Stem Cell Transplant for Sickle Cell Disease

Treatment Overview

Stem cell transplant is a possible cure for sickle cell disease. It's usually considered only for children younger than 16 who have severe complications from the disease.

Stem cells can be found in bone marrow. Bone marrow is the substance in the centre of your bones that produces red blood cells. A person with sickle cell disease has bone marrow that produces red blood cells with defective hemoglobin S. But if that bone marrow is replaced with healthy bone marrow, a person's body may start to produce normal hemoglobin.

Stem cell transplants require bone marrow from another person (donor). This is called an allogeneic stem cell transplant.

Before the transplant, bone marrow stem cells are taken from someone who has closely matching bone marrow. This is most often a healthy brother or sister. The child who has sickle cell disease is then treated with drugs that destroy the child's bone marrow cells. After that, the donated bone marrow stem cells are injected into a vein.

After the process is complete, the donor's bone marrow starts to replace the recipient's bone marrow. These new cells restore the immune system and make normal red blood cells.

Until recently this treatment was mostly done for children. That's because the risk for serious problems increases with a person's age. But new methods of doing stem cell transplant are making it possible to successfully treat adults.

What To Expect

You may spend up to 4 weeks or longer in the hospital after the transplant. How long you stay depends on whether you got your own stem cells or donor stem cells. It also depends on your health and whether you have problems during or after the transplant.

You'll need constant care for a while after you are home. For the next 6 to 12 months, you'll see your doctor and have your blood tested often. You may get blood transfusions until you can make enough blood cells of your own. If the stem cells came from a donor, your doctor will check for signs that your body is rejecting the cells. Your doctor will want to see you if you have any sign of an infection.

Your doctor will let you know when it's safe for you to go public places where you could be exposed to germs from other people.

Your immune system will need time to get back to normal. It may take several years.

Why It Is Done

Stem cell transplants offer a potential cure for a child's sickle cell disease. They are usually considered only for children younger than 16 who have:^{footnote 1}

• Severe sickle cell disease complications, including repeat strokes, episodes of acute chest syndrome, and painful events.
• An available donor (someone who has closely matching bone marrow).

The risks of stem cell transplant become greater as a person gets older and/or develops damage to major organs. For these reasons, a bone marrow transplant is not a treatment option for most adults who have sickle cell disease. But research on bone marrow transplants in adults is ongoing.

How Well It Works

If it works, a stem cell transplant can cure sickle cell disease. This treatment has been successful in about 85 out of 100 children who had transplants.^{footnote 1, footnote 2} But the risk of dying after a transplant is about 5%.^{footnote 3}

Risks

• Any stem cell transplant is risky because complications, such as severe infections and immune system problems, can occur.
  • If the recipient's natural defence (immune) system isn't weakened enough by the medicines given before the transplant, it can attack the new stem cells and cause the transplant to fail.
  • If the donor's stem cells don't match the recipient's closely enough, the donor's new immune system cells may attack certain organs in the recipient (graft-versus-host disease).
  • Other complications can include seizures and bleeding in the brain.
• Life-threatening problems can happen. (About 5 out of 100 stem cell transplant recipients die.)^{footnote 3}
• A person may be unable to have children (infertile) after a stem cell transplant. But newer methods of doing this procedure are reducing this risk.