SICKLE CELL ANEMIA
What Is Sickle Cell Anemia?
Sickle cell anemia, also called Hemoglobin SS Disease, is an inherited blood disorder, characterized primarily by chronic anemia and periodic episodes of pain. The underlying problem involves hemoglobin, a component of the red cells in the blood. The hemoglobin molecules in each red blood cell carry oxygen from the lungs to the body organs and tissues and bring back carbon dioxide to the lungs.
In sickle cell anemia, the hemoglobin is defective. After the hemoglobin molecules give up their oxygen, some of them may cluster together and form long, rod-like structures. These structures cause the red blood cells to become stiff and to assume a sickle shape.
Sickled red cells, unlike normal red cells, which are usually smooth and donut-shaped, cannot squeeze through small blood vessels. Instead, they stack up and cause blockages that deprive the organs and tissue of oxygen-carrying blood. This process produces the periodic episodes of pain and ultimately can damage the tissues and vital organs and lead to other serious medical problems.
Unlike normal red blood cells, which last about 120 days in the bloodstream, sickled red cells die after only about 10 to 20 days. Because they cannot be replaced fast enough, the blood is chronically short of red blood cells, a condition called anemia.
What Causes Sickle Cell Anemia?
Sickle cell anemia is caused by an error in the gene that tells the body how to make hemoglobin. The defective gene tells the body to make the abnormal hemoglobin that results in deformed red blood cells.
Children who inherit copies of the defective gene from both parents will have sickle cell anemia. Children who inherit the defective sickle hemoglobin gene from only one parent will not have the disease, but will carry the sickle cell trait. Individuals with sickle cell trait generally have no symptoms, but they can pass the sickle hemoglobin gene on to their children.
What Are the Signs and Symptoms of Sickle Cell Anemia?
The clinical course of sickle cell anemia does not follow a single pattern; some patients have mild symptoms, and some have very severe symptoms. The most common symptoms are severe pain and anemia. However, the basic problem is the same--the sickle-shaped red blood cells tend to get stuck in narrow blood vessels, blocking the flow of blood.
How Is Sickle Cell Anemia Detected?
Early diagnosis of sickle cell anemia is critical so that children who have the disease can receive proper treatment.
More than 40 states now perform a simple, inexpensive blood
test
for sickle cell disease on all newborn infants. This test is
performed at the same time and from the same blood samples as
other routine newborn screening tests. Hemoglobin electrophoresis
is the most widely used diagnostic test.
If the test shows the presence of sickle hemoglobin, a second blood test is performed to confirm the diagnosis. These tests also tell whether the child carries the sickle cell trait.
How Is Sickle Cell Anemia Treated?
Although there is no cure for sickle cell anemia, doctors can do a great deal to help sickle cell patients, and treatment is constantly being improved. Basic treatment of painful crises relies heavily on pain-killing drugs and oral and intravenous fluids to reduce pain and prevent complications.
Blood transfusions are used to treat and to prevent some of the complications of sickle cell anemia. Transfusions correct anemia by increasing the number of normal red blood cells in circulation. Transfusions are used to treat spleen enlargement in children before the condition becomes life-threatening. Regular transfusion therapy also can help prevent recurring strokes in children at high risk of crippling nervous system complications.
Giving young children with sickle cell anemia oral penicillin
twice a day, beginning when the child is about 2 months old
and continuing until the child is at least 5 years old, can
prevent pneumococcal infection and early death in these children.
