Bone marrow transplantation involves the replacement of the dead cells in the bone marrow with live bone marrow cells, either from the same or from another individual.

What are the reasons for a bone marrow transplantation?

The many different types of cells in the blood are all produced in the bone marrow, a spongy substance in the centre of most bones. 'Stem cells' develop in the bone marrow and mature to produce the different cells of the blood. If a person's bone marrow is destroyed (as a result of cancer, for example) and the cells within it die, no new red or white blood cells can be produced.

What happens during bone marrow transplantation?

Different types of preparations from the marrow can be used; in the past, whole bone marrow was used, but it is becoming more common (as scientific advances are made) to select the 'stem cells' and use them in a 'stem-cell transfer'.

First of all, bone marrow cells must be harvested. This is performed under general or spinal anaesthetic and some marrow is removed from your own or a donor's hip bone using a syringe and needle. The marrow is often stored and may be treated with special hormones and the stem cells may be purified.

What happens before bone marrow transplantation?

The preparations for this procedure are often lengthy if the bone marrow cells come from a donor other than yourself. A correct 'match' has to be made with a special blood type (or tissue type known as 'HLA') between yourself and the donor. The HLA type of the donor has to be as similar to yours as possible. For this reason, close relatives are often the donors of choice in bone marrow transplantation.

What are the possible common complications?

The period of time between the bone marrow transplant itself and the point when the transplanted bone marrow cells actually 'take' and begin to grow is relatively unpredictable, but roughly between two to three weeks. During this time your body effectively has no immune system and you are at increased risk from infection.

Another possible complication of receiving bone marrow cells from a donor is called 'graft-versus-host disease'. This occurs when the white blood cells of the donor attack the tissues of your body. This is becoming much rarer now that HLA matching (tissue typing) is more accurate.

What happens after bone marrow transplantation?

Once it appears that the procedure has been successful and you are no longer at increased risk of infection you will be allowed to leave the hospital. The specialist team who looks after you will keep a very close eye on you through regular outpatient appointments. You will be told specifically what problems to look out for, such as fever.

What is the outcome of bone marrow transplantation?

The success of bone marrow transplantation depends very much on the reason that it was done, the method used and the age of the patient (the younger, the better). As many of the methods employed are still very new and advances are being made all the time, this type of treatment looks ever more promising. With some leukaemias, bone marrow transplant offers the best chance of a cure.