Related Subjects:
| Oncological Emergencies
| Acute Myeloid Leukaemia (AML)
| Acute Lymphoblastic Leukaemia (ALL)
| Chronic Lymphocytic Leukaemia (CLL)
| Chronic Myeloid Leukaemia (CML)
| Immune Thrombocytopenic Purpura (ITP)
| Multiple Myeloma
| Graft-versus-Host Disease (GVHD)
| Cytomegalovirus (CMV) Infections
About Bone Marrow Transplantation
- Also known as Hematopoietic Stem Cell Transplantation (HSCT).
- Involves replacing damaged or destroyed bone marrow with healthy stem cells.
- Used to treat various haematological malignancies and non-malignant conditions.
Mechanism
- Damaged bone marrow is destroyed using high-dose chemotherapy and/or radiotherapy (myeloablation).
- Healthy stem cells are infused to restore normal haematopoiesis.
- Stem cells can be obtained from the patient (autologous) or a donor (allogeneic).
- Engraftment occurs over 2-4 weeks, during which new blood cells are produced.
- High risk of opportunistic infections during the neutropenic phase.
Types of Bone Marrow Transplantation
- Allogeneic BMT
- Uses stem cells from an HLA-matched donor—either a sibling (1 in 4 chance of a match) or an unrelated volunteer.
- Donor cells are collected from bone marrow or peripheral blood after mobilization.
- Beneficial graft-versus-tumor effect but risk of graft-versus-host disease (GVHD).
- Autologous BMT
- Uses the patient's own stem cells collected before myeloablative therapy.
- Eliminates risk of GVHD and need for immunosuppression.
- Stem cells are harvested from peripheral blood after mobilization with G-CSF or GM-CSF.
- May carry a risk of reinfusing malignant cells; purging techniques can be used.
- Syngeneic BMT
- Stem cells are obtained from an identical twin.
- No risk of GVHD and no need for immunosuppression.
- Very rare due to the low incidence of identical twins.
- Umbilical Cord Blood Transplantation
- Stem cells are collected from the umbilical cord and placenta after birth.
- Cord blood has a high concentration of hematopoietic stem cells.
- Useful for patients without a suitable donor; lower risk of GVHD.
- Limited cell dose may be inadequate for adults; primarily used in pediatric patients.
Complications
- Infections: Severe neutropenia increases risk of bacterial, fungal, and viral infections.
- Graft-versus-Host Disease (GVHD):
- Acute GVHD affects skin, liver, and gut.
- Chronic GVHD can involve multiple organs.
- Managed with immunosuppressive therapy.
- Graft Failure: Failure of engraftment leading to persistent pancytopenia.
- Organ Toxicities: Due to high-dose chemotherapy/radiation (e.g., hepatic veno-occlusive disease).
- Secondary Malignancies: Increased risk due to prior chemotherapy/radiation.
- Mortality: Transplant-related mortality varies but can be significant; careful patient selection is crucial.
- Supportive Care: Necessary until engraftment; includes transfusions, prophylactic antimicrobials, and nutritional support.
Indications for Bone Marrow Transplantation
- Leukaemias: Acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML), chronic myeloid leukaemia (CML).
- Lymphomas: Hodgkin's lymphoma, non-Hodgkin's lymphoma.
- Multiple Myeloma
- Myelodysplastic Syndromes
- Aplastic Anaemia
- Sickle Cell Disease
- Thalassaemia Major
- Paroxysmal Nocturnal Haemoglobinuria
- Solid Tumours: Neuroblastoma, Ewing's sarcoma (in select cases).
References