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When you think of a transplant, you may have an image of a major surgical procedure to replace a diseased organ. But stem cell transplants don't involve surgery. And the "organ" involved is bone marrow — not a solid organ such as a liver.
If your bone marrow stops working, your body won't produce enough healthy stem cells. And that means you may not have enough healthy white blood cells, red blood cells or platelets, putting you at risk of life-threatening infections, anemia and bleeding.
A stem cell transplant is the infusion of healthy stem cells into your body. If all goes well, these healthy stem cells take hold in your body and begin normal production of blood cells.
Although the procedure is generally called a stem cell transplant, it's also known as a bone marrow transplant or an umbilical cord blood transplant, depending on the source of the stem cells.
Stem cell transplants are used to treat people whose stem cells have been damaged by disease or treatment of a disease. Stem cell transplants can benefit a variety of both cancerous (malignant) and noncancerous (nonmalignant) diseases.
For instance, in aplastic anemia, a noncancerous condition, your bone marrow stops making enough new blood cells. A stem cell transplant destroys the dysfunctional marrow, and healthy stem cells are infused. If all goes well, the new stem cells migrate to the marrow and begin working normally.
Similarly, in leukemia, the unhealthy bone marrow is destroyed because it doesn't work properly and may contain cancer cells. When healthy stem cells are transplanted, normal cell production can resume. In addition, immune factors in the transplanted cells may help destroy any cancer cells that remain in your bone marrow.
Usually you remain at home until your transplant is actually scheduled. During that time, your health care team may recommend that you work on building up your strength and maintaining a healthy diet.
Pretransplant tests and procedures
Once donor stem cells become available, you undergo many tests and procedures to assess your health and the status of your condition, and to ensure that you're physically prepared for the transplant.
In addition, an intravenous (IV) catheter is typically surgically implanted, usually in your chest near your neck. This is often called a central line, and it usually remains in place for the duration of your treatment. It's through the central line that the transplanted stem cells will be infused. The central line is also used to collect blood samples, give chemotherapy, provide blood transfusions and even supply nutrition when necessary.
The conditioning process
After you complete your pretransplant tests and procedures, you begin a process known as conditioning. During conditioning, you undergo chemotherapy and possibly radiation in order to:
- Destroy cancer cells
- Suppress your immune system so that your body doesn't reject the transplanted stem cells
The type of conditioning process you undergo depends on a number of factors, including your disease, overall health and the type of transplant planned — whether you get stem cells donated from someone else (allogeneic transplant) or whether the stem cells come from your own body (autologous transplant).
Conditioning generally occurs in the week leading up to your stem cell transplant. In some cases, you receive high doses of chemotherapy and total body irradiation (TBI). On the other hand, you may receive only high doses of chemotherapy and no radiation at all. The type of conditioning you undergo depends on your unique circumstances.
The conditioning process may be done in the hospital or on an outpatient basis. It can cause numerous side effects and complications because your bone marrow and stem cells are destroyed in anticipation of the transplant, and even if your conditioning process is outpatient, you may need hospitalization for side effects.
Side effects of the conditioning process can include:
- Nausea and vomiting
- Hair loss
- Mouth sores or ulcers
- Infections, such as pneumonia
- Infertility or sterility
- Premature menopause
- Organ failure, such as heart, liver or lung failure
- Secondary cancers
You may be able to take medications or other measures to reduce such side effects.
'Mini' stem cell transplants
A less intense conditioning process is available through what's known as a "mini" stem cell transplant. It's also called a reduced-intensity conditioning transplant or a nonmyeloablative transplant.
Reduced-intensity conditioning doesn't try to kill all of the cancer cells that may be in your body. Instead, it relies on the donor's immune system cells to fight your cancer cells.
A less intense conditioning regimen may seem attractive because it may pose fewer life-threatening complications. But this kind of transplant isn't appropriate for all situations. Mini stem cell transplants are typically used only for people who can't endure the harsher conditioning regimen, such as older adults or people in poorer health, and for people whose disease isn't rapidly progressing. In some cases, they may not be as successful as full transplants.
Stem cell transplants are typically performed in specialized medical centers. These centers generally have dedicated transplant units, with a team of specialists caring for you. This team often includes doctors, transplant nurses and coordinators, mental health professionals, occupational therapists and dietitians.
Stem cell transplantation involves infusing, or injecting, donor stem cells through your central line. This usually takes one to five hours. The transplanted stem cells make their way to your bone marrow cavities, where they begin creating new bone marrow and stem cells. It can take several weeks, though, for your blood counts to begin recovering.
If you receive bone marrow or blood stem cells that have been thawed, you may notice an odor wafting in your room for a day or two after the transplant. This is caused by the substance used to preserve the cells.
Just before the transplant, you may have received medications to reduce the side effects the preservative can cause. These side effects include:
Not everyone experiences side effects from the preservative, and for some people those side effects are minimal.
As you wait for your new stem cells to begin functioning, you will be at risk of such complications as infections and bleeding. In addition, you may still be recovering from problems related to conditioning.
Depending on your treatment protocol, you may stay in the hospital until your blood counts recover or you may return home but remain under close medical care. Some people who have inpatient transplants are able to leave the hospital within three to five weeks, but others may face much longer hospitalizations. Some transplant facilities require transplant recipients to remain nearby for 100 days to allow close monitoring.
In the days and weeks after your stem cell transplant, you may have many of the same kinds of tests and procedures to monitor your condition that you had before the transplant. You may also need supplemental nutrition to compensate for nausea and diarrhea.
To combat various complications, you may need to take numerous medications. You may also need periodic transfusions of red blood cells and platelets until your bone marrow begins producing enough of those cells on its own.
It usually takes about a full year for your blood cells and immune system to recover to normal levels. In general, recovery from a stem cell transplant that uses your own harvested stem cells is quicker than one that uses donor stem cells.
During hospitalization and once you return home, you must take special precautions to prevent infections.
These precautions include:
- Wearing a filtration mask to protect against airborne bacteria and viruses
- Avoiding contact with people who have any symptoms of illness, including colds
- Avoiding crowds
- Avoiding zoos, parks and areas heavily populated with birds
- Not swimming or using a hot tub
- Having someone else clean your home, particularly bathrooms and sinks
Be alert for signs of infection and report them immediately to your health care team. Such signs may include feeling ill, loss of appetite, nausea, fever, runny nose, sore throat or cough.
With your blood counts recovering, you should begin feeling better. Mouth sores and diarrhea may go away or become less severe. Your appetite may improve and you may begin feeling physically stronger. Even after you go home, you'll need regular medical care to monitor your condition, though. Your health care team will provide instructions about any special care or precautions to take once you're home.
Emotional and lifestyle issues
The diagnosis of a life-threatening illness can generate enormous stress for you and your family. Coping with side effects, prolonged periods of isolation, low energy and limited activity can lead to feelings of anger, grief and depression. These are normal responses to a prolonged and sometimes difficult treatment period.
Members of your health care team can address the emotional aspects of your stem cell transplant. Physical and occupational therapists can advise you on relaxation, increasing your endurance and exploring new activities. Mental health professionals, social workers and chaplains can help you cope with anxiety and depression, and help you remain positive.
A stem cell transplant poses many risks of complications, some potentially fatal. Although some people experience few problems with a transplant, others must endure frequent tests and repeated hospitalizations.
Complications that can arise with a stem cell transplant include:
- Graft-versus-host disease
- Stem cell (graft) failure
- Organ damage
- Blood vessel damage
- Secondary cancers
A stem cell transplant can cure some diseases and put others into remission. Most people who have a stem cell transplant expect the procedure to extend their life, and it often does.
Some people sail through stem cell transplantation with few side effects and complications. Others experience numerous problems, both short- and long-term. The severity of side effects and the success of the transplant vary from person to person.
Most people who have a stem cell transplant and don't have a relapse of their disease go on to enjoy a good quality of life. Many are able to return to work or school and resume their normal activities.
Before having a transplant, make sure you understand the risks and benefits, and how your own situation will affect your transplant experience.