.png)
By: Tejas Yerramilli - 07/21/2024
Because bone marrow transplants are surgical procedures, most donors who match with patients prefer to donate STEM cells instead, as this is equally as effective with a far less intrusive procedure. That being said, the following report will give an insight into what a bone marrow transplant actually is, and what potential donors will go through in the donation process as well.
Introduction
Bone marrow transplants procedures (a BMT for short) are procedures used in order to replace damaged or diseased bone marrow with new, healthy stem cells. Some diseases that would require a BMT would be leukemia, lymphoma, and anemia in some severe cases just to name a few. A BMT can be a life-saving procedure for the patient in question, and helps the body produce healthy stem cells, which can lead to a cure or long-term remission for patients.
What is an allogeneic bone marrow transplant?
An allogeneic bone marrow transplant is a procedure in which bone marrow is harvested from a donor who is a match for the patient and introduced to the patient's body in order to combat certain diseases that impair the body’s ability to produce healthy stem cells. In order for a donor to be considered, they must have a HLA (human leukocyte antigen) match with the patient. HLAs are protein sets that are found on cells in the body, and they are responsible for distinguishing between foreign cells and ones that are native to one’s own body. This type of transplant differs from autologous bone marrow transplants by way of allogeneic transplants consisting of harvesting from a donor, while in autologous transplants, the cells harvested come directly from the patients themselves.
Different types of donors
There are several different types of donors that can be used in the context of an allogeneic BMT. These include:
- Sibling donors
Sibling donors that have a HLA match with the patient are considered to be one of if not the best type of donors, because the exactness of the match makes it so that there are less complications and a higher average success rate than with other donor types.
- Matched unrelated donors
A matched unrelated donor is one that is found through registries that has a HLA match with the patient. This is where organizations like SAMI come in, as there are not enough South Asian donors listed on registries, causing many patients to go without finding a match.
- Partial match for family members
Almost all patients with family members willing to donate have one that is above a 50% HLA match, and these family members can be considered as possible donors as well. This does come with some risks however, as because of the lower HLA match, the possibility of Graft-Versus-Host disease (in which the cells from the donor attack the patient's cells) is increased as well.
Brief overview of procedure
1. Evaluation
The patient in question undergoes several tests in order to determine whether or not they would be suitable candidates to receive a BMT.
2. Conditioning
The patient goes through radiation and chemotherapy. The purpose of this is to attempt to get rid of the diseased cells and put a tamper on the immune system in order to get the body ready to receive new, healthy cells.
3. Harvesting
The two major ways to harvest stem cells from a donor include extracting cells from the pelvic bone of the donor under general anesthesia, as well as peripheral blood stem cell collection. In the former, the donor is put under anesthesia in order to minimize discomfort, and marrow is extracted straight from the bone. In the latter however, the donor is given growth factors so that there is an excess of stem cells in the bloodstream. On the day of the collection, blood is drawn and filtered from the stem cells in order to harvest.
4. Transplantation
When the day of the transplant arrives, the harvested stem cells from the matched donor are injected into the patient’s bloodstream. From this point, the cells travel to the bone marrow and (barring any complications) start to produce healthy blood cells.
Care during post-transplant period
After the transplant, the engrafting process begins to take place. Engrafting is when the donated stem cells begin producing blood cells for the patient's body, and this usually takes anywhere from a few days to weeks. After this, the patient must come in for regular check-ups in order for their physicians to assess their current state and see whether or not diseases like Graft-Versus-Host disease have set in. In addition, because of the patient's compromised immune system, they must be extremely careful not to contract illnesses during this period, as it could take months, or even years for their immune system to fully recover.
Wrap-up
In conclusion, allogeneic bone marrow transplants can be life saving procedures that offer a potential for a brighter future for patients suffering from extreme blood disorders or blood cancer. Every year, thousands of lives are saved by way of allogeneic BMTs, and with your help, we can make it thousands more. By getting swabbed and joining a registry and having the possibility of being matched with a patient, you could help in the fight against blood cancer and disorders. With new advancements coming in this field every day, we must hope for a better future for those patients suffering from these illnesses, and continue to offer our support as well.
Resources:
Comments