Doctors at Massachusetts General Hospital have enrolled the first of 15 planned patients in the ITN's expanded clinical trial of mixed chimerism, a technique designed to replace the need for long-term immunosuppression in kidney transplantation. The patient, who suffered from end-stage renal failure caused by Alport's Syndrome, received bone marrow and a kidney from the same living donor on January 27, 2009. Both donor and recipient are currently doing well. The current study is an expanded, follow-up study to a previous ITN-sponsored trial where 4 of 5 subjects were able to stop immunosuppression for up to 5 years, as reported in the New England Journal of Medicine in January 2008.
The technique differs from typical kidney transplant procedures in that bone marrow from the same donor is transplanted at the same time. As a result, the recipient’s immune system is a mixture of cells from their own immune system and their donor’s. As shown at the right, the cells of each person's immune system that are primed to attack "foreign cells", will essentially attack each other, cancelling each other out as they mature in the thymus. What is left is a mixture of mature donor and recipient immune cells that are not programmed to react to each other - or the newly transplanted kidney. Ideally, this will alleviate the need for anti-rejection medicines.
The new study will be taking place at 3 clinical centers in the US: the Penn Transplant Institute at the University of Pennsylvania, Philadelphia; New York-Presbyterian Hospital, New York and Massachusetts General Hospital in Boston. The clinical trial is open to individuals with a suitable living donor who are awaiting their first or second transplant. Individuals who may be interested in participating in the study should contact study coordinators at (617) 726-2631 or refer to the trial’s listing on clinicaltrials.gov .