Blood and Marrow Transplant
The Blood and Marrow Transplant (BMT) unit at Sydney Children’s Hospital, Randwick (SCH) is one of the oldest and largest paediatric transplant programs in the Southern Hemisphere. Since 1975, more than 1,000 patients have undergone transplants for treatment of a wide variety of malignant and non-malignant diseases. SCH is a leader in the area of umbilical cord blood transplant, having performed the first transplant of this type in the Southern Hemisphere and more than any other institution in Australia.
Rationale for BMT
BMTs can be used to treat, and potentially cure, malignant and non-malignant diseases of the bone marrow, immune deficiencies and metabolic disorders.
- Malignant Diseases: ALL, AML, Neuroblastoma, NHL
- Non-Malignant Bone Marrow Diseases: Severe Aplastic Anaemia, Fanconi Anaemia, Thalassemia, Haemophagocytosis
- Metabolic Disease: Adrenoleukodystrophy, Metachromatic leukodystrophy, Hurler’s syndrome
- Immunodeficiencies: Wiskott Aldrich Syndrome, Severe Combined Immunodeficiency, Chronic Granulomatous Disease
Types of Transplants
Allogenenic : Blood stem cells are used from a donor, either related or unrelated.
Autologous: Blood stem cells are collected from the patient and reinfused at a specific time in the treatment.
Aim of a transplant
- Malignant disease – High dose chemotherapy with or without total body irradiation is given over a period of 5 – 10 days to destroy residual disease. This destroys the child’s own bone marrow in the process. Donor bone marrow is given to “rescue” the child.
- Non-Malignant disease (haematological, immune, metabolic) – The diseased or malfunctioning bone marrow is destroyed and replaced by healthy donor bone marrow.
Sources of Donor Blood and Marrow
Bone marrow blood stem cells are harvested from the donor’s hip bones under a general anaesthetic. The procedure takes one to two hours. The healthy donor experiences some discomfort in hips post operatively, but can be discharged from hospital the following day.
Peripheral Blood Stem Cells (PBSC)
PBSCs are collected via a process called apheresis. Blood is collected from a large vein in the arm and passed through a cell separator machine. The blood stem cells are collected for the transplant and the remaining blood is returned to the donor via a large vein in the other arm. The procedure can take several hours.
Umbilical Cord Blood
Umbilical cord blood is collected immediately following the birth of a baby. The blood is collected from the cord and placenta. It incurs no risk to the baby or mother. Once collected it is cryopreserved and stored for future use. There are many cord blood banks throughout the world, including one at SCH.
Choice of transplant and source of blood stem cells
The type of transplant (allogeneic or autologous) and the source of stem cells depend upon your child’s disease and donor availability.
Searching for a suitable donor
The most suitable donor for an allogeneic transplant is a fully matched family donor. Blood tests will be performed on your child’s immediate family. There is a 25% chance that each sibling will be a match for your child. If there are no suitable family donors, an unrelated donor search will be conducted by the Australian Bone Marrow Donor Registry.
Phases of transplant
- Conditioning therapy: Your child is admitted to the BMT unit and commences high dose chemotherapy with or without radiotherapy. The treatment is given over approximately one week. This prepares the child to receive the donor blood/marrow cells. It also helps to prevent rejection of the donor cells
- Transplant day: The donor cells are given to your child via the central venous line (LINK 3.3c). The cells may be fresh or cryopreserved. The cells can either be pushed into the central line or infused over two to four hours, depending upon the volume of the cells.
- Engraftment: It can take between 14 and 28 days for the donor cells to start producing immature blood cells. White blood cells are the first line of cells to engraft post-transplant and therefore a good indicator of engraftment. The varying length of times for engraftment to occur is dependent on several factors including the type of donor cells used.
- While waiting for the transplanted cells to engraft, your child will require multiple antibiotics, and blood/platelet transfusions to help prevent and fight infection and prevent bleeding. This is known as supportive care and will also include pain relief, intravenous or nasogastric nutrition and medication to prevent graft versus host disease.
The following is a list of complications which are well recognised and can be treated accordingly:
- Nausea, vomiting, diarrhoea
- Kidney and liver problems
- Graft versus Host disease (allogeneic transplants only)
- Rejection: This is a rare occurrence.
Your child will need to be in isolation from the time of admission for transplant until up to 3 months post-transplant or as instructed by the BMT team. In hospital, your child can be visited by both parents, siblings over the age of 6 years and 4 other chosen people.
The average length of stay in hospital is four to six weeks. On discharge from hospital, your child will be seen two to three times per week in the outpatients clinic. There will be several medications your child will need to receive on a daily basis for many weeks. If you live in rural NSW, you may need to stay in Sydney for at least three months post-transplant in Ronald McDonald House.
There are long term complications associated with the BMT. These are mostly related to the high dose chemotherapy and the radiotherapy. Your child’s consultant will discuss these with you prior to the transplant. Click here for more information.
Sydney Cord Blood Bank http://www.sch.edu.au/departments/acbb/
Bone Marrow Transplant Network NSW www.bmtnsw.com.au
Australian Bone Marrow Donor Registry www.abmdr.org.au
National Marrow Donor Program www.marrow.org
Children’s Oncology Group www.childrensoncologygroup.org
Centre for International Blood & Marrow Transplant Research www.cibmtr.org