Bone Marrow Transplant

Bone marrow is the soft spongy tissue that lies within the hollow interior of long bones. Bone marrow in large bones produces new blood cells. The bone marrow contains stem cells. These are cells at a very early stage of development that develop into the three different types of blood cell. When the cells are fully mature, they are released into the bloodstream. Hence, bone marrow works as a factory for blood.

When things go wrong in the blood e.g. blood cancer (leukaemia), aplastic anaemia (empty bone marrow), its origin is in the stem cells in the bone marrow. Hence, bone marrow transplantation or stem cell transplantation can be a curative treatment for such conditions.

What is bone marrow transplantation or Stem Cell Transplantation?
The two terms "bone marrow" and "stem cell" transplants are sometimes used interchangeably. However, all bone marrow transplants are stem cell transplants but not all stem cell transplants are bone marrow transplants.

Bone marrow transplant procedure is performed to replace a person's faulty bone marrow with a healthy bone marrow. It is not only for cancerous conditions like blood cancer but also for 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.

In the past, patients who needed a stem cell transplant received a bone marrow transplant because the stem cells were collected from the bone marrow. These days, stem cells are usually collected from the blood, instead of the bone marrow. This is why they are now more commonly called stem cell transplants.

• Leukaemia (Blood cancer)
• Lymphoma (Lymph gland cancer)
• Myeloma (Bone marrow cancer)
• Germ cell cancers
• Thalassemia
• Sickle cell disease
• Gaucher's disease
• Immunodeficiency conditions
• Aplastic anaemia

Before stem cell transplant, stem cells are collected from either the bone marrow or the blood. Patient is given very high doses of chemotherapy, usually over a few days. Sometimes, radiotherapy is also given to the whole body, known as total body irradiation (TBI). 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, patient is given the stem cells that were collected before the treatment. These stem cells start producing mature blood cells again.