Autologous versus Allogeneic Transplants

There are two types of stem cell transplants: autologous and allogeneic. Each of these stem cell procedures has its own distinct process. Moreover, autologous stem cell transplants and allogenic stem cell transplants are each associated with distinct benefits and risks which should be taken into account when deciding which of these stem cell treatments a patient should undergo.

What is an Autologous Stem Cell Transplant?

An autologous stem cell transplant is one in which the patient receives stem cells from his own blood. This type of stem cell treatment is preferred in certain cases, and is usually used in the treatment of solid tumors, including lymphoma, sarcoma, brain tumors and neuroblastoma. It is also generally used in cases when surgery is performed on the blood vessels, urinary tract and heart.

One advantage of this stem cell treatment procedure is that in an autologous stem cell transplant, the body recognizes the cells and therefore does not reject or attack them, an occurrence known as Graft-versus-Host Disease (GVHD)

In addition, autologous transplants have the added advantage of avoiding the sometimes difficult process of finding a donor for stem cell treatment.

What is an Allogeneic Stem Cell Transplant?

An allogeneic stem cell transplant is a procedure in which a patient receives stem cells from a donor. Allogeneic transplants are preferred in certain cases, such as in the treatment of leukemia.

The donor used in an allogeneic stem cell transplant can be the patient's identical twin, sibling, family member or an unrelated donor.

One limitation of allogeneic stem cell treatment is that this procedure carries the risk of developing GVHD, whereby the patient's body rejects the donor stem cells. Human leukocyte antigens (HLA) matching can help minimize this risk; in this procedure, the HLA of the patient and donor are matched as closely as possible.

HLA are found on the surface of all types of cells in the body and help to identify an object that is foreign to the body, in which case the immune system is alerted in order to fight the perceived threat. In addition, allogeneic stem cell transplant require the use of strong medication in order to prevent this risk of GVHD.

Should I Undergo an Autologous or Allogenic Stem Cell Transplant?

Your health care provider will determine which form of stem cell transplant is best for your condition. The criteria used to make this decision is based primarily on what disease the patient has. This is because patients with certain diseases respond better to stem cells from a donor, while in other cases, patients with other types of diseases respond best when the stem cells are derived from their own body.

Disorder	Autologous	Allogeneic
Blood disorders	Studies still pending	Effective
Immunodeficiency	Results variable	Effective
Leukemia; acute lymphocytic; acute myelogenus; chronic myeloctyic	Results variable	Effective
Metabollic disorders	Studies still pending	Studies still pending
Neuroblastoma	Preferred method despite variable results	Results variable
Non-Hodgkins lymphoma	Results variable	Effective
Sarcomas; liposarcoma and yolk sac sarcoma	Studies still pending	Studies still pending

Other important criteria used when deciding whether a patient should undergo an autologous or allogeneic stem cell transplant include the severity of the disease, as well as the patient's age.