A new transplant technique has enabled five kidney recipients to survive for several years without taking drugs that suppress their immune systems, scientists reported today.
Doctors produced the result by injecting transplant recipients with blood stem cells taken from their donors' bone marrow. The stem cells multiplied and protected the transplanted organ from an immune system attack.
Normally, recipients must follow a lifelong regimen of immunosuppressant drugs for their transplanted organs to survive. Those drugs greatly increase the risk of infections, cancer, high blood pressure and other serious medical problems.
Transplant experts expressed excitement over the findings, reported today in The New England Journal of Medicine, while calling them "very preliminary." The results need to be replicated in larger numbers of patients over a longer time, they cautioned.
In addition, the new findings don't mean patients who have already received transplants can stop taking their drugs. Only new patients who receive organs from living donors are eligible for the still-experimental therapies.
But the reports provide evidence that immune tolerance to transplants can be achieved in humans, as it has in animals.
Dr. Suzanne Ildstad, director of the institute for cellular therapeutics at the University of Louisville Health Sciences Center, said she thinks it will be possible within a few years to eliminate immune-suppressing drugs for many transplant patients.
In one of the new studies, scientists at Harvard Medical School and Massachusetts General Hospital reported that four people who received kidneys from living donors are alive and well after forgoing the usual medications for two to five years.
In the other study, Stanford University scientists have discontinued immune-suppressing therapy for more than two years in a middle-aged man who received a kidney from a brother.
Judith Graham writes for the Chicago Tribune.