Over the years, there have been a lot of controversies bordering on the use of stem cells for treatment of medical disorders. At the heart of the controversies is where the cells should come from and who it should come from (Nisbet, 2003). Despite these controversies, advancements in health and medicine have led to the use of certain stem cells for the treatment of health disorders. The two kinds of stem cells mostly used are the allogenic and autologous stem cells. Both cells are very distinct.
Autologous stem cells are harvested from the recipient and also used on the same person. This implies that your own stem cells are transplanted from one region of your body and also used on another region of the same body. Conversely, autologous cells are transplanted from another person entirely and then used on a different person (the donor and the recipient respectively) (Shustov, 2013).
Autologous and allogenic stem cells are defined based on their origin. Hence, each kind of cell has different major sources. Allogenic cells are derived from a donor. Excellent sources of allogenic cells include the umbilical cord and the placenta. Of course cells from these sources can best be used on infants and young children. Allogenic stem cells suitable for adults are gotten from the bone marrow of the donor (Gratwohl 2009).
Autologous stem cells are derived from the blood of the patient himself. The blood is drawn and the cells harvested before treatment. The stem cells can also be harvested from the bone marrow. (The Leukemia & Lymphoma Society 2015). The ethics surrounding the use of stem cells for treatment is not debatable. This is because the harvesting of the cells does not cause harm to the donor. This is quite different from the use of embryonic stem cells. Use of stem cells from the embryo results in the death of the embryo. An informed consent from both the recipient and the donor perfects the use of the stem cells (Kitzinger & Williams 2005).
Autologous stem cells are find applications in the treatment of myelomas and leukemia. Allogenic stem cells also find application in the treatment of lymphomas, myelomas and leukemia (American Cancer Society 2016). Both allogenic band autologous stem cell therapy are used to treat similar cancer cases hence the need to determine which will give a favorable prognosis. Stem cell therapy is mostly used for the treatment of cancer. Multiple myeloma is a classic example of cancer that can be treated with stem cell therapy.
There are certain procedures that must be followed when one is giving or receiving stem cells. For the recipient, room must be made in the bone marrow prior to transplantation of the cells. This can be done through radiation or chemotherapy. This is done a week or two before the transplant. A central venous catheter will be inserted into the patient before infusion of the stem cells. The procedure is not a painful one and the patient may remain awake during the procedure (American Cancer Society 2016). Process of donation is a little more invasive and requires surgery. Understanding how this process works is very important because it allows the assessment of the effectiveness of the stem cells once the patient receives them. Knowing about the procedure is also important because it will help in the identification of the potential risks which may arise before, during and after the treatment.
Stem cells are effective for the treatment of cancer. Allogenic and autologous are different in nature and thus are used in different therapies. In some cases, the treatment may overlap. Both therapies (allogenic and autologous) have certain benefits and limitations, hence there is need to compare both.
COMPARING ALLOGENIC AND AUTOLOGOUS TREATMENTS
Allogenic and autologous have their own outstanding benefits as to why one should be preferred to the other. We will start with the autologous. One benefit of the autologous treatment is that your own stem cells will return to you. This might be obvious but one important fact is that because these cells were drawn from your body, the chances of a rejection or autoimmune reactions are drastically reduced (The Leukemia & Lymphoma Society 2015).
Another advantage of an autologous treatment is that your risk of getting an infection from the potential donor is drastically reduced (American Cancer Society 2016). An extensive screening process is employed when getting the cells from donors but there is still that slight chance of you getting the infection from the donor. Reducing such risks would appeal greatly to the patient who obviously doesn’t want to get sick from something that should make them better.
Allogenic treatment does have its own advantages. One main advantage for the allogenic treatment would be the graft versus cancer effect. What is the graft versus cancer effect? This occurs when donor stem cells uses their own immune system to destroy cancer cells in the body of the recipient. The immune cells from the donor may be stronger than the immune system of the recipient and thus, will attempt to fight the cancer cells in the recipient (Shustov 2013). Stem cells from the donor are tested prior to transplantation. Of course they must be free from infections and cancer before they can be transplanted.
Donations for stem cell transplants may be direct. This implies that your family member may donate to you if his or her stem cell matches yours. Cornelissen et al. (2008) did a study on patients suffering from acute lymphoblastic leukemia. He compared the free survival rates of the disease between related and unrelated donors. Results from the related donor group were better than that from the nonrelated donors. This supports the notion that allogenic treatment can have positive effects but is also dependent on the specificity of the donor. Chances of survival are higher when the donor is closely related to the recipient. This is due to the fact that the rate of cell rejection is lower as the donor’s cells are similar to that of the recipient. This implies that patients with sibling donors for allogenic transplants have a high survival rate.
Both stem cells also have limitations just as they have immense benefits.
What are the limitations of the autologous stem cells?
A study was conducted by Björkstrand et. al. (2011) on Myeloma patients. The goal was to examine the effects of autologous stem cell transplants. One group had only an autologous stem cell transplant while the other group had both an autologous and subsequently an analogous stem cell transplant. The group that got both treatments had a better prognosis than the group that had just one (autologous) treatment. This study showed that a combination of autologous and allogenic treatment had a long-term efficiency than just the autologous treatment.
Allogenic treatment also has its own limitations. The main issue with this kind of treatment is that the cell, tissue, or organ that is transplanted could be rejected by the body of the recipient. This is poses a serious problem to patients whose main hope of recovery is the transplant. Also, it may result in a waste of funds if it does not work in the end. Also, there is the risk that the recipient could develop an invasive fungal infection. The major cause of such infection is a shortage in red blood cell count combined with the medications administered after getting an allogenic therapy (Neofytos et al. 2009). Some drugs can effectively treat this infection, but if left unnoticed, may be very fatal.
There are some minor limitations that may result from allogenic stem cell transplants. One of these is the chance of getting an infection from the donor (American Cancer Society 2016). However, the risk now is lesser because a comprehensive screening process is carried out prior to the therapy. Another limitation is the risk of the patient having a recurrence of a previous infection due to an alteration of the immune system (American cancer Society 2016). The body is faced with the task of adapting to a change in the immune system of the body which could cause a malfunctioning of the immune system.
We have established that there are unique differences between the allogenic and autologous stem cells. The main differences include their origin, the disease they are used to treat, and their capability of fighting off the disease. The biggest risk of the allogenic therapy is the rejection of stem cells from a donor. Of course this can be improved by getting the right matches of the stem cells, or by minimizing the chances of a rejection with medications.
Autologous transplant is beneficial in that there are lesser chances of rejection.
Björkstrand B, Iacobelli S, Hegenbart U, et al. (2011). Tandem Autologous/Reduced-Intensity Conditioning Allogeneic Stem-Cell Transplantation versus Autologous Transplantation in Myeloma: Long-Term Follow-Up. Journal of Clinical Oncology. 29(22): 3016-3022.
Cornelissen JJ, van der Holt B, Verhoef GE, van’t Veer MB, van Oers MH, Schouten HC, et al. (2008). Myeloablative allogeneic versus autologous stem cell transplantation in adult patients with acute lymphoblastic leukemia in first remission: a prospective sibling donor versus no-donor comparison. Blood. 113(6):1375-1382.
Gratwohl A, Stern M, Brand R, Apperley J, Bladomero H, Witte T, Dini G, Rocha V, Passweg J, et al. (2009). Risk score for outcome after allogeneic hematopoietic stem cell transplantation. Cancer. 115(20): 4715-4726.
Kitzinger J, Williams C. (2005). Forecasting science futures: Legitimizing hope and calming fears in the embryo stem cell debate. Social Science &Medicine. 6(3): 731-740.
Neofytos D, Horn D, Anaissie E, Steinbach W, Olyaei A, Fishman A, Pfaller M, Chang C, Webster K, Marr K. (2009). Epidemiology and Outcome of Invasive Fungal Infection in Adult Hematopoietic Stem Cell Transplant Recipients: Analysis of Multicenter Prospective Antifungal Therapy (PATH) Alliance Registry. Infectious Disease Society of America. 40(3):265-273.
Nisbet M.C, Brossard D, Kroepsch A. (2003). Framing Science: The Stem Cell Controversy in an Age of Press/Politics. The International Journal of Press/Politics 8(2):36-72.
Shustov A. (2013). Controversies in autologous and allogeneic hematopoietic cell transplantation in peripheral T/NK-cell lymphomas. Best Practice & Research Clinical Haematology. 26(1); 8999.
Stem Cell Transplantation. (2015). The Leukemia & Lymphoma Society. Available from: https://www.lls.org/treatment/types-of-treatment/stem-cell-transplantation.
Types of Stem Cell Transplants for Cancer Treatment. (2016) May 11. American Cancer Society. Available from: https://www.cancer.org/treatment/treatments-and-side-effects/treatmenttypes/stem-cell-transplant/types-of-transplants.html