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Allogeneic Bone Marrow Transplants
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.
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Debunking Common Misconceptions
By: Tejas Yerramilli - 07/27/2024
With the rapid progress of today’s digital world, the spread of misinformation, especially that of medical topics, has spread quickly across the internet. If a person sees a false fact or statistic online, they might talk about it with people in their lives, or even post about it themselves, thus spreading something untrue that could be harmful to someone’s health. In the case of blood diseases and the donation of stem cells, there are a few common misconceptions that can cause confusion and hesitation, therefore hindering the ability to save lives.
Understanding Blood Diseases
Leukemia, although likely the most well-known blood disease, is just one of many, and these diseases include types of severe anemia and cancer that usually hinder the body’s ability to make and distribute healthy blood cells.
- Myth: Blood diseases are ALWAYS fatal
- Fact: Although some blood diseases have high mortality rates, many can be treated with the aid of catching it early
- Myth: Only the elderly have/get blood diseases
- Fact: People of all ages can have blood diseases
Donating
The donation of stem cells by a donor who is a proven match with the patient is often life-saving, and can offer a potential cure to many suffering from a variety of different blood diseases.
- Myth: The donation of stem cells is extremely painful and can be dangerous for the donor
- Fact: Stem cell donations are safe and involve at most minimal discomfort for the donor
- Myth: ONLY family members can be possible donors for patients suffering from blood disease
- Fact: Although it is true that family members are often good matches for patients due to their similar genetic makeups (which is why donations from siblings, who share the most similar genetic makeup to the patient are common), completely unrelated donors from registries found across the country are also possible matches for patients in need
- Myth: Donating stem cells PERMANENTLY weakens your immune system
- Fact: Donating stem cells does not permanently weaken one’s immune system, although there might be some temporary side effects after donation, such as nausea or dizziness
- Myth: Stem cell donation requires the donor to stay at the hospital for a lengthy amount of time
- Fact: Stem cell donation is almost always an outpatient procedure, meaning the donor will usually go home the same day they donate
Ethnic Diversity in Donating
One of the most common misconceptions is that a donor’s ethnic background does not factor into the process of a patient finding a match. This is completely false. A person’s ethnic background is a large factor to consider when finding a potential match, which is why SAMI’s mission is so relevant. With South Asian donors only taking up 3% of the total registry, many patients in need of a donor are going without one.
- Myth: Recruitment efforts for donors do not need to consider ethnic diversity
- Fact: With the vast majority of the registry being comprised of Caucasian donors, targeted recruitment (like what is being done at SAMI) is extremely important in order to maximize the number of lives saved
- Myth: Different ethnic groups have the same genetic markers as others
- Fact: The matching process is based on different HLA types, and these vary drastically between ethnic groups, which is why it is so crucial to have as many donors as possible representing them
Wrap-up
In conclusion, misinformation is running rampant throughout the world, and its impact on the world of medicine has been devastating. People being uneducated about the importance of joining a registry for donating has forced an untold number of patients to go without potentially life-saving donors, especially in ethnic minorities. The number of people with blood diseases is not going down, and the need for donors from ethnic minorities has never been higher. If you are reading this and are not on a registry, please consider signing up. The number of South Asians around the world has recently surged to over 2 billion, and a 3% share in registries is simply nowhere close to enough to accommodate the number of people who are in need of donors.
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The Father of Stem Cell Transplantation
By: Tejas Yerramilli - 08/19/2024
Who started stem cell transplantation? Although the first person to perform a stem cell transplant was Georges Mathes in 1958, Dr. E. Donnall Thomas is considered to be the father of stem cell transplantation because of his revolutionary research in the field of stem cell transplantation (bone marrow transplants in particular). Stem cell transplantation is one of the most transformative and life-changing procedures in today’s world, and the man who pioneered them is just as incredible.
Thomas had always had a passion for medicine and the sciences in his childhood, and attended the University of Texas, Austin for his undergraduate schooling. After graduating, he moved on to Harvard Medical school where he earned his M.D.. Early on in his residency program at Peter Brent Brigham Hospital, Thomas developed a fascination for blood related diseases (leukemia in particular), something that would shape the entire trajectory of his career. By the time the 50’s rolled around, he had begun looking into bone marrow transplantation as a means of treating and curing these blood related diseases, something that was a completely new and revolutionary idea at the time.
Thomas was inspired by early experiments with mice. After exposing them to large amounts of radiation, researchers would experiment with using bone marrow in order to replenish and regenerate new red blood cells. It was through these experiments on mice that he knew bone marrow transplantation had a possibility of being feasible to perform on humans, and he thus began his research into the field, eventually performing new experiments of his own.
Thomas had made some serious progress in his research, and by 1955, he felt confident enough to attempt his first bone marrow transplant on a patient. Doris Buckner was suffering from leukemia, and the donor Thomas and his team used for the procedure was Buckner’s identical twin sister, which was considered an extremely good match. Tragically, however, Buckner’s body rejected the transplant, and she passed away a few months later, rendering the procedure unsuccessful.
After this, Thomas moved to the Mary Imogene Bassett Hospital in New York, where he worked tirelessly for the next few years on combating graft-versus-host disease, one of the most common complications of transplantation. In 1969, Thomas moved across the country to Seattle in order to join the now renowned Fred Hutchinson Cancer Research Center, where he arguably did his most significant and well remembered work.
Almost 20 years after the tragedy of Doris Buckner, Thomas and his team were able to conduct some of the first successful bone marrow transplants in the early part of the 70s, cementing Thomas’ legacy as one of the most influential and significant medical minds of our time.
Wrap-up
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As a result of his groundbreaking research, Thomas was awarded the Nobel Prize in 1990, an award he won alongside the man who pioneered kidney transplantation, Dr. Joseph Murray. After winning the prize in 1990, Thomas chose to retire, but still remained close to the scientific community and remained a non-active member of the Fred Hutchinson Cancer Research Center. In his retirement, Thomas was renowned for his life’s work, and continued to mentor young scientists until his passing in 2012. Dr. E. Donnall Thomas was one of the most brilliant and innovative minds of the modern age, and has without a doubt earned the title of “The Father of Stem Cell Transplantation”.​
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