By Michelle Fay Cortez - Wed Mar 07 19:16:55 GMT 2012

Kidney transplant patients given a mixture of stem cells from their organ donor were able to quit taking anti-rejection medicine in a small study, suggesting that life-long reliance on the toxic drugs may be avoidable.

Five of eight patients treated were able to stop taking about a dozen pills a day to suppress their immune systems. The drugs, which prevent rejection and stop tissue from a donated kidney from attacking the patient, can damage the transplant and cause diabetes, infections, heart disease and cancer.

The breakthrough, reported in the journal Science Translational Medicine, mixed stem cells from the donors infection-fighting immune system with the patients natural immune system. The result enabled tissue from both to co-exist in the transplant patient without either being seen as foreign by the immune system, researchers said.

The results may potentially have an enormous, paradigm- shifting impact on solid-organ transplantation, wrote James Markmann and Tatsuo Kawai from Massachusetts General Hospital in Boston, in an editorial accompanying the study. Although only a taste of things to come, few transplant developments in the past half-century have been more enticing than these that put transplantation tolerance within our grasp.

The findings are particularly striking since the patients werent perfect tissue matches with the living donors. The mismatch traditionally makes it more difficult for the donated organ to survive since the patients immune system perceives the unfamiliar tissue as a threat.

Its been a longstanding goal in transplantation to achieve tolerance, to get the recipient to see the donor organ as part of itself, said Joseph Leventhal, a surgeon at Northwestern Memorial Hospital in Chicago and the lead author. A road to tolerance now exists, he said.

Having two immune systems blend into one is called a chimerism. The long-lasting effect seen in the study may stem from the manipulation of stem cells taken from the donor in advance of the surgery, according to the report.

The cells were sent to Suzanne Ildstad, director of the Institute of Cellular Therapeutics at the University of Louisville in Kentucky. There facilitating cells that help transplants take hold were identified and used to enrich the mixture, which was given to the patient the day after surgery.

The researchers didnt provide details on how they crafted the stem cell mix, which may make it difficult for other investigators to confirm the findings, Markmann and Kawai wrote.

Read this article:
Stem Cells Help Kidney-Transplant Patients Skip Rejection Drugs in Study