How you prepare

You'll undergo a series of tests and procedures to assess your general health and the status of your condition, and to ensure that you're physically prepared for the transplant. The evaluation may take several days or more.

In addition, a surgeon or radiologist will implant a long thin tube (intravenous catheter) into a large vein in your chest or neck. The catheter, often called a central line, usually remains in place for the duration of your treatment. Your transplant team will use the central line to infuse the transplanted stem cells and other medications and blood products into your body.

Collecting stem cells for transplant

If a transplant using your own stem cells (autologous transplant) is planned, you'll undergo a procedure called apheresis (af-uh-REE-sis) to collect blood stem cells.

Before apheresis, you'll receive daily injections of growth factor to increase stem cell production and move stem cells into your circulating blood so that they can be collected.

During apheresis, blood is drawn from a vein and circulated through a machine. The machine separates your blood into different parts, including stem cells. These stem cells are collected and frozen for future use in the transplant. The remaining blood is returned to your body.

If a transplant using stem cells from a donor (allogeneic transplant) is planned, you will need a donor. When you have a donor, stem cells are gathered from that person for the transplant. This process is often called a stem cell harvest or bone marrow harvest. Stem cells can come from your donor's blood or bone marrow. Your transplant team decides which is better for you based on your situation.

Another type of allogeneic transplant uses stem cells from the blood of umbilical cords (cord blood transplant). Mothers can choose to donate umbilical cords after their babies' births. The blood from these cords is frozen and stored in a cord blood bank until needed for a bone marrow transplant.

The conditioning process

After you complete your pretransplant tests and procedures, you begin a process known as conditioning. During conditioning, you'll undergo chemotherapy and possibly radiation to:

• Destroy cancer cells if you are being treated for a malignancy
• Suppress your immune system
• Prepare your bone marrow for the new stem cells

The type of conditioning process you receive depends on a number of factors, including your disease, overall health and the type of transplant planned. You may have 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
• Diarrhea
• Hair loss
• Mouth sores or ulcers
• Infection
• Bleeding
• Infertility or sterility
• Anemia
• Fatigue
• Cataracts
• Organ complications, such as heart, liver or lung failure

You may be able to take medications or other measures to reduce such side effects.

Reduced-intensity conditioning

Based on your age and health 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 conditioning kills some cancer cells and somewhat suppresses your immune system. Then, the donor's cells are infused into your body. Donor cells replace cells in your bone marrow over time. Immune factors in the donor cells may then fight your cancer cells.

Overview

An allogeneic stem cell transplant uses healthy blood stem cells from a donor to replace bone marrow that's not producing enough healthy blood cells. An allogeneic stem cell transplant is also called an allogeneic bone marrow transplant.

Bone marrow transplants for adults and children may involve of use of one’s own cells (autologous transplant), cells from a donor (allogeneic transplant) or cells from an umbilical cord (cord blood transplant). The blood stem cells used in an allogeneic stem cell transplant can be:

• Collected from the donor's blood
• Collected from the bone marrow within a donor's hipbone
• Collected from the blood of a donated umbilical cord

Before undergoing an allogeneic stem cell transplant, you'll receive high doses of chemotherapy or radiation to destroy your diseased cells and prepare your body for the donor cells.

Why it's done

An allogeneic stem cell transplant may help treat or cure more than 75 conditions.

Blood and bone marrow cancers

These include:

• Hodgkin disease.
• Non-Hodgkin lymphoma.
• Leukemia.
• Multiple myeloma.
• Myelodysplastic syndromes, a group of blood cancers in which blood cells in bone marrow don't mature.
• Myeloproliferative neoplasms, a group of blood cancers in which the bone marrow makes too many red blood cells, white blood cells or platelets.

Blood conditions

Other conditions that an allogeneic stem cell transplant may help treat include:

• Adrenoleukodystrophy, a condition passed through families that damages the membrane that protects the nerve cells in the brain.
• Aplastic anemia, a condition in which the bone marrow stops making enough new blood cells.
• Immune deficiencies, conditions that make it hard for the body to fight infections.
• Gene changes that affect the body's process of turning food into energy, called metabolism.
• Sickle cell disease, a blood condition passed through families that causes red blood cells to take a different shape, block blood flow and cause pain.

Risks

The main risks of allogeneic stem cell transplant include:

• Rejection. Your body may reject the donated cells before they can begin making new cells in your bone marrow.
• Graft-versus-host disease (GVHD). This is when the immune cells from the donor's stem cells, called the graft, attack your cells, called the host.

• Side effects of chemotherapy or radiation. These may include tiredness, not wanting to eat, stomach upset, mouth sores, hair loss, infections and skin rash.

  Other side effects may include organ damage, new cancers and not being able to have children, called infertility. Talk with your care team about what to expect from your treatment.

What you can expect

Before

Before you have an allogeneic stem cell transplant, you:

• Get high doses of cancer treatment. This process is called conditioning. During conditioning, the high doses of chemotherapy or radiation therapy kill cancer cells. This is done if you're being treated for cancer that might spread to other parts of the body.

  The treatment also weakens your immune system to keep it from rejecting the donor cells. And the treatment gets your bone marrow ready for new stem cells.

  The treatment you have depends on your condition and other factors. Some older adults or people who aren't strong enough for the full conditioning treatment have what's called a reduced-intensity allogeneic stem cell transplant or a mini-transplant. They get stem cells from a donor, but the conditioning uses lower doses or other types of chemotherapy and radiation.

• Get matched to a donor. Healthcare professionals compare a sample of your blood with blood from possible donors. The match is based on markers that are on most cells in the body, called human leukocyte antigens. A close match raises the chances of a successful transplant and lowers the risk of complications.

  The donor may be a family member or someone from a donor registry who isn't related to you. To raise the number of possible donors, some transplant centers have started to do half-match transplants. These are called haploidentical transplants. More study is needed on the long-term results of half-match transplants.

During

The procedure involves getting stem cells from a donor through a vein. This is called an infusion. The procedure takes 1 to 5 hours to transfer all the cells.

From your bloodstream, the donor cells travel to your bone marrow and begin making new blood cells. This is called engraftment.

After

After your transplant, your care team watches you for complications. You may spend 60 to 100 days in or near the hospital. Expect to have blood tests and appointments often to check your body's response to the transplant and to watch for infection. You may need to get donor blood through a vein, called a transfusion, until your bone marrow starts to make enough cells on its own.

You may stay under the care of your transplant center during follow-up. Or your transplant team may make a care plan for you to follow with your main healthcare professional.

After the first 100 days, you have follow-up appointments every three months for a year. For year two, you go every six months. After that, your appointments are every 12 months.

It may take a few weeks for the donor cells to settle into your bone marrow and begin making new cells. Even after the cells engraft, your immune system may be weakened for a year or two.

You may need to take medicines to help prevent complications such as graft-versus-host disease and infections. You also may take medicines for the side effects of chemotherapy and radiation. And you need to eat a healthy diet and exercise after your transplant.

Results

An allogeneic stem cell transplant can cure some conditions and help manage others. It can extend your life and improve your quality of life.