What happens during a bone marrow transplant?
DEAR DOCTOR :
I have leukemia. Thankfully, a family member was a bone marrow match. Can you tell me what to expect during my bone marrow transplant procedure?
A bone marrow transplant can be a life-saving treatment. To understand how it works, you need to understand how blood cells are created. And what leukemia is.
Your blood contains red and white blood cells. There are several types of white blood cells, which are a key part of your immune system. All your blood cells are made by blood stem cells, which live primarily in the spongy center of your big bones.
In the years before you got leukemia, each of your blood cells was programmed to live for a while, and then to die — only to be replaced by new, young cells.
When you developed leukemia, genetic changes in some white blood cells suddenly kept them from dying. As a result, the number of that type of white blood cell kept growing. An ideal treatment would kill just the cancerous white blood cells, and allow noncancerous new cells to replace them. The ideal treatment has not been discovered. Bone marrow transplant, while less than ideal, is such an important advance that it was honored with the Nobel Prize.
In a bone marrow transplant, all of your white blood cells — healthy and cancerous — are killed by drugs, radiation or both. Then healthy blood stem cells are infused into your blood. Those cells find their way to your bone marrow, and start to make healthy new red and white blood cells. The new cells will multiply. I’ve put an illustration of the transplant process below.
The healthy blood stem cells may be collected from your blood, before the main radiation or chemotherapy begins. The cells are treated to remove any cancer cells, and then stored until the transplant. In your case, the healthy blood stem cells will come from another person (a donor). The donor’s cells must be a good “match” for you — this means certain markers on their cells and your cells are as similar as possible. This reduces the risk that the cells will be rejected by your body.
Bone marrow transplants are usually used to treat leukemia, lymphomas, Hodgkin’s disease and multiple myeloma, because these cancers affect the bone marrow directly. The procedure is also used for some noncancerous conditions, such as sickle cell anemia.
You will stay in the hospital for several weeks after the transplant. Until your bone marrow cells multiply to a certain level, you will be at increased risk of infection. Other serious risks include severe bleeding, liver problems and increased risk of developing another cancer.
Another possible problem is that cells from a donor might not match your cells well enough and the new donor cells will begin attacking the cells of your body. This is called graft-versus-host disease. You will take medications to reduce the risk of this happening. Despite the dangers, bone marrow transplantation is usually successful. more