Bone marrow transplant is a treatment that saves the lives of people suffering from deadly diseases such as cancer, but like all transplants, it is suffering from lack of donors.

The role of the marrow is to produce all the formed elements of the blood: red blood cells (or erythrocytes), white blood cells (or leucocytes) and platelets (or thrombocytes).

Normally, these cells are continuously renewed through a stock of stem cells in the bone marrow, i.e., “virgin” cells which can evolve in all types of cell.

This marrow is located in the center of long bones like the humerus in the arm, and flat bones, such as pelvic bone in the pelvis. It is very different from the spinal cord, which is part of the nervous system located in the channel formed by the stacking of the vertebrae.

Transplanting Bone Marrow-The Hows and Whys:

A marrow transplant involves taking a sample of bone marrow from a donor and reimplanting it in a patient.

Several diseases can be treated by this act. This is the case of leukemia and lymphoma, because in these diseases, cancer cells invade the marrow and then prevent it from functioning properly.

This is also the case of aplasia in which bone marrow is no longer functioning and no longer produces white blood and red blood cells.

Finally, we can also make a transplant when a harmful treatment destroys the bone marrow and therefore its cells: when there is no more red blood cells, there is a risk of anemia. The lack of white blood cells leads to infections, and disappearance of platelets is a source of bleeding.

The main problem in bone marrow transplant is graft rejection, i.e., when the recipient does not accept the donor’s marrow.

In fact, each individual has his own characteristics. His tissues are defined genetically, and the immune system is programmed to eliminate all foreign elements in the body. All these properties of the tissue are called the “HLA system”.

When we transplant an organ that meets the HLA criteria, it is said to be compatible. In this case, the body of the recipient accepts it, and the immune system does not destroy the transplanted organ. It is recognized as belonging to the body.

Two Types of Transplants:

The allograft, which uses donors, and the donor can be unrelated or part of the family (family related donor). Of course, the chances of finding a stranger with a compatible marrow, therefore accepted by the patient, are much rarer than in the case of a brother or sister.

Transplants are much more effective when the donor is related to the recipient. The problem is that in a family, only one child in four has the same HLA system as his sick brother.

Finally, there is the autologous bone marrow transplant, which uses the patient’s own marrow. It is collected, frozen during an aggressive treatment of the patient and then reimplanted later.