What is Allogeneic Bone Marrow Transplant?
Allogeneic bone marrow transplant (BMT) is a complex medical procedure used to treat a variety of hematologic disorders, including leukemia, lymphoma, aplastic anemia, and certain genetic conditions. The process involves replacing a patient’s damaged or diseased bone marrow with healthy bone marrow from a genetically similar donor. Bone marrow is a spongy tissue found in the center of bones where blood cells are produced. Allogeneic BMT involves using stem cells from a donor’s bone marrow or blood to repopulate the recipient’s bone marrow. This procedure is designed to restore the recipient’s ability to produce healthy blood cells and to treat diseases where the bone marrow is either damaged or malfunctioning.
Indications for Allogeneic BMT
Allogeneic BMT is considered for a range of conditions, including:
- Hematologic Malignancies: Leukemias (e.g., acute myeloid leukemia, acute lymphoblastic leukemia), lymphomas (e.g., Hodgkin’s lymphoma, non-Hodgkin’s lymphoma).
- Non-Malignant Hematological Disorders: Aplastic anemia, sickle cell disease, thalassemia.
- Genetic Disorders: Certain inherited metabolic disorders and immune deficiencies.
Types of Donors
- Related Donor: Typically a sibling or other family member who has a compatible human leukocyte antigen (HLA) profile.
- Unrelated Donor: An individual who is not related but has a matching HLA profile, often found through registries.
- Umbilical Cord Blood: Stem cells collected from the umbilical cord and placenta of a newborn, which can be used if a suitable donor is not available.
Pre-Transplant Preparation
- Pre-Transplant Evaluation: Comprehensive assessments including physical exams, blood tests, imaging studies, and HLA typing to ensure the patient is suitable for the transplant and to identify the most appropriate donor.
- Conditioning Regimen: A preparatory treatment regimen involving high-dose chemotherapy and/or radiation therapy to eradicate the patient’s existing bone marrow and suppress their immune system to prevent rejection of the new marrow.
Transplantation
- Harvesting: The donor’s bone marrow or peripheral blood stem cells are collected. Peripheral blood stem cell collection is less invasive and is done using a procedure called apheresis.
- Infusion: The harvested stem cells are infused into the recipient’s bloodstream through a central venous catheter. This is typically done in a sterile environment to minimize the risk of infection.
Post-Transplant Care
- Engraftment: The process by which the transplanted stem cells begin to grow and produce new blood cells. This can take several weeks and requires close monitoring.
- Supportive Care: Includes managing side effects, such as infections, anemia, and bleeding, and providing medications to prevent rejection and graft-versus-host disease (GVHD).
Complications
Graft-Versus-Host Disease (GVHD)
GVHD occurs when the donor’s immune cells attack the recipient’s tissues. It can be acute or chronic and affects various organs, including the skin, liver, and gastrointestinal tract. Management involves immunosuppressive medications.
Infections
Due to the immunosuppressive nature of the conditioning regimen and post-transplant medications, patients are highly susceptible to infections. Prophylactic antibiotics, antifungals, and antivirals are commonly used.
Organ Toxicity
Chemothe*rapy and radiation can cause damage to organs such as the lungs, liver, and kidneys. Regular monitoring and supportive treatments are required to manage these potential complications.
Relapse
In some cases, the underlying disease may return after the transplant. This requires additional treatments, including possibly another transplant or targeted the*rapies.
Recovery & care after Allogenic Bone Marrow Transplant
You’ll be asked to stay back in the hospital for a few days to monitor your recovery during which the medical team will help you out with the required medicine doses and diet chart. However, once you are released, the care and recovery are completely dependant on the patient. Please keep these pointers in mind:
Maintain a strict diet. Ask your doctor or medical team for a dietary chart and abide by it strictly to improve your recovery rate.
- Ask your doctor about vaccinations necessary to help you improve your immune system.
- Always take your medicine doses on time and don’t make any changes in your everyday medical routine unless advised otherwise by the doctor.
- Avoid weight gain at all cost.
- Avoid strenuous physical activities but make sure you exercise to keep yourself from unwanted weight gain.
FAQs
What is the usual hospital stay for an allogenic transplant?
Hospital stays depend on the patient’s recovery rate. However, a minimum 2-4 week is given to monitor the condition and patients might be asked to stay back or visit for routine follow-ups to consistently monitor their recovery.
What is the success rate for allogenic transplant?
Usually, allogenic transplant success rates heavily depend on how close a match the donor is. With the right donor, the success rates can be as high as 60-80%
What are the chances of my family members being my donors?
Almost 7 out of 10 cases noted that family members weren’t a close match. The match works only 1 out of 4 times for brothers or sisters. This is why the bone marrow registry is also consulted and 1 out of 430 matches are selected to be the perfect match
Will donating bone marrow affect me in any way?
Usually, only 4-6% of the donor’s bone marrow is extracted and the bone marrow regenerates itself within 4-6 weeks. Donating bone marrow will not affect donors permanently.
Are there any symptoms or risks to donating bone marrow?
Risks are rare and affect only 1% of bone marrow donors seriously. However, donors may feel certain side effects in terms of headache, muscle pain, nausea, or common flu symptoms. However, if any symptoms persist for more than a week, contact the medical team immediately.
What happens if my transplant fails?
Even though it’s rare, a failed transplant is possible. However, in that case, doctors usually recommend a second transplant.
What happens if my cancer comes back?
The sole purpose of the medical procedure is to kill or prolong the diseased cells affecting you. Even though the success rate is high, some patients have experienced a relapse. However, this is rare and in such cases a second transplant is advised by the doctors.