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Bone Marrow Donation
Bone Marrow Donation
Bone marrow is a blood-based substance that can be found inside the body's hollow bones. Marrow produces platelets, the red and white blood cells that form the basis of the body's immune system. Marrow for transplant is usually collected from the iliac crest, which is part of the pelvic bone.
A bone marrow transplant is the process of infusing healthy marrow into a person to replace diseased or damaged bone marrow. The original marrow is eradicated using high dose chemotherapy or radiation.
There are two different types of bone marrow transplants:
Allogeneic bone marrow transplant involves the infusion of bone marrow from one person to another. To be successful they should be as closely matched as possible and the most suitable donor is therefore usually a full brother or sister.
Autologous transplant is the removal, storage of, and reintroduction of the patientís own bone marrow.
Bone marrow transplants can be an option for patients suffering from certain types of leukaemia or aplastic anaemia, where the patientís own marrow stops producing blood cells. A transplant may also be necessary for children with rare metabolic disorders, which are usually genetically inherited.
A transplant from a donor is actually the only possible treatment for some ailments including Chronic Myeloid Leukaemia, and for inherited metabolic disorders, like Hurler's Syndrome.
The ideal bone marrow donor is a tissue matched brother or sister but due to falling family sizes throughout Europe and America, such fully matched transplants will not be an option for many.
Matched Unrelated Donor (MUD) transplants provide an alternative for such patients with no family donor and increasing numbers are being performed each year. Patients and donors are matched by their tissue types.
You can register as a volunteer bone marrow donor if you are a fit and healthy blood donor under the age of 45. Your coded tissue type will be held on the register until you reach the cut-off age of 55.
You can still help even if you are over the cut-off age for donating marrow. Patients with leukaemia and aplastic anaemia usually lack platelets, the blood cells essential for clotting. Some of these patients develop antibodies to platelets that do not match their tissue type and will need to have platelets that are matched to them. The Irish Blood Transfusion Service organises a platelets panel for donors to contribute matching platelets to leukaemia patients.
When an unrelated search for a patient begins, there may be a number of donors who match up with the patient. Some of these donors will be asked to attend for further tests to check their compatibility with the patient.
Around 40mls of blood will be taken from each potential donor. Some of this blood will be used to check the donorís bloodís healthiness and the rest will be used for tissue typing to evaluate how close a match they are with the patient. The potential donor who matches the patient the closest will be asked to donate their marrow.
Marrow extraction, sometimes referred to as 'harvesting' of the marrow, is performed in St James's Hospital, Dublin, which has considerable experience in this procedure. If you are selected as a donor and wish to proceed, the Medical Director of the Bone Marrow Registry and the Harvest Physician in St James's Hospital will give you full information on the procedure and the risks associated with it. You will also have a medical performed by an independent doctor.
If you are selected for further testing, you will have a number of weeks to decide about continuing. However, although all donations, including bone marrow, are voluntary, once the patient has started their treatment to destroy their own bone marrow (between two and ten days before the transplant) the process is irreversible. If the donor pulls out at this stage, it will most likely lead to the death of the patient.
Because of the amount of marrow needed, the donor needs to be given a general anaesthetic.
In the operating theatre a needle is used to remove marrow from a number of different bones. The harvesting of bone marrow usually lasts 1-2 hours. No surgical incision or stitches are involved but several puncture holes will be made in the skin and through the bone. Approximately one litre of marrow and blood will be extracted which represents about 5% of a person's total marrow. Ninety per cent of donors leave hospital 24 hours after the harvest.
Some donors will feel discomfort for a number of days after the procedure. It is recommended that you should take two weeks off work afterwards. The Blood Transfusion Service Board will make arrangements with your employer to ensure that you are not out of pocket.
As the process is anonymous the donor will not be given any identifying information about their recipient before transplant. Afterwards, the donor may send a card to the patient through the Bone Marrow Registry but they will not be allowed give any personal details or expectations of the outcome of the transplant. If the patient does not wish to reply the Registry will not usually forward any more cards from the donor. Current policy is to allow the donor and recipient to meet after two years if both have expressed a wish to do so. However, this may change in future as a number of Registries do not allow any contact between the donor and recipient.
Peripheral stem cell donation is an alternative method from donating bone marrow, which is sometimes used if the patient who is undergoing the transplant fails to engraft or if the patient counts do not recover sufficiently (this only happens in about 1 in 100 cases).
In this procedure, the donor is given a medication called G-CSF, which causes stem cells to be released from the bone marrow into the circulating blood. The stem cells can then be taken from your blood. At the moment, this is only sometimes given as an option if a second donation is needed. However, this situation could change in the near future, as the Bone Marrow Registry is actively looking at allowing stem cell donation using G-CSF for first donations.
The National Bone Marrow Registry is based at the National Blood Centre, the headquarters of the Irish Blood Transfusion Service. Their address is: James Street, Dublin 8. Tel: (01) 4322800; Fax: (01) 4322930; Email at email@example.com
Reviewed: September 28, 2006
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Last Reviewed: 28th September 2006
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