US News reports on a new study, March 21th involving novel technique that uses a kidney transplant recipient's own stem cells and it suggests that this may someday replace or reduce the initial use of anti-rejection medications.
Six months after a kidney transplant, only around 8% of people given their own mesenchymal stem cells faced organ rejection compared with 22% of people on standard anti-rejection drugs.
"Mesenchymal stem cells are stem cells that can be differentiated into a variety of cells," explained author of the study Dr Camillo Ricordi, of the University of Miami Miller School of Medicine. "If you infuse mesenchymal stem cells at the time of the transplant, you could replace the use of powerful anti-rejection drugs, and maybe replace immunosuppressants altogether," he said.
One of the biggest remaining hurdles in organ transplantation remains the need for powerful anti-rejection and immune-suppressing medications after the transplant.
"Basically, the way we prevent kidney rejections is by putting you on very powerful anti-rejection drugs and immunosuppressive agents to prevent your cells from attacking the foreign organ," said Dr. Robert Provenzano, chair of the department of nephrology, hypertension and transplantation at St. John Providence Health System in Detroit. "But, the current standard has some problems, like an increased risk of infections and the possibility of creating a cancer."
The body's immune system sends out surveillance cells to protect the body against foreign invaders, such as a bacteria, virus or, in this case, a new organ, Provenzano said. The current method of preventing these cells from attacking the new organ is essentially to destroy the surveillance cells. But mesenchymal cells can naturally suppress those surveillance cells so they don't attack, he said.
To see if this suppression would be enough to prevent rejection, Ricordi and his colleagues, including researchers from Xiamen University in China, recruited 159 people with serious kidney disease who were on dialysis. They ranged in age from 18 to 61.
The study participants all had medically well-matched relatives willing to donate a kidney for transplant.
Each was randomly assigned to receive one of three treatments after transplant. One group got standard treatment with anti-rejection medication (induction therapy) and immune-suppressing medication known as calcineurin inhibitors (CNIs). Another group was infused with their own stem cells and the standard dose of CNIs, while the final group received stem cells plus a lower dose of CNIs (80 percent of the standard dose).
Survival rates for the patients and their new kidney were similar for all three groups at 13 to 30 months, the study found.
Results of the study appeared in the Journal of the American Medical Association. The technique could be used in the transplantation of islet cells (in the pancreas) for people with type 1 diabetes, and for other organ transplants, such as the liver.
