Evaluation of the Living Kidney Donor Candidate
Living kidney has major advantages over deceased donor kidney. In general, recipients of living kidney benefit from shorter waiting time, higher likelihood of preemptive transplantation, lower risk for delayed graft function (DGF), and has superior graft survival with a half-life of 12 to 15 years compared to 9 to 11 years for deceased donors.1
A living donor evaluation is the process intended to protect the donor and to ensure that the donor is healthy enough to undergo surgery with minimal risk of developing adverse medical, psychosocial, and financial outcome after kidney donation.
The donor’s physician must balance a “do no harm” position with the autonomy of the donor, and carefully discuss the potential risks of donation.
The Organ Procurement and Transplantation Network (OPTN) has developed policies for all U.S. transplant centers and the minimum kidney donor suitability requirements and has incorporated these within existing global policies for all living donors prior to kidney donation.
Informed consent is a core value in living donor evaluation based on the long-standing and widely held ethical principles.
The donor must have the ability to understand the risks, benefits, and consequences of donation and the capacity to make decision.
The donor must be willing to donate, free from inducement and coercion.
The donor should be informed of all of the following3:
The donor may decline to donate at any time in a way that is protected and confidential.
The transplant center will provide an ILDA to assist the donor during evaluation process.
There are alternative treatments available for the recipient such as continuation of hemodialysis and deceased donor transplantation if deceased organ may become available before completing living donor evaluation.
There may be health conditions that could be discovered from the evaluation process, which may be required to be shared with public health authorities.
There are surgical, medical, psychosocial, and financial risks associated with living donation, which may be temporary or permanent to the donor, including uncertainty in the risk estimates when it cannot be accurately quantified based on available data.
The donor may require long-term routine medical follow-up after donation.
The transplant center makes the final determination whether the donor is eligible for donation based on the results of their evaluation. Different transplant centers may evaluate the donor using different selection criteria.
It is a crime to receive anything of value such as money, property for their donation.
Independent Living Donor Advocate
The ILDA is a person or a team who is not involved in the potential recipient evaluation and is independent of the decision to transplant the potential recipient.3
The transplant center must provide ILDA for the donor to help the donor during evaluation process and to advocate the rights of the donor.
The ILDA must fulfill the qualification and training requirements including knowledge of living organ donation, transplantation, medical ethics, informed consent, and the potential impact of family or other external pressure on the living donor’s donation.4
ABO Blood Typing
ABO blood typing should be drawn on two separate occasions prior to donation to reduce risk of unintended blood type incompatible transplantation.3
ABO subtyping is performed to evaluate anti-A antibodies in recipients with blood type B or O receiving a kidney from donors with blood type A.
A2 kidney has a very low A antigen expression in the renal cortex and the entire vascular bed endothelium. This low A antigen expression in A2 kidney allows recipients of blood type B or O to receive a kidney from A2 donor if recipient has low anti-A titers.
The rhesus (Rh) factor is of little concern because it is not expressed on endothelial cells.
Human Leukocyte Antigen Typing
Transplant programs routinely performed human leukocyte antigen (HLA) typing in order to counsel the patients about matching and graft survival.
This includes HLA typing for major histocompatibility complex (MHC) class I (A, B, C) and MHC class II (DP, DQ, DR).
HLA matching is traditionally recorded as the number of A, B, and DR mismatched antigens.
For example, if a donor and a recipient share the same A, B, and DR antigens, this would be a 0A, 0B, 0DR mismatch.
Poor HLA matching does not preclude living kidney transplant as it still offers better graft survival than deceased donor kidney transplant with zero antigen mismatches.
Recipients with anti-HLA antibodies are at a higher rate of graft rejection.
Living donor psychosocial evaluation must be performed by a psychiatrist, psychologist, master’s prepared social worker, or clinical social worker.3
Psychosocial evaluation is performed for the following main reasons:
To evaluate for any psychosocial issues or the presence of behavior that may increase risk for disease transmission, smoking, alcohol, drug abuse.
To determine that the donor has the capacity to understand the short- and long-term medical and psychological risks of donation.
To assure that the decision to donate is free of inducement, coercion, or undue pressure by exploring the reasons for donating and the nature of the relationship to that transplant candidate.
To assess the donor’s ability to make an informed decision and the ability to cope with the major surgery and related stress.
To review donor’s occupation, employment, health insurance, living arrangements, and social support.
To determine that the living donor understands the potential financial implication of living donation.
Significant psychiatric problems are generally considered a contraindication for donation.
The medical evaluation must be done by a physician or surgeon experienced in living donation.
Its purpose is to ensure that the donor is healthy enough to undergo the surgical procedure and that the donor is medically eligible for kidney donation.
Eligibility for kidney donation includes:
The donor has normal kidney function appropriate with age and normal structures.
The donor has minimal pre-existing risk for developing future kidney disease.
The donor has no concurrent medical conditions that might require treatment that could deteriorate residual kidney function.
The donor has no risk of transmitting a disease to the recipient such as an infection or a malignancy.
OPTN has defined absolute exclusion criteria when donor is both less than 18 years old and incapable of making decision.
Currently there is no absolute upper age limit for donation but the older donor has a higher likelihood of complications; therefore it is important to consider other comorbidities when evaluating older donor, particularly coronary artery disease.
A 2007 survey reported that most programs accepted candidate without upper limit of age.8
Long-term graft survival from older living donor is better than elderly deceased donor and similar to young deceased donor.
Hypertension is a contraindication for donation when the donor has uncontrolled hypertension or history of hypertension with end organ damage (e.g., microalbuminuria >30 mg/day, impaired renal function, cardiovascular events such as myocardial infarction or stroke, left ventricular hypertrophy).
Selection criteria for hypertension are more flexible especially if donor is older. The decision to accept the donor with hypertension should be individualized based on lifetime predicted end-stage renal disease (ESRD) risk to take into consideration.
Many centers allow mild hypertension that is controlled with one medication.
TABLE 27-1 GENERAL ASSESSMENT OF THE LIVING KIDNEY DONOR