Sickle cell anemia is an inherited condition characterized by the formation of rigid and crescent-shaped red blood cells that are destroyed prematurely, resulting in a shortage of red blood cells in the body. Usually, the red blood cells are round and bi-concave in shape and are flexible, permitting them to move inside the blood vessels. However, in sickle cell anemia, the red blood cells become inflexible, crescent-shaped and rigid, especially during stressful conditions. They tend to clump, blocking several important blood vessels.
The individual affected with sickle cell anemia is at the risk of developing several complications including anemia, ischemia, pain, heart failure, renal failure, swelling, jaundice, difficulty in breathing, and fatal outcomes (Mayo, 2007). The condition is most frequent in the Black population, and also those of the Mediterranean descent. It also occurs to a lower extent in the Latin American, Caribbean and the Middle East populations. In the US, about 13 % of the Black population have the heterogeneous form of sickle cell anemia, whereas, 0.3 % of the Black population develop the homozygous form of sickle cell anemia.
Individuals who have the homozygous form develop sickle cell anemia and have the signs and symptoms, whereas those with the heterozygous form develop sickle cell trait, and are likely to develop milder symptoms (Merck, 2009). Causes The condition is caused due to homozygous inheritance of the defective of the Hb-S gene. Both copies of the defective gene need to be inherited from the parents in order to develop the signs and symptoms of the condition.
The defective gene expresses a defective form of hemoglobin known as ‘Hb-S’ resulting in the tendency to clump, become fragile and breakdown during low oxygen conditions. Offspring who inherited the Hb-S gene from one parent, and the Hb-A gene from another, are likely to develop sickle cell trait, which is a milder form of sickle cell anemia. An individual who inherits Hb-S from one parent and other abnormal forms of hemoglobin from others are likely to develop thalassemia and other types of sickle cell disorders (Mason, 2008).
The valine in the 6th position amino acid of the beta chain is changed to glutamic acid, in Hb-S. During low oxygen conditions, Hb-S tends to crystallize or develop into a semi-solid thus resulting in sickling of the RBC and subsequent clumping. This causes infarction and results in destruction of the red blood cells (Merck, 2009). The sickle cell gene is passed on from parents to child, and the child would develop the condition only if both the parents pass on the defective Hb-S gene.
The parents can either suffer from sickle cell anemia or sickle cell trait. Scientists consider that sickle cell anemia developed thousands of years ago. People who one copy of the defective gene (sickle cell trait), were resistant to malaria. People who had both copies of the defective gene died from sickle cell anemia, whereas those who were normal died from the rampant forms of malaria prevalent in Africa, India and the Middle East. However, people who had sickle cell trait, were resistant to malaria, and managed to survive.
They passed on the defective gene from one generation to another, and in children whose both parents had the defective Hb-S gene, they developed sickle cell anemia (Mayo, 2007). Signs and Symptoms Some individuals suffering from sickle cell anemia may have little or no symptoms. In others, anemia may develop along with jaundice and bone pain. The symptoms usually get severe during stressful activities leading to disability and fatal outcomes. Some of the activities during which the condition can get worsened include strenuous exercises, mental stress, military training, athletic training, dehydration, etc.
The symptoms are usually experienced more often in people who suffer from the homozygous version of the disease (Merck, 2009). In infants, the symptoms usually develop 4 months following birth. Babies tend to develop swollen hands and legs. In some adults and children hospitalization may be required to manage the complications. A person suffering from sickle cell anemia develops anemia resulting in tiredness, fatigue, breathlessness and weakness. The episodes of pain and swelling usually develop during the sickle cell crisis.
The pain usually arises from the bones and can remain for several hours or days. In some patients, the pain is very severe in intensity requiring hospitalization. As the sickle celled RBC’s tend to clump and get destroyed in the body, jaundice develops resulting in damage to the liver and the kidneys. Such people are also likely to develop problems with the spleen resulting in frequent infections. In children, the ability to grow and develop is seriously affected. Some people also develop visual problems, as the blood vessels that supply the retina get clogged (Mayo, 2007).
The other problems that can develop in sickle cell anemia include heart attacks, cardiomegaly, formation of ulcers on the ankles, hemathrosis of the joints, abdominal pain, vomiting, nausea, chest pain, pleural effusion, pulmonary hypertension, erectile dysfunction (pain during erections), ischemic strokes, CNS vasculitis, blood in urine, excessive thirst, blindness, tachycardia, palpitations, etc (Mason, 2008, & Merck, 2009). Children and adults suffering from sickle cell anemia are also likely to develop a condition in which difficulty in breathing develops along with severe chest pain, known as ‘chest syndrome’.
This is due to an embolus or thrombi blocking an important blood vessel (Merck, 2009). Individual s affected with sickle cell trait is likely to remain symptom-free but develop symptoms during heavy and strenuous exercises. Some of the problems that are likely to develop include hematuria, muscle problems, renal problems, and sudden death (Merck, 2009). Diagnosis The diagnosis of sickle cell anemia is made based upon the history, symptoms, signs, complete blood count, hemoglobin studies and the sickle cell test.
Besides, other test may be required depending on the symptoms and the problems that the individual can develop. These include CT or MRI scans (to demonstrate strokes), bilirubin tests (to demonstrate jaundice), urine tests (to demonstrate the presence of blood, urine casts and creatinine), peripheral blood smear (to demonstrate the sickle cells), genetic tests (to determine the presence of sickle cell anemia or trait, etc (Mason, 2008). The hemoglobin electrophoresis tests helps to determine the levels of various types of hemoglobin that are present in the blood.
Sickle cell anemia can also be detected in the fetus by testing the amniotic fluid (Mayo, 2007). During jaundice, the serum bilirubin levels are elevated. The white blood cell counts and the platelet counts are also high in people suffering from sickle cell anemia. The best way to test for the process of sickling would be to take an unstained drop of blood in a slide, adding a reducing agent and cover sealing it with Vaseline (Merck, 2009). Treatment The symptoms of sickle cell anemia can be controlled and the anemia can be relieved by known techniques.
All activities that are stressful and can result in a sickle cell crisis should be avoided. Even during minor helath problems, the affected individual should seek medical attention. Such individuals are at the risk of developing infections, and hence should receive vaccination against H. Influenza (Merck, 2009). Some individuals suffering from sickle cell anemia may require hospitalization and provide them with intravenous fluid support and pain relief. In serious cases in which RBC’s are destroyed in huge numbers, transfusions may be required.
Besides, if the patient is at a risk for stroke, heart attacks, pulmonary infarction, etc, immediate medical support needs to be provided (Merck, 2009). Children suffering from sickle cell anemia require antibiotics when they are 2 months of age till the age of 5 years so as to prevent infections. Prompt treatment of infections is required for the rest of the life. During the sickle cell crisis painkillers such as aspirin may be administered. Oxygen may also be required after stressful activities in order to prevent the development of a crisis (Mayo, 2007).
One of the drugs that can be administered to treat the condition is hydroxyurea (an anticancer drug), that increases the concentration of Hemoglobin-F and decreases the production of hemoglobin-S. Hence there are reduced chances of the cells becoming sickled. However, use of the drug over long periods can result in the development of leukemia and other cancers (Mayo, 2007). Bone marrow transplant involves transferring normal bone marrow tissue to the bone marrow of the affected individual. This would result in the production of normal hemoglobin and hence and improvement in the condition.
However, the bone marrow type of the donor needs to be similar to that of the recipient. Besides, immunosuppressant’s need to be administered for a long period of time, which can negatively affect the general, health of the child (Mayo, 2007). Scientists are also exploring the use of gene therapy in the treatment of sickle cell anemia. Besides, individuals suffering from other problems in sickle cell anemia require other treatment measures including dialysis (for kidney failure), gall bladder surgery (for gallstones), partial exchange transfusion (for chest syndrome), neurosurgery (for strokes), etc (Mason, 2008).
Outcome Usually, individuals meet with fatal outcomes following sickle cell crisis and other problems during their 20’s or 30’s. However, using better treatment options, life can be prolonged to the age of 40 to 50 years (Mason, 2008). Complications Some of the complications that can develop in sickle cell anemia include sickle cell crisis, chest syndrome, painful erections, gallstones, pneumonia, pulmonary infarctions, renal failure, heart attacks, strokes, skin ulcers, spleen dysfunction, liver damage, frequent infections, anemia, blindness, etc (Mason, 2008).