Sickle Cell Disorders
Sickle cell disease is the most common hereditary blood disorder in the world. It most commonly affects black Africans and Americans, as well as some persons of Mediterranean, East Indian or Latin American descent. In the United States, it is estimated that 70,000 Americans of various ethnic backgrounds are affected with sickle cell disorders. About 8% of the African-American population carries the sickle cell trait. Sickle cell disease affects approximately 1 in 400 African-Americans.
Types of Sickle Cell Disease
Sickle cell diseases are a group of hereditary hemoglobinopathies. Hemoglobinopathies are a group of diseases caused by abnormal hemoglobin in the blood. Hemoglobin is the component of the blood cell that transports oxygen from the lungs to body organs and tissues and returns carbon dioxide to the lungs. Sickle cell anemia, which is commonly known, is but one type of sickle cell disease. There are several other sickling disorders including: hemoglobin SC disease, hemoglobin SD disease and hemoglobin SOArab disease. All of these disorders have defects in the hemoglobin causing red blood cells to distort into a sickle shape. Hemoglobin S, one of the four components of the hemoglobin molecule, is responsible for the distortion of the hemoglobin in sickle cell disorders. Collectively, persons with these disorders have a prevalence of hemoglobin S in their cells. Because of the distortion caused by the defective hemoglobin, the red blood cells can become stiff and rigid, causing blockage or rupturing of small blood vessels that supply oxygen to the organs and tissue. Sickle cell diseases cause chronic anemia (low blood counts), can cause decreased resistance to infections, can damage organs (particularly the lungs and kidneys), and are responsible for both acute and chronic pain.
Treatment
Treatment primarily consists of management of
symptoms. Antibiotics and vaccines are used to
treat and prevent infections. A variety of
pain medications (narcotics such as morphine,
oxycodone and methadone) are used to treat the
painful conditions associated with sickle cell
disorders. Patients also need to drink large
amounts of fluids to prevent dehydration.
Only one drug has been approved by the U.S. Food and Drug Administration (FDA) to treat sickle cell disease, hydroxyurea. Hydroxyurea causes the body to produce fetal hemoglobin. Fetal hemoglobin is normally only found in children for a short time after birth before it is naturally replaced by adult hemoglobin. Studies have found that persons with sickle cell disease who had a high concentration of fetal hemoglobin in their blood experience a milder disease. Hydoxyurea holds a lot of promise for increasing the lifespan and lowering the complications of persons with sickle cell disorders.
Sickle Cell Trait
Having the sickle cell trait does not mean having a sickle cell disease. Although some carriers of a sickle cell trait may experience minor symptoms, the defective gene must be inherited from each parent to have a sickle cell disease. Blood tests can be performed at infancy to determine if the child has the disease or is a carrier of the sickle cell trait. Early diagnosis of sickle cell diseases is crucial so that children can receive proper medical care. Proper care requires a comprehensive approach to treating the disease including therapy for pain, infections, other complications and treatment of the psychological aspects of having the disease.
