Bone marrow transplantation is a procedure wherein stem cells from bone marrow that produce various blood cells like red blood cells, white blood cells and platelets are injected into a recipient. These stem cells are also referred to as hematopoietic stem cells. Nowadays, hematopoietic stem cells may also be obtained from peripheral blood after treatment with certain growth factors or from umbilical cord. Thus, the term “Hematopoietic stem cell transplantation” is now preferred to “Bone marrow transplantation” to include these other sources of hematopoietic stem cells.
TThe bone marrow is a soft, spongy portion within a bone. It contains immature cells called stem cells that have a continuous ability to produce different types of blood cells i.e. red blood cells, white blood cells and platelets. These are released into the blood stream. Bone marrow is of two types, red marrow and yellow marrow. In children, most of the marrow is red marrow and is rich in stem cells. In adults, however, a large portion of the bone marrow is converted into yellow marrow due to infiltration of fat cells. Red marrow in adults is usually restricted to a few bones like the hip bones, breast bone, ribs, shoulder blades, skull, backbone, and the ends of the arm and thigh bones.
BMT is actually means infusion of stem cells (collected either from bone marrow or peripheral blood or cord blood) into the recipient. The type of bone marrow that is used for the transplant distinguishes the different types of BMT.
- Autologous BMT is done by using the patient’s own stem cells.
- Allogeneic BMT involves using the stem cells of a donor. The donor may be a relative, usually a brother or sister, or an unrelated (anonymous) donor. The donor needs to be Histocompatible Leukocyte antigen (HLA) match.