9/8/2011: Sickle Cell Disease – the 411
What is Sickle Cell Disease?Sickle cell disease is one of the most common genetic diseases in the United States. There are more than 80,000 people in the U.S. living with sickle cell. It is a lifelong disease that affects the red blood cells of your body. Hemoglobin is the protein that carries oxygen in your red blood cells. In people with sickle cell this protein is abnormal. This abnormality causes red blood cells to develop a hard, sickled shape instead of the normal soft, stretchable, doughnut shape of a healthy red blood cell. Due to their sickled shape, sickle cells often become stuck in blood vessels and block the flow of blood to certain areas of the body. These blockages often lead to pain. Sickle cells are also fragile and break apart easily; this is called hemolysis. As a result, sickle cells die very quickly in circulation, about every 15-20 days, compared to a normal red blood cell that lasts about 120 days. The excess breakdown of red blood cells in patients with sickle cell disease can cause a patient to be anemic. Anemia is a condition in which there are too few red blood cells or hemoglobin in a person’s circulation.
What is Sickle Cell Trait?You are born with two copies of every gene–one from your mother and one from your father. In order to have sickle cell disease, you must inherit two abnormal sickle cell genes, one from each of your parents. If you inherit one abnormal gene and one normal gene, you are said to be a “carrier” and have “sickle cell trait.” An estimated 3.5 million Americans live with sickle cell trait. Patients with sickle cell trait do not have sickle cell disease and or symptoms of sickle cell; therefore, carriers are often unaware that they have sickle cell trait. This is why it is important to undergo testing to see if you carry the trait. The only way to determine if you have sickle cell trait is to undergo a special blood test called hemoglobin electrophoresis. If two parents with sickle cell trait have a baby, that child has a 25% chance of having sickle cell disease, regardless of the infant’s sex.
What are the complications?As sickle cells often get stuck in blood vessels, a complication of sickle cell disease can be organ damage. This is specifically caused by the blockage of blood flow to a specific organ. Stroke, kidney disease, gallstones, infections, leg ulcers, and pain are other complications of sickle cell disease.
What are recent advances in sickle cell disease?In the 100 years since sickle cell disease was discovered, there have been major medical advances. Presently, all babies born in the U.S. are screened for sickle cell disease. If an infant is found to have sickle cell disease, the parents are notified and the baby is started on antibiotics to prevent infections common in those with sickle cell disease. Antibiotics are continued throughout childhood until immunizations have been completed. Preventative antibiotic treatment for sickle cell patients was a medical breakthrough and has greatly increased the lifespan of those affected with the disease. Prior to antibiotic treatment, patients often died of infections in childhood. Research has shown that newborns should be screened for sickle cell disease not only to be placed on preventative antibiotics, but also to allow for stroke prevention measures to be taken. Stroke is a complication of sickle cell disease. In adults, the only FDA approved medication for sickle cells disease is hydroxyurea. Hydroxyurea reduces painful crisis episodes and decreases the need for blood transfusions.