Doctors at Massachusetts General Hospital in January reported that they had been able to wean four of five kidney transplant patients off anti-rejection drugs, a feat that could eventually lead to a sharp reduction in the use of immunosuppressant medications, according to the Los Angeles Times. By simultaneously giving recipients bone marrow from living donors, physicians were able to induce what is known as a state of tolerance, in which a recipient's immune system does not recognize the new organ as foreign.
The procedure was more remarkable in that the recipients were given kidneys that were not perfect tissue matches, making them more susceptible to rejection. "There ...