A blood and marrow stem cell transplant replaces a person's abnormal or faulty stem cells with healthy ones from another person (a donor). This procedure allows the recipient to get new stem cells that work properly.

 

Stem cells are found in bone marrow – a sponge-like tissue inside the bones. Stem cells develop into the three types of blood cells that the body needs:

 

Red blood cells carry oxygen through the body.

White blood cells fight infection.

Platelets help blood clot.

 

Small numbers of stem cells also are found in the blood and in the umbilical cord (the cord that connects a fetus to its mother's placenta).

 

Another type of stem cell, called an embryonic stem cell, can develop into any type of cell in the body. These cells aren't found in bone marrow.

 

Overview

Doctors use stem cell transplants to treat people who have:

 

Certain types of cancer, such as leukemia. The high doses of chemotherapy and radiation used to treat some cancers can severely damage or destroy bone marrow. A transplant replaces the stem cells that the treatment destroyed.

Severe blood diseases, such as thalassemia, aplastic anemia, and sickle cell anemia. In these diseases, the body doesn't make enough red blood cells or they don't work properly.

Certain immune-deficiency diseases that prevent the body from making some kinds of white blood cells. Without these cells, a person can develop life-threatening infections. A transplant provides stem cells that replace the missing white blood cells.

 

Types of transplants

Two main types of stem cell transplants are autologous and allogenic.

 

For an autologous transplant, a person's own stem cells are collected and stored for use later on. This works best when a person still has enough healthy stem cells even though he or she is sick. For a person with cancer, doctors also make sure that cancer cells are removed or destroyed from the collected cells.

 

For an allogenic transplant, a person gets stem cells from a donor. The donor can be a relative (like a brother or sister) or an unrelated person. A person also may get stem cells from umbilical cord blood donated by an unrelated person.

 

To prevent problems, the donor's stem cells should match the recipient's as closely as possible. Donors and recipients are matched through a blood test called HLA tissue typing.

 

Collection process

Stem cells used in transplants are collected from donors in several ways. They can be collected:

 

Through a type of blood donation called apheresis. A needle is placed in the donor's arm to draw blood. Then, his or her blood is passed through a machine that removes the stem cells from the blood. The rest of the blood is returned to the donor.

Directly from a donor's pelvis. This procedure isn't used very much anymore because it must be done in a hospital using local or general anesthesia. A hollow needle is inserted repeatedly into the pelvis, and marrow is sucked out of the bone.

From an umbilical cord and placenta. Blood containing stems cells may be collected from an umbilical cord and placenta after a baby is born. The blood is frozen and stored at a cord blood bank for future use.

 

Outlook

Stem cell transplants have serious risks. Some complications are life threatening. For some people, however, a stem cell transplant is the best hope for a cure or a longer life.

 

Who needs a blood and marrow stem cell transplant?

You may need a blood and marrow stem cell transplant if you have a disease or condition that prevents your body from making enough healthy blood cells.

 

These diseases and conditions include:

 

Some types of cancer, such as leukemia, lymphoma, myeloma, and breast cancer

Severe blood diseases, such as thalassemia, aplastic anemia, and sickle cell anemia

Immune-deficiency diseases, such as severe combined immunodeficiency syndrome, congenital neutropenia, and chronic granulomatous disease

 

Your primary care doctor and an oncologist or hematologist will determine whether you need a stem cell transplant. An oncologist specializes in treating cancer. A hematologist specializes in blood diseases and conditions.

 

When deciding whether you need a stem cell transplant, your doctors will consider:

 

The type of disease you have and how severe it is

Your age and overall health

Other possible treatment options

 

Your doctors also will order tests to make sure you're healthy enough to have the procedure. They also want to find out whether you have any medical problems that could cause complications after the transplant.

 

What to expect before the transplant

 

Finding a donor

If you're going to receive stem cells from another person, your doctors will want to find a donor whose stem cells match yours as closely as possible.

 

A close match can reduce the risk that your immune system will attack the donor cells. It also reduces the risk that cells from the donor's marrow or blood will attack your body.

 

HLA tissue typing

People having transplants are matched with donors through a test called HLA tissue typing. HLAs are proteins found on the surface of white blood cells. Your immune system uses HLAs to tell which cells belong to you and which don't.

 

Because HLA markers are inherited, an identical twin is the best donor match. Brothers or sisters also can be good matches. However, many people don't have a good match within their families.

 

If no matching donor is found in your family, the search widens to include people outside the family. Millions of volunteer donors are registered with the National Marrow Donor Program. Your doctors will look for:

 

Donors who are an HLA match but not a family member

Family members who aren't exact HLA matches

Unrelated donors who aren't exact HLA matches

Umbilical cord blood that's an HLA match

 

People who provide their own stem cells for use later don't need to go through HLA matching.

 

Medical tests and exams

You also will need other medical tests and exams before a stem cell transplant. Your doctors will want to make sure you're healthy enough to have a transplant. They also want to find out whether you have any medical problems that could cause complications after the transplant.

 

Blood tests

Blood tests are used to check for HIV, herpes, pregnancy, and other conditions. These tests help doctors learn about your overall health.

 

Chest X-ray and lung function tests

A chest X-ray provides a picture of your heart and lungs. It can show whether the heart is enlarged or whether the lungs have extra blood flow or extra fluid.

 

Lung function tests tell doctors whether you have any lung infection or disease. They also show how well your blood is able to carry oxygen through your body.

 

Computed tomography scan, skeletal X-ray, or bone scan

Computed tomography (CT) scans, skeletal X-rays, and bone scans provide detailed images of the body. They're used to see whether you have any tumors in your bones that might cause a problem for a transplant.

 

Dental exam

A complete dental exam is used to check for problems that might cause an infection after your transplant.

 

Heart tests

Heart tests, including EKG (electrocardiogram) and echocardiography, are used to find any conditions that might get worse after the transplant.

 

An EKG detects and records the electrical activity of your heart. Echocardiography uses sound waves to create a moving picture of your heart. The picture shows how well your heart is working and its size and shape.

 

Bone marrow biopsy

A bone marrow biopsy helps show whether your bone marrow is making enough healthy blood cells. If you're being treated for a blood cancer, this test shows whether your cancer is inactive.

 

What to expect during the transplant

A blood and marrow stem cell transplant has three parts: preparation, transplant, and recovery in the hospital.

 

Preparation

You will check in to the hospital a few days before the transplant. Using a simple surgical procedure, doctors will place a tube in a large vein in your chest. This tube is called a central venous catheter, or a central line. It allows easy access to your bloodstream.

 

Doctors use the central line to give you fluids, medicines, and blood products and to collect blood samples. The tube will stay in place for at least 6 months after your transplant.

 

To prepare your body for the transplant, your doctors will give you high doses of chemotherapy and possibly radiation. This treatment destroys the stem cells in your bone marrow that aren't working properly. It also suppresses your body's immune system so that it won't attack the new stem cells after the transplant.

 

The high doses of chemotherapy and radiation can cause side effects, including nausea (feeling sick to your stomach), vomiting, diarrhea, and tiredness. Medicines can help with these symptoms.

 

In older patients or those who aren't very strong, doctors may choose "reduced-intensity" treatment. This involves lower doses of chemotherapy or radiation.

 

Because your immune system is very weak after this treatment, you can easily get an infection. As a result, you will stay in a hospital room that has special features that keep the room as clean as possible.

 

Doctors, nurses, and visitors also have to wash their hands carefully and follow other procedures to make sure you don't get an infection. For example, they may wear a face mask while in contact with you.

 

Preparation before a transplant may take up to 10 days. The time depends on your medical situation, general health, and whether you need chemotherapy or chemotherapy and radiation.

 

Transplant

During the transplant, which is like a blood transfusion, you get donated stem cells through your central line. Once the stem cells are in your body, they travel to your bone marrow and begin making new red blood cells, white blood cells, and platelets.

 

You're awake during the transplant. You may get medicine to help you stay calm and relaxed. Doctors and nurses will check your blood pressure, breathing, and pulse, and watch for signs of fever or chills. Side effects of the transplant can include headache or nausea – but you may not have side effects.

 

The transplant takes an hour or more. This includes the time to set up the procedure, the transplant itself, and time to check you afterward.

 

Recovery in the hospital

You will stay in the hospital for weeks or even months after your stem cell transplant. In the first few days after the procedure, your blood cell levels will continue to go down. This is because of the chemotherapy or radiation you got before the transplant.

 

Your doctors will test your blood 7 to 10 days after the transplant to see whether new blood cells have begun to grow. They will check your blood counts every day to track your progress.

 

You will stay in the hospital until your immune system recovers and doctors are sure that your transplant was successful. During your time in the hospital, your doctors and nurses will carefully watch you for side effects from chemotherapy and radiation, infection, and graft-versus-host disease (GVHD) and graft failure.

 

Side effects from chemotherapy or radiation

The chemotherapy and possible radiation you get before the transplant have side effects. These side effects begin to appear a few days after the transplant. Some of these side effects are painful or uncomfortable; others are very serious. They include:

 

Painful sores in the mouth.

Nausea, diarrhea, and intestinal cramps.

Skin rashes.

Hair loss.

Liver damage. This occurs in about 10 percent of people who go through the transplant preparation.

Interstitial pneumonia. This is a kind of pneumonia that affects certain tissues in the lungs. It affects about 5 percent of people who go through the transplant preparation.

 

Doctors use mouth rinses, medicines, and other treatments to treat these side effects. Some go away on their own once your blood cells begin to grow and your immune system recovers.

 

Infection

You can easily get an infection after the transplant because your immune system is weak. Some infections are serious. Infections can be caused by:

 

Bacteria, such as those in your mouth or around your central line

Viruses, such as herpes or cytomegalovirus

Fungus or yeast, such as candida

 

To prevent infections, you will stay in a single room. The air will be filtered to keep germs out. Doctors, nurses, and others who visit you will wear face masks and wash their hands very carefully. Your doctor may have you take medicine to fight infections even if you don't already have an infection.

 

You also can take other steps to prevent infections.

 

Bathe or shower daily.

Carefully clean your teeth and gums.

Keep the area clean where your central line enters your body.

Avoid foods, such as raw fruits and vegetables, that may have harmful bacteria.

 

Graft-versus-host disease and graft failure

Donated stem cells can attack your body. This is called graft-versus-host disease. Your immune system also can attack the donated stem cells. This is called graft failure. These events can be minor or life threatening. They can happen soon after transplant or can develop slowly over months.

 

What to expect after the transplant

You will stay in the hospital for weeks or even months after your blood and marrow stem cell transplant. Your doctors want to be sure that you're healthy and strong enough to go home.

 

They want to make sure:

 

Your bone marrow is making enough healthy blood cells

You have no severe complications

You feel well and your mouth sores and diarrhea have improved or gone away

Your appetite has improved

You have no fever or vomiting

 

During the first weeks and months after you leave the hospital, you will make frequent trips to an outpatient clinic. This allows your doctors to track your progress. These visits will happen less often over time.

 

Staff at the clinic will teach you and your caregiver how to care for your central line, how to watch for and prevent infections, and other ways to care for you. They also will tell you who to call and what to do in case of emergency.

 

Recovery from a stem cell transplant can be slow. It takes 6 to 12 months to recover normal blood cell levels and immune function. During this time, it's important for you to take steps to reduce risk of infection, get plenty of rest, and follow your doctors' instructions about medicines and checkups.

 

Risks

The main risks of a blood and marrow stem cell transplant are infection, graft-versus-host disease (GVHD), and graft failure.

 

Infection

You can easily get an infection after the transplant because your immune system is weak. The risk for infection decreases as your immune system recovers.

 

You can take steps to prevent infections, such as washing your hands and staying away from crowds. Doctors use medicines to prevent and treat infections.

 

Graft-versus-host disease

GVHD is a common complication if you receive stem cells from a donor. In GVHD, the new stem cells attack your body.

 

Acute GVHD occurs within 90 to 100 days after the transplant. Chronic GVHD begins more than 90 to 100 days after the transplant or goes beyond 90 days after the transplant.

 

GVHD can be minor or life threatening. Signs and symptoms include:

 

A rash that starts on the palms and soles of your feet and spreads to your mid-section. Over time, the rash may cover your entire body. Skin can blister or peel if the rash is very bad.

Nausea (feeling sick to your stomach), vomiting, loss of appetite, abdominal cramps, and diarrhea. Doctors determine how bad GVHD is based on the severity of diarrhea.

Jaundice (yellowing of the skin and eyes) and abdominal pain, which indicate liver damage.

 

Medicines are used to treat GVHD. Acute GVHD is treated with glucocorticoids, such as methyl prednisone, prednisone in combination with cyclosporine, antithymocyte globulin, or monoclonal antibodies.

 

Chronic GVHD is treated with steroids – usually cyclosporine and prednisone on alternating days.

 

Older people, people who have had acute GVHD before, and people who received stem cells from mismatched or unrelated donors are more likely to develop GVHD.

 

Doctors can reduce your chances of getting GVHD by:

 

Closely matching your stem cells to your donor's through HLA tissue typing.

Using medicines to suppress your immune system.

Removing T cells from donor cells. T cells attack your body in GVHD.

Using umbilical cord blood as the source of donor cells.

 

Graft failure

Graft failure occurs when your immune system rejects the new stem cells. It also can occur if not enough stem cells are used, the new stem cells are damaged during storage, or your bone marrow is damaged after the transplant.

 

Graft failure is more likely in people who receive less preparation for their transplants. People who get stem cells from a poorly matched donor also are more likely to have graft failure.

 

Other risks

Complications from chemotherapy and radiation treatment (used to prepare for a transplant) can occur long after a transplant. These complications include infertility, cataracts, new cancers, and damage to the liver, kidneys, lungs, or heart.