What is a bone marrow transplant?
A bone marrow transplant is a medical procedure done to replace bone marrow that has been damaged or destroyed by disease, infection, or chemotherapy. This procedure involves the transplantation of blood stem cells, which travel to the bone marrow where they produce new blood cells and promote the growth of new marrow. The bone marrow is the spongy fatty tissue found inside the bones. Create the following parts of the blood:
- Red blood cells, which transmit oxygen and nutrients throughout the body
- White blood cells, which fight infection
- Platelets, which are responsible for clot formation
The bone marrow also comprises immature blood-forming stem cells recognized as hematopoietic stem cells or HSCs. Most cells are previously differentiated and can only make copies of themselves. However, these stem cells are unspecialized, which means that they have the potential to multiply through cell division and remain stem cells or differentiate and mature into many different types of blood cells. HSC found in the bone marrow will produce new blood cells throughout its life. A bone marrow transplant replaces damaged stem cells with healthy cells. This helps your body make enough white blood cells, platelets, or red blood cells to prevent infection, bleeding disorders, or anemia.
Healthy stem cells can originate from a donor or they can come from your own body. In such cases, the stem cells can be harvested or cultured before chemotherapy or radiation treatment begins. Those healthy cells are then kept and used in transplantation.
Types of a bone marrow transplant
There are normally three types of bone marrow transplants:
Autologous bone marrow transplantation: In this case, the stem cells are harvested before chemotherapy or radiation treatment and stored in a freezer. After the treatment is finished, they are transferred back to normal cells. This procedure is also known as a salvage transplant.
Allogeneic bone marrow transplantation: In this case, the stem cells are taken from another person or a donor. It is important that the cells partially match for the process to work. A special test is performed to confirm the match. Most family members, like a brother or sister, are chosen as donors. Unrelated donors must be searched through bone marrow registries.
Umbilical cord blood transplant: This is a type of allogeneic bone marrow transplant in which stem cells are taken from a baby’s umbilical cord immediately after birth and stored in a freezer for future transplantation. Since blood cells are immature, a perfect match is not required. Fewer stem cells mean that blood counts may take longer to recover.
Purpose of a bone marrow transplant
Bone marrow transplants are done when a person’s bone marrow is not healthy enough to function properly. This could be due to chronic infections, diseases, or cancer treatments. Some of the reasons for a bone marrow transplant include:
- Aplastic anemia, which is a disorder in which the bone marrow stops making new blood cells
- Cancers that affect the marrow, such as leukemia, lymphoma, and multiple myeloma
- Damaged bone marrow due to chemotherapy
- Congenital neutropenia, which is an inherited disorder that causes recurrent infections.
- Sickle cell anemia, which is an inherited blood disorder that causes deformed red blood cells
- Thalassemia, which is an inherited blood disorder in which the body produces an abnormal form of hemoglobin, an integral part of red blood cells
How does the transplant work?
Before the transplant, you receive chemotherapy (chemotherapy) with or without radiation to destroy diseased blood-forming cells and bone marrow. Then healthy cells are given to you (this is not surgery). The new cells enter the bloodstream through an intravenous (IV) line or tube. It’s like receiving blood or medicine through an IV. The cells reach the marrow, where they grow and begin to make healthy red blood cells, white blood cells, and platelets.
A bone marrow transplant can cause the following symptoms:
- Chest pain
- Drop-in blood pressure
- Fever, chills, flushing
- Weird taste in the mouth
- Difficulty breathing
The possible complications of a bone marrow transplant depend on many things, including:
- Your age
- Your overall health
- What a good match was your donor
- The type of bone marrow transplant you customary (autologous, allogeneic, or umbilical cord blood)
Complications can include:
- Bleeding in the lungs, intestines, brain, and other areas of the body
- Coagulation in the small veins of the liver
- Injury to the kidneys, liver, lungs, and heart
- Growth retardation in children who receive a bone marrow transplant
- Early menopause
- Graft failure, which revenues that the new cells do not relax in the body and start producing stem cells
- Graft versus host disease (GVHD), a condition in which donor cells attack their own body
- Infections, which can be very serious
- Swelling and pain in the mouth, throat, esophagus, and stomach, called mucositis
- Stomach problems, including diarrhea, nausea, and vomiting
How to prepare before bone marrow transplant?
Pre-transplant tests and procedures
You will undergo a sequence of tests and procedures to assess your general health and the status of your condition and to ensure that you are physically ready for the transplant. The evaluation may take several days or more.
Also, a surgeon or radiologist will implant a long, thin tube (IV catheter) into a large vein in your chest or neck. The catheter, often called a central line, usually stays in place during treatment. Your transplant team will use the dominant line to fill the transplanted stem cells, drugs, and blood products into your body.
Stem cell collection for autologous transplantation
If a transplant with your own stem cells (autotransplantation) is planned, you will undergo a procedure called apheresis to collect blood stem cells.
Before apheresis, you will receive daily injections of development factors to increase stem cell production and move the stem cells into the circulating blood so they can be collected.
During apheresis, blood is haggard from a vein and circulated through a machine. The machine separates your blood into different parts, including the stem cells. These stem cells are collected and frozen for future use in transplantation. The remaining blood is returned to your body.
Stem cell collection for allogeneic transplantation
If you have a stem cell transplant from a donor (allogeneic transplant), you will need a donor. Once a donor is found, stem cells are collected from that person for transplantation. Stem cells can originate from your donor’s blood or bone marrow. Your transplant team decides which one is best for you based on your situation.
Another type of allogeneic transplant uses stem cells from the umbilical cord blood (cord blood transplant). Mothers can choose to donate umbilical cords after the birth of their babies. The blood from these cords is frozen and stored in a cord blood bank until it is needed for a bone marrow transplant.
The conditioning process
After completing the pre-transplant tests and procedures, a process known as conditioning begins. During conditioning, you will undergo chemotherapy and possibly radiation to:
- Kill cancer cells if you are being treated for malignancy
- Suppress your immune system
- Prepare your bone marrow for the fresh stem cells
The type of conditioning process you receive depends on several factors, including your condition, your general health, and the type of transplant planned. You may receive both chemotherapy and radiation or just one of these treatments as part of your conditioning treatment.
Side effects of the conditioning process can include:
- Nausea and vomiting
- Hair loss
- Sores or ulcers in the mouth
- Infertility or sterility
Organ complications, such as heart, liver, or lung miscarriage You may be able to take medicine or other measures to reduce these side effects.
Depending on your age and medical history, your doctor may recommend lower doses or different types of chemotherapy or radiation for your conditioning treatment. This is called reduced-intensity conditioning.
Reduced-intensity training kills some cancer cells and suppresses your immune system. The donor cells are then infused into your body. Donor cells replace bone marrow cells over time. Immune factors in donor cells can fight cancer cells.
How is a bone marrow transplant performed?
With the help of a central venous catheter, which is essentially a tube, healthy stem cells are injected into your blood. This is installed in the upper right part of your chest, neck, or arm. The tube allows the healthy stem cells contained in the fluid to go directly to the heart.
These healthy stem cells then spread through your body and eventually form in the bone marrow. This is where the growth and production of stem cells by the marrow will begin. Surgery is usually not necessary.
What is recovery corresponding to a bone marrow transplant?
Recovery from a bone marrow/stem cell transplant receipts a long time. Recovery often has stages, beginning with intensive medical monitoring after the day of the transplant. As your long-term recovery progresses, you will eventually move on to a schedule of regular medical check-ups over the next several months and years.
During the initial recovery period, it is important to watch for signs of infection. The intensive chemotherapy treatments you receive before your transplant also damage your immune system. This is so your body can receive the transplant without aggressive stem cells. It takes time for your immune system to work again after a transplant. This means that you are more likely to get an infection right after a transplant.
To reduce your risk of infection, you will receive antibiotics and other medications. If you had an ALLO transplant, your medications will include medications to prevent and/or control GVHD. Follow the advice of your healthcare team on how to prevent infection right after your transplant.
It is mutual to develop an infection after a bone marrow transplant, even if you are very careful. Your doctor will monitor you carefully for signs of infection. You will have regular blood tests and other tests to understand how your body and immune system are replying to the donor cells. You can also receive blood transfusions through your catheter.
Your health care team will also develop a long-term recovery plan to manage late side effects, which can occur many months after your transplant. Learn more about the possible side effects of a bone marrow transplant.
A bone marrow transplant is considered an important medical procedure and increases your risk of experiencing:
- A drop in blood pressure
- A headache
- Difficulty breathing
The above symptoms are usually short-lived, but a bone marrow transplant can cause complications. Your chances of emerging these complications depend on several factors, including:
- Your age
- Your health in general
- The disease for which you are being treated
- The type of transplant you received
- Complications can be mild or very serious and can include:
- Graft versus crowd disease (GVHD), which is a condition in which donor cells does your body
- Graft failure, which occurs when the transplanted cells do not start producing new cells as planned
- Bleeding in the lungs, brain, and extra parts of the body
- Cataracts, characterized by clouding of the lens of the eye
- Damage to vital organs
- Early menopause
- Anemia, which occurs when the body does not make enough red blood cells
- Nausea, diarrhea, or vomiting
- Mucositis, which is a condition that causes inflammation and pain in the mouth, throat, and stomach
They can help you weigh the risks and complications against the possible benefits of this procedure.