Minnesota native Anthony Thein didn't hesitate back in 1967 when doctors asked him to donate a kidney to his ailing brother. "If you think it might help somebody survive, you say, 'Yes, of course,'" Thein says.
But kidney transplants from living donors were still uncommon in the late 1960s, and the operation carried risks for both parties. Doctors didn't know whether living with just one kidney could entail long-term medical repercussions.
"Yeah, we really did something crazy 42 years ago," Anthony says today.
Perhaps not. Researchers report in today's New England Journal of Medicine that people who donate a kidney have about the same probability of survival over several decades as people in the general population. And donors seem to have adequate kidney function and even less risk of severe kidney disease than occurs in the general public, nephrologist Hassan Ibrahim of the University of Minnesota and his colleagues report.
To arrive at these findings, the researchers pored over a database of kidney transplants performed at the University of Minnesota between 1963 and 2007 and tried to reach as many of the donors as possible. Using this data and death records from the Social Security Administration, the scientists were able to asses the mortality rate among 3,698 people who gave away a kidney within that time span.
The survival curves of these donors and the general public are close, even favoring the donors slightly. And the rate of end-stage renal disease, which necessitates dialysis and can put a person on a waiting list for a new kidney, was lower among the donors than in the general population.
The researchers also randomly selected 255 of the donors to undergo kidney function tests between 2003 and 2007. The team compared those results against tests done on a group of people who had both kidneys and who matched the donors in race, gender, body weight and age.
An analysis showed the donors had acceptable measures of basic kidney functions and even outperformed the control group on blood pressure measurements, says Ibrahim.
Self-reported information suggested the donors had a slightly better overall quality of life than people in the general population.
To be eligible to donate a kidney, a person must pass a physical examination and cannot have diabetes, high blood pressure or other serious ailments.
With that in mind, it's not surprising that kidney donors would have good mortality rates and better health-related quality of life than people in the general population, say physicians Jane Tan and Glenn Chertow of Stanford University School of Medicine, writing in the same NEJM issue. "Nevertheless," they note, "it is somewhat surprising and quite reassuring that rates of end-stage renal disease were also lower in kidney donors than in the general population."
These broader findings have been reflected in a personal way in Anthony Thein's life. Now 70 and semiretired, Thein says he hasn't encountered any problems from lacking a kidney, although he does sport a sizable scar across his midsection — a testament to being among the earliest donors. Donors' scars today are much smaller.
"Actually, I'm proud of my scar," he says. "It's sort of like a badge of honor."
Advice: Consider kidney donation.
Read the appeal of a woman with kidney disease for a kidney donor. Thanks to Nathan Seppa for his article yesterday in Science News, reprinted here.
