Altered Stem Cells Limit Transplant Rejection

Approach Could Free Organ Patients From Anti-Rejection Drugs

By Salynn Boyles
WebMD Health News

Reviewed by Laura J. Martin, MD

March 7, 2012 -- New research holds the promise of freeing many organ transplant patients from a lifetime of anti-rejection drugs.

In the first study of its kind, eight kidney transplant patients received stem cells from their kidney donors manipulated to "trick" their bodies into accepting the foreign organ as its own.

Transplant recipients who are not perfectly matched with their donors typically take several drugs a day for the rest of their lives to keep their bodies from rejecting the new organ and to treat the side effects of those drugs.

Lindsay Porter, who was the last of the eight patients enrolled in the new study, had her kidney transplant in the summer of 2010 and was weaned off all anti-rejection drugs within a year.

The Chicago actress and mother says she feels better than she has in 15 years and sometimes has to remind herself that she had a kidney transplant.

"I was 45 when I had the surgery, and I knew I would probably need another kidney at some point," she tells WebMD. "The opportunity to have a transplant that would last for the rest of my life and to avoid all of those drugs was very appealing."

Stem Cells Made Transplant Friendly

The ongoing research is the culmination of many years of work by researcher Suzanne Ildstad, MD, of the University of Louisville, and other researchers, including transplant surgeon Joseph Leventhal, MD, PhD, of Chicago's Northwestern University.

The new wrinkle is that organ donors who are not a perfect genetic match with the patient donate blood as well as a kidney for the procedure.

Bone marrow stem cells collected from the blood were processed in an 18-hour procedure to remove cells associated with organ rejection, leaving behind "facilitating" cells that do not promote rejection, Ildstad says.

Porter and the other patients in the study had chemotherapy about a month before their surgeries to suppress their own immune systems before receiving the manipulated donor stem cells in an effort to increase the likelihood that those stem cells would reprogram the body to accept the transplant.

The procedures were performed in the eight patients between February 2009 and July 2010, and five of the eight have maintained normal kidney function and were able to stop taking all anti-rejection drugs within a year of having their transplants.

Ildstad says the stem cell approach may prove useful for other solid-organ transplants and for many other conditions, including type 1 diabetes and sickle cell anemia.

Research Is a Possible 'Paradigm Shift' for Transplants

Leventhal says the research team is now working to modify the approach so that it can be used when the transplanted kidney comes from a donor who has died.

About two-thirds of the roughly 17,000 kidney transplants performed in the U.S. each year involve deceased donors.

He says once this hurdle is overcome, the enriched stem-cell technique could end the need for immunosuppressive drugs in transplant patients.

"These drugs are, quite frankly, toxins," he tells WebMD. "We use them as a means to an end, but they very negatively impact quality of life and how long transplanted organs last."

In an editorial published with the study, Massachusetts General Hospital transplant researchers James F. Markmann, MD, and Tatsuo Kawai, MD, noted that the research has the potential to have "an enormous paradigm-shifting impact" on solid-organ transplants.

The study and editorial appear in the March 7 issue of the journal Science Translational Medicine.

"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," they wrote.

Lindsay Porter is just grateful to be able to keep up with a very active 5-year-old son.

"Frankly, every day that I am not on immunosuppressive drugs is a much better day for my body," she says.


The only purpose of the kidneys is to filter blood. See Answer

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SOURCES: Leventhal, J. Science Translational Medicine, March 7, 2012.Joseph Leventhal, MD, PhD, transplant surgeon, Northwestern Memorial Hospital; associate professor of surgery and director of kidney and pancreas transplantation, Northwestern University Feinberg School of Medicine, Chicago, Ill.Suzanne T. Ildstad, MD, director, Institute for Cellular Therapeutics, professor of transplantation and surgery, University of Louisville, Louisville, Ky.Lindsay Porter, transplant recipient, mother and actress, Chicago, Ill.News release, Northwestern University.

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