About bone marrow transplants
Bone marrow transplantation is a medical procedure in which stem cells from bone marrow that produces 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. The term “Hematopoietic stem cell transplantation” is also known as “Bone marrow transplantation. Hematopoietic stem cells may also be obtained from peripheral blood after treatment with certain growth factors or from umbilical cord.
What is bone marrow?
Bone Marrow is the soft, organic and sponge like material in the cavities of bone. Sponge Soft material also known as medulla. The soft blood-forming tissue fills the cavities of bones and contains fat and immature and mature blood cells, including white blood cells, red blood cells, and platelets. Bone marrow forms around 4% of total body weight (around 2.6 kg in a healthy adult).
At the time of birth and in early stage of childhood most of the marrow is red. As there will enhancement into age of the person it is converted into the yellow type. About half of adult bone marrow is red.
In adult marrow is present in skull, the sternum, ribs, vertebral column, clavicle, humerus and part of the femur.
Types of the Bone Marrow:
Red Marrow: Responsible for producing red blood cells, white blood cells and platelets.
Yellow Marrow: Responsible for production and regulation of the fat cells.
Function of the Bone Marrow:
- The major function of bone marrow is to generate blood cells.
- Bone marrow contains two main types ofstem cells. Hematopoietic stem cells, found in red marrow, are responsible for the production of blood cells.
- Bone marrowmesenchymal stem cells (multipotent stromal cells) produce the non-blood cell components of marrow.
- It produce the non-blood cell components of marrow, including fat, cartilage, fibrous connective tissue (found in tendons and ligaments), stromal cells that support blood formation.
- It also helps to remove old cells from circulation.
What is Bone Marrow Transplantation (BMT)?
Bone marrow transplantation is the medical surgical process which is used to replace the defective bone marrow (damaged or destroyed by disease, infection, or chemotherapy).
This process includes the transplantation of blood stem cells which travel towards bone marrow where they produce new blood cells and promote growth of new marrow.
Depend upon the bone marrow that is used for the transplant categories different types of Bone marrow transplantation (BMT).
- Autologous Bone marrow transplantation (BMT) is done by using the patient’s own stem cells, if the illness does not involve bone marrow (eg, Hodgkin’s disease, non-Hodgkin’s lymphoma).
- Allogeneic Bone marrow transplantation (BMT) is done by 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. It is called a syngeneic transplant if the donor is an identical twin.
The two types of allogeneic transplants are:
- Myeloablative: The aim of this transplant is to destroy patient’s marrow and kill the cancer cells.
- Non-myeloablative: The aim of this transplant is to suppress patient’s marrow and allow the donor cells to grow and attack the cancer cells. This is the graftversus-tumour effect.
Necessities of bone marrow transplantation
- Bone marrow are performed is a person has defective marrow (destroyed by disease, infection, or chemotherapy)
Following are some reason for bone marrow transplant:
- Sickle cell anemia, lymphoma, leukemia is a disorders in which marrow is not able to new red blood cells, deviation in blood count , Formation of abnormal WBC.
- Inherited immune system disorders (severe combined immunodeficiency) are an immune disorder which is present at birth.
- Wiskott- Alsrich syndrome is an inherited immune system disorder which is also present at birth.
- Thalassemia which is an inherited blood disorder where the body makes an abnormal form of hemoglobin, an integral part of red blood cells.