Sickle Cell Anemia

Understanding Sickle Cell Anemia

Sickle cell anemia is not as new as scientific documentation indicates. It was first documented in Africa in the 1870s and resulted in many deaths prior to the research that made management of it more effective. While there is no cure for the disease, there are interventions and treatment available that helps in minimizing and alleviating the symptoms of the disease. The following paper provides an overview of sickle cell anemia and current research on it to broaden the general understanding of this disease.

I. History

Hemoglobinopathy is the study of genetic abnormalities that involves the globin chains of hemoglobin, the red component in the blood that carries oxygen. The most common of these include the sickle cell trait. The first documented case of sickle cell disease was that of dental student Walter Clement Noel of Chicago in 1904 but symptoms associated with the disease is mentioned in African writings, referring the condition as chwecheechwe, abututuo, nuidudui and nwiiwii. When Noel was admitted, an intern named Ernest Irons noticed that Noel's blood presented unusual features, that of many elongated cells. The attending physician, James Herrick was informed and they proceeded to document the progression of the disease over two-and-a-half years. It took Noel nine years to succumb, presumably as a consequence of his condition.

A researcher named Haln first coined the term "sickle cell" but it was V.E. Emmel who documented that the sickle cell trait could be present in healthy individuals without developing anemia.

By the 1940s, it was established that the sickle cell was a result of abnormal hemoglobin but not the mechanism that led to the abnormality. In the 1950s, American scientist Vernon Ingram isolated the culprit, an amino acid called valine, which took the place of glutamic in the beta globin chain of hemoglobin. It may sound a trifling change, but it has had a profound impact on those who have it. ("Genetic basis of hemoglobinopathies- the history of sickle cell")

II. Causes

Sickle cell is a genetic disorder that turns red blood cells, which should be round and flexible into stiff and sickle-shaped cells, which is why it is called sickle cell. This is due to mutations in the beta-hemoglobin (HBB) gene. (Roberts)

Because they are inflexible, it is unable to travel smoothly in the blood vessels, bunching up and slowing the flow, preventing the efficient delivery of oxygen. This results in pain, organ damage and infection. The anemia results from the early death of these cells with a life span of 20 days as opposed to the normal 120 days for normal cells. The body is unable to keep up the supply of new cells. ("BabyCenter editorial staff")

It is transmitted via autosomal recessive inheritance, meaning it is passed from generation to generation and may present without any symptoms unless both parents carry the genes. In order for sickle cell trait to manifest into sickle cell anemia, a person must have two defective genes, one from each parent. In the US it is commonly found in people of African, Spanish, Mediterranean, Middle Eastern and Indian descent. (Mayo Clinic Staff)

III. Diagnosis and Complications/Symptoms

The diagnosis of sickle cell anemia involves a blood test that looks for the presence of hemoglobin S, the form that underlies sickle cell anemia. Newborns are routinely tested for it but adults and older children can also be tested. A positive screening will indicate the need for further testing that will determine if one or two genes are present. The sudden death of Missouri University (MU) football player Aaron O'Neal due to lymphocytic meningitis later indicated involvement of sickle cell anemia to the condition. As a result, MU athletes, three of whom are already positive for sickle cell but are so far asymptomatic, are voluntarily subjecting themselves to screening procedures for the disease. This is based on the known effects of strenuous activity for people who have sickle cell anemia. A report from the National Collegiate Athletic Association claim that at least 15 athletes have died due to complications associated with sickle cell anemia. Those found to be positive for the sickle cell trait are asked to sign a medical waiver. (Lange)

Sickle cell anemia presents with a variety of symptoms including:

Ð'* Pain

Ð'* Enlargement of the spleen

Ð'* Damage to liver and kidneys

Ð'* Viral and bacterial infections as a result of a malfunctioning spleen

Ð'* Stroke from blocked blood vessels

Ð'* Aplastic crisis, which is when red cell production stops for ten days as a result of an infection

Ð'* Acute chest syndrome similar to pneumonia when sickled cells get trapped in the lungs, eventually damaging the lungs

Ð'* Eye problems in the retina due to lack of oxygen, which may lead to blindness

Ð'* Jaundice

Ð'* Gallstones

Ð'* Open sores on the legs due to skin cells dying from lack of oxygen

Ð'* Painful erections or priapism for men due to sickled cells getting lodged in the penis, leading eventually to impotence

IV. Treatment and medications

The only real potentially effective cure for sickle cell anemia is a bone marrow transplant but this is not an option for the majority of the affected population because of the dearth of suitable donor. Much of the treatment protocol focuses at preventing crises from occurring as well as relieving the effects of the symptoms and complications. The treatment protocols used for the disease include:

Ð'* Antibiotics, mostly penicillin for children from 2 months to 5 years of age

Ð'* Pain medications such as acetaminophen or stronger medication as well as anti-inflammatory medications.

Ð'* Hydroxyurea, a prescription drug normally used for cancer treatment, believed to stimulate fetal hemoglobin that prevents production of sickle cells

Ð'* Blood transfusions using only red blood cells to increase the number of red blood cells in the system to alleviate the anemia to lessen the risk of stroke

Ð'* Supplemental