Bioethics Forum Essay
What Every Prospective Living Kidney Donor Should Know
Kidney donation has extended the lives and improved the quality of life of many people with end-stage renal disease (ESRD). Living donation has shortened the time some people with ESRD have to wait for a kidney transplant. Prospective living donors have more to consider, however, than how well their kidney will function in a recipient or possible perioperative or postoperative complications for them. What is missing from what they are told when they are interviewed by transplant centers is information about the lifetime, or 40-year, risk of ESRD after kidney donation.
Prospective living kidney donors may be informed of the 20-year risk, which is comparable to that of nondonors. But the risk rises significantly over 40 years. There is a growing call for the lifetime risk to be disclosed. Donors should be informed of it in making a decision that could adversely affect them many years later.
Lifetime risk for a donor is based on a combination of reduced kidney function (as measured by a test called the glomerular filtration rate) in the remaining kidney and the probable development of diseases such as type 2 diabetes, hypertension, and glomerulonephritis, all of which impair kidney function. Kidney disease may take 30 or more years to develop in the general population. One-third of living kidney donors in the United Network for Organ Sharing (UNOS) registry are under 35 years old. Many of them are in their 20’s. For a healthy 25-year old, the relative 20-year risk of ESRD after donation is low. But there is anexponential increase in this risk by the time they are 65 or older. At 40 years post-donation, the risk for all donors outpaces that of the general population of healthy nondonors. The risk is especially high among young black donors, underscoring the need to evaluate them more carefully than other candidates.
Many people aware of the long-term risk may still donate a kidney. They may rationally accept it in donating to a family member because of shared interests and the emotional bond between them. Others may accept the risk in agreeing to participate in paired kidney exchanges, where those who are immune incompatible with a loved one in need of a kidney donate to another person so that their sibling or partner can receive a transplant. Still others may donate to strangers for altruistic reasons, motivated by an intention to meet another person’s critical need while giving less weight to their own interests. Recipients of successful transplants benefit physiologically from receiving a healthy kidney that extends their life and psychologically from the improvement in their quality of life compared with dialysis. Donors benefit psychologically from knowing that their action has had these positive effects.
Still, the longer-term risk of ESRD may require an adjustment of the balance between benefit and potential harm for individual donors. Even if they are aware of what might happen to them 40 years later, donors may conclude that the immediate benefit of added life years and improved quality of life for a kidney transplant recipient would outweigh any remote harm to them associated with ESRD as they age. A 25-year-old donor may discount the probability of developing kidney disease at age 65. The donor may also reason that lifetime risk of ESRD applies to groups rather than individuals. Temporally discounting this risk may be rational, depending on the value one assigns to the different stages of one’s life and how donation at a certain age may be part of that value.
But no one can predict whether or not they will develop conditions that will impair the function of their remaining kidney later in life. For this reason, transplant centers have an ethical obligation to present information about long-term risk of ESRD to prospective living kidney donors. Doing so respects their autonomy as rational decision-makers and is necessary for them to make a fully informed decision about whether to consent to donation. There may be differences in how people assess the elevated risk of ESRD 40 years after donation. Information about long-term probable outcomes for donors must be presented to them in a nondirective way, avoiding terms like “high” or “low” risk that could unduly influence their decision-making. Equally important, a claim that the estimated lifetime risk is not known could preclude fully informed consent.
The point of providing this information is not to discourage living kidney donation but to make prospective donors aware of a disease that may befall them many years after donating. There are both deontological and consequentialist issues. The deontological issue pertains to the donor’s right to be informed of the long-term risk of ESRD. The consequentialist issue pertains to how their renal function and overall health may be affected 40 years after giving up a kidney. Twenty-year post-transplant data do not sufficiently address these issues. Transplant centers interviewing and evaluating prospective living kidney donors should present all medically relevant information about long-term risk to allow them to make decisions consistent with their values and interests over the course of their lives.
Walter Glannon, PhD, a Hastings Center fellow, is a professor emeritus of philosophy at the University of Calgary.