Reported by Julielynn Wong, MD

A single gene may shed light on why more than half of transplanted kidneys fail in 10 years, a new study found.

The study of nearly 4,500 European transplant recipients, some whom were followed for 20 years, found kidneys with one version of the gene were 69 percent more likely to fail, sending patients back to dialysis and a transplant waiting list.

But with a wait list 74,000 names long and only17,500 kidneys donated annually, doctors wont be excluding any organs based on the gene variant just yet.

We just dont have enough donor kidneysto go around now, said Dr. Michael E. Shapiro, associate professor of surgery at New Jersey Medical School/University of Medicine and Dentistry New Jersey, who was not involved in the study. So wecouldntexclude such kidneys based solely on genetic variation.

The study authors are unsure why the gene variant is linked to a higher risk of kidney failure after a transplant, but they suspect it might have to do with the anti-rejection drugs needed to prevent the immune system from attacking the new organ. Those drugs can cause kidney failure if they accumulate in high levels, they said.

But because kidneys are such a rare and valuable resource, even those more likely to fail in the long run will continue to be transplanted. The alternative is dialysis, a process that artificially filters blood, according to Dr. Stanley Jordan, medical director of the Kidney Transplant Program at Cedars-Sinai Medical Center in Los Angeles, who was not involved with the study.

And dialysis has its drawbacks.

We know that remaining on dialysis has a very high mortality rate, as high as 20 percent per year for some patients, said Jordan.

Dialysis costs roughly $85,000 per year, compared with $19,000 per year for a working transplanted kidney, Jordan said, citing a 2011 report on the United States Renal Data System website. But the cost of treating a failed kidney transplant can be as high as $230,000 in the first year, with Medicare usually bearing the brunt of these costs, he added.

Original post:
Gene Linked to Kidney Failure