Sickle Cell Anemia

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KEY POINTS

• Sickle cell anemia is an inherited life-long condition caused by abnormal, sickle-shaped red blood cells. The abnormal blood cells are stiff and sticky. They can block blood flow in the blood vessels of the limbs and organs causing pain and organ damage and raising the risk for infection.
• Treatment includes medicines, blood transfusions, and sometimes bone marrow transplants.
• To prevent sickle cell crises, it helps to avoid strenuous exercise, smoking, and dehydration from excessive sweating, vomiting, or diarrhea.

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What is sickle cell anemia?

Sickle cell anemia is a blood disease that causes abnormal red blood cells. Sickle cell anemia is an inherited, lifelong disease. Red blood cells contain an iron-rich protein called hemoglobin. This protein carries oxygen from your lungs to the rest of your body. If you have sickle cell anemia, most of your red blood cells have an abnormal type of hemoglobin called hemoglobin S. Hemoglobin S changes the shape of your red blood cells. Instead of being soft and round, the cells are a stiff crescent (sickle) shape. This shape makes it harder for the blood cells to pass through small blood vessels. Sickle cells are stiff and sticky. They can block blood flow in the blood vessels of the limbs and organs causing pain and organ damage. This can raise the risk for infection.

Normal blood cells usually last about 4 months and are always being replaced. Normal red blood cells look like doughnuts without holes in the center. They move easily through your blood vessels. The abnormal blood cells are fragile and last only a few weeks. Your body may not be able to make new red blood cells fast enough. This can cause a shortage of red blood cells. The shortage of red blood cells is called anemia.

What is the cause?

Sickle cell anemia is inherited. Genes are in each cell of your body. They contain the information that tells your body how to develop and work. Changes in the genes can be passed from parents to children. If you inherited the gene from both of your parents, it is likely you will have the disease. If you inherited the faulty gene from just 1 of your parents, usually you will not have the disease, but you can pass the gene on to your children (sickle cell trait).

People from Africa, South or Central America, Caribbean islands, Turkey, Greece, Italy, India, and Saudi Arabia have a high risk of the disease. In the US, sickle cell anemia affects mainly African Americans and Hispanic Americans.

What are the symptoms?

The symptoms are different from person to person and can range from mild to severe. Most people with sickle cell anemia have times when they have symptoms and times when they do not have symptoms. The most common symptoms are related to anemia and pain.

Symptoms of anemia may include:

• Feeling tired all the time
• Shortness of breath, dizziness, headaches, coldness in hands or feet
• Skin more pale than usual
• Yellowing of skin or eyes

When abnormal red blood cells block the flow of blood and cause symptoms, it is called a “crisis.” The most common symptom of a sickle cell crisis is pain. The pain is usually felt in the part of the body where the sickling cells are blocking blood flow. Crises may start suddenly and last from a few days to several weeks. The pain may be mild to severe. Although not as common as a crisis, you may also have ongoing pain, which is often felt in the bones.

Sickle cells crises can cause damage to many organs. Damage to the spleen can make it easier to get an infection and harder to fight certain infections. Symptoms may include:

• Ongoing fever higher than 101°F (38.3°C)
• Cough that produces mucus
• Vomiting
• Diarrhea
• Stomach pain

What are the complications of sickle cell anemia?

Abnormal red blood cells can cause problems in any part of your body. Some of the possible problems are:

• Infections such as pneumonia or meningitis
• High blood pressure in the lungs that can cause trouble breathing and heart damage
• Acute chest syndrome, which is a life-threatening lung problem that causes fever, chest pain or pressure, cough, or shortness of breath
• Kidney or bone infections
• Gallstones
• Loss of vision caused by damage to blood vessels in the eyes
• Hip and shoulder joint damage
• Stroke

Males who have sickle cell anemia may have painful, unwanted erections that do not return to normal within 4 hours. Over time, damage to tissues in the penis may make it hard for a man to have erections.

• Too much blood collecting in the spleen
• Painful leg sores

How is it diagnosed?

In the US, sickle cell anemia is usually diagnosed at birth with a newborn screening test.

Sickle cell anemia can be diagnosed before birth with DNA testing of a baby's cells. This is done by:

• Chorionic villus sampling (CVS), which takes a small sample of tissue from the placenta (the tissue that carries oxygen and food from the mother’s blood to the baby’s blood). This test is usually done between the 10th and 13th weeks of pregnancy.
• Amniocentesis, which uses a needle put through the mother’s belly to test the fluid that surrounds the baby. This test is usually done between the 15th and 18th weeks of pregnancy.

If you have never been screened for sickle cell anemia, you may have blood tests to look for anemia, sickle-shaped red blood cells, and abnormal hemoglobin.

How is it treated?

Sickle cell anemia has no common cure. Treatments may improve the anemia and lower complications. Blood and marrow stem cell transplants may offer a cure for a small number of people.

If you have sickle cell anemia, it is very important for you to work with healthcare providers who have experience treating sickle cell disease.

Treatments may include:

• Pain medicine
• Medicine to try to prevent sickle cell crisis. Taken daily, this medicine may help you have fewer crises. It can also shorten how long each crisis lasts.
• Vaccines such as Haemophilus influenzae type b, hepatitis A and B, influenza (flu), meningitis, and pneumococcal vaccines to prevent infection. People with sickle cell anemia are more likely to have serious infections, ranging from flu to pneumonia. Infections can cause a sickle cell crisis.
• Blood transfusions
• Antibiotics
• Folic acid to help make red blood cells
• Bone marrow transplant
• Gene therapy is being studied as a possible treatment for sickle cell anemia. Gene therapy adds a healthy version of a hemoglobin gene to blood stem cells.
• Medicine to remove extra iron in your body. You should not take iron supplements if you have sickle cell disease. Sickle cell anemia is not caused by too little iron in the blood. Taking iron supplements can be harmful because the extra iron builds up in your body and can damage your organs.

How can I take care of myself?

To try to prevent sickle cell crises, avoid things that lower the blood oxygen, such as:

• Strenuous exercise
• Extreme hot or cold temperatures
• High altitude
• Tight clothing
• Things that can make the blood vessels narrower, such as:
  • Some medicines
  • Cigarette smoking
  • Illegal drugs, such as cocaine
• Also try to avoid dehydration. A loss of too much fluid from your body can cause sickling. Your body may lose too much fluid from:
  • Heavy sweating
  • Urinating a lot, which can happen with uncontrolled diabetes or taking diuretics (water pills)
  • Fever
  • Vomiting or diarrhea

Talk about how you feel with your health care team. Talking to a professional counselor also may help.

If you are considering getting pregnant, talk with your healthcare provider about any special care you may need to limit risks to yourself and the baby.

Follow the full course of treatment prescribed by your healthcare provider. Ask your provider:

• How and when you will get your test results
• If there are activities you should avoid and when you can return to your normal activities
• How to take care of yourself at home
• What symptoms or problems you should watch for and what to do if you have them

Make sure you know when you should come back for a checkup.

How can I help prevent sickle cell anemia?

People who have the gene may pass the disease on to their children. Couples can get tested for the gene that causes sickle cell disease. If one of you has the gene, you will need to decide whether to take the chance of passing the disease on to your children. You may want to talk with a genetic counselor if anyone in your family has sickle cell anemia.

For more information, contact:

• National Organization for Rare Disorders: Sickle Cell Disease
  203-744-0100
  https://rarediseases.org/rare-diseases/sickle-cell-disease/
• Sickle Cell Information Center
  404-616-3572
  https://scholarblogs.emory.edu/scinfo/patients-families/