The impact of accepting living kidney donors with mild hypertension or proteinuria on transplantation rates

Rethinking incompatibility in kidney transplantation

Donor/recipient incompatibility in kidney transplantation classically refers to ABO/HLA-incompatibility. Kidney paired donation (KPD) was historically established to circumvent ABO/HLA-incompatibility, with the goal of identifying ABO/HLA-compatible matches. However, there is a broad range of donor factors known to impact recipient outcomes beyond ABO/HLA-incompatibility, such as age and weight, and quantitative tools are now available to empirically compare potential living donors across many of these factors, such as the living donor kidney donor profile index (LKDPI). Moreover, the detrimental impact of mismatch at other HLA antigens (such as DQ) and epitope mismatching on posttransplant outcomes has become increasingly recognized. Thus, it is time for a new paradigm of incompatibility that considers all of these risks factors together in assessing donor/recipient compatibility and the potential utility for KPD. Under this new paradigm of incompatibility, we show how the LKDPI and other tools can be used to identify donor/recipient incompatibilities that could be improved through KPD, even for those with a traditionally "compatible" living donor.

Increasing transplantability in Brazil: time to discuss Kidney Paired Donation

Introduction:

Kidney transplantation (KT) is the best treatment for chronic kidney disease. In Brazil, there are currently more than 26 thousand patients on the waitlist. Kidney Paired Donation (KPD) offers an incompatible donor-recipient pair the possibility to exchange with another pair in the same situation, it is a strategy to raise the number of KT.

Discussion:

KPD ceased being merely an idea over 20 years ago. It currently accounts for 16.2% of living donors KT (LDKT) in the USA and 8% in Europe. The results are similar to other LDKT. It is a promising alternative especially for highly sensitized recipients, who tend to accumulate on the waitlist. KPD is not limited to developed countries, as excellent results were already published in India in 2014. In Guatemala, the first LDKT through KPD was performed in 2011. However, the practice remains limited to isolated cases in Latin America.

Conclusion:

KPD programs with different dimensions, acceptance rules and allocation criteria are being developed and expanded worldwide to meet the demands of patients. The rise in transplantability brought about by KPD mostly meets the needs of highly sensitized patients. The Brazilian transplant program is mature enough to accept the challenge of starting its KPD program, intended primarily to benefit patients who have a low probability of receiving a transplant from a deceased donor.

Data and optimisation requirements for Kidney Exchange Programs

Kidney Exchange Programs (KEP) are valuable tools to increase the options of living donor kidney transplantation for patients with end-stage kidney disease with an immunologically incompatible live donor. Maximising the benefits of a KEP requires an information system to manage data and to optimise transplants. The data input specifications of the systems that relate to key information on blood group and Human Leukocyte Antigen (HLA) types and HLA antibodies are crucial in order to maximise the number of identified matched pairs while minimising the risk of match failures due to unanticipated positive crossmatches. Based on a survey of eight national and one transnational kidney exchange program, we discuss data requirements for running a KEP. We note large variations in the data recorded by different KEPs, reflecting varying medical practices. Furthermore, we describe how the information system supports decision making throughout these kidney exchange programs.

Significance of ambulatory blood pressure monitoring in assessment of potential living kidney donors

The most recent British Transplant Society (BTS) guidelines recommend that office blood pressure (BP) monitoring in living donors is sufficient for the assessment of hypertension (HTN) and those with BP >140/90 should be further assessed using ambulatory BP monitoring (ABPM). ABPM can detect diurnal and nocturnal variation in BP, thus it can identify masked HTN. The aim of the current study is to assess reliability of ABPM vesus office BP monitoring for assessment in living kidney donors. Office and ABPM of all potential kidney donors at a single center from April 2009 to March 2017 were retrospectively reviewed and compared. Age, sex, body mass index, kidney function, and echocardiography results were collected and analyzed. Two hundred and sixteen kidney donors were stratified based on their BP readings into four groups; group 1 (masked HTN: normotensive in office and hypertensive in ABPM), group 2 (sustained normotension: normotensive in office and in ABPM), group 3 (sustained HTN: hypertensive in office and in ABPM), group 4 (white-coat HTN: hypertensive in office and normotensive in ABPM). Thirteen percent of patients were diagnosed with masked HTN. Office systolic BP monitoring was significantly higher in patients older than 50 years old compared to other younger populations. However, this significant difference in systolic BP was diminished when assessment with ABPM was performed. In conclusion, ABPM is a reliable modality for the identification of masked HTN and white coat HTN. Masked HTN is correlated with increased risk of end organ damage and risk of death in potential kidney donors. Transplant physicians cannot rely solely on office BP monitoring in the assessment of potential living kidney donors. ABPM should be integral part of routine assessment of potential living kidney donors.

Red herrings in crossmatching kidneys for transplant

Crossmatching of prospective renal transplant donors against recipients is a mandatory component of the transplant workup, being performed for over 40 years now. Allografting patients with human leukocyte antigens which are recognized by preformed antibodies constitutes the main cause of hyperacute or acute rejections. The existence of these donor-specific anti-human leukocyte antigen antibodies (DSAs) is regarded as a contraindication for graft trans-plantation, both cadaveric and live kidney. We present two unusual cases in which both complement-dependent cytotoxicity crossmatch and DSA by Luminex were falsely positive due to autoimmune and infectious causes, but single-antigen bead assay showed these antibodies to be against nondonor antigens. After treating their basic disease, thought to be responsible for false-positive DSA, these patients became DSA negative and underwent transplantation with an uneventful posttransplant period. Our aim through these examples is to highlight the problem of false-positive crossmatch in potential renal allograft transplant recipients. Further, we propose antigenic determination of donor-specific antibodies in such patients where we suspect the immune system to be chronically activated to pick up false-positive cases and therefore increase the donor pool without compromising the transplant outcome.

Kidney exchange strategies: new aspects and applications with a focus on deceased donor-initiated chains

Kidney paired donation (KPD) is a valuable way to overcome immunological incompatibility in the context of living donation, and several strategies have been implemented to boost its development. In this article, we reviewed the current state of the art in this field, with a particular focus on advanced KPD strategies, including the most recent idea of initiating living donor (LD) transplantation chains with a deceased donor (DD) kidney, first applied successfully in 2018. Since then, Italy has been running a national programme in which a chain-initiating kidney is selected from a DD pool and allocated to a recipient with an incompatible LD, and the LD's kidney is transplanted into a patient on the waiting list (WL). At this stage, since the ethical and logistic issues have been managed appropriately, KPD starting with a DD has proved to be a feasible strategy. It enables transplants in recipients of incompatible pairs without the need for desensitizing and also benefits patients on the WL who are allocated chain-ending kidneys from LDs (prioritizing sensitized patients and those on the WL for longer).

Current protocols and outcomes of ABO-incompatible kidney transplantation

One of the principal obstacles in transplantation from living donors is that approximately 30% are immunologically incompatible because of the presence in the recipient of antibodies directed against the human leukocyte antigen system of the donor or because of the incompatibility of the ABO system. The aim of this review is to describe the more recent data from the literature on the different protocols used and the clinical outcomes of ABO-incompatible kidney transplantation. Two different strategies are used to overcome these barriers: desensitization of the recipient to remove the antibodies and to prevent their rebound after transplantation and the exchange of organs between two or more pairs. The largest part of this review is dedicated to describing the techniques of desensitization. Even if the first reports of successful renal transplantation between ABO-incompatible pairs have been published by 1980, the number of ABO-incompatible transplants increased substantially in this century because of our improved knowledge of the immune system and the availability of new drugs. Rituximab has substantially replaced splenectomy. The technique of apheresis has improved and more recently a tailored desensitization proved to be the more efficient strategy avoiding an excess of immunosuppression with the related side effects. Recent reports document outcomes for such transplantation similar to the outcomes of standard transplantation.

Canadian Society of Transplantation and Canadian Society of Nephrology Commentary on the 2017 KDIGO Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors

Purpose of review:

To review an international guideline on the evaluation and care of living kidney donors and provide a commentary on the applicability of the recommendations to the Canadian donor population.

Sources of information:

We reviewed the 2017 Kidney Disease: Improving Global Outcomes (KDIGO) Clinical Practice Guideline on the Evaluation and Care of Living Kidney Donors and compared this guideline to the Canadian 2014 Kidney Paired Donation (KPD) Protocol for Participating Donors.

Methods:

A working group was formed consisting of members from the Canadian Society of Transplantation and the Canadian Society of Nephrology. Members were selected to have representation from across Canada and in various subspecialties related to living kidney donation, including nephrology, surgery, transplantation, pediatrics, and ethics.

Key findings:

Many of the KDIGO Guideline recommendations align with the KPD Protocol recommendations. Canadian researchers have contributed to much of the evidence on donor evaluation and outcomes used to support the KDIGO Guideline recommendations.

Limitations:

Certain outcomes and risk assessment tools have yet to be validated in the Canadian donor population.

Implications:

Living kidney donors should be counseled on the risks of postdonation outcomes given recent evidence, understanding the limitations of the literature with respect to its generalizability to the Canadian donor population.

Ways to Overcome Organ Shortage: Increasing Donor Pool by Accepting Suboptimal Kidney Donors

Many factors affect organ donations worldwide, including religious factors, legislative decisions, economic factors, presence of organ procurement organizations, cultural issues, the presence of commercial transplant, and other unknown factors. The number of patients with end-stage renal disease has increased by 6% worldwide. Even with more transplant procedures, these numbers have not combated the dramatically increased number of patients on wait lists. With regard to potential living donors, around 50% are either blood group or HLA incompatible with the recipient, which then requires patient desensitization or paired kidney donation or a combination of both. Survival rates of kidney donors and the general population are almost the same 35 to 40 years after donation. Although the renal consequences of diabetes after kidney donation are almost the same as that shown in the general population, other risk factors should be considered, such as hypertension, proteinuria, and low glomerular filtration rate, before donation. It is so far unknown whether donors with impaired glucose tolerance can safely donate. With diabetes, what was considered normal blood sugar in 1960 to 1990 is now considered frank diabetes. What was considered normal blood pressure is now considered hypertension. Because individuals with these parameters were accepted as organ donors in the past and have been shown to maintain good health, it is worth considering the safe use of organs from donors with early diabetes and hypertension. Whereas young donors may have not reached the age at which hypertension, diabetes, and other kidney diseases develop, older donors have the lowest likelihood of developing end-stage renal disease after donation. As a general approach, young donors can be accepted if they have high glomerular filtration rate, but young donors from certain ethnic minorities and/or extensive family history of chronic kidney disease and those less than 18 years old should not be considered.

Strategies for long-term preservation of kidney graft function

Kidney transplantation has become a routine procedure in the treatment of patients with kidney failure, and requires collaboration of experts from different disciplines, such as nephrology, surgery, immunology, pathology, infectious disease medicine, cardiology, and oncology. Grafts can be obtained from deceased or living donors, with different logistical requirements and implications for long-term graft patency. 1-year graft survival rates are greater than 95% in many centres but improvement of long-term function remains a challenge. New developments in molecular immunology and computational biology have increased precision of donor and recipient matching of HLA and non-HLA compatibility. Individual omics-wide molecular diagnostics, extracorporeal therapies, and drug developments allow for precise individual decision making and treatment. Tolerance induction by mixed chimerism without toxic conditioning and with a low risk of graft versus host disease is a visionary but realistic goal. Some of these innovations are already used in modern transplant centres and will allow advancement in long-term allograft preservation.

Providing Better-Matched Donors for HLA Mismatched Compatible Pairs Through Kidney Paired Donation

BACKGROUND

Participation of compatible pairs (CP) in kidney paired donation (KPD) could be attractive to CPs who have a high degree of HLA mismatch, if the CP recipient will gain a better HLA match. Because KPD programs were not designed to help CP, it is important to define allocation metrics that enable CP to receive a better-matched kidney, without disadvantage to incompatible pairs (ICP).

METHODS

Simulations using 46 ICPs and 11 fully HLA-mismatched CPs were undertaken using the Australian KPD matching algorithm. Allocations were preformed adding 1 CP at a time or all 11 CPs at once, and with and without exclusion of unacceptable antigens selected to give a virtual calculated panel-reactive antibody ranging 70% to 80% to improve HLA matching in CP recipients.

RESULTS

On average, most CP recipients could be matched and had a lower eplet mismatch (EpMM) with the matched donor (57 ± 15) than with their own donor (78 ± 19, P < 0.02). However, only recipients who had an EpMM to own donor greater than 65 achieved a significant reduction in the EpMM with the matched donor. The gain in EpMM was larger when CPs were listed with unacceptable antigens. Furthermore, inclusion of 1 CP at a time increased matching in ICP by up to 33%, and inclusion of all 11 CPs at once increased ICP matching by 50%.

CONCLUSIONS

Compatible pair participation in KPD can increase match rates in ICP and can provide a better immunological profile in CP recipients who have a high EpMM to their own donor when using allocation based on virtual crossmatch.

Challenges of kidney paired donation transplants involving multiple donor and recipient surgeons across Australia

BACKGROUND

The Australian kidney paired donation program adopted the principles of within-chain simultaneous live donor surgery and of organ transport, with the requirement of keeping cold ischemia time (CIT) to <12 h. Whether these principles could be adhered to and what impact on transplant outcome they might have is unknown.

METHODS

We evaluated the logistic challenges and outcomes of the first 100 kidney transplants performed in the Australian kidney paired donation program.

RESULTS

Within 4 years, 17 donor surgeons at 12 centres were involved in 37 chain exchange surgeries. Sixteen kidneys were transplanted at the same hospital and 84 required transport to the recipient hospital. Mean (±SD) within chain anaesthetic induction time variability was 8 ± 18 min and mean individual surgeon operating time was 115 ± 44 min. In two cases, delays during donor surgery resulted in increased CIT by 1 h because of deferred transport. CIT was 2.6 ± 0.6 h for non-shipped and 6.8 ± 2.8 h for shipped kidneys, four kidneys had CIT of 12-14 h. Immediate allograft function was observed in 85% of recipients, with no difference between shipped and non-shipped kidneys. There were only two cases of delayed graft function requiring temporary dialysis; both had CIT <7 h. There was no difference in serum creatinine at 1 month between non-shipped and shipped kidneys (105 ± 26 versus 112 ± 50 µmol/L) and allograft survival at 1 year was 97%.

CONCLUSION

The study provided a favourable audit of kidney transplant activity, despite challenges of simultaneous surgery, organ transport coordination and prolonged CIT. The decision to ship donor kidneys rather than the donor was demonstrated to be feasible and safe.

Outcomes of kidney paired donation transplants in relation to shipping and cold ischaemia time

To assess the impact of shipping distance and cold ischaemia time (CIT) of shipped organs in a kidney paired donation (KPD) programme, we evaluated the outcomes of the initial 100 kidney transplants performed in the Australian KPD programme. In a 44-month period, 12 centres were involved in fifteen 2-way, twenty 3-way, one 4-way and one 6-way exchanges. Sixteen kidneys were transplanted at the same hospital (CIT 2.6 ± 0.6 h) and 84 required transport to the recipient hospital (CIT 6.8 ± 2.8 h). A spontaneous fall in serum creatinine by at least 10% within 24 h was observed in 85% of recipients, with no difference between nonshipped and shipped kidneys. There were two cases of transient delayed graft function requiring dialysis and patient and graft survival at 1 year were 99% and 97%, respectively. There was no difference in recipients of nonshipped compared with shipped kidneys with regard to serum creatinine at 1 month (mean difference (MD) 7.3 μmol/l, 95% CI -20.2 to 34.8, P = 0.59), 1-year graft survival (MD 3.9%, 95% CI -5.4 to 13.2, P = 0.41) or patient survival (MD -2.4%, 95% CI -10.0 to 5.2, P = 0.54). Despite prolonged CIT for interstate exchanges, the programme's decision to ship donor kidneys rather than the donor appears to be safe.

Four years of experience with the Australian kidney paired donation programme

New approaches to increase kidney transplantation rates through expansion of live donor kidney transplantation have become necessary due to ongoing shortage of deceased donor organs. These strategies include desensitization in antibody-incompatible transplants to overcome the barrier of blood group incompatibility or human leucocyte antigen antibodies between recipient and donor and kidney paired donation (KPD) programmes. In KPD, a kidney transplant candidate with an incompatible live donor joins a registry of other incompatible pairs in order to find potentially compatible transplant solutions. To match the largest possible number of donor-recipient pairs while minimizing immunologic risk, KPD programmes use sophisticated algorithms to identify suitable matches with simultaneous two-way or more complex multi-way exchanges as well as including non-directed anonymous donors to start a chain of compatible transplantations. Because of the significant immunologic barriers when fewer donor options are available, the optimal solution for difficult-to-match, highly sensitized patients is access to more potential donors using large multi-centre or national KPD registries. This review focuses on the first 4 years of experience with the Australian multi-centre KPD programme that was established in October 2010.

Kidney paired donation: principles, protocols and programs

Due to the ongoing shortage of deceased-donor organs, novel strategies to augment kidney transplantation rates through expanded living donation strategies have become essential. These include desensitization in antibody-incompatible transplants and kidney paired donation (KPD) programs. KPD enables kidney transplant candidates with willing but incompatible living donors to join a registry of other incompatible pairs in order to find potentially compatible transplant solutions. Given the significant immunologic barriers with fewer donor options, single-center or small KPD programs may be less successful in transplanting the more sensitized patients; the optimal solution for the difficult-to-match patient is access to more potential donors and large multicenter or national registries are essential. Multicenter KPD programs have become common in the last decade, and now represent one of the most promising opportunities to improve transplant rates. To maximize donor-recipient matching, and minimize immunologic risk, these multicenter KPD programs use sophisticated algorithms to identify optimal match potential, with simultaneous two-, three- or more complex multiway exchanges. The article focuses on the recent progresses in KPD and it also reviews some of the differences and commonalities across four different national KPD programs.

Risk factors for perioperative complications in hand-assisted laparoscopic donor nephrectomy

Living donor kidney transplant is the preferred treatment for end-stage renal disease; however, the shortage of kidney donors remains a big problem. One of the major reasons for the shortage of living donors is the risk of potentially serious surgical complications of a procedure in which the donor has no personal medical benefit. Therefore it is important to understand the risk factors for perioperative complications associated with donor nephrectomy. Hand-assisted laparoscopic donor nephrectomy is the preferred approach for kidney procurement in many medical centers. This review gives an overview of the risk factors in donor nephrectomy and more specifically in hand-assisted laparoscopic donor nephrectomy.

Strategies to increase the donor pool and access to kidney transplantation: an international perspective

In this position article, DESCARTES (Developing Education Science and Care for Renal Transplantation in European States) board members describe the current strategies aimed at expanding living and deceased donor kidney pools. The article focuses on the recent progress in desensitization and kidney paired exchange programmes and on the expanded criteria for the use of donor kidneys and organs from donors after circulatory death. It also highlights differences in policies and practices across different regions with special regard to European Union countries. Living donor kidney paired exchange, the deceased donor Acceptable Mismatch Programme and kidneys from donors after circulatory death are probably the most promising innovations for expanding kidney transplantation in Europe over the coming decade. To maximize success, an effort is needed to standardize transplant strategies, policies and legislation across European countries.

The use of immunoglobulin therapy for patients undergoing solid organ transplantation: an evidence-based practice guideline

This guideline for the use of immunoglobulin (IG) for sensitized patients undergoing solid organ transplantation (SOT) is an initiative of the Canadian Blood Services and the National Advisory Committee on Blood and Blood Products of Canada to (1) provide guidance for Canadian practitioners involved in the care of patients undergoing SOT and transfusion medicine specialists on the use of IG and (2) standardize care, limit adverse events, and optimize patient care. A systematic expert and bibliography literature search up to July 2008 was conducted, with 791 literature citations and 45 reports reviewed. To validate the recommendations, the guideline was sent to physicians involved in SOT in Canada and a patient representative. The recommendations identify (1) sensitized patients undergoing SOT that would have a better survival and decreased morbidity by receiving IG preoperatively, postoperatively, and for the treatment of organ rejection; (2) patients who may not have any benefit from receiving IG; and (3) potential adversities to IG.

Elective surgical patients as living organ donors: a clinical and ethical innovation

We propose a new model for living organ donation that would invite elective laparoscopic cholecystectomy patients to become volunteer, unrelated living kidney donors. Such donors would be surgical patients first and living donors second, in contrast to the current system, which 'creates' a surgical patient by operating on a healthy individual. Elective surgery patients have accepted the risks of anesthesia and surgery for their own surgical needs but would face additional surgical risks when a donor nephrectomy is combined with their cholecystectomy procedure. Because these two procedures have never been performed together, the precise level of additional risk entailed in such a combined approach is unknown and will require further study. However, considering the large number of elective cholecystectomies performed each year in the United States, if as few as 5% of elective cholecystectomy patients agreed to also serve as living kidney donors, the number of living kidney donors would increase substantially. If this proposal is accepted by a minority of patients and surgeons, and proves safe and effective in a protocol study, it could be applied to other elective abdominal surgery procedures and used to obtain other abdominal donor organs (e.g. liver and intestinal segments) for transplantation.

Risk factors for end-stage renal disease: 25-year follow-up

BACKGROUND

Few cohort studies have focused on risk factors for end-stage renal disease (ESRD). This investigation evaluated the prognostic value of several potential novel risk factors for ESRD after considering established risk factors.

METHODS

We studied 177 570 individuals from a large integrated health care delivery system in northern California who volunteered for health checkups between June 1, 1964, and August 31, 1973. Initiation of ESRD treatment was ascertained using US Renal Data System registry data through December 31, 2000.

RESULTS

A total of 842 cases of ESRD were observed during 5 275 957 person-years of follow-up. This comprehensive evaluation confirmed the importance of established risk factors, including the following: male sex, older age, proteinuria, diabetes mellitus, lower educational attainment, and African American race, as well as higher blood pressure, body mass index, and serum creatinine level. The 2 most potent risk factors were proteinuria and excess weight. For proteinuria, the adjusted hazard ratios (HRs) were 7.90 (95% confidence interval [CI], 5.35-11.67) for 3 to 4+ on urine dipstick, 3.59 (2.82-4.57) for 1 to 2+ on urine dipstick, and 2.37 (1.79-3.14) for trace vs negative on urine dipstick. For excess weight, the HRs were 4.39 (95% CI, 3.38-5.70) for class 2 to class 3 obesity, 3.11 (2.51-3.84) for class 1 obesity, and 1.65 (1.39-1.97) for overweight vs normal weight. Furthermore, several independent novel risk factors for ESRD were identified, including lower hemoglobin level (1.33 [1.08-1.63] for lowest vs highest quartile), higher serum uric acid level (2.14 [1.65-2.77] for highest vs lowest quartile), self-reported history of nocturia (1.36 [1.17-1.58]), and family history of kidney disease (HR, 1.40 [95% CI, 1.02-1.90]).

CONCLUSIONS

We confirmed the importance of established ESRD risk factors in this large cohort with broad sex and racial/ethnic representation. Lower hemoglobin level, higher serum uric acid level, self-reported history of nocturia, and family history of kidney disease are independent risk factors for ESRD.

Routine Use of Ambulatory Blood Pressure Monitoring in Potential Living Kidney Donors

BACKGROUND AND OBJECTIVES

Most transplant centers exclude prospective living kidney donors with hypertension from donation. Centers routinely identify hypertension using BP measured in the clinic, but it is not clear that clinic BP accurately detects the presence or absence of hypertension in potential donors. We therefore conducted a prospective study to determine the impact of routine ambulatory BP monitoring on diagnosis of hypertension in potential donors and the value of other baseline characteristics in predicting ambulatory BP results.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We compared classification of hypertension status by clinic BP and by ambulatory BP monitoring in 178 potential living kidney donors.

RESULTS

Of 63 individuals with hypertension by clinic BP, 62% had white-coat hypertension by ambulatory BP and were therefore eligible to donate. Of 115 individuals who were normotensive by clinic BP, 17% had masked hypertension by ambulatory BP and were excluded from donation. Individuals with masked hypertension were older, were more likely to be male, and had a somewhat higher clinic BP than individuals with sustained normotension. Individuals with white-coat hypertension had a somewhat lower clinic diastolic BP than individuals with sustained hypertension.

CONCLUSIONS

Routine ambulatory BP monitoring may identify a large number of individuals with white-coat hypertension and a smaller but significant number of individuals with masked hypertension, ensuring adequate protection of potential donors and accurate assessment of donor risk. Differences in baseline characteristics are small and are not clinically useful in distinguishing individuals with masked hypertension from individuals with sustained normotension or individuals with white-coat hypertension from individuals with sustained hypertension, demonstrating the importance of ambulatory BP monitoring in this population.

Marginal kidney donor

Renal transplantation is the treatment of choice for a medically eligible patient with end stage renal disease. The number of renal transplants has increased rapidly over the last two decades. However, the demand for organs has increased even more. This disparity between the availability of organs and waitlisted patients for transplants has forced many transplant centers across the world to use marginal kidneys and donors. We performed a Medline search to establish the current status of marginal kidney donors in the world. Transplant programs using marginal deceased renal grafts is well established. The focus is now on efforts to improve their results. Utilization of non-heart-beating donors is still in a plateau phase and comprises a minor percentage of deceased donations. The main concern is primary non-function of the renal graft apart from legal and ethical issues. Transplants with living donors outnumbered cadaveric transplants at many centers in the last decade. There has been an increased use of marginal living kidney donors with some acceptable medical risks. Our primary concern is the safety of the living donor. There is not enough scientific data available to quantify the risks involved for such donation. The definition of marginal living donor is still not clear and there are no uniform recommendations. The decision must be tailored to each donor who in turn should be actively involved at all levels of the decision-making process. In the current circumstances, our responsibility is very crucial in making decisions for either accepting or rejecting a marginal living donor.

Medical Risks in Living Kidney Donors: Absence of Proof Is Not Proof of Absence

Living-kidney donation has become increasingly widespread, yet there has been little critical analysis of existing studies of long-term medical outcomes in living donors. This review analyzes issues in study design that affect the quality of the evidence and summarizes possible risk factors in living donors. Virtually all studies of long-term outcomes in donors are retrospective, many with large losses to follow-up, and therefore are subject to selection bias. Most studies have small sample sizes and are underpowered to detect clinically meaningful differences between donors and comparison groups. Many studies compare donors with the general population, but donors are screened to be healthier than the general population and this may not be a valid comparison group. Difficulties in measurement of BP and renal function may underestimate the impact of donation on these outcomes. Several studies have identified possible risk factors for development of hypertension, proteinuria, and ESRD, but potential vulnerability factors in donors have not been well explored and there is a paucity of data on cardiovascular risk factors in donors. Prospective registration of living kidney donors and prospective studies of diverse populations of donors are essential to protect living donors and preserve living-kidney donation.