Experimental Procedure Allows Patients To Tolerate Mismatched Kidney Transplants

(Ivanhoe Newswire) – An experimental procedure may help some kidney transplant patients stop taking immunosuppressive drugs.

A new study from Massachusetts General Hospital finds the procedure worked in four out of five patients. The technique induces immune tolerance to HLA (human leukocyte antigen) mismatched kidney transplants – the most difficult immunological barrier to transplantation.

“We are very encouraged by our initial success in inducing tolerance across the HLA barrier, something that has been a major goal of transplant immunology for years,” senior author David H. Sachs, M.D., Massachusetts General Hospital Transplantation Biology Research Center, was quoted as saying. “While we need to study this approach in a larger group of patients before it is ready for broad clinical use, this is the first time that tolerance to a series of mismatched transplants has been intentionally and successfully induced.”

Sachs and his colleagues have been trying to induce immune tolerance for more than 30 years. They developed an approach in which the organ recipient gets bone marrow along with the organ from the donor. The result is an immune system that combines elements of both the donor and recipient.

Organ recipients first have a treatment designed to partially destroy their bone marrow along with an antibody that reduces the level of T cells – the immune system component mainly involved in organ rejection. After patients get the transplanted kidney and bone marrow they spend about two weeks in a relatively sterile environment. This allows the bone marrow to regenerate and produce new immune cells that tolerate the donor organ.

Results show all four of the successfully transplanted patients in the study still have normal kidney function from two to more than five years later.

This article was reported by Ivanhoe.com, which offers Medical Alerts by e-mail every day of the week. To subscribe, click on: http://www.ivanhoe.com/newsalert/.

Sign up for a free weekly e-mail called First to Know by clicking here.

SOURCE: New England Journal of Medicine, 2008