Mahatma Gandhi Cancer Hospital & Research Institute has launched its state-of-the-art Bone Marrow Transplant (BMT) facility at HealthCity, Arilova, Visakhapatnam, which is the first such exclusive BMT unit in Andhra Pradesh. The unit has four transplant cubicles for transplant patients’ use before and after the procedure. All cubicles are of class-10000 clean room standard and with HEPA filtration systems and positive pressure ventilation. The transplant programme team provides specialized service under Hemato Oncology department. The team is committed to providing quality service to all children & adults needing this procedure.
Bone Marrow is the soft and spongy tissue found within bones which is rich in stem cells. The most primitive of these stem cells are the pluripotent stem cells, which are different from the other cells in the following aspects :
- They produce cells identical to themselves
- They have the capacity to produce one or more subsets of mature cells
These stem cells are of prime importance in Bone Marrow Transplant, which is more appropriately known in clinical terminology as Hematopoietic Stem Cell Transplant (HSCT).
Other sources of stem cells have gained popularity in the last decade, because their harvesting is better tolerated by the donor while delivering almost identical success rates when compared to Bone Marrow Transplant. These include Peripheral Blood Stem Cells and Cord Blood Stem Cells.
Bone Marrow Transplant procedure is performed not only for cancerous conditions like blood cancer but also for a genetic condition like Thalassemia. Here, the cancerous or genetically abnormal stem cells are eradicated by chemotherapy and immuno-suppressive medicines and new functionally normal stem cells are given which later populate the bone marrow and blood with normal non-cancerous cells and genetically normal cells.
The conditions which necessitate a Bone Marrow Transplant (BMT) can be broadly classified into 2 groups
- Acute Myeloid and Lymphoblastic Leukemia
- Chronic Myeloid and Lymphocytic Leukemia
- Relapsed Hodgkin’s and Non-Hodgkin’s Lymphoma
- Myelodysplastic Syndrome
- Myeloproliferative Neoplasms (Primary Myelofibrosis, etc)
- Multiple Myeloma
- Aplastic Anemia
- Haemoglobinopathies such as Thalassemia and Sickle Cell Anemia
- Immunodeficiencies disorders
- Inborn errors of metabolism
- Storage disorders
Before stem cell transplant, stem cells are collected from either the bone marrow or the blood. The patient is given high doses of chemotherapy, usually over a few days. Sometimes, radiotherapy is also given to the whole body, known as total body irradiation (TBI). This process is known as “conditioning”.
As well as destroying any remaining cancer cells, the high doses of chemotherapy also destroy the stem cells in the bone marrow. After the chemotherapy, the patient is given the stem cells that were collected before the treatment. These stem cells start producing mature blood cells again.
Types of transplant – There are Two main types
A. Autologous BMT
In this procedure, patients own stem cells are collected and these stem cells are used after the high-dose treatment.
B. Allogeneic BMT
This uses stem cells from a donor and also known as an allograft. An allogenic transplant is more complicated procedure than an autologous one and only carried out in a very few specialized hospitals in India. Recovery may take several months or longer. The donor is another person whose tissue has the same genetic type (HLA type) as the person needing the transplant (recipient). It is more likely that the recipient will find a suitable donor in a brother or sister. This however, happens only 25 to 30 percent of the time.
If a family member does not match the recipient, the request is sent to the unrelated bone marrow transplant registry database to look for a suitable unrelated individual whose tissue type is a close match. It is more likely that a donor who comes from the same racial or ethnic group as the recipient will have the same HLA type.
Steps involved in Bone Marrow Transplant
1. Peripheral Blood Stem Cell Collection
The Peripheral Blood Stem Cell Transplant method is more commonly performed when compared to the Bone Marrow Harvest method and it is less invasive and easy to perform. Some studies even suggest that the stem cell yield by this method is higher when compared to bone marrow harvest. The process takes 4-6 hours after administering the necessary medication for 4 days.
Donors are injected with Granulocyte Colony Stimulating Factor (GCSF) for a duration of 4 days to stimulate stem cell proliferation. The donor stem cells are collected by a process called apheresis.
2. Conditioning of the Patient
The conditioning process involves high doses of chemotherapy and sometimes radiation. It is carried out for three reasons :
- Destruction of the existing bone marrow cells to make room for the transplanted stem cells
- Destroy any existing cancer cells
- Suppression of activity of the immune system to decrease chances of rejection of donor stem cells.
3. Transplanting the Stem Cells
The process of Bone Marrow Transplant does not involve the physical insertion of the marrow stem cells into the marrow of the recipient. It is more of an intricate and delicate blood transfusion method. The harvested stem cells are administered via a central venous catheter into the bloodstream. The donor stem cells have the property of stem cell homing whereby they migrate to the patient’s bone marrow and override his defective stem cells. This restores the ability of the patient’s bone marrow to produce blood elements.
Risks of Bone Marrow Transplant (BMT)
1. Graft versus host disease (GvHD)
In this disease, the transplanted stem cells (“graft”) attack the recipient’s cells (“host”) as they are recognized as alien cells.
There are two types of GvHD
Acute GvHD – Occurs during the first three months following the transplant.
Chronic GvHD – Develops after 3 months and can cause symptoms for many years.
As a consequence of chemotherapy and bone marrow suppression, the body is transiently unable to procedure cells to combat infections.