The key difference between autologous and allogeneic stem cell transplant is that, in autologous stem cell transplant, one’s own cells are used in transplantation, while in allogeneic stem cell transplant, a donor is matched prior to transplantation and then administered.
Stem cell transplantation is a technique mainly used in the treatment of cancer. In stem cell transplantation, the stem cells with suitable advanced characteristics are administered so that they develop into immunological cells capable of destroying cancer cells. Its other function is to protect the non-malignant cells in the body. Autologous and allogeneic stem cell transplant are two types of stem cell transplantation techniques. Autologous stem cell transplant utilizes one’s own stem cells for the transplant, while allogeneic stem cell transplant utilizes stem cells of a matched donor.
CONTENTS
1. Overview and Key Difference
2. What is Autologous Stem Cell Transplant
3. What is Allogeneic Stem Cell Transplant
4. Similarities Between Autologous and Allogeneic Stem Cell Transplant
5. Side by Side Comparison – Autologous vs Allogeneic Stem Cell Transplant in Tabular Form
6. Summary
What is Autologous Stem Cell Transplant?
Autologous stem cell transplant is the process where one’s own cells are removed and replaced back during stem cell therapy. It is important to note that this form of therapy is very important in cancer treatment. Cancer treatment involves chemotherapy and radiotherapy, which damage the normal cells as well. Autologous stem cell transplant revolves around the concept of harvesting stem cells from the bone marrow prior to cancer therapies. Following cancer therapy, the stem cells are re-introduced into the same person.
The main advantage of this method is the usage of one’s own cells in the stem cell transplant. Therefore, there can be minimized adverse immunological responses following transplant. Moreover, the grafting failure rate is very less in autologous stem cell transplant. The new cells arising after the stem cell transplant will mimic the host.
Autologous stem cell transplant takes place during conditions such as leukemia, lymphoma, and multiple myeloma. However, immunological disorders such as Systemic lupus erythematosus also use autologous stem cell transplant during its treatment.
Figure 01: Stem Cell Transplant
The main disadvantage of this method is that the cells collected before the treatment can have cancer cells along with the normal cells. Upon transplanting, the cancer cells may still possess the ability to proliferate as cancer cells evade the immune system. Therefore, the purpose of the stem cell transplant is lost.
However, in certain types of autologous stem cell transplantation, the cells are treated prior to administration. But this may destroy the ability of the cells to proliferate fast and take more time to adapt as a normal cell. Sometimes, some other types of autologous stem cell transplants are followed by the administration of anti-cancer drugs. This will reduce the risk of developing cancer post autologous stem cell transplantation.
Tandem transplants are also a type of autologous stem cell transplant. A tandem transplant is when two autologous transplantations take place in a row.
What is Allogeneic Stem Cell Transplant?
Allogeneic stem cell transplant is the transplant that involves donors that are capable of donating stem cells for transplant. Therefore, it is a non-self method of stem cell transplant. It the most common method of stem cell transplant. Prior to the transplant, the donor and recipients tissue types should possess a very close match. Usually, the preferred choice of the donor is a close relative of the recipient. However, there can also be matched, unrelated donors.
Figure 02: Allogeneic Stem Cell Transplant
The main advantage of allogeneic stem cell transplant is the fact that new donor cells have the ability to make their own immune cells. These immune cells will boost the killing of cancer cells rather than using a harmful method of high dose cancer therapy. The donor cells are always cancer-free; therefore, the risk of recipient developing cancer is minimized. Moreover, the donor can also donate white blood cells upon requirement.
However, the main disadvantage of allogeneic stem cell transplant is the immunological havoc it might create within the recipient’s system. The immunological responses of the new stem cells may also act on normal cells and cause more host diseases. This can give rise to an immune-suppressed condition in the host. Moreover, the new stem cells from the donor might not be able to adapt to the new environment; thus, there is a greater risk of destruction of the donor stem cells. Allogeneic stem cell transplant is also widely used in the treatment of lymphoma, multiple myeloma and leukemia.
What are the Similarities Between Autologous and AllogeneicStem Cell Transplant?
- Both types of stem cell transplants are used as cancer therapy for leukemia, lymphoma and multiple myeloma.
- These therapies act as a safer alternative to chemotherapy and radiation therapy.
- Both types involve the intravenous administration of stem cells.
- Stem cells can develop into cells with immunological property.
- Both are personalized treatment methods; therefore, the specificity is high in both methods.
What is the Difference Between Autologous and Allogeneic Stem Cell Transplant?
The key difference between autologous and allogeneic stem cell transplant relies on the type of stem cells used in the transplant process. In autologous stem cell transplant, one’s own cells are used in the transplant. But, in allogeneic stem cell transplant, a matched donor is used to donate the stem cells. Due to this difference, the response of the host may alter, and the risk of developing cancer also varies.
The immunological response does not vary much in autologous stem cell transplant while it varies widely in allogeneic stem cell transplant. Moreover, the chance of developing cancer again is high in autologous stem cell transplant compared to allogeneic stem cell transplant. So, it is also a major difference between autologous and allogeneic stem cell transplant.
The below info-graphic summarizes the difference between autologous and allogeneic stem cell transplant.
Summary – Autologous vs Allogeneic Stem Cell Transplant
Autologous and Allogeneic stem cell transplants are used in the treatment of cancer. Autologous stem cell transplant extracts the stem cells from the same person and reintroduces them during the transplant. In contrast, Allogeneic stem cell transplant utilizes the stem cells of a matched donor that can either be a relative or a non -relative who can donate cancer-free healthy stem cells to a recipient. Due to this difference between autologous and Allogeneic stem cell transplant, the manner in which they act inside the host also differs. The immunological responses also differ in the two types of transplantation.
Reference:
1. Champlin, Richard. “Selection of Autologous or Allogeneic Transplantation.” Holland-Frei Cancer Medicine. 6th Edition., U.S. National Library of Medicine, 1 Jan. 1970, Available here.
Image Courtesy:
1. “Stem cell transplant” By Tareq Salahuddin (CC BY 2.0) via Flickr
2. “Bone Marrow Transplant” By Mugwump12 – Own work (CC BY-SA 3.0) via Commons Wikimedia