What Is a Bone Marrow Transplant?
Your blood cells start out as very young cells called hematopoietic stem cells. After they mature, they travel out of your bone marrow and into your blood. A bone marrow transplant is also called a stem cell transplant.
Damaged bone marrow makes too few blood cells and not enough cells for your immune system. A transplant can cure certain diseases or some types of cancer. It also means a long recovery process and a risk of serious side effects. Your doctor can talk with you about all the pros and cons of the transplant.
Why Is a Bone Marrow Transplant Done?
Your bone marrow holds your hematopoietic stem cells. They grow to become:
- Red blood cells, which carry oxygen around your body
- White blood cells, which help your immune system
- Platelets, which let your blood clot
A bone marrow transplant may:
- Replace stem cells that were destroyed by chemotherapy for cancer
- Replace diseased marrow that can’t make its own stem cells
- Add donor cells to help find and kill cancer cells
You may need a transplant if you have:
Types of Bone Marrow Transplants
There are a two main types of bone marrow transplants:
- Autologous. Your medical team collects stem cells from your own marrow or blood and stores them while you get cancer treatment. Then, they put the stem cells into your bloodstream. The cells travel to your bone marrow and multiply to help it make healthy stem cells again.
- Allogeneic. After cancer treatment, you get stem cells from a person whose bone marrow closely matches yours. This may be a close family member, like a parent or sibling, or someone from a national donor list. If the donor is an identical sibling whose tissue type is the exact same as yours, it’s called a syngeneic transplant. Doctors can also use stem cells from the blood in a newborn’s umbilical cord.
Preparing for a Bone Marrow Transplant
Your doctor will decide whether a bone marrow transplant would work for you. They’ll give you a physical exam and tests to check your blood and how well your heart, lungs, liver, and other organs are working.
If a transplant seems like a good option, they’ll talk with you about what type of procedure you’ll have and what you can expect.
A few days before your transplant, you’ll go to the hospital and get a tube called a central venous catheter put into a vein in your chest. Your medical team will use it to take blood and give you medicine. It will stay there until after your treatment.
Collecting cells for an autologous bone marrow transplant
Your doctor might use a long needle to take stem cells from the marrow in your hip bone. It’s done in an operating room under general anesthesia, which means you’re asleep and don’t feel anything. The procedure takes 1 or 2 hours. You can go home that day or the next morning. You might feel sore and weak for a few days.
They can also take cells directly from your blood with a procedure called apheresis. You’ll need to get a drug called filgrastim, which triggers your bone marrow to make and release a lot of stem cells, for a few days beforehand. Then, your medical team will take blood from a vein in your arm and run it through a machine that separates out the stem cells. The other cells go back into your bloodstream. Apheresis is an outpatient procedure, which means you won’t have to stay in the hospital. It usually takes 2 to 4 hours.
Collecting cells for an allogeneic bone marrow transplant
Your doctor will match you with someone who has the same type of protein on their white blood cells, called a human leukocyte antigen (HLA). Your HLA type is something that runs in your family.
Whether they’re a relative or a stranger, the donor will go through the same process to collect their stem cells. If parents choose to donate cells from an infant’s umbilical cord blood, they’ll be collected at birth, after the cord is clamped and cut.
Bone Marrow Transplant Procedure
You’ll start with a process called conditioning. This usually involves a high dose of chemotherapy, maybe with radiation, for about 10 days. It’s different for everyone and is based on your overall health and the condition being treated.
Conditioning makes room for new cells to grow in your bone marrow. It also briefly weakens your immune system to keep your body from fighting the new cells.
Side effects of conditioning may include:
- Mouth sores
- Nausea and vomiting
- Trouble eating
- Hair loss
- Lung or breathing problems
- Premature menopause
- Fertility problems
After a few days of rest, you’ll get new blood stem cells through the central venous catheter. You’ll probably be awake for this, but it shouldn’t hurt.
Once the new cells reach your marrow, they’ll grow into red and white blood cells and platelets. This process, called engraftment, can take 2 to 4 weeks.
Bone Marrow Transplant Recovery
The recovery process is different for everyone, but you’ll probably spend several weeks in the hospital. Your immune system will be weak, so you’ll take medicines to prevent infections. You may also need blood transfusions.
For the first few weeks, your doctors will test your blood often to check for engraftment. They might also take a small sample of your bone marrow for this.
You can usually leave the hospital after you meet certain criteria, including specific blood cell counts and no fever for 2 days. You’ll also have to have someone at home who can help take care of you.
Your immune system can take a year or longer to recover after your transplant. You’ll need to see your doctor often and keep taking medications to prevent infections and graft-vs.-host disease. This is when the new cells attack your own.
Your medical team may recommend that you see a specialist called a dietitian. They can work with you to create a diet plan that will help prevent infections and keep you healthy. They may tell you to:
You probably won’t be able to return to work or other activities for a while. And your doctor might tell you to make a few lifestyle changes, such as:
Risks of Bone Marrow Transplants
A bone marrow transplant can have complications, such as:
- Low blood cell counts
- Skin rash
- Fertility problems
- Muscle spasms or leg cramps
- Numbness in your arms or legs
- Painful inflammation in your mouth and digestive tract
- Liver or kidney problems
- Trouble breathing
- Organ damage
A transplant also makes it more likely that you’ll have another cancer later on.
It’s rare, but some of these problems can be deadly.
If you get a transplant from a donor, watch for symptoms of graft-vs.-host disease. These include:
Graft-vs.-host disease can become a long-lasting condition. If it does, you may have:
Bone Marrow Transplant Outlook
Your doctor will tell you what they’re looking for in order to declare a transplant a success. This might include blood counts that are back to safe levels and a disease that’s under control.
The success of a bone marrow transplant depends on a lot of things, including:
- Your age
- Your overall health
- The type of procedure you had
- How it affects your disease
- How well you tolerate certain procedures or treatments
- Whether you have any complications
Transplants have cured thousands of people of their diseases. Doctors are also finding new ways to make them better.
If you find yourself struggling with stress or emotional issues after your transplant, talk with your doctor or a social worker. They can help you find resources like support groups with people who know what you’re going through.