This is an uncommon anemia that develops when red blood cells are destroyed faster than bone marrow can replace them. The result is a shortage of red blood cells to transport oxygen. Early destruction can result from genetic defects or acquired defects.
Genetic defects in the red blood cells' physical or chemical makeup can lead to a rigid or elongated shape. The deformity causes red blood cells to become trapped in the spleen, where most are destroyed before the end of their normal lifespan. More commonly, defective hemoglobin causes red blood cells to develop a crescent (sickle) shape. Sickle cells lodge in small arteries, causing acute pain and blood clots.
Acquired defects can occur when certain infections or the use of antibiotics or anti-inflammatory drugs break down red blood cells. Occasionally, one can acquire a mild form of anemia through an autoimmune process. Some artificial heart valves increase the risk of red blood cell destruction by directly injuring cells.
Sickle Cell Anemia
Sickle Cell anemia is a group of inherited red blood cell disorders. Normal red blood cells are round like doughnuts, and move through small blood tubes in the body to deliver oxygen. Sickle red blood cells become hard, sticky and crescent-shaped. When these cells go through the capillaries, they clog the flow and break apart. This can cause pain, damage, a low blood count or anemia.
There is a substance in the red cells called hemoglobin that carries oxygen. One little change in this substance causes the hemoglobin to form long rods in the red cell when it gives away oxygen. These rigid rods change the red cell into a sickle shape.
A person inherits the abnormal hemoglobin from both parents who may be carriers of the sickle cell trait or have sickle cell disease. In this case one is born with the sickle cell hemoglobin and it is present for life. Sickle cell occurs in many ethnic groups including African Americans, Arabs, Greeks, Italians, Latin Americans and Native Americans. All races should be screened for this hemoglobin at birth.
A simple blood test called the hemoglobin electrophoresis can be performed by a doctor or local sickle cell foundation. This test will determine whether a person is a carrier of the sickle cell trait or has the disease. Most states in the US now perform the sickle cell test when babies are born. Sickle cell trait does not adversely affect an individual's life expectancy.