Overview of Bone Marrow Transplantation

Overview of Bone Marrow Transplantation Bone marrow transplants is recognized as a very effective treatment for certain types of cancer or diseases like leukemia, aplastic anemia, immune deficiency disorders, lymphoma multiple myeloma or some solid tumors like breast or ovarian cancer Bone marrow transplant is a medical procedure that transfuses marrow from one person to another or to the same person . Bone Marrow is the sort sponge-like material found inside human and most animal bones. It has many blood vessels and special fibers that hold blood-forming cells and fat together. The main function of bone marrow is to make three blood cells types: red blood cells, white blood cells or platelets. Red blood cells carry oxygen to other cells. White blood cells fight infection. Platelets help blood to clot. In people with leukemia, aplastic anemia or some immune deficiency diseases the stem cells in the bone marrow malfunction making an excessive number of defective immature blood cells (leukemia) , low blood cell counts(aplastic anemia) or the malfunction cells will attack the body rather than protecting it (autoimmune diseases). The immature or defective blood cells will interfere with production of normal blood cells and will invade other tissues by going through the bloodstream. Bone marrow transplants are usually used after initial treatment fails or the disease or cancer returns. Patients must receive large doses of chemotherapy and radiation to eliminate abnormal stem cells, also to disable the immune system and destroy the bone marrow. This is called conditioning. A large dose of chemotherapy and radiation will leaves the patients without the ability to form new stem cells and without an immune system making the patents more open to infection but a bone marrow transplant must be performed to replace the damaged or diseased bone marrow with healthy ones. Older patients or patients with additional health problems will receive small doses. It is designed to weaken but not destroy bone marrow. The transplant does not provide 100% assurance that the disease or cancer will not come back but the transplant can increase the likelihood of a cure or prolong the period of disease-free survival for many patients. If the patient received high doses of chemotherapy and radiation treatment, engraftment will make the body resume producing of stem and blood cells and immune system will develop again from the transplanted cells, and the patients that receive low doses, engraftment means a new immune system will develop alongside the remaining but weak immune system. Before conditioning a small flexible tube call a catheter or central venous line will be inserted into a large vein in the chest just above the heart. The catheter is there to administer drugs, blood products to the patient painlessly and withdraw many blood samples that are required during the course of the treatment. There are different types of bone marrow transplants. Autologous transplant; transplanted cells came from the body of the patients, allogeneic transplant; transplanted cells that come from a donor who may or may not be related syngeneic transplants; transplanted cells that come from an identical twin sibling (also a type of allogeneic) The type and severity of the disease determine if a patient should have a bone marrow transplant. A patient can be their own bone marrow donor (autologous) only if the disease is in remission or if the condition being treated does not involves the bone marrow like breast or ovarian cancer. The bone marrow will be taking from the patient before the transplant and any lingering abnormal cells will be removed. In an allogeneic transplant the patient doctor will look for a donor that matches the patients HLA tissue (human leukocyte antigen). HLA is a marker that the immune system uses to recognize which cells belongs there and which cells dont. HLA tissues types are inherited so the best chance of finding a match is with a sibling. Before the patient undergoes a bone marrow transplant he or she must be healthy enough to go through with procedure. General physical condition, age, the stage of the disease, and the diagnosis are considered by the doctor when determining whether or not the patient should undergo a transplant. Then there are many more tests that will be taking to ensure that the patient is in physically fit for the transplant. Whether the donor or the patient provides the marrow used in the transplant the procedure used to collect the bone marrow (bone marrow harvest) is the same. Bone marrow harvesting is done in the hospital operating room. It is done under general anesthesia and it involves little risk and little discomfort. When the donor is under anesthesia the bone marrow will be collected from the hip bone. The bone marrow is thick and is a red liquid. This is a one to two hour outpatient surgical procedure. There will be several skin and bone punctures on each hip, this is required to get the right amount of bone marrow. The donors marrow is completely replenished within a few weeks. After the patient bone marrow is destroyed by chemotherapy and radiation treatments the transplant will now take place. Health marrow is infused into the blood stream though the catheter in the same way any blood product is given. It is not a surgical procedure. If the procedure is successful the transplanted cells will grow and develops in the bone marrow cavities. This process is called engraftment. While the patients is waiting for the transplanted bone marrow to migrate to the cavities of the large bones and start making new blood cells the patient is very susceptible to infection and bleeding. This is the most critical time. Blood transfusions and many antibiotics will be given to the patient to help fight and prevent infection.