Results of clinical study presented at international transplant meeting
SAN FRANCISCO, April 24 -- Organ rejection occurs less often and is less severe in heart and lung transplant patients who receive infusions of bone marrow from the same donor, researchers from the University of Pittsburgh Medical Center (UPMC) reported today at the International Society for Heart and Lung Transplantation Annual Meeting.
"These results are particularly significant because hearts and lungs are usually more prone to rejection than other organs. Their cell composition contains fewer donor immune system cells that serve as natural defenses against an attack by the recipient's immune system; donor bone marrow seems to enhance the immune capabilities and reduce the likelihood of rejection," explained Kenneth McCurry, M.D., assistant professor of surgery, division of cardiothoracic surgery, at UPMC.
Controlling rejection is the key to successful organ transplantation. For the most part, surgeons rely on drugs that suppress the patient's immune response as their main line of defense against an immune system attack. But despite newer and better drugs, organ rejection can still occur, even years after transplantation.
The study included 31 heart and 26 lung transplant patients who received donor bone marrow within 72 hours of their transplant operations. The results were compared to 24 heart and 26 lung recipients who received organ transplants without bone marrow.
By giving donor bone marrow, the researchers' aim was to enhance the cellular environment called chimerism, defined as the coexistence of recipient and donor immune cells. Having already proved that chimerism is present in long-term survivors of kidney and liver organ transplants, some of whom have been weaned from a life-long regimen of immunosupressant drugs, researchers wanted to promote, even hasten this biological process with bone marrow.