25 kg/m2, P<0.05). The e-GFR ratio increased according to post-nephrectomy duration, and the mean increment degree of e-GFR ratio after nephrectomy calculated by linear regression analysis was 1.94% per year. Unlike the early decrement of e-GFR ratio after nephrectomy, donor factors such as degree of obesity and donor sex did not affect the late increment of e-GFR ratio after nephrectomy (P>0.05).

Conclusions

Our data showed that long-term compensation of the renal function after nephrectomy occurs independently of preoperative donor characteristics.

Changes in kidney function follow living donor nephrectomy

Better understanding of kidney function after living donor nephrectomy and how it differs by donor characteristics can inform patient selection, counselling, and follow-up care. To evaluate this, we conducted a retrospective matched cohort study of living kidney donors in Alberta, Canada between 2002-2016, using linked healthcare administrative databases. We matched 604 donors to 2,414 healthy non-donors from the general population based on age, sex, year of cohort entry, urban residence and the estimated glomerular filtration rate (eGFR) before cohort entry (nephrectomy date for donors and randomly assigned date for non-donors). The primary outcome was the rate of eGFR change over time (median follow-up seven years; maximum 15 years). The median age of the cohort was 43 years, 64% women, and the baseline (pre-donation) eGFR was 100 mL/min/1.73 m². Overall, from six weeks onwards, the eGFR increased by +0.35 mL/min/1.73 m² per year (95% confidence interval +0.21 to +0.48) in donors and significantly decreased by -0.85 mL/min/1.73 m² per year (-0.94 to -0.75) in the matched healthy non-donors. The change in eGFR between six weeks to two years, two to five years, and over five years among donors was +1.06, +0.64, and -0.06 mL/min/1.73 m² per year, respectively. In contrast to the steady age-related decline in kidney function in non-donors, post-donation kidney function on average initially increased by 1 mL/min/1.73 m² per year attributable to glomerular hyperfiltration, which began to plateau by five years post-donation. Thus, the average change in eGFR over time is significantly different between donors and non-donors.

Living Kidney Donor Evaluation

Long-term safety of living kidney donation (LKD), especially for young donors, has become a real matter of concern in the transplant community and may contribute to creating resistance to LKD. In this context, the criteria that govern living donor donations must live up to very demanding standards as well as adjust to this novel reality. In the first part, we review the existing guidelines published after 2010 and critically examine their recommendations to see how they do not necessarily lead to consistent and universal practices in the choice of specific thresholds for a parameter used to accept or reject a living donor candidate. In the second part, we present the emergence of a new paradigm for LKD developed in the 2017 Kidney Disease: Improving Global Outcomes guidelines with the introduction of an integrative risk-based approach. Finally, we focus on predonation renal function evaluation, a criteria that remain central in the selection process, and discuss several issues surrounding the donor candidate's glomerular filtration rate assessment.

A prospective controlled study of metabolic and physiologic effects of kidney donation suggests that donors retain stable kidney function over the first nine years

While there have been numerous studies of living kidney donors, most have been retrospective without suitable controls and have yielded conflicting results. To clarify this we studied 205 living donor candidates and 203 controls having no medical conditions precluding donation. Before and at six months, one, two, three, six, and nine years after donation we measured iohexol glomerular filtration rate, clinic blood pressure, urine protein excretion and metabolic parameters reported to be affected by kidney function. We measured 24 hour ambulatory blood pressure at three, six, and nine years and at six and nine years blood pressure after treadmill exercise, carotid-femoral pulse wave velocity and arterial elasticity. Between six months and nine years, the mean (95% confidence interval) change in glomerular filtration rate was significantly different among 133 donors 0·02 (-0·16-0·20) mL/min/1·73m²/year versus -1·26 (-1·52--1·00) mL/min/1·73m²/year in 113 healthy controls. Blood pressure, urine protein, urine albumin, glucose, hemoglobin A1c, insulin, and lipoproteins were not different in controls versus donors; but parathyroid hormone, homocysteine and uric acid remained higher at nine years. At six and nine years carotid-femoral pulse wave velocity was not different, but the mean small artery elasticity was significantly lower in 141 donors 6·1 mL/mmHg x100, versus 113 controls 7·1 mL/mmHg x100, and 6·1 mL/mmHg x100 in 137 donors versus 7·6 mL/mmHg x100 in 112 controls at six and nine years, respectively [significant adjusted difference of 1·1 mL/mmHg x100]. Thus, donors remain healthy with stable kidney function for the first nine years, but differences in metabolic and vascular parameters could be harbingers of adverse outcomes requiring future interventions.

Increase in interventricular septum thickness may be the first sign of cardiovascular change in kidney donors

BACKGROUND

Because of the inadequate number of deceased kidney donors, living kidney donation remains an important issue for kidney transplantation. Previous studies have shown that living donation does not differ life expectancy and progression to end-stage renal disease compared with the normal population. In this study, we investigated short-term cardiovascular changes after donor nephrectomy.

METHODS

Thirty-four patients who underwent donor nephrectomy between January 2015 and July 2015 at Ege University Renal Transplantation Unit were included in the study. Arterial stiffness, multifrequency bioimpedance analysis, renal ARFI elastography, and echocardiography performed prior to the donor nephrectomy and 6 months after nephrectomy.

RESULTS

A total of 34 kidney donors were enrolled in this study. Twenty donors were female (59%) and 14 donors were male (41%). The pathological evaluation of donor kidneys using implantation renal biopsy sample revealed mean Karpinski Renal Score of 1.5 and the mean glomerulosclerosis ratio was 5% for all donated kidneys. Arterial stiffness, systolic and diastolic blood pressure measures, body fluid composition, and left atrial size did not change significantly during the follow-up. However, interventricular septum thickness of donors increased by 1 mm during a 6-month period (9.6 mm vs 10.6 mm, P = .002).

CONCLUSION

We observed an increase in interventricular septum thickness in kidney donors during a 6-month follow-up. In order to evaluate the net effect of this change on donor morbidity, prospective studies investigating an increased number of donors with long-term follow-up should be needed.

Cases in Precision Medicine: APOL1 and Genetic Testing in the Evaluation of Chronic Kidney Disease and Potential Transplant

This article discusses potential indications for genetic testing in an African American patient with chronic kidney disease who is being evaluated for a kidney transplant. Two known risk variants in the APOL1 (apolipoprotein L1) gene predispose to kidney disease and are found almost exclusively in persons of African ancestry. APOL1 risk variants are considered, including whether clinicians should incorporate genetic testing in the screening process for living kidney donors. In addition to APOL1 testing, the role of diagnostic exome sequencing in evaluating potential transplant recipients and donors with a positive family history of kidney disease is discussed.

Increase in 24-Hour Protein Excretion Immediately After Donation Is Associated With Decreased Functional Recovery in Living Kidney Donors

OBJECTIVES

In this study, we evaluated the occurrence of proteinuria in living kidney donors during the immediate postdonation period, aiming to determine its clinical significance in renal function recovery.

PATIENTS AND METHODS

We enrolled living kidney donors with predonation protein excretion rate (PER) < 150 mg/24 h. Participants were divided into 2 groups according to immediate postdonation PER (4 days after nephrectomy): non-microproteinuria (non-mPr; PER < 150 mg/24 h), n = 244; and immediate postdonation microproteinuria (ImPr; PER ≥ 150 mg/24 h), n = 605.

RESULTS

Estimated glomerular filtration rate (eGFR) did not differ significantly between groups immediately after nephrectomy but was consistently lower in the ImPr group 1 week to 1 year postdonation (1-year postdonation eGFR: ImPr group, 63.6 ± 12.1 mL/min/1.73 m²; non-mPr group, 68.6 ± 12.3 mL/min/1.73 m²; P = .001). Immediate postdonation microproteinuria was an independent predictor of eGFR at 1 year postdonation (β [standard error] = -2.68 [1.15], 95% confidence interval -4.94 to -0.42, P = .02), along with predonation eGFR, age, and sex. Immediate postdonation microproteinuria was more common in donors who were older or male and occurred in 71.3% of kidney donors, suggesting renal injury in this period.

CONCLUSIONS

Although proteinuria generally resolves, its impact persists and can impair renal function recovery. Donors who are older and male are more likely to undergo immediate hyperfiltration after donation.

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.

[Long term renal function outcomes and predictive factors of chronic renal failure after living kidney donation]

INTRODUCTION

Living donor kidney transplants give the best results in term of renal function and are the principal solutions for the transplant shortage. However, donors selection and kidney function evaluation after surgery are essential. The objective of this study was to evaluate the prevalence and to identify the predictive factors of chronic renal failure for the donor, after living donor nephrectomy.

MATERIALS AND METHODS

It was a retrospective and monocentric study, including all the patients who underwent a living donor nephrectomy from 2007 to 2015 at the hospital of the Conception in Marseille. The primary study endpoint was renal function mesured by the glomerular filtration rate (GFR in mL/min) at 1 year and 5 years after surgery. The identification of moderate kidney failure predictive factors was achieved by an univariate and a multivariate analysis under Cox model.

RESULTS

Ninety-one patients were included. There was 40,7 % of men and media nage was 49 years (21; 70). Median pre-operative GFR was 94mL/min (67; 160). Median follow-up was 24 months (1; 120). Post operative GFR at 1 month, 1 year and 5 years was respectively 63mL/min (33; 90), 65mL/min (38; 107) and 67mL/min (56; 126) ans significantly lower than pre operative GFR (respectively P<0,001, P<0,001 et P=0,005). The prevalence of moderate kidney failure at 1 month, 1 year and 5 years was respectively 43,1 %, 33,3 % ans 25 %. In univariate and multivariate analysis, the only parametre significantly associated with a 1 year GFR>60mL/min wasp re operative GFR>90mL/min OR 3,61 IC95 % (1,27; 10,28) P=0,02.

CONCLUSION

Living donor nephrectomy leads to an important medium to long term loss of renal function. Donors with pre operative GFR<90mL/min should benefit from a rigorous supervision and nephrological care.

LEVEL OF EVIDENCE

3.

Kidney donor outcomes ≥ 50 years after donation

Many living kidney donors (LDs) are young at donation; yet there are little data on long-term LD follow-up. We report on 66 LDs who donated ≥50 years ago: 22 (33.3%) are still alive (current age, 78.5 ± 7.25 years); 39 (59%) died (mean age at death, 74.2 ± 12.3 years); and 5 are lost to follow-up (mean age at last contact, 68.7 ± 4.6 years). Those who died were older at donation (P < .001). Causes of death included 12 (30.8% of deaths) cardiovascular diseases, 9 (23.0%) respiratory failures, 5 (12.8%) malignancies and 4 (10.3%) infections, and 9 (23%) were unknown or miscellaneous. Forty-nine living donors (74%) developed hypertension at a mean age of 59.9 ± 14.0 years; 12 (18%) developed diabetes at a mean age of 62 ± 19.4 years; and 11 (16.7%) developed proteinuria at a mean age of 60.6 ± 18.2 years-each at a similar incidence as seen in the age-matched general population. At last follow-up, the eGFR by CKD-EPI (mean ± SD) for donors currently alive was 60.2 ± 13.4 mL/min/1.73 m² ; for those that died, 54.0 ± 21.5 mL/min/1.73 m² ; for those lost to follow-up, 55.6 ± 7.5 mL/min/1.73 m² . ESRD developed in 2 (3.3%). SF-36 quality of life health survey scores (n = 21) were similar to the age-matched general population.

Evaluation of Living Kidney Donor and Recipient Candidates: The Experience of Our Center

PURPOSE

We evaluated potential kidney living donors and recipients for donation in our transplant center.

MATERIALS AND METHODS

Candidates to be kidney living donors and kidney transplant recipients (KTxR) were retrospectively evaluated. All candidates were informed and assessed by transplant coordinator and nephrologists. All data were obtained from archive records.

RESULTS

The mean ages of 194 kidney living donors and 182 KTxR were 45.7 ± 13.1 and 37.7 ± 14.6 years, respectively. Percentages of female candidates were 55.2% and 34.1% among kidney living donors and KTxR respectively. The kidney living donor candidates were the patients' mothers (27.3%), spouses (24.2%), siblings (21.6%), fathers (12.4%), and sons or daughters (6.2%) of KTxRs and others (8.2%). The numbers of donors with body mass index (BMI) > 30 kg/m² and > 35kg/m² were 56 (28.9%) and 17 (8.8%) respectively. Due to withdrawal from donation (21.2%) and renal problems (15.3%), 85/194 (43.8%) kidney living donors were excluded. Of the remaining 51/182 (28%) KTxR candidates, 26/182 (14.2%) were unsuitable because their panel-reactive antibody (PRA) > 20%. Sixty-six KTxR were performed in our center. Nine donor candidates were rejected due to obesity (BMI > 35 kg/m²).

CONCLUSION

Most of our kidney living donors were mothers, housewives, and uneducated persons. Due to high percentages of suitability among candidates of KTxRs and kidney living donors as 72% and 56% may be an advantage for living kidney donation. However, PRA positivity in the recipients drew attention as a major barrier. The high incidence of obesity among the donor candidates suggests that societies must be more sensitive about this issue.

Current Management of Patients With Acquired Solitary Kidney

Persons with acquired solitary kidney, including those who have had a unilateral nephrectomy for living kidney donation, renal malignancies, or trauma, have decreased renal mass that leads to increased intraglomerular pressure and glomerular hyperfiltration. These physiologic adaptations of solitary kidney may exacerbate other preexisting and genetic conditions that could create a predisposition to or worsen glomerular pathologies, leading to unfavorable renal outcomes. Hence, these persons may benefit from special care and lifestyle modifications, including nutritional interventions. There is a lack of consensus and evidence for proper surveillance and management after nephrectomy, and misconceptions in both directions of having a “normal” versus “abnormal” kidney status may cause confusion among patients and healthcare providers pertaining to long-term kidney health monitoring and management. We have reviewed available data on the impact of lifestyle modifications, particularly nutritional measures, and pharmacologic interventions, on short- and long-term outcomes after nephrectomy. We recommend avoidance of excessively high dietary protein intake (>1 g/kg per day) and high dietary sodium intake (>4 grams/d), adequate dietary fiber intake from plant-based foods, a target body mass index of <30 kg/m² (in non-athletes and non-bodybuilders), and judicious management of risk factors of progressive chronic kidney disease (CKD), and future studies should help to better determine optimal care practices for these persons.

Hyperfiltration-mediated Injury in the Remaining Kidney of a Transplant Donor

Kidney donors face a small but definite risk of end-stage renal disease 15 to 30 years postdonation. The development of proteinuria, hypertension with gradual decrease in kidney function in the donor after surgical resection of 1 kidney, has been attributed to hyperfiltration. Genetic variations, physiological adaptations, and comorbidities exacerbate the hyperfiltration-induced loss of kidney function in the years after donation. A focus on glomerular hemodynamics and capillary pressure has led to the development of drugs that target the renin-angiotensin-aldosterone system (RAAS), but these agents yield mixed results in transplant recipients and donors. Recent work on glomerular biomechanical forces highlights the differential effects of tensile stress and fluid flow shear stress (FFSS) from hyperfiltration. Capillary wall stretch due to glomerular capillary pressure increases tensile stress on podocyte foot processes that cover the capillary. In parallel, increased flow of the ultrafiltrate due to single-nephron glomerular filtration rate elevates FFSS on the podocyte cell body. Although tensile stress invokes the RAAS, FFSS predominantly activates the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis. Distinguishing these 2 mechanisms is critical, as current therapeutic approaches focus on the RAAS system. A better understanding of the biomechanical forces can lead to novel therapeutic agents to target FFSS through the cyclooxygenase 2-prostaglandin E2-EP2 receptor axis in hyperfiltration-mediated injury. We present an overview of several aspects of the risk to transplant donors and discuss the relevance of FFSS in podocyte injury, loss of glomerular barrier function leading to albuminuria and gradual loss of renal function, and potential therapeutic strategies to mitigate hyperfiltration-mediated injury to the remaining kidney.

Correlation and Prediction of Living-Donor Remaining Function by Using Predonation Computed Tomography-Based Volumetric Measurements: Role of Remaining Kidney Volume

OBJECTIVES

Kidney volume in healthy living donors may serve as a surrogate marker of renal function. Here, we evaluated whether preserved kidney volume correlated with and could predict donor renal function at 2 years postdonation using the CKD-EPI estimated glomerular filtration rate equation.

MATERIALS AND METHODS

Healthy living donors (n = 208) with computed tomography volume measurements were evaluated for renal function before and after donation. Preserved kidney volume was adjusted to body surface area. Demographic characteristics (including race/ethnicity and sex) and renal function variables of donors were analyzed for postdonation renal function.

RESULTS

Donor mean age was 39.4 ± 10.7 years (36.2% males, 91.9% white). Median adjusted preserved kidney volume was 180.6 mL. At 2 years postdonation, median estimated glomerular filtration rate was 62.4 mL/min (interquartile range, 54.8-73.2 mL/min). Predonation estimated glomerular filtration rate, age, and adjusted preserved kidney volume were found to be inde-pendent predictors of 2-year estimated glomerular filtration rate (P < .001). We further analyzed data by stratifying preserved kidney volumes into tertiles. Mean 2-year estimated glomerular filtration rates were 57.9 ± 12, 65 ± 16, and 73 ± 17 mL/min for lowest to highest tertile groups, respectively (P < .05). The odds ratio of having a 2-year postdonation estimated glomerular filtration rate of < 60 mL/min for donors in the lowest tertile group was 3.51 (95% confidence interval, 1.9-6.4; P < .001), whereas the risk for donors in the highest tertile group was 0.23 (95% confidence interval, 0.12-0.44; P< .001). Sensitivity analysis result was 0.764 (95% confidence interval, 0.69-0.82; P = .005) for adjusted preserved kidney volume and estimated glomerular filtration rate of < 60 mL/min.

CONCLUSIONS

Remaining kidney volume before donation correlated with and predicted estimated glomerular filtration rate after donation. Remaining kidney volume should be assessed when selecting kidneys from healthy donors.

Risks of Living Kidney Donation: Current State of Knowledge on Outcomes Important to Donors

In the past decade, there have been increasing efforts to better define and quantify the short- and long-term risks of living kidney donation. Recent studies have expanded upon the previous literature by focusing on outcomes that are important to potential and previous donors, applying unique databases and/or registries to follow large cohorts of donors for longer periods of time, and comparing outcomes with healthy nondonor controls to estimate attributable risks of donation. Leading outcomes important to living kidney donors include kidney health, surgical risks, and psychosocial effects of donation. Recent data support that living donors may experience a small increased risk of severe CKD and ESKD compared with healthy nondonors. For most donors, the 15-year risk of kidney failure is <1%, but for certain populations, such as young, black men, this risk may be higher. New risk prediction tools that combine the effects of demographic and health factors, and innovations in genetic risk markers are improving kidney risk stratification. Minor perioperative complications occur in 10%-20% of donor nephrectomy cases, but major complications occur in <3%, and the risk of perioperative death is <0.03%. Generally, living kidney donors have similar or improved psychosocial outcomes, such as quality of life, after donation compared with before donation and compared with nondonors. Although the donation process should be financially neutral, living kidney donors may experience out-of-pocket expenses and lost wages that may or may not be completely covered through regional or national reimbursement programs, and may face difficulties arranging subsequent life and health insurance. Living kidney donors should be fully informed of the perioperative and long-term risks before making their decision to donate. Follow-up care allows for preventative care measures to mitigate risk and ongoing surveillance and reporting of donor outcomes to inform prior and future living kidney donors.

How a Donor Nephrectomy Population Can Help Give Perspective to the Effects of Renal Parenchymal Preservation During Partial Nephrectomy

Introduction: Volume of renal parenchymal loss is known to affect postoperative renal function after partial nephrectomy (PN). We utilize a novel comparison using donor nephrectomy (DN) patients to demonstrate the primary effect parenchymal volume loss plays on postoperative renal function following PN. Materials and Methods: Records of 250 living donor (DN) and 118 PN patients were retrospectively reviewed. Baseline characteristics and preoperative estimated glomerular filtration rate (eGFR)s were recorded. Percent changes in eGFR and incidences of surgically induced chronic kidney disease (CKD-S) in short, intermediate, and long-term postoperative periods were compared. Univariate and multivariate analyses of prognostic factors for development of CKD-S were performed. The PN group was further divided into subgroups with different lengths of warm ischemia time (WIT) and compared with DN patients. Results: At baseline, DN patients were younger, less likely to be male, had lower body mass index, lower American Society of Anesthesiologists, and higher preoperative eGFR (all p < 0.001). At hospital discharge, intermediate follow-up, and latest follow-up, renal function changes in DN and PN groups were -40.5% vs. -3.6%, -34.1% vs. -5.5%, and -33.2% vs. -4.4%, respectively (all p < 0.001). More DN than PN patients developed CKD-S (p < 0.001). DN was a significant risk factor for the development of chronic kidney disease on univariate and multivariate analyses (p < 0.001). On subgroup analysis, both subgroups with WIT 1 to 30 minutes and 31 to 60 minutes had less renal function decline at all time points compared with DN (p < 0.001). Conclusions: Volume of renal parenchyma retained is the dominant driver of postoperative renal function after nephrectomy, compared with all other factors. Surgeons should minimize parenchymal loss during PN to optimize postoperative renal function.

Assessment of renal function in living kidney donors before and after nephrectomy: A Japanese prospective, observational cohort study

OBJECTIVE

To investigate the utility of estimated glomerular filtration rate for assessing kidney function in living kidney donors before and after nephrectomy.

METHODS

A total of 101 donors underwent inulin clearance measurements before and 1 year after nephrectomy. The mean of three inulin clearance values was used as the measured glomerular filtration rate. Estimated glomerular filtration rate based on serum creatinine and cystatin C levels was calculated using the Japanese estimated glomerular filtration rate equation, Chronic Kidney Disease Epidemiology Collaboration formula and new full age spectrum equation. Age-adjusted chronic kidney disease was defined as glomerular filtration rate <75 mL/min/1.73m² for donors aged <40 years, <60 mL/min/1.73m² for donors aged 40-65 years and <45 mL/min/1.73m² for donors aged >65 years.

RESULTS

The postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rate were 36.0% and 27.0%, respectively. In younger donors (aged <50 years), postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rates were 5.3% and 26.3%, respectively. In older donors (aged >70 years), postoperative measured glomerular filtration rate <60 mL/min/1.73m² and age-adjusted chronic kidney disease rates were 75.0% and 33.3%, respectively. Donor age and measured glomerular filtration rate were significant predictors of postoperative measured glomerular filtration rate. The Japanese estimated glomerular filtration rate equation based on creatinine and cystatin C showed the strongest correlation with measured glomerular filtration rate. However, the Japanese estimated glomerular filtration rate equation based on creatinine overestimated the prevalence of measured glomerular filtration rate <60 mL/min/1.73m² , whereas the Japanese estimated glomerular filtration rate based on cystatin C underestimated it.

CONCLUSIONS

Aged donors might have an increased risk of lower glomerular filtration rate after donor nephrectomy; post-surgery, long-term monitoring of renal function is recommended. Measurement of glomerular filtration rate should be carried out for donors, especially pre-surgery. A more precise glomerular filtration rate equation is required in the future.

Long term metabolic and renal outcomes of kidney donors compared to controls with excellent kidney function

BACKGROUND

Only few studies of living kidney donors have included controls that were similarly healthy, including excellent kidney function.

METHODS

In this study, we aimed to estimate long term metabolic and renal outcome in a cohort of 211 living donors compared to two control groups: paired-matched controls, and another control group of 2534 healthy individuals with excellent kidney function.

RESULTS

Donors presented with higher estimated Glomerular Filtration Rate (eGFR): (97.6 ± 15.2 vs 96.1 ± 12.2 vs 94.5 ± 12.4 ml/min/1.73m2) and lower urine albumin to creatinine ratio (UACR) (4.3 ± 5.9 vs 5.9 ± 6.1 vs 6.1 ± 6.9 mg/g) for donors, matched controls and healthy controls, respectively (p <  0.001). In a mean follow up period of 5.5 for donors, donors presented with positive eGFR slopes during the first 3 years post donation, followed by negative slopes, compared to constantly negative slopes presented in the control group (p <  0.05). The variables related to the slope were being a donor, baseline eGFR, Body Mass Index (BMI) and age but not eGFR on the last day of follow-up or increased delta UACR. There was a significant increase in UACR in donors, as well as a higher rate of albuminuria, associated with a longer time since donation, higher pre-donation UACR and higher pre-donation BMI. Healthy controls had a lower BMI at baseline and gained less weight during the follow up period. Donors and controls had similar incidence of new onset diabetes mellitus and hypertension, as well as similar delta systolic and diastolic blood pressure. Donors were more likely to develop new onset metabolic syndrome, even after adjustment for age, gender and BMI. The higher incidence of metabolic syndrome resulted mainly from increased triglycerides and impaired fasting glucose criteria. However, prevalence of major cardiovascular events was not higher in this group.

CONCLUSIONS

Donors are at increased risk to develop features of the metabolic syndrome in addition to the expected mild reduction of GFR and increased urine albumin excretion. Future studies are needed to explore whether addressing those issues will impact post donation morbidity and mortality.

Predictors of Outcomes of Living Kidney Donation: Impact of Sex, Age and Preexistent Hypertension

CONTEXT

Living kidney donation is considered a safe procedure with excellent outcomes. The great demand for organs has changed the suitability criteria for donation and older or hypertensive donors are increasingly accepted.

METHODS

We reviewed the charts of 200 adults who donated a kidney at the University Hospital Hannover. Data regarding diastolic, systolic, mean blood pressure, renal function, and proteinuria at baseline and post-donation follow-up visits were recorded. A Mann-Whitney U test was performed to compare the post-nephrectomy development of blood pressure, estimated glomerular filtration rate (eGFR), and proteinuria between men and women, hypertensives and normotensives, and older (≥65 years) and younger (<65 years) donors. Multivariable time-dependent Cox regression models were used to evaluate eGFR decline post-donation, after adjustment for covariates.

RESULTS

The majority of donors were female (64.5%), and 29.0% had pre-existing hypertension. The mean age at donation was 49 years, and 9.5% were older than 65 years. During a median follow-up of 3 years, no significant differences in proteinuria and change in renal function were observed between both sexes or hypertensive and normotensive donors. In contrast, older donors exhibited a faster decline in renal function. Mean eGFR (chronic kidney disease epidemiology collaboration equation) pre-donation was 99.6 ± 21.9 mL/min in younger donors and 77.6 ± 17.7 mL/min in older donors (P < .001). The respective mean values at the last follow-up visit were 81.3 ± 24.0 and 46.8 ± 17.9 mL/min (P < .001). After adjustment for sex and preexisting hypertension, compared to younger donors, older donors had a 2.39 hazard ratio for eGFR decline.

CONCLUSION

Older adults display a faster decline in renal function after donation and thus should be carefully evaluated for suitability before donation.

Risk of adverse maternal and fetal outcomes during pregnancy in living kidney donors: A matched cohort study

BACKGROUND

We examined the risk of adverse pregnancy outcomes in primiparous kidney donors compared to matched controls.

METHODS

Fifty-nine women with a history of kidney donation prior to their first pregnancy with normal renal function and no history of kidney disease, diabetes or chronic hypertension were matched 1:4 by age (within 2 years) and race to women with two kidneys using data from an integrated healthcare delivery system. Adverse pregnancy outcomes were defined as preterm delivery (delivery <37 weeks), delivery via cesarean section, gestational hypertension, preeclampsia/eclampsia, gestational diabetes, length of stay in the hospital >3 days, infant death/transfer to acute facility and low birthweight (<2500 g).

RESULTS

Living kidney donors did not have a higher risk of adverse outcomes compared to matched controls. There was a trend toward an increased risk of preeclampsia/eclampsia in kidney donors but it did not reach statistical significance (Odds ratio [OR]: 2.96, 95% CI: 0.98-8.94, P = 0.06). However, in kidney donors ≤30 years of age, there was a fourfold increased risk of preeclampsia/eclampsia (OR: 4.09, 95% CI: 1.07-15.59, P = 0.04).

CONCLUSION

Overall, the risk of pregnancy-associated complications following kidney donation is small but potential female kidney donors should be counseled on the possible increased risk of preeclampsia.

Maternal and fetal outcomes of pregnancies in kidney donors: A 30-year comparative analysis of matched non-donors in a single center

Background

Woman kidney donors face obstetric complication risks after kidney donation, such as gestational hypertension and preeclampsia. Studies on childbirth-related complications among Asian women donors are scarce.

Methods

This retrospective cohort study included woman donors aged 45 years or younger at the time of kidney donation in a single tertiary hospital between 1985 and 2014. Pregnancy associated complications were investigated using medical records and telephone questionnaires for 426 pregnancies among 225 donors. Matched non-donor controls were selected by propensity score and the maternal and fetal outcomes were compared with those of donors. Primary outcomes were differences in maternal complications, and secondary outcomes were fetal outcomes in pregnancies of the donor and control groups.

Results

A total of 56 cases had post-donation pregnancies. The post-donation pregnancies group was younger at the time of donation and older at the time of delivery than the pre-donation pregnancies group, and there were no differences in primary outcomes between the groups except the proportion receiving cesarean section. Comparison of the complication risk between post-donation pregnancies and non-donor matched controls showed no significant differences in gestational hypertension, preeclampsia, or composite outcomes after propensity score matching including age at delivery, era at pregnancy, systolic blood pressure, body weight, and estimated glomerular filtration ratio (odds ratio, 0.63; 95% confidence interval, 0.19–2.14; P = 0.724).

Conclusion

This study revealed that maternal and fetal outcomes between woman kidney donors and non-donor matched controls were comparable. Studies with general population pregnancy controls are warranted to compare pregnancy outcomes for donors.

Glomerular filtration rate: new age- and gender- specific reference ranges and thresholds for living kidney donation

BACKGROUND

There is a need for a large, contemporary, multi-centre series of measured glomerular filtration rates (mGFR) from healthy individuals to determine age- and gender-specific reference ranges for GFR. We aimed to address this and to use the ranges to provide age- and gender-specific advisory GFR thresholds considered acceptable for living kidney donation.

METHODS

Individual-level data including pre-donation mGFR from 2974 prospective living kidney donors from 18 UK renal centres performed between 2003 and 2015 were amalgamated. Age- and gender-specific GFR reference ranges were determined by segmented multiple linear regression and presented as means ± two standard deviations.

RESULTS

Males had a higher GFR than females (92.0 vs 88.1 mL/min/1.73m2, P < 0.0001). Mean mGFR was 100 mL/min/1.73m2 until 35 years of age, following which there was a linear decline that was faster in females compared to males (7.7 vs 6.6 mL/min/1.73m2/decade, P = 0.013); 10.5% of individuals aged > 60 years had a GFR < 60 mL/min/1.73m2. The GFR ranges were used along with other published evidence to provide advisory age- and gender-specific GFR thresholds for living kidney donation.

CONCLUSIONS

These data suggest that GFR declines after 35 years of age, and the decline is faster in females. A significant proportion of the healthy population over 60 years of age have a GFR < 60 mL/min/1.73m2 which may have implications for the definition of chronic kidney disease. Age and gender differences in normal GFR can be used to determine advisory GFR thresholds for living kidney donation.

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.

Pregnancy in women known to be living with a single kidney

There is a paucity of data on pregnancy outcome in women living with a single kidney from all causes. Current thinking is extrapolated from living kidney donors, a group biased by strict selection criteria. We present a cohort of 26 women with a solitary functioning kidney; 11 women had an acquired single kidney of whom only 1 was a living donor and 15 had a congenital single kidney. Median time living with a single kidney was 28 years. None booked with hypertension or proteinuria. Urinary tract infection complicated 50% of pregnancies. Worryingly, 35% developed pre-eclampsia, gestational proteinuria or gestational hypertension. We propose pre-conceptual counselling, education on how to protect their single kidney, pre eclampsia prophylaxis with low-dose aspirin and close monitoring for urinary tract infection, hypertension and proteinuria with lower thresholds for pharmaceutical management. We have devised a Patient Information leaflet - 'Living with a single kidney, pregnancy and beyond'.

Preeclampsia Risks in Kidney Donors and Recipients

PURPOSE OF REVIEW

To review the studies and practice guidelines on the preeclampsia risks in kidney donors and recipients.

RECENT FINDINGS

There is a small increased risk of gestational hypertension and preeclampsia in pregnancies that follow kidney donation. Kidney Disease Improving Global Outcomes (KDIGO) Clinical Practice Guideline (2017) and the 2015 American Society of Transplantation (AST) consensus conference statement recommends counseling kidney donors about this increased risk. There is no observed increase in fetal complications or eclampsia post-kidney donation. Preeclampsia is more commonly observed in kidney transplant recipients than the general population and these patients should be co-managed with an obstetrician with experience in managing high risk pregnancies. Although preeclampsia has not been found to have a deleterious effect on renal graft function, it can cause premature delivery. Risk calculators have been proposed and an elevated pre-pregnancy creatinine seems to be an important risk. KDIGO Clinical Practice Guidelines (2009) recommends attempting pregnancy when kidney function is stable with proteinuria of less than 1 g per day. The use of novel biomarkers for preeclampsia has not been published in this population. Preeclampsia is an important concern for female kidney donors and recipients of child-bearing age. These individuals should be appropriately counseled.

Identifying Outcomes that Are Important to Living Kidney Donors: A Nominal Group Technique Study

BACKGROUND AND OBJECTIVES

Living kidney donor candidates accept a range of risks and benefits when they decide to proceed with nephrectomy. Informed consent around this decision assumes they receive reliable data about outcomes they regard as critical to their decision making. We identified the outcomes most important to living kidney donors and described the reasons for their choices.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Previous donors were purposively sampled from three transplant units in Australia (Sydney and Melbourne) and Canada (Vancouver). In focus groups using the nominal group technique, participants identified outcomes of donation, ranked them in order of importance, and discussed the reasons for their preferences. An importance score was calculated for each outcome. Qualitative data were analyzed thematically.

RESULTS

Across 14 groups, 123 donors aged 27-78 years identified 35 outcomes. Across all participants, the ten highest ranked outcomes were kidney function (importance=0.40, scale 0-1), time to recovery (0.27), surgical complications (0.24), effect on family (0.22), donor-recipient relationship (0.21), life satisfaction (0.18), lifestyle restrictions (0.18), kidney failure (0.14), mortality (0.13), and acute pain/discomfort (0.12). Kidney function and kidney failure were more important to Canadian participants, compared with Australian donors. The themes identified included worthwhile sacrifice, insignificance of risks and harms, confidence and empowerment, unfulfilled expectations, and heightened susceptibility.

CONCLUSIONS

Living kidney donors prioritized a range of outcomes, with the most important being kidney health and the surgical, lifestyle, functional, and psychosocial effects of donation. Donors also valued improvements to their family life and donor-recipient relationship. There were clear regional differences in the rankings.

Causes and timing of end-stage renal disease after living kidney donation

End-stage renal disease (ESRD) is a risk after kidney donation. We sought, in a large cohort of kidney donors, to determine the causes of donor ESRD, the interval from donation to ESRD, the role of the donor/recipient relationship, and the trajectory of the estimated GFR (eGFR) from donation to ESRD. From 1/1/1963 thru 12/31/2015, 4030 individuals underwent living donor nephrectomy at our center, as well as ascertainment of ESRD status. Of these, 39 developed ESRD (mean age ± standard deviation [SD] at ESRD, 62.4 ± 14.1 years; mean interval between donation and ESRD, 27.1 ± 9.8 years). Donors developing ESRD were more likely to be male, as well as smokers, and younger at donation, and to have donated to a first-degree relative. Of donors with a known cause of ESRD (n = 25), 48% was due to diabetes and/or hypertension; only 2 from a disease that would have affected 1 kidney (cancer). Of those 25 with an ascertainable ESRD cause, 4 shared a similar etiology of ESRD with their recipient. Almost universally, thechange of eGFR over time was stable, until new-onset disease (kidney or systemic). Knowledge of factors contributing to ESRD after living kidney donation can improve donor selection and counseling, as well as long-term postdonation care.

Postdonation Anemia in Living Kidney Donors

BACKGROUND

The effect of nephrectomy on development of anemia in living kidney donation has not been well studied. We hypothesized that the remaining kidney volume and function after donation are determinants of hemoglobin (Hb) concentration and postdonation anemia (PDA).

METHODS

We studied 398 living kidney donors (LKDs) who donated from January 2001 to December 2013. Demographic variables, hematologic variables, renal mass, and renal function were investigated as factors associated with PDA with the use of univariate and multivariable logistical regression analysis. Renal mass was determined from kidney volume measured with the use of computerized tomographic scans.

RESULTS

Prevalence of PDA in LKDs was 11.8% at a median follow-up time of 601 days. In univariate analyses, PDA was more prevalent in women than in men (72% vs 28%; P = .048). Age and race were not associated factors. Kidney volume was lower in donors with PDA than in those without PDA (326 ± 52 mL vs 368 ± 70 mL; P < .001). Donors with and without PDA had similar predonation and postdonation glomerular filtration rates. In the multivariable logistic regression analysis, total kidney volume and predonation anemia remained as independent factors associated with PDA.

CONCLUSIONS

PDA is prevalent after living kidney donation, with donor kidney volume and predonation hemoglobin levels being independent determinants for PDA.

Radiofrequency Ablation of Small Renal Masses: Outcomes, Complications and Effects on Renal Function

Introduction

To describe oncological outcomes, effects on renal function and complications with radiofrequency ablation (RFA) of T1 renal tumors in an 8-year experience.

Materials and Methods

A retrospective study of RFA in 89 consecutive patients between 2005 and 2013 was undertaken. Those with metastatic disease, incomplete follow-up, genetic pre-disposition to renal tumors and biopsy proven benign pathology were excluded, with 79 patients meeting inclusion criteria. Data was collected on demographics, oncological outcomes, complications and effects on renal function.

Results

We demonstrate 94% disease-free survival at median follow-up of 29 months in a population consisting of 42 T1a and 37 T1b tumors. No disease related deaths were recorded in the follow-up period. Post-RFA decline in renal function was shown to correlate with tumor size and increased age (p = 0.0009/0.0021). Pre-existing renal impairment was a risk for post-RFA function decline (p < 0.005). Two complications were encountered in the series.

Conclusion

RFA produces durable oncological outcomes in T1 tumors with a minimal effect on renal function and low risk of complications. Patients at risk of developing renal impairment can be identified from described risk factors.

Assessment of Glomerular Filtration Rate and End-Stage Kidney Disease Risk in Living Kidney Donor Candidates: A Paradigm for Evaluation, Selection, and Counseling

Living donor kidney transplantation is the preferred treatment option for ESRD. However, recent data suggest a small increase in the long-term risk of kidney failure in living kidney donors when compared to healthy nondonors. These data have led to a need for reconsideration of how donor candidates are evaluated and selected for donation. A Kidney Disease: Improving Global Outcomes (KDIGO) work group completed a comprehensive clinical practice guideline for evaluation of living kidney donor candidates in 2017, based on systematic evidence review, de novo evidence generation, and expert opinion. Central to the evaluation framework is assessment of glomerular filtration rate (GFR), which is used to screen for kidney disease and aid the prediction of long-term kidney failure risk after donation. Accurate estimation of the level of GFR and risk of kidney failure, and communication of estimated risks, can support evidence-based donor selection and shared decision-making. In this review, we discuss approaches to optimal GFR estimation in the donor evaluation process, long-term risk projection, and risk communication to donor candidates, integrating recommendations from the new KDIGO guideline, other recent literature, and experience from our own research and practice. We conclude by highlighting topics for further research in this important area of transplant medicine.

[Outcome of living kidney donors for transplantation]

Nowadays, several treatments exist to treat terminal chronic renal failure. Best results for the recipients are obtained with kidney transplantation concerning mortality and quality of life. Transplantation is also the cheaper option for society. Living kidney donation raises the issue of the becoming of the donor, an absolutely healthy subject who gets to a surgical procedure. The becoming of living kidney donors has been compared with the one of controls subjects in several studies. The evaluations focused on the complications of nephrectomy in the short and long-term: kidney failure, hypertension, proteinuria, possibility of pregnancy, quality of life, and mortality. The first results did not show any risk linked to kidney donation, compared to general population. However, since 2013, kidney donors were found at higher risk for kidney failure and even for mortality, compared with controls selected like donor candidates. The risk of kidney donation is nevertheless acceptable and minimal, on the condition of rigorous selection of candidates and regular follow-up.