Single-centre long-term follow-up of live kidney donors demonstrates preserved kidney function but the necessity of a structured lifelong follow-up

Living kidney donation in a developing country

Background

Living kidney donation has been advocated as a means to ameliorate the chronic shortage of organs for transplantation. Significant rates of comorbidity and familial risk for kidney disease may limit this approach in the local context; there is currently limited data describing living donation in Africa.

Methods

We assessed reasons for non-donation and outcomes following donation in a cohort of 1208 ethnically diverse potential living donors evaluated over a 32-year period at a single transplant centre in South Africa.

Results

Medical contraindications were the commonest reason for donor exclusion. Black donors were more frequently excluded (52.1% vs. 39.3%; p<0.001), particularly for medical contraindications (44% vs. 35%; p<0.001); 298 donors proceeded to donor nephrectomy (24.7%). Although no donor required kidney replacement therapy, an estimated glomerular filtration rate below 60 ml/min/1.73 m2 was recorded in 27% of donors at a median follow-up of 3.7 years, new onset albuminuria >300 mg/day was observed in 4%, and 12.8% developed new-onset hypertension. Black ethnicity was not associated with an increased risk of adverse post-donation outcomes.

Conclusion

This study highlights the difficulties of pursuing live donation in a population with significant medical comorbidity, but provides reassurance of the safety of the procedure in carefully selected donors in the developing world.

A Systematic Review of Renal Functional Reserve in Adult Living Kidney Donors

Introduction

The kidney’s capacity to increase its glomerular filtration rate (GFR) in response to a higher functional demand is known as the renal functional reserve (RFR). Good short-term outcomes after living kidney donation have led to more acceptance of borderline donors (with hypertension, obesity, older age) due the ongoing shortage of donor organs. Given recent concerns about increased long-term risk in some donor subgroups, better donor stratification is needed. Measurement of RFR could inform assessment of donor risk.

Methods

A systematic literature review of studies that assessed RFR in donors pre- and/or post-donation was performed. Given study heterogeneity, descriptive analysis and narrative synthesis was conducted.

Results

Sixteen of 3250 identified studies published between 1956 and 2019 met inclusion criteria. Most studies were cross-sectional and conducted before (n = 8) and/or after (n = 16) kidney donation. Methods for measurement of GFR, effective renal plasma flow (ERPF) and RFR were not standardized. Changes in filtration fraction (FF) and ERPF relative to GFR observed after donation varied depending on stimulus used to induce RFR. Overall, RFR fell after donation; however, over the shorter term, RFR was largely preserved in young healthy donors. RFR was more significantly reduced in donors with hypertension, obesity, or older age.

Conclusion

Existing data suggest possible blunting of RFR post-donation in older, obese, and hypertensive donors, which may represent increased single-nephron GFR at baseline. The long-term implications of these changes deserve further study to determine utility in informing selection of borderline kidney donors.

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

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

Living Anonymous Renal Donors Do Not Regret: Intermediate and Long-Term Follow-Up with a Focus on Motives and Psychosocial Outcomes

BACKGROUND Living anonymous donation (LAD) of kidneys was introduced in Sweden in 2004. This study reports on outcomes of Swedish LAD experiences from 2004 to 2016, focusing on donors' motives, the care they received, psychosocial aspects, and medical status at follow-up. MATERIAL AND METHODS Donor data were collected through a physician interview, medical check-up, review of medical charts, the Hospital Anxiety Depression Scale (HADS), and a routine national questionnaire. Of the 26 LADs during the study period, 1 donor died and 1 declined to participate, leaving a study population of 24. RESULTS Half of the donors were male, which is a higher proportion than for directed living donors. The major motive detected was altruism. Of the 24 LADs, 96% were very satisfied and would donate again if possible, 46% noted increased self-esteem, and a third were happier after the donation. Sixty-two percent received anonymous information about the recipient and 40% would have liked to meet the recipient. HADS scores were normal. Two donors had antidepressant treatment, 1 of whom had received treatment before donation. Half mentioned that the pre-donation assessment took too long. At follow-up, mean eGFR was 62±12 mL/min/1.73 m², of which 16 were in CKD II and 8 were in CKD III. Four donors had developed hypertension, 1 of whom also developed type 2 diabetes. CONCLUSIONS Swedish LADs are very satisfied and medical outcomes are acceptable. We propose that the transplant community and the National Board of Health and Welfare take a more active approach to informing the general public about LAD.

Anxiety, depression, and regret of donation in living kidney donors

Background

Previous studies have reported a wide range of prevalence of post-donation anxiety, depression, and regret in living kidney donors (LKDs). It is also unclear what risk factors are associated with these outcomes.

Methods

We screened 825 LKDs for anxiety and depression using 2-item GAD-2 and PHQ-2 scales and asked about regret.

Results

Overall, 5.5% screened positive for anxiety, 4.2% for depression, and 2.1% reported regretting their donation. While there was moderate correlation between positive anxiety and depression screens (r = 0.52), there was no correlation between regret and positive screens (r < 0.1 for both). A positive anxiety screen was more likely in LKDs with a positive depression screen (adjusted relative risk [aRR] 13.72, 95% confidence interval [CI] 6.78–27.74, p < 0.001). Similarly, a positive depression screen was more likely in LKDs with a positive anxiety screen (aRR 19.50, 95% CI 6.94–54.81, p < 0.001), as well as in those whose recipients experienced graft loss (aRR 5.38, 95% CI 1.29–22.32, p = 0.02). Regret was more likely in LKDs with a positive anxiety screen (aRR 5.68, 95% CI 1.20–26.90, p = 0.03). This was a single center cross-sectional study which may limit generalizability and examination of causal effects. Also, due to the low prevalence of adverse psychosocial outcomes, we may lack power to detect some associations between donor characteristics and anxiety, depression, or regret.

Conclusions

Although there is a low prevalence of anxiety, depression, and regret of donation among LKDs, these are interrelated conditions and a positive screen for one condition should prompt evaluation for other conditions.

Effect of unilateral nephrectomy on urinary angiotensinogen levels in living kidney donors: 1 year follow-up study

Background:

Urinary angiotensinogen (uAGT) has recently been proposed as a marker of kidney injury and activated intrarenal renin–angiotensin system. We investigated the effects of living donor nephrectomy on uAGT levels, blood pressure, estimated glomerular filtration rate, proteinuria and compensatory hypertrophy in the remaining kidney of living kidney donors.

Methods:

Twenty living kidney donors were included in the study and followed for 1 year. uAGT levels were measured with enzyme-linked immunosorbent assay preoperatively and postoperatively at the 15th day, 1, 6 and 12 months.

Results:

Four donors were excluded from the study due to lack of data. The mean baseline estimated glomerular filtration rate was 98 ± 15 ml/min/1.73 m². Serum creatinine, uAGT/creatinine, uAGT/protein levels were higher and estimated glomerular filtration rate was lower than baseline values at all time periods. Urinary protein/creatinine levels increased after donor nephrectomy, but after 6 months they returned to baseline values. Renal volume increased after nephrectomy, but these changes did not show any correlation with uAGT/creatinine, uAGT/protein, estimated glomerular filtration rate or systolic/diastolic blood pressures. uAGT/creatinine at 6 months and urinary protein/creatinine ratio at 12 months showed a positive correlation (P=0.008, r=0.639).

Conclusion:

After donor nephrectomy, increasing uAGT levels can be the result of activation of the intrarenal renin–angiotensin system affecting the compensatory changes in the remaining kidney. The long-term effects of increased uAGT levels on the remaining kidney should be examined more closely in future studies.

Few Gender Differences in Attitudes and Experiences after Live Kidney Donation, with Minor Changes Over Time

BACKGROUND We sought to study gender differences and differences over time with respect to demographics, relation to recipient, donor motives, and experiences of live kidney donation. MATERIAL AND METHODS In all, 455 consecutive live kidney donors, representing all of the donors at our center between 1974 and 2008 were considered for this study. There were 28 deceased donors and 14 donors who had moved abroad, leaving 413 donors; 387 (94%) agreed to participate in this study. A questionnaire was sent and the answers was analyzed for gender differences and, where relevant, for changes over time. RESULTS In all sub-periods, female donors made up the majority (55-62%), except for sibling donors (45%) and child-to-parent donors (40%). No significant gender differences were seen in perceived information given before donation. For males, it was more common that the recipient took the initiative to donate. For females, the motivation for donating was more frequently to help the recipient and because others wanted them to donate. For males, it was more common to feel a moral obligation. Post-operatively, females more frequently felt sad and experienced nausea, and more frequently felt that the donation had a positive impact on their lifes. With the introduction of minimally invasive surgical techniques, donors experienced fewer problems from the operation, with no gender difference. CONCLUSIONS Females donate more frequently than males, a difference that did not change over time. Only a few gender differences were seen in donor motives and the donation experience; however, these differences may be relevant to address the gender imbalance in kidney donations.

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

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

Evaluation of renal function in a specific population of living kidney donors

BACKGROUND

The increase in candidates for kidney transplant has led to growth in the number of living donor transplants. Therefore, studies that adequately evaluate the possible long-term consequences of elective transplant nephrectomy are needed.

OBJECTIVE

To evaluate the possible long-term adverse effects of transplant nephrectomy on the renal function of living kidney donors.

DESIGN

A cross-sectional study.

PARTICIPANTS

Thirty-three living kidney donors registered in the transplant programme of a centre in Alagoas, Brazil.

MEASUREMENTS

Demographic characteristics, anthropometric measures, clinical data and biomarkers (creatinine, eGFR, microalbuminuria, cholesterol and triglycerides) were measured. Creatinine clearance was calculated using the Cockcroft-Gault and Modification of Diet in Renal Disease formulae.

RESULTS

Of the 33 individuals, 63.63% were female, and the median age was 45 years. Additionally, 24.24% of these individuals had altered blood pressure, 39.39% had altered abdominal circumference (AC) and 36.36% were obese, with a body mass index ≥30. Furthermore, 33.33% of these individuals had elevated triglyceride levels. The average eGFR was 97.33 (33.03-175.9) ml/min/1.73 m² (CG) and 84.14 (29.4-131) ml/min/1.73 m² (MDRD). The microalbuminuria level was altered in 12.12% patients.

CONCLUSION

Kidney donation is unquestionably a safe procedure. However, a better understanding of the long-term consequences of living donor kidney transplantation is still needed. This knowledge may have important implications for the follow-up of these patients. Our study has demonstrated a non-negligible presence of an early marker of glomerular injury and a decrease in the GFR of some patients, thereby reinforcing the proposal for long-term follow-up of living kidney donors.

Five-year follow-up after live donor nephrectomy - cross-sectional and longitudinal analysis of a prospective cohort within the era of extended donor eligibility criteria

To establish the outcome of live kidney donors 5 years after donation, we investigated the risk for progressive renal function decline and quality of life (QoL). Data on estimated glomerular filtration rate (eGFR), creatinine, hypertension, QoL and survival were assessed in a prospective cohort of 190 donors, who donated between 2008 and 2010. Data were available for >90%. The mean age predonation was 52.8 ± 11.5 years, 30 donors having pre-existent hypertension. The mean follow-up was 5.1 ± 0.9 years. Eight donors had died due to non-donation-related causes. After 5 years, the mean eGFR was 60.2 (95% CI 58.7-62.7) ml/min/1.73 m² , with a median serum creatinine of 105.1 (95% CI 102.5-107.8) μmol/l. eGFR decreased to 33.6% and was longitudinally lower among men than women and declining with age (P < 0.001), without any association on QoL. Donors with pre-existent and new-onset hypertension demonstrated no progressive decline of renal function overtime compared to nonhypertensives. No donors were found with proteinuria, microalbuminuria or at risk for end-stage renal disease. After an initial decline postdonation, renal function remained unchanged overtime. Men and ageing seem to affect renal function overtime, while decreased renal function did not affect QoL. These data support further stimulation of living kidney donation programmes as seen from the perspective of donor safety.