Organ transplants usually require transplant patients to take anti-rejection drugs that suppress the immune system of the patients. Transplant patients must take these drugs for the rest of their lives to prevent the patient’s immune system from attacking and damaging the transplanted organ. These anti-rejection drugs, however, have serious side effects. These drugs can prevent the immune system from fighting infections, and this means that viruses can attack the pancreas, thus leading to diabetes, and tumors can pop up without being restricted by the immune system. Anti-rejection drugs include such drugs as glucocorticoids, cyclophosphamide (very potent), folic acid analogues like methotrexate, purine analogues like azathioprine, and mercaptopurine, cyclosporin, tacrolimus, and sirolimus, and a cytotoxic antibiotic like dactinomycin.
In order to decrease the need for immunosuppressive drugs, a new technique is being developed that adds adult stem cells plus an initial anti-rejection drug treatment seems to allow the immune systems of kidney transplant patients to accept their transplanted organ without the need for lifelong drug therapy.
The procedure goes something like this: First the patient receives the new kidney, followed by a targeted dose of radiation to weaken their immune system and make some room for new immune cells. Next comes a bone marrow transplant from the same donor who donated the kidney. These bone marrow stem cells mix with the patient’s cells and the transplant patient now has an immune system that is a mosaic of their own original immune system and that of the donor’s. This new immune system views the transplanted kidney as a “perfect match.” Thus far, 8 out of 12 patients who have received the new kidney plus the additional bone marrow transplant are progressing without any need for anti-rejection drugs. Adult bone marrow stem cells provide the life-saving support needed for organ transplants.