Bone Marrow Transplant – A Boon

A bone marrow transplant (BMT) is needed when the bone marrow stops working or doesn’t produce enough healthy blood cells. Bone Marrow is the spongy tissue present in the cavities created by the cancellous arrangement of the core of our bones. They are responsible for the production of various blood cells and platelets.

Bone Marrow is found in the large bones of the body such as the hip, thigh, shoulder blade, and breast bone. They are also found in the skull, spine, and ribs. It plays a vital role in the body’s immune response and blood cell production.

When the bone marrow gets damaged or diseased, it results in low blood cell production and a weak immune response. To treat the issue, a bone marrow transplant is carried out in which healthy stem cells from a donor are infused into the patient’s body. For this reason, it is also called a stem-cell transplant. 

The main objective of bone marrow transplant is to transfer hematopoietic cells from a healthy donor by extraction or harvesting, and infusion into a diseased person. The process though sounds simple, in reality, is complex. To carry out the process, the patient is first admitted to a special aseptic area in the hospital which is HEPA (high-efficiency particulate air) filtered. The area is a highly sterilized environment where the patient is kept for 3-4 weeks. 

What Are the Types of Bone Marrow Transplants?

The different types of bone marrow/stem cell transplants are: 

Autologous transplantation. Stem cells for this transplant come from the patient’s body. Cancer is sometimes treated with high-dose, intensive chemotherapy, or radiation therapy. This type of treatment can damage your stem cells and immune system. Therefore, before starting cancer treatment, doctors remove or preserve stem cells from your blood or bone marrow.

Allogeneic bone marrow transplant. The donor and patient have the same genetic profile. Stem cells can be collected through bone marrow extraction or apheresis, typically from a sibling who matches the patient genetically. Other donors may include parents, unrelated bone marrow transplants (UBMT), or (MUD)for a matched unrelated donor.

Cord blood transfusion. Stem cells are taken from the umbilical cord immediately after birth. Compared to stem cells extracted from the bone marrow of another child or adult, these stem cells develop into mature, functioning blood cells more quickly and effectively. When necessary for transplantation, stem cells are counted, typed, and tested before being frozen.

What is The Bone Marrow Transplant Procedure?

The stem cell transplant procedure usually involves several steps, including: 

• Treatment: Chemotherapy or radiation therapy suppresses or destroys the patient's bone marrow. 
• Transplantation: Healthy stem cells are then transplanted into the patient's bloodstream. 
• Engraftment: New stem cells move to the bone marrow and begin to produce new blood cells.
• Recovery: The patient's immune system slowly begins to heal and new blood cells are formed. 

The bone marrow transplant procedure can cause side effects and it can take several weeks or months for the patient to fully recover. The success of a stem cell transplant depends on several factors, including the general health of the patient, the stage of the disease, and the type of stem cells used.

Why is Bone Marrow Transplant Important?

Bone marrow transplantation is used to treat many diseases and cancers. If the doses of chemotherapy or radiation therapy is given to treat cancer are so high that a person's bone marrow stem cells are prominently damaged or destroyed as a result of the treatment, a bone marrow transplant may be required. A bone marrow transplant may also be necessary if some disease has killed the bone marrow. 

A stem cell transplant is used: 

• To replace diseased or non-functioning bone marrow with healthy, functioning bone marrow (such as leukemia, aplastic anemia, and sickle cell anemia).
• To regenerate a new immune system that will fight dwelling or residual leukemia or other cancers not killed by the chemotherapy or radiation used in the transplant.
• To replace bone marrow with genetically healthy and functioning stem cells to prevent any further damage from a genetic disease process (like Hurler's syndrome and adrenoleukodystrophy).

How Is Bone Marrow Donated?

Peripheral blood stem cell donation and bone marrow donation are the two basic ways to donate bone marrow.

The most frequent type of donation is peripheral blood stem cell donation (PBSC). Giving a donor a drug that raises the quantity of blood-forming cells in their bloodstream is a non-surgical approach. Then, similar to donating blood, these cells are harvested via a procedure called apheresis.

In bone marrow donation, a needle and syringe are used to extract bone marrow straight from the donor's hip bone. Under general anaesthesia, the treatment is carried out, and the donor often stays in the hospital for one or two days to recover. Compared to PBSC, this technique is less popular. The bone marrow transplant cost is not fixed and varies from country to country and also on health providers.

Complications and Side Effects After Bone Marrow Transplant

Complications may vary depending on the following factors: 

• Type of bone marrow transplant 
• Type of disease requiring transplantation 
• Preliminary treatment 
• Age and general health of the recipient 

These complications can also occur alone or together: 

• Infections. Infections are likely in a patient with severe bone marrow suppression. Bacterial infections are the most common. Viral and fungal infections can be life-threatening. Any infection can prolong hospital stay, prevent or delay transplantation and/or cause permanent organ damage. 
• Low platelets and red blood cells. Thrombocytopenia (low platelet count) and anemia (low red blood cell count) caused by bone marrow dysfunction can be dangerous and even life-threatening. Low platelets can lead to dangerous bleeding in the lungs, gastrointestinal (GI) tract, and brain. 
• Fluid overload. Fluid overload is a complication that can lead to pneumonia, liver damage, and high blood pressure. The main cause of the fluid overload is that the kidneys are unable to handle a large amount of fluid given in the form of intravenous (IV) medications, nutrition, and blood products.
• Breathing difficulties. Respiratory status is an important function that can be compromised during delivery. Infection, airway inflammation, fluid overload, graft-versus-host disease, and bleeding are all potentially life-threatening complications that can occur in the lungs and pulmonary system.