SGH scores another first in stem cell transplants
Singapore General Hospital, in collaboration with the National University Hospital, has chalked up another world-class achievement in stem cell therapy. Doctors in the team treating a 5 year old boy with Thalassaemia Major have successfully performed the first case of cord blood transplant from an unrelated donor.
This is the first known case in the world of such a transplant conducted successfully for a patient with Thalassaemia Major. It marks yet another significant milestone in the development of leading edge stem cell therapy conducted at SGH. In 1995, SGH successfully performed the world's first recorded case of peripheral blood stem cell transplant from an unrelated donor for a patient with Thalassaemia Major. In that case, the stem cells were extracted through the blood instead of the conventional method of extraction from the bone marrow, making the ground breaking transplant the first of its kind in the world. Today, the patient is a healthy 10 year old boy attending primary school.
A lifeline for child with Thalassaemia Major
This current medical breakthrough involves a 5 year old Malaysian Chinese boy, born with Thalassaemia Major, a hereditary blood disorder where the body is unable to produce enough haemoglobin leaving the patient persistently and severely anaemic, requiring frequent and regular blood transfusions. Frequent blood transfusions often leave sufferers of Thalassaemia Major at risk of infections like hepatitis and possible iron overloading resulting in multiple organ failure. There is also a general immune suppressive effect. The majority of patients die of heart failure and do not have a life expectancy beyond 15 to 20 years. In this particular case, there were no matched sibling donors for either a bone marrow transplant or a cord blood transplant. When the boy was first referred to Associate Professor Patrick Tan, Head of the SGH Department of Haematology, a search with the Singapore Bone Marrow Donor Programme found no matched donor then. A/Prof Tan reviewed the case again this year, for consideration for a cord blood transplant and a new search was activated. Fortunately, a good cord blood sample was found and the cord blood transplant took place on 3 July 2001, at the National University Hospital, where the patient is being co-managed by the Department of Paediatrics.
Success factor - good sample of cord blood
One of the success factors attributed to the transplant was the availablity of a good sample of cord blood. The cord blood was collected from a Chinese baby delivered in SGH in 1998. The exceedingly high cell dose in the sample and the fact that it fully matched in the direction of rejection ensures a high chance of engraftment - a critical issue in all transplants for Thalassaemia Major. The cord blood sample contains 60-million cell dose per kilogram. Cell dose refers to the number of cells per kilogram of the patient's body weight and is a critical factor in predicting the patient's survival. The success of the cord blood transplant depends directly on the dose of stem cells received in the transplant - the larger the cell dose, the better the outcome. In this case, the cell dose contained in the sample is four times higher than the international recommended cell dose of 15-million cell dose per kilogram for cord blood transplant, which means that it has excellent potential for a successful transplant.
All signs pointing to complete recovery
Since the transplantation, the patient has not required any red cell transfusions. Preliminary blood studies show that he no longer has Thalassaemia Major and the
stem cells are functioning properly within his marrow by producing various kinds of blood cells. He is now producing normal red cell corpuscles unlike those seen in Thalassaemia Major, which are small and pale. The patient was discharged on 8 August, 36 days after the transplant. However he will still require to be monitored at the specialist clinic twice a week for 100 days.
Cord blood transplantation is a viable option
With the results indicating that the patient has been cured of Thalassaemia Major, cord blood transplantation from an unrelated donor has now been proven to be a valid alternative to bone marrow transplant from a sibling. This breakthrough achievement not only sets a milestone in the medical history of Singapore, it also highlights the successful outcome that arose from the close collaboration and teamwork between the SingHealth and the National Healthcare Group, the two healthcare clusters to which SGH and NUH belong to.
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