Impact of easing kidney donor rules modest: study

By Clementine Wallace

NEW YORK (Reuters Health) - Accepting living donors for kidney transplants who have mildly elevated blood pressure or proteinuria (abnormal urinary protein excretion) -- two markers of kidney deterioration -- would lead to only a modest increase in kidney transplantation rates, researchers report.

Raising awareness among potential donors would have more impact, they say.

In their study, Dr. Martin Karpinski, from the University of Manitoba, in Winnipeg, and colleagues found that accepting donors with these mild conditions would increase transplantation rates by just 3 percent.

"The number of donors who might actually have a condition mild enough that they could accept the risk of donation is relatively small compared to the other barriers," Karpinski told Reuters Health. "So it's important to go on promoting overall living kidney donation and explore how we can overcome the barrier of immunologic incompatibility."

Many transplantation programs exclude potential living kidney donors with mild hypertension or proteinuria because these conditions are associated with an increased risk for chronic kidney disease and end-stage renal disease. While the level at which they can be considered "acceptable" remains controversial, there has been increasing pressure to include "marginal donors," according to the authors.

"There are many different strategies that are being pursued to increase the number of living kidney donors and this is one of them," said Karpinski. "So we wanted to quantify what the impact might be, relative to what the impact of other strategies might be."

To do so, Karpinski and his team studied data on 352 wait-listed recipients at four Canadian transplantation centers, analyzing the reasons for living kidney donor exclusion.

The results showed that only 35 percent of patients on these waiting lists actually had one or more potential living donors come forward. "This number is quite low and shows that a big effort could already be done at this level -- to increase the overall number of living donors," said Karpinski.

Among the 180 potential living donors evaluated, the primary reason for exclusion was immunologic incompatibility. Hypertension or proteinuria was less common reasons for exclusion (17 percent).

Acceptance of donors with these conditions would have resulted in transplantation of only 3 percent (12 of 352) of the wait-list population, the team concludes.

SOURCE: American Journal of Kidney Diseases, February 2006.