A bone marrow transplant is a procedure to replace damaged or destroyed bone marrow with healthy bone marrow stem cells.
Bone marrow is the soft, fatty tissue inside your bones. The bone marrow produces blood cells. Stem cells are immature cells in the bone marrow that give rise to all of your different blood cells.
Most cells in the body have already evolved in unique ways to suit their organs by the time a person is born. But bone marrow cells do not evolve in any way, meaning that even an adult’s bone marrow may contain primitive cells that had been present in him as an embryo. This is unique to the bone marrow.
Further, these cells retain the ability to divide and become various specialised cells. This means that these bone marrow cells can evolve into any cell type present in the body, leading them to be named ‘Pluripotent Stem Cells’.
Though a person’s cells have already finished their development by the time they are born, blood cells are constantly being produced and destroyed. The main function of the bone marrow cells is to constantly produce new blood cells.
Production of the most important blood cells such as Red Blood Cells which carry oxygen around the body, White Blood Cells which protect the body against foreign substances, Platelets which aid the clotting of blood, are done by the ‘Stem Cells’ in the bone marrow.
The requirement of a bone marrow transplant surgery
Your doctor may recommend a bone marrow transplant if you have:
- Certain cancers, such as leukemia, lymphoma, myelodysplasia, and multiple myeloma
- A disease that affects the production of bone marrow cells, such as aplastic anemia, congenital neutropenia, severe immunodeficiency syndromes, sickle cell anemia, and thalassemia
- Had chemotherapy that destroyed your bone marrow
There are 3 kinds of bone marrow transplants
- Autologous bone marrow transplant The term auto means self. Stem cells are removed from you before you receive high-dose chemotherapy or radiation treatment. The stem cells are stored in a freezer. After high-dose chemotherapy or radiation treatments, your stems cells are put back in your body to make normal blood cells. This is called a rescue transplant.
- Allogeneic bone marrow transplant The term allo means other. Stem cells are removed from another person, called a donor. Most times, the donor's genes must at least partly match your genes. Special tests are done to see if a donor is a good match for you. A brother or sister is most likely to be a good match. Sometimes parents, children, and other relatives are good matches. Donors who are not related to you, yet still match, may be found through national bone marrow registries.
- Umbilical cord blood transplant This is a type of allogeneic transplant. Stem cells are removed from a newborn baby's umbilical cord right after birth. The stem cells are frozen and stored until they are needed for a transplant. Umbilical cord blood cells are very immature so there is less of a need for perfect matching. Due to the smaller number of stem cells, blood counts take much longer to recover.
