Stem Cell Transplantation (Bone Marrow Transplant) | Step By Step!

All living organisms started life from one cell. As humans, life started as a zygote, which is the fusion between a female ovum and a male sperm. Therefore, all of our cells originated from one, and this one cell undergoes division into different “lines” of cells that subdivides further into more specialized types. Blood cells originate from a specific line of cells called hemopoietic stem cells. The site of such cells differs according to the stage of the human embryo, but by the time a human fetus is born, all of their hemopoietic stem cells are located in their bone marrow. The bone marrow is located in a cavity within the long bones, like those of our arms and legs, and some bones in our axial skeleton which includes the skull, ribs and pelvis.

The bone marrow is broadly classified into two types: red or “active” marrow which contains active cells that divide repeatedly to supply new cells, and yellow or “inactive” bone marrow which contains more fat and less active cells. When a human fetus is born, most of his marrow is active but as he or she ages, their bone marrow gradually transforms into the inactive form. By adulthood, most of our marrow in long bones becomes yellow except for a few sites in our central skeleton, mostly the ribs, pelvis and our breastbone, the sternum. This is not an absolute fact and, in many conditions, whether in disease or in response to some drugs, our yellow marrow may transform into the red type to satisfy the need of the body for more red cells or in response to an artificially administered stimulant such as erythropoietin.

What is stem cell transplantation?

Organ transplantation often means removing an organ and implanting it somewhere else where it can thrive and not die. This process can occur within the same body, between different bodies of the same species or even between some members of different species. In humans, only the first two types are done within the clinical practice, although tissues from animals may be used in limited procedures, especially in heart surgery.

The blood is a tissue, and blood donation is a form of tissue transplantation, but blood cells have limited time spans and need to be renewed via their stem cells located in the bone marrow. Stem cell transplantation solves this problem by introducing such cells which are able to divide into the body of the person in need for a permanent solution.