Can bone marrow transplant help in thalassaemia?
Q: My nephew is suffering from thalassaemia major. He is 8 years of age and regularly undergoes blood transfusion. He does not have a sibling. I would like to know what is the success rate of bone marrow transplant, which is the best institute for it in India, is it harmful for the donor and other related information on this topic. I would request you to provide information on support groups for thalassaemics in India?
A:Beta thalassaemia syndromes are a group of hereditary disorders characterised by a genetic defect in the synthesis of beta-globin chains of haemoglobin. There are 2 beta genes and in beta thalassaemia, one or both genes may be affected by a mutation. This causes impaired synthesis of the beta globin chain, which is a constituent of normal haemoglobin and thus anaemia results. If both genes are affected (homozygous state), beta thalassaemia major results in which there is severe transfusion-dependent anaemia while if only one gene is affected (heterozygous state), there is beta thalassaemia trait (also called thalassaemia minor or carrier state) causing mild-to-moderate anaemia. The first successful bone marrow transplantation (BMT) for beta thalassaemia major was performed in the early 1980s in Seattle, U.S. Thus began the use of BMT as a potential cure for nonfatal but severely disabling illnesses. Around the same time, Doctor Guido Lucarelli in Pesaro, Italy attempted a similar bone marrow transplant. His team has done pioneering work and is perhaps the most successful group in the world offering bone marrow transplantation for the cure of beta thalassaemia major. They have devised a staging system to predict the outcome of transplantation in children up to age 16 years and adults who are candidates for this procedure. The Lucarelli Staging System is based on the amount of liver damage sustained as a consequence of iron overload from chronic transfusion therapy and the adequacy of Desferal chelation therapy. The 3 important factors are - absence of liver enlargement, absence of portal fibrosis on liver biopsy and no iron overload. Generally speaking, the younger the recipient, the more optimistic the outcome. Dr. Mammen Chandi at Christian Medical Collage, Vellore, successfully did the first BMT in thalassaemia in India. The cost of BMT in India is around Rs.4-5 lakhs and this is being done at Christian Medical Collage, Vellore, Tata Memorial Hospital, Mumbai, and Institute Rotary Cancer Hospital (IRCH), All India Institute of Medical Sciences, New Delhi. BMT in thalassaemia aims to: destroy and prevent regeneration of defective stem cells (cells giving rise to all blood cells); suppress the immunity of the recipient to allow for engraftment of donor normal marrow cells by giving immunosuppressive drugs or irradiation; and infuse donor stem cells which have a normal beta globin gene. The biggest obstacle is finding a donor for transplantation. Since beta thalassaemia major is no longer considered a fatal disease, criteria for donation differs from the criteria for BMT for a patient with a fatal disease such as cancer. Usually a patient suffering from cancer is given very toxic chemotherapy to kill the cancer cells and then is rescued from the chemotherapy with a bone marrow transplant. In the case of thalassaemia, the goal of the chemotherapy is to remove most or all of the blood forming cells (stem cells) from the recipient and replace them with donor stem cells in order to repopulate the bone marrow space and make new, normal blood cells. In a cancer patient, the best (genotypic) match is used for the transplant. In a beta thalassaemia major patient, the match must be the perfect (HLA-identical) match. The closest perfect match is usually a sibling who has the same antigenic makeup (is HLA identical to the recipient) as the individual who has thalassaemia. There is only a one in four chance a sibling will have the required immunologic criteria for a bone marrow donation. There are many children who have thalassaemia who have no siblings or no siblings who are HLA-identical for donation. The 3 types of donors thus can be: a) Identical twin donors, b) Matched related donors & c) Matched unrelated donors.