Autologous vs. Allogeneic

There are two types of stem cell transplants: autologous and allogeneic.

When a person receives stem cells that have come from their own blood, it is referred to as an autologous transplant. For some diseases, an autologous transplant is the preferred method. A benefit of an autologous transplant is that the body is able to recognize the stem cells and therefore does not attack them or reject them (graft-versus-host disease or GVHD). Additionally, the difficulty of locating a donor can be avoided.

An allogeneic transplant is when the stem cells come from someone other than the person who requires them. For some diseases, like leukemia, an allogeneic transplant is the preferred method. While there is an increased risk of a person�s body rejecting the donor stem cells, by closely matching a patient�s HLA with the transplanted stem cells, adverse effects can be minimized. However, a person who receives an allogeneic transplant will require heavy medication in order to avoid GVHD.

It has been found that where the stem cells come from can make a difference in the likelihood of helping a disease. While in some cases patients seem to respond better to transplants of stem cells that have come from a donor, for other illnesses patients respond best when the transplanted stem cells have come from themselves. Depending on the form of disease that needs to be treated, along with the degree of severity, and the transplant recipients� age, one form of transplant may be favored over the other.

Disorder	Autologous Stem Cell Transplant	Allogeneic Stem Cell Transplant
Leukemia : acute lymphocytic, acute myelogenus, chronic myelocytic	variable results	effective
Non-Hodgkins lymphoma	variable results	effective
Sarcomas : liposarcoma and yolk sac sarcoma	studies still investigating	studies still investigating
Neuroblastoma	variable results although it is the preferred method	variable results
Blood disorders	studies still investigating	effective
Immunodeficiency	variable results	effective
Metabolic Disorders	studies still investigating	studies still investigating