Hemopoietic stem cell transplantation
Transplantation of healthy bone marrow in place of damaged one is hemopoietic stem cell transplantation.
Healthy stem cells are transplanted which are capable of producing new blood cells, and helps to form new bone marrow.
First successful transplantation was done in New York- 1957 (Syngeneic transplant); in monozygotic twins, in complain of leukemia. First allogeneic transplant was done in Minnesota in 1968; in complain of combined immunodeficiency syndrome.
What is bone marrow?
It is spongy fatty tissue inside the bone. It produces; red blood cells, white blood cells, platelets and contains hemopoietic stem cells.
Indications:
- Aplastic anemia: Bone marrow stops production of new blood cells.
- Leukemia
- Chemotherapy: Responsible for bone marrow damage
- Sickle cell anemia, lymphoma, multiple myeloma
- Severe combined immune deficiency syndrome
- Solid tumors
Types:
|
Autologous transplant |
Allogeneic transplant |
Syngeneic transplant |
|
Person’s own stem cells. |
Donor’s stem cells are transplanted, considering that
donor is close genetic match. |
Donor and recipient are identical twins. |
|
In this procedure; stem cells of own body are harvested
before chemotherapy. |
There are high chances of Graft Versus Host Disease. |
There are almost nil chances of Graft Versus Host Disease
or graft failure. |
|
After treatment, cells are re-introduced. |
||
|
It thus, reduces severe complications. |
||
|
However, it is not possible in case of abnormal stem
cells. |
Preparation and technique:
Preparative regimen.
Hematopoietic stem cell collection.
Instant infusion or crayopreservative followed by infusion.
Technique:
Prior to procedure person has to undergo blood tests and physical examinations, as per suggested by one's physician.
For autologous transplant: Sample is collected from hip bone, under general anesthesia. These procedure may take from 1 to 2 hours.
Apheresis: collection of stem cells from blood. It is out patient procedure.The bone marrow is triggered through drug (filgrastim), to produce more stem cells. Then blood is collected through vein and stem cells are separated. It takes approximately 2 to 3 hours.
For allogeneic transplant: Donor's protein (HLA); is matched with receiver's HLA (Human Leukocyte Antigen) which runs in family.
If in case umbilical cord blood is preserved during the time of birth; it can be helpful for receiver.
Complications:
- Veno-occlusive disease
- Idiopathic pneumonia syndrome
- Graft rejection
- Graft Versus Host Disease (GVHD): It's the reaction between T-cells from donor in allogeneic transplant and recipient's HLA. It can be acute or chronic.
Acute develops within 3 months. Prophylaxis medications are given; such as calcineurin inhibitors, methotrexate and anti-thymocyte globulins.
Chronic: Develops after 3 months. Multiple organs are involved. Treatment is same as acute.
References:
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6560153/
2. https://www.webmd.com/cancer/multiple-myeloma/bone-marrow-transplants
3. https://www.healthline.com/health/bone-marrow-transplant
Ask your query. ConversionConversion EmoticonEmoticon