The Chart

Donating kidney may raise disease risk slightly

Those who make life-saving kidney donations may face a slightly increased risk of suffering from end-stage renal disease themselves, according to a study published Tuesday in the Journal of the American Medical Association (JAMA).

The study authors compared living kidney donors to healthy individuals who would also likely qualify to donate but never did. While the actual donors had an estimated lifetime risk of 90 out of 10,000 for end-stage renal disease (ESRD), the nondonors’ risk was slightly lower at 14 out of 10,000.

“As a medical community, we feel that it’s our imperative to understand, as well as we possibly can, what these risks are and communicate them with people,” says study author Dr. Dorry Segev, a professor of surgery at John Hopkins University School of Medicine.

“It’s one thing to say, ‘We think the risk is really low.’ It’s another thing to sit down with someone and say, ‘This is the actual, exact risk.’”

Despite the slight increase in risk among donors compared to healthy non-donors, the overall risk of end-stage renal disease remains very low; even lower than among the general population, which has an estimated lifetime risk of 326 per 10,000, according to the study.

That is in large part because potential donors are screened aggressively – receiving everything from blood tests to CT scans to psychological evaluations – to ensure they are fit enough to make a donation in the first place.

“If you donate a kidney, you can be very confident that your risk of kidney failure is very low. That, to me, is the key finding,” says Dr. Marcello Tonelli, a nephrologist at the University of Alberta. 

Tonelli, who co-authored the accompanying editorial in JAMA, points out that given some of the limitations of this study, "the low absolute risk of ESRD should reassure future donors of the safety of living kidney donation."

In a similar 2010 study, the same team of researchers found no significant increase in actual mortality following kidney donation.

“What I tell donors when we discuss risk after donation is: imagine if it's not in your stars to get kidney failure, then you're not going to get kidney failure, whether you donated or not,” says Segev.

But if you have an underlying kidney disease doctors can't screen for, or develop something like high blood pressure later in life that puts your kidneys at risk, Segev says, "now you’re starting from a lower place.”

Each year, about 6,000 healthy Americans donate one of their kidneys. This study included nearly all of them – 96,217 total - from 1994 to 2011, and compared them with a smaller group of comparably healthy non-donors from a Centers for Disease Control and Prevention national survey.

Despite the findings, “(Donors) are doing something that is a profound benefit to another human being at a very small risk to themselves,” says Segev.

“If you’re donating to a loved one - somebody you live with, somebody you care about, you are bringing their life back.  There’s actually a benefit to donors that goes beyond a measurable medical benefit.”