A bone marrow transplant delivers healthy bone marrow stem cells into the patient. It replaces bone marrow that is either not working properly or has been destroyed (ablated) by chemotherapy or radiation.
Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells. The stem cells can develop into the red blood cells that carry oxygen through your body, the white blood cells that fight infections, and the platelets help with blood clotting.
If there is a problem with your bone marrow, a transplant can give you healthy new marrow. You could need a transplant because of a disease, such as bone marrow diseases or cancers like leukemia or lymphoma. Or you might need one if a strong cancer treatment kills your healthy blood cells.
People with cancer sometimes donate bone marrow before treatment to be transplanted later. But often the new marrow comes from a donor, either a close family member or someone unrelated.
What Is The Basic Process?
The first step is the collection of the bone marrow or stem cells (the harvest) from the donor. We now know that the umbilical cord blood is also a rich source of stem cells.
The second step is to completely destroy the existing bone marrow and thereby help the patient receive the new stem cells.
The third step is to infuse the bone marrow or the stem cells through the intravenous route, like a blood transfusion. There may be no signs of a new bone marrow growing for two to three weeks, and occasionally it may be a few months before the new bone marrow produces all the components of the blood adequately.
What is bone marrow, bone marrow transplantation and why it is done ?
Bone marrow is the spongy tissue that fills bone cavities and is responsible for producing blood elements like white blood cells, red blood cells and platelets. During the treatment of cancer, leukemia, lymphoma, a high doses of chemotherapy and radiotherapy damages bone marrow and body fall short of blood cells. In such cases, damaged bone marrow is replaced by new one either from donor, whose HL-A (human compatibility antigens) are similar to that of patient-the process termed as allogenic bone marrow transplant or from patient itself –the process called autologous bone marrow transplant.
TYPES of Bone Marrow Transplantation
Autologous and Allogeneic Transplants
Two important requirements for a bone marrow transplant are the donor and the recipient. Sometimes, the donor and the recipient may be the same person. This type of transplant is called an autologous transplant. It is typically used in cases in which a person’s bone marrow is generally healthy but will be destroyed due to medical treatment for diseases such as breast cancer and Hodgkin’s disease. Most bone marrow transplants are autologous. If a person’s bone marrow is unsuitable for an autologous transplant, the bone marrow must be derived from another person in an allogeneic transplant.
Allogeneic transplants are more complicated because of proteins called human lymphocyte antigens (HLA) that are on the surface of bone marrow cells. If the donor and the recipient have very dissimilar antigens, the recipient’s immune system regards the donor’s bone marrow cells as invaders and launches a destructive attack against them. Such an attack negates any benefits offered by the transplant.
All bone marrow transplants have risks. The risk is higher or lower depending on many factors. Some of these factors are:
- What disease you have ?
- What type of treatment (chemotherapy, radiation) you have before the bone marrow transplant?
- How old you are?
- How healthy you are when you have your transplant?
- How good a match your donor is?
- What type of bone marrow transplant patient you are having (autologous, allogeneic, or umbilical cord blood)?
- Chest pain
- Drop in blood pressure
- Shortness of breath
- Funny taste in the mouth