Graft-versus-host Disease (GVHD)
Graft-versus-host disease (GVHD) arises from an immune response in patients who have received donated tissues (i.e. a graft or blood stem cell transplant) that is not identical to their own. In such cases, the patient’s body undergoes a natural response, which is to defend against the intruding tissue by attacking it. GVHD can develop very quickly or slowly and in either case, the symptoms can be numerous and severe. The best way to prevent GVHD is to match the transplanted cells or tissues as closely as possible to the host patient.
Health Canada has given conditional approval for the use of Prochymal, a mesenchymal stem cell product for the treatment of steroid-resistant and/or immunosuppressant-resistant acute GVHD in pediatric patients. Final approval is conditional on the results of clinical studies currently underway. In the meantime, researchers are looking at umbilical cord stem cells (a source of blood and mesenchymal stem cells) as a promising transplant option and are continuing to study both the still-unknown properties of mesenchymal stem cells as well as methods to improve the yield of stem cells in cord blood units to ensure sufficient numbers of cells are available for transplant.