New Approches to The Treatment of
Sickle Cell Anemia

Bone Marrow Transplant

Bone marrow transplant (BMT) is a complex medical procedure that has been used for many years to treat patients with various kinds of cancers, such as leukemia. The bone marrow is the place where all of the blood cells are produced: red blood cells (that contain hemoglobin), white blood cells (that fight infection) and platelets (that help blood clotting).

In the past few years, this treatment has been used for some children and young adults with sickle cell anemia. Not everyone who has sickle cell anemia can have a transplant nor should everyone with sickle cell anemia have a transplant.

The procedure involves taking bone marrow from either a brother or sister (donor sibling) of the patient with sickle cell anemia. First, the donor must be a "match" for the child with sickle cell anemia. This "match" involves some very complex tests that are done on each child's blood. Only about 1 in 4 siblings will be a match for the brother or sister. Also, the donor must NOT have sickle cell anemia. It would not help to transplant bone marrow from someone who makes sickle cells into someone who already has them. Taking bone marrow from the donor involves an operation under general anesthesia, but it is not very dangerous.

Before the child with sickle cell anemia (recipient) can receive the bone marrow transplant, he or she must be given very strong medicines that will destroy the child's own bone marrow cells. Then the donor's marrow is given to the recipient in a way that looks much like a blood transfusion only it is the donor's bone marrow cells that are going into the patient's body. During this time, and for some months afterwards, there are very serious risks of infection for the child.

After a few weeks, if all goes well, the donor's bone marrow cells will begin to make normal red blood cells (and white cells and platelets) in the patient. If that happens, the patient will no longer have sickle cells in their blood and should not have any symptoms of the disease.

Part of the problem is trying to decide who should have a bone marrow transplant. Not every child with sickle cell anemia is seriously ill. Most children have not had a major complication from the disease such as stroke. And not every child will have a "matched" sibling so that even if someone needed a transplant, there might not be a suitable donor for them. There are risks to having a bone marrow transplant. The child who receives the transplant can become very ill and possibly die from the procedure. It is a major medical decision to undergo such a procedure.

Doctors are working on ways to try to identify patients who are likely to have the more serious complications of sickle cell anemia, i.e. stroke, before these events happen. Perhaps in the future, we will be able to recommend bone marrow transplant to those children who are at increased risk for serious complications from sickle cell disease before any major life-threatening event happens. Ask your doctor for more information about bone marrow transplant.

Hydroxyurea

Hydroxyurea is actually a chemotherapy medicine that has the side effect of increasing the amount of fetal hemoglobin in the blood. Fetal hemoglobin is produced before the baby is born and protects the red cells from taking on the sickle shape.

In a large study of adult patients with sickle cell anemia who were given Hydroxyurea, patients had less hospitalizations and less problems with acute chest syndrome. The medicine did not increase fetal hemoglobin levels in all patients. To be effective, this medication must be taken every day.

Some doctors have started to use Hydroxyurea in children who have had serious problems with the disease. It is too early to know if there is any long term benefit to taking this medication.

There are a variety of side effects associated with Hydroxyurea. It can cause skin and nail changes, anemia, sores in the mouth, lowering of the white blood cell counts and platelets. There may also be some long term effects on a child's growth and fertility. Hydroxyurea may also affect a developing fetus and it should not be taken by someone who is planning a pregnancy.

Blood Work

Your child will need to have periodic blood tests. One test, called a complete blood count or CBC, is done to determine the amount of white blood cells, hemoglobin and platelets in the child's blood (see below). The child with sickle cell disease usually has a low red blood count (low hemoglobin or anemia).

It is important for you to know the hemoglobin level and retic count (see below) that is normal for your child.

The most common blood work drawn on children with sickle cell disease will be discussed in this section. There will be times that other blood may be drawn from your child. Do not ever hesitate to find out what tests are being done and why.

• CBC (COMPLETE BLOOD COUNT) -
  When blood is drawn for this test your doctor is looking at three different values.
  
  • WBC (white blood cells) - These cells help the body to fight infection.
    
  • Hemoglobin - hemoglobin is inside the red blood cells and gives the blood its red color and carries oxygen to the muscles, organs, and body tissues.
    
  • Platelets - The part of the blood that helps make blood clot.

• RETICULOCYTE OR RETIC COUNT
  Reticulocytes are young red blood cells. Children with sickle cell disease make more young red blood cells because their red blood cells don't live very long. The retic count will then be high.

• TYPE AND CROSS MATCH
  This test is done before giving blood transfusions to make sure that the blood your child will be given matches your child's blood type. It is done before every transfusion is given.

• HEMOGLOBIN ELECTROPHORESIS
  This test will show the type of hemoglobin you and your child have. Normal hemoglobin is shown by "AA", sickle cell trait hemoglobin by "AS", and sickle cell hemoglobin by "SS".

Blood Transfusions

Blood transfusions can be very important in treating some of the problems of sickle cell disease. Your sickle cell doctor will not give a transfusion unless it is absolutely necessary. Many parents are very anxious about transfusions. These concerns are real. If you have religious beliefs or concerns about receiving blood transfusions, please discuss them with your child's doctor or nurse.

Since people with sickle cell disease cannot be transfused with blood that has the sickle trait, family members often cannot donate blood for the child's transfusions. People are always concerned about the risk of getting infections like AIDS and hepatitis from a transfusion. All blood donors are routinely screened for hepatitis and AIDS. We will only transfuse your child if we feel that the risk of the transfusion is less than the risk of the sickle cell problem we are treating.

Anesthesia

Before your child receives anesthesia for any reason, let your child's sickle cell doctor know. It is important for your child's sickle cell specialist to know even if general anesthesia is planned for dental work. Special precautions are required for a child with sickle cell disease before he/she receives any type of anesthesia. This must be discussed with your doctor before any procedure is done.

Always let all your child's doctors, including dentists, know that your child has sickle cell disease.

Surgery

Before your child has minor or major surgery, contact your child's sickle cell doctor and the child's regular doctor. These doctors can help the surgeon and hospital staff prepare the child for surgery and help manage his care afterward.