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.
Key words : Diabetes mellitus, Glomerular filtration rate, Hypertension
Over the past decade, the number of people with end-stage renal disease (ESRD) is increasing worldwide.1 For patients with ESRD, renal transplant is better than dialysis for various reasons. In countries such as India, about 80 000 patients are added annually to the pool of those diagnosed with ESRD; however, only 2.4% undergo transplant.2 In recent years, the number of living-donor transplants has surpassed deceased-donor transplants worldwide.3 However, the number of patients on wait lists for kidney transplant is increasing by 10% annually, whereas the annual increase in the number of renal transplants is only 4%.4 The average wait period for deceased-donor organs is more than 5 years in the United States.5 Efforts are being made to increase the availability of organs for donation, and the use of “expanded criteria donors” or “suboptimal donors” is one of these efforts.
The term “suboptimal donors” is not yet clearly defined. It simply means use of living donors with some acceptable medical risks. With the increase in demand for allografts, many centers worldwide have started to use marginal kidneys with informed consent. Although the short-term and long-term outcomes with such grafts have been inferior to normal criteria kidneys, their use has significant survival advantages versus those shown in patients on wait lists who remain on dialysis.6
Fifty years after the first successful living-donor renal transplant, evidence has clearly shown few long-term medical risks to healthy donors after nephrectomy. However, potential underreporting of donor complications by transplant teams for various reasons should be kept in mind while interpreting the published literature.
Evidence greatly suggests that optimal living donors do not face risks of ESRD any higher than those of age-matched peers.7,8 However, this evidence cannot be applied to donors who are suboptimal. In fact, more emphasis is needed on investigating whether suboptimal living donors develop chronic kidney disease rather than ESRD.
Elderly Living Donors
The definition of “normal” glomerular filtration rate (GFR) changes with age and decreases over time.9-11 There is an acute decrease in GFR of approximately 30% after unilateral nephrectomy; however, the impact of unilateral nephrectomy on this rate of decline in GFR is unknown. The influence of donor age on outcomes of living-donor kidney transplant is not clear. Kumar and associates12 reported no differences in graft and patient survival between the use of elderly donors and the use of younger donors at 1 year and 5 years after transplant. In addition, there was no morbidity or deterioration of preoperative blood pressure and renal function at 1 year in the elderly donors. Similar results were reported by other authors.13 However, contrary to the above findings, other reports have suggested poorer survival in elderly donor groups.14-17 Poorer outcomes of an older kidney graft might be due to anatomic and physiologic changes that occur during aging.18 Thus, rates of short-term morbidity and mortality do not seem to be higher for elderly donors, but no data on long-term outcomes for this specific group are available.
Hypertensive Living Donors
Individuals with blood pressure ≥ 140/90 mm Hg are generally not acceptable as donors. However, patients with easily controlled hypertension with GFR ≥ 80 mL/min and urinary albumin excretion < 30 mg/day may represent a low-risk group for development of kidney disease after donation and may be acceptable as kidney donors. It may be medically sound to accept a hypertensive donor if age is over 50 years, blood pressure is controlled on a single antihypertensive agent, and there is no target organ damage.
Living Donors With Diabetes Mellitus
Patients with diabetes mellitus have an increased risk of postsurgical complications and future development of renal failure compared with risk shown in the general population. It has been suggested19 that nephrectomy in a patient with type 2 diabetes mellitus may increase the progression of disease and microalbuminuria. However, because concrete evidence is not yet available, guidelines have been issued from an international forum for living donor care. The guidelines suggest that individuals with a history of diabetes mellitus or fasting blood glucose of ≥ 126 mg/dL on at least 2 occasions should not donate. No comments were made regarding the acceptance of any related donor of an individual with diabetic nephropathy.
Ethical Issues in Accepting Complex Living Kidney Donors
When considering suboptimal living donors, one should remember the basic ethical principles of benefit to the recipient and no harm to the donor. Living donors subject themselves to harm voluntarily, typically for the benefit of another person, rather than gaining direct physical or financial benefit. Thus, donor autonomy and risk-benefit assessment are paramount.
Future Strategies for Complex Living Kidney Donation
It is worth emphasizing that easing the donor criteria would not significantly boost the availability of organs. As previously reported,20 accepting living donors with mild hypertension or proteinuria for kidney transplants would lead to only a modest increase in transplant rates (3%), although every single additional transplant counts. The decision to accept a medically complex living donor is based on uncertain medical, ethical, and legal factors, and transplant centers must make their decisions on an individual basis.
With the ever-increasing pressure to accommodate more renal transplant recipients and the related paucity of active deceased donors, there is a tremendous pressure on the transplant surgeon to accept less than ideal living donors for organ donation. In our decision process, we need to consistently review ourselves from a risk-benefit aspect of the procedure.
Volume : 18
Issue : 1
Pages : 16 - 18
DOI : 10.6002/ect.TOND-TDTD2019.L21
From the 1Department of Nephrology, Dr. Soliman Fakeeh Hospital, Jeddah, Saudi
Arabia; the 2Bengaluru Hospital, Bengaluru, India; the 3King Saud Bin Abdulaziz
University for Health Science, Riyadh, Saudi Arabia; and the 4Nephrology
Department, National Guard Hospital, Riyadh, Saudi Arabia
Acknowledgements: The authors have no sources of funding for this study and have no conflicts of interest to declare.
Corresponding author: Faissal A. M. Shaheen, Dr. Soliman Fakeeh Hospital, Jeddah, Saudi Arabia