Questions about Bone-Marrow Transplantation
Why can transplanting bone marrow help?
A thalassemic's bone marrow is not able to make a normal amount of red blood cells. If the malfunctioning bone marrow can be replaced with the normal bone marrow, that problem is solved.
Who can give bone marrow for a thalassemic?
It is necessary to have a "fully compatible donor" with tissues that match the thalassemic patient exactly, so that the thalassemic's body will not reject them. You can find out if someone is a fully commpatible donor or not, by special blood tests. The most likely donors are a brother or a sister of the thalassemic patient. On average, one in four of a thalassemic's brothers or sisters is suitable donor. Parents and unrelated people are very rarely a close enough match.
Is it dangerous for the donor to give bone marrow?
Marrow is taken out of a bone that contains a lot of it, like the hip-bone, by sucking it up a needle into a syringe. This does no harm, but it could be painful, so the donor is given a general anesthetic. The risk of bone marrow transplantation is the same as the risk of a general anesthetic, that is, it is very small.
How is a bone-marrow transplant done in practise?
To transplant bone-marrow, the first step is to make space in the thalassemic child's bones, for the new bone marrow. to do this, the patient is treated with drugs (called cyclophosphamide and busulphan) to kill the thalassemic patient's own bone-marrow. The drugs are given by month, and can make the patient feel quite ill. Suppressing the bone marrow takes about n days.
Once space has been made, marrow is taken from the donor, and "transplanted" into the recipient. This is done by putting it into a blood bag and running it into a vein, just like a blood transfusion.
Is bone-marrow transplantation dangerous
Yes, it is. As we said, the patient has to be "prepared" by getting rid of their own bone-marrow. As white blood cells and platelets are also made in the marrow, they are got rid of too.
But the white blood cells are an important part of our defence against infections, so if a patient who has been prepared for bone-marrow transplantation catches an infection. They can die from it. When the new marrow has become settled, it makes new white blood cells as well as normal red blood cells, so the danger of infection fades away.
Sometimes the patient's body reacts against the transplanted marrow and kills it. When this happens the graft fails, and the patient continues to need regular blood transufions.
Sometimes the new marrow can react against the patients body. This can lead to graft-versus-host disease, which is usually relatively mild, but sometimes is very severe.
Is it possible to measure the risks, and the results, of bone-marrow transplantation?
Yes. Firstly, it is important to realise that the risk of bone-marrow transplantation is different in different countries, and also changes with time, as we become more experienced.
Here we give the results obtained by Professor Lucarelli, at Pesaro in Italy, who has done more marrow transplants for thalassemia that anyone else. One in ten (10 %) of the patients die as a result of the "preparation". In another 10 %, the patient's body rejects the donated marrow, and their thalassemia comes back, or else the transplanted marrow tries to reject the patient is able to stop blood transfusions. These are results for children under 7 years old. Now Professor Lucarelly is transplanting older patients, up to about 13 years old. Their results are not quite so good.
How can you decide whether to have a bone-marrow transplant or not?
Firstly, it is necessary to have a fully compatible donor. So the thalassemic patient must have at least one healthy brother or sister. Blood tests will show whether they match the patient fully. If the patient has no brothers or sisters, at present there is really no possibility of a bone-marrow transplant.
Secondly, the thalassemic patient must be less than 13 years old, and preferable less than 7 years old. Transplantation fails more often, and is more risky, in older patients.
Thirdly you need to have considered the points for and against a transplant very carefully, in discussion with your own doctor, and also with the transplant specialist. Bone-Marrow transplantation is a gamble, and both parents and patient need to consider all the possibilities before making up their minds.
Fourthly, bone-marrow transplantation is expensive. If it is available on the Health Service in your country, of course this need not be a problem, Otherwise, obviously, it must be paid for. A transplant in Pakistan (Zia-ud-Din Hospital, Karachi *Not Successful*) or India (Apollo Hospital, Chennai) costs the equivalent of $13,000 (9 Lakh Pk Rupees) to $14,000 (10 Lakh Pk Rupees)1. A transplant in any other country costs may vary.
1As of April 1999, The Dollar Was Worth approximately 65 Pakistani Rupees