Scientists hope to enlist cells in rejection fight
For transplant patients, the side effects of anti-rejection drugs can be daunting. They include wide-ranging mood swings, diabetes, high blood pressure, high cholesterol and brittle bones. So scientists on the hunt for alternatives are hoping the body's own cells may someday help decrease the need for medications.
"It's called cell-based therapy. ... It's like a 'cell drug,' " said Dr. V.K. Gadi, a cancer specialist and researcher at the Fred Hutchinson Cancer Research Center.
One approach involves T regulatory cells, a type of immune cell that calms the body's initial response to a foreign invader — the transplanted organ — to bring the system back in balance. Scientists envision multiplying the transplant recipient's T regulatory cells in the lab and then injecting them back into the body before the transplant to prevent defense cells from rejecting the organ.
"The T regulatory cells say, 'Whoa, don't kill everything in sight!' " Gadi said.
Gadi is experimenting with dog cells in the lab, and other researchers are exploring the method in the transplantation of pancreatic islet cells for the treatment of type 1 diabetes.
Another technique under study is the injection of certain stem cells from the organ donor into the organ recipient. That would help the organ recipient's immune system be more accepting of the new organ. The method already is used in some bone-marrow transplants.
A third technique would blunt inflammation, the initial immune reaction to a donor organ, by preventing a biochemical that stimulates immune cells from reaching the cells.
All of the methods raise the risk of infection in the patient, Gadi said. But that's also a side effect of current anti-rejection drugs.
Widespread use of the techniques is probably years away, he said.
