Bone marrow transplant (BMT) also called as hematopoietic stem cell transplant (HSCT) is the procedure that is used to replace the unhealthy bone marrow with new and healthy bone marrow. Bone marrow is the soft, fatty tissue inside the bones that is responsible for the production of blood cells. There are several medical conditions due to which the bone marrow become dysfunctional and therefore needs to be replaced. Further there are multiple types of Bone Marrow Transplants based on the donor of the bone marrow or stem cells.

When is Bone Marrow Transplant (BMT) required?

Allogenic bone marrow transplant (BMT) is typically recommended to treat certain medical conditions where the bone marrow is dysfunctional.

• Cancers like leukaemia, myelo-dysplasia etc.
• Diseases that affect the production of bone marrow cells like
  • Aplastic anaemia (acquired or inherited)
  • Other marrow failure states (ex: congenital neutropenia, amegakaryocytic thrombocytopenia etc)
  • Sever immunodeficiency syndrome’s
  • Sickle cell anaemia
  • Thalassemia major

Autologous bone marrow transplant (High dose chemotherapy + autologous stem cell rescue) is recommended to treat where we need to give high dose of chemotherapy to treat underlying disease following which autologous harvested bone marrow is given as rescue. The indications include:

• Cancers Like:
  • Neuroblastoma
  • Medulloblastoma
  • Wilm’s Tumor
  • Lymphoma’s
  • Multiple Myeloma Etc.
• It can also be used to treat various autoimmune diseases, the commonest indication being multiple scelerosis.

Autologous Bone Marrow Transplant

Autologous bone marrow transplant (High Dose Chemotherapy & Autologous Stem Cells Rescue) – The stem cells are taken from the patient prior to procedure, frozen & stored and then re-introduced in the patient’s system after the patient has received chemotherapy. This type of bone marrow transplant is typically used for cancers like neuroblastoma, medulloblastoma, Wilm’s tumor, lymphomas, multiple myeloma etc and also for autoimmune diseases like multiple sclerosis etc.

Allogeneic Bone Marrow Transplant

Allogenic transplant – In case the donor is other than the patient, the transplant is termed as allogenic. Depending on the donor, it can be further divided into:

• Matched related donor transplant – Donation made by a HLA matched family member like brother, sister, father, mother etc.
• Matched unrelated donor transplant – Donation is made by someone other than a family member who is found to be a complete HLA match with the recipient.
• Umblical cord blood transplant – Umblical cord blood rich in stem cells is taken from the umbilical cord and placenta of the baby. It is frozen and stored for use in the time of need.
• Haplo-Identical transplant – Donor and the patient are a half match like a parent and offspring etc. (Any matching <90% is considered as half match).

Haploidentical Transplant

• T-Cell Depletion is mandatory in haploidentical transplant.
• T-Cell Depletion can be done in two ways: IN VIVO (T cell depleted by using high dose of chemotherapy inside the body) or IN VITRO T cell depletion (T cell depletion by using a machine outside the body). Both these modalities have their advantages and disadvantages. Choice depends on a number of patient and donor related factors.