The first study, by researchers at Stanford University, details the case of a man who received a kidney from his brother. Researchers altered the man's immune system using antibodies and irradiation and then infused his brother's blood cells into his marrow.
It was found that these cells acted as a mediator between the body's immune system and the organ preventing rejection of the latter. The patient in question has now completed two full years without any immuno-suppressive drugs.
In the second study researchers at Massachusetts General Hospital tested a new technique on five patients. First they partially destroyed the bone marrow in these patients and then injected blood and marrow cells from the donor.
Four out of five patients were able to tolerate the subsequent kidney transplant and were weaned off from immuno-suppressive drugs within 9 to 14 months.
"While we need to study this approach in a larger group of patients before it is ready for broad clinical use, this is the first time that tolerance to a series of mismatched transplants has been intentionally and successfully induced," said lead researcher Dr. David Sachs.
