Allogeneic Bone Marrow Transplantation
An allogeneic bone marrow transplant uses bone marrow cells from another person (donor). The donor could be a family member (usually a sibling) or be unrelated. Bone marrow cells from unrelated donors come through programs such as the National Marrow Donor Program or one of the Umbilical Cord Blood banks recently established around the country.
There are three benefits of allogeneic bone marrow transplantation. The first is similar to that with autologous bone marrow transplantation: the ability to administer very high doses of chemotherapy and radiotherapy to hit the cancer the hardest. The second benefit is the possibility of a "graft versus tumor effect." (Physicians refer to transplanted organs or bone marrow as grafts.) When an allogeneic transplant is performed successfully, the recipient in effect receives a new immune system (from the donor's cells). The new immune system can then attack the cancer in the recipient. This effect is particularly powerful in leukemias, and its importance in NHL is being actively studied. A serious side effect of an allogeneic transplant may occur if this new immune system reacts against your normal cells in what is called "graft-versus-host disease." However, when this occurs along with a graft-versus-tumor effect, the benefit to you may outweigh any unwanted side effects.
A third benefit of this type of bone marrow transplant is of particular importance in diseases in which there may be cancer cells in your bone marrow (which can happen with NHL) because with allogeneic transplantation you receive "new" healthy bone marrow.