Acute vascular rejection (AVR) remains a serious complication of heart transplantation. When the immune suppressant cyclosporin A is administered to recipients in the C3H-to-BALB/c heterotopic cardiac transplant model, however, survival of the grafts has been extended to as long as 15 days, which is nearly twice as long as graft survival time in untreated patients. Now, Canadian researchers have demonstrated a method for preventing AVR altogether.
Led by Dr. Hao Wang of the London Health Sciences Centre in Ontario, Canada, the scientists used a bone graft from a third-party donor, in addition to cyclosporin A, for immune modulation of the antibody-mediated AVR. The results indicated indefinite allograft survival, for more than 100 days, without any signs of AVR.
The stem cells from the bone marrow were found to stimulate the generation of T regulatory cells as well as dendritic cells, which also resulted in radioresistance. By contrast, bone marrow mononuclear cells did not improve survival.
As the authors conclude, "Due to the fact that current immunosuppressive approaches are clinically ineffective at preventing AVR, this study provides promise for further investigations of BM (bone marrow) components as a means of addressing a currently unmet medical need."
Two of the authors of this study were also involved in a previous study published in April of this year in which adult stem cells derived from adipose (fat) tissue were found to exhibit immune modulation in three patients with multiple sclerosis.
While adult stem cells are most widely known for their ability to regenerate damaged tissue, their immunomodulatory properties also hold great therapeutic promise for a number of currently untreatable conditions.
(Please see the related news article on this website, entitled, "Adult Stem Cells From Fat Help Multiple Sclerosis Patients", dated April 24, 2009, as originally reported in the Journal of Translational Medicine).