Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. When bone marrow transplant occurs, this spongy healthy tissue is used to replace unhealthy blood-forming cells.
The important thing to remember about bone marrow is that it contains stem cells, which are immature cells. These immature 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.
Bone marrow transplant is required if there is a problem with the bone marrow, if it is diseased with cancers like leukemia or lymphoma. You might need a transplant if a strong cancer treatment kills your healthy blood cells.
Bone marrow is usually collected from the hip bone (or pelvic bone) or less commonly from the breast bone (or sternum). The procedure is done under anaesthesia. Needles are inserted into the bone and marrow is withdrawn. The procedure takes about an hour. This process is called ‘harvesting’.
To prepare for the transplant, you may be given strong chemotherapy and/or radiation therapy. This treatment kills your unhealthy cells. Then healthy blood-forming cells are given to you in your vein. This is like a blood transfusion. The transplanted cells begin to grow and make the red blood cells, white blood cells and platelets your body needs. It typically takes three to four weeks for the cells to mature.
The cells used in transplants can come from three sources: bone marrow (as described earlier), peripheral (circulating) blood or blood collected from an umbilical cord after a baby is born. Umbilical cord blood is rich in blood-forming cells. The donated cord blood is tested, frozen and stored at a cord blood bank for future use. Your transplant doctor will choose the source of cells that is best for you.
You can use your own blood-forming cells or cells collected from someone else. This choice depends on your disease and other health factors. Your transplant doctor decides what kind of donor to use. In autologous transplant your own cells are used. The cells are collected from your bloodstream (or, less often, from your marrow) and stored for your transplant.
A transplant using cells from a family member, unrelated donor or cord blood unit is called an allogeneic transplant. A transplant using cells from an identical twin is called a syngeneic transplant. If your transplant donor is other than yourself then the tissue type has to match. So your best chance of finding a match is with a brother or sister. However, 70 per cent of patients do not have a suitable donor in their family.
If there is no donor in the family then you need to find a donor who can match your tissue type. For this your doctor goes to Be The Match Registry , operated by the National Marrow Donor Program (NMDP), which provides access to more than 12 million volunteer donors on the global donor listing. This includes more than 7 million volunteer donors and nearly 90,000 cord blood units.
Unfortunately, not everyone finds a suitable match. In that case your doctor will look at other treatment options. These options might include using a partly matched family member (haploidentical donor).
The procedure is associated some risk of complications like infection, bleeding, pain and others. How well you do after transplant depends on many factors such as: what type of bone marrow transplant you had, how well your donor’s cells match yours, your age and overall health and many other factors. If the transplant works, you can go back to most of your normal activities.
If you want to be a donor then visit National Marrow Donor Program (www.marrow.org).
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