Bone marrow is a soft, spongy, fatty tissue that is present inside the bones, which produces blood-forming cells (stem cells). These cells are immature cells that can form blood cells like white blood cells, red blood cells and platelet or more bone marrow cells. It is a vital part of the human body. If the bone marrow is damaged or destroyed due to any disease condition or extreme treatment of cancer (radiotherapy or chemotherapy), a bone marrow transplant may be needed.
Bone marrow transplant involves replacing the destroyed or damaged bone marrow with a healthy bone marrow.
A bone marrow transplant can be performed in any patient whose bone marrow is damaged or destroyed, in conditions like:
- Aplastic anaemia
- Sickle cell disease
- Immune deficiencies
- Brain tumours
- Diamond Blackfan anaemia
- Cancer of the kidneys
- Hurler's syndrome
- Adrenoleukodystrophy disorder
PREPARATION BEFORE PROCEDURE
Several tests and procedures are done to evaluate the general health of the patients. Before the surgery, one or two catheters (long, thin tubes) are placed into a large vein in the chest or neck. These tubes are used to inject the transplanted stem cells, medications, and nutrition. It stays at its place throughout the treatment.
The stem cells are then collected by any of the following methods:
- Bone marrow harvest: Under the effect of general anaesthesia, the bone marrow is removed from the back of the hip bones of the donor. The amount of marrow removed may vary depending on the weight of the patient.
- Leukapheresis: In this procedure, the donor receives an injection of growth factor for several days to increase the production of stem cells and move them from the bone into the blood. Then through the IV line, the blood is removed from the donor. The white blood cells (that contain stem cells) are separated from the blood in a machine and removed, which is given to the recipient later. The red blood cells are transferred back to the donor.
Before the procedure, the patient receives chemotherapy alone or along with radiation therapy. It is given to prepare the bone marrow for new stem cells, destroy the diseased blood-forming cells and marrow, and to suppress the immune system. The dose of chemotherapy and radiation therapy may vary depending on the age and health of the patient.
Based on who the donor is, bone marrow transplants are of the following types:
- Autologous bone marrow transplant: In this method, the healthy stem cells are taken from the same body to replace the unhealthy bone marrow. The stem cells are removed before giving chemotherapy or radiation therapy. These cells are then stored in the freezer and placed back in the body after completing chemotherapy or radiation therapy.
- Allogenic bone marrow transplant: In this method, the stem cells are taken from a donor, whose genes partly match the genes of the patient. The donor can be parents, siblings or other relatives. Sometimes an unrelated donor may also be matched through national bone marrow registries.
- Umbilical Cord blood transplant: In this method, right after the childbirth, the stem cells are removed from the umbilical cord of the infant. These stem cells are frozen until required for transplant.
The stem cells are injected into the body through the catheter. These new cells go in the bloodstream and create their way to the marrow. In the marrow, they grow and start to produce new healthy red blood cells, platelets and white blood cells.
The frozen stem cells contain a preservative that protects the cells. This preservative may show some side effects like headache, shortness of breath, headache, and taste change. Therefore, medication is given to the patient to reduce these side effects. The patients also receive IV fluids before and after the transplant to remove the preservative from the body.
Based on the type of transplant and the risk of complications, the patients may be asked to stay near the hospital for close monitoring for a few weeks to months. If the patient develops complications of infection, he or she may have to stay in the hospital for a few more days.
It may take a few weeks for blood count to increase. After a few days or weeks of the transplant, some blood tests and other tests may be performed to evaluate the health condition.
Some medications may be prescribed to manage complications like diarrhoea and nausea.
Until the bone marrow starts producing cells independently, the patient may require periodic transfusion of platelets and red blood cells.
After the transplant, the patient is at increased risk of infections and complications for several months to years. Thus, proper care needs to be taken.
The following measures may aid in preventing the complications and speed up the recovery process:
- Maintain a healthy weight
- Eat plenty of fruits and vegetables (except grapefruit)
- Avoid alcohol consumption
- Stay hydrated
- Exercise regularly