Sickle cell anemia is a chronic hemolytic anemia that results from a defective hemoglobin molecule (hemoglobin S) where the red blood cells (RBC) roughen and become sickle-shaped. The highest frequency of the condition is among native Africans, Mediterranean populations, and African-Americans.

Sickle cell anemia results from homozygous inheritance of the hemoglobin S-producing gene, wherein the amino acid valine replaces glutamic acid in the B hemoglobin chain. Abnormal properties resulting from this mutation cause chronic hemolysis of red cells, as well as irreversible sickling of the red cells. Factors predisposing the person to sickle cell crisis may include: deoxygenation, such as in pneumonia; hypoxia; scuba diving; exposure to cold; acidosis, infection, and hemoglobin levels greater than 8.5g/dl.

Symptoms may include the following:

• pain in the bones

• arthralgia

• joint swelling

• acute attacks of abdominal pain

• ulceration of the lower extremities

• sickle-shaped erythrocytes in the blood

• tachycardia

• cardiomegaly

• systolic and diastolic murmurs

• chronic fatigue

• unexplained dyspnea or dyspnea on exertion

• hepatomegaly

• splenomegaly

• jaundice

• pallor

• chest pain

• increased susceptibility to infection

There may be signs and symptoms less directly related to vaso-occlusion including psychosocial problems and susceptibility to infection. The person in vaso-occlusive crisis (sickle cell crisis) may have severe abdominal, thoracic, muscular, or bone pain. Other signs and symptoms of vaso-occlusive crisis may include the following:

• pale lips, tongue, palms, or nail beds

• lethargy

• lifelessness

• difficulty in awakening

• irritability

• elevated temperature

• jaundice

• dark urine.

Patients who develop aplastic crisis experience rapidly lowering hemoglobin and hematocrit levels and reticulopenia.

Tests conducted for the condition may include:

• the Sickledex solubility test

• hemoglobin electrophoresis

• complete blood count (CBC)

• peripheral blood smears

Bone marrow studies show bone marrow depression in cases of aplastic crisis.

Treatment is directed toward alleviating specific symptoms of the condition and preventing painful crises. Treatment given to minimize complications may include the following:

• pneumococcal vaccine and Haemophilus influenza B

• anti-infectives

• chelating agents

• antisickling agents may be tried

• folic acid (usually given once a day)

• analgesics (for pain management during acute painful episodes)

• periodic hospitalization for transfusion of packed red blood cells (RBCs)

In acute episodes of sickle cell anemia, crisis treatment may include the following:

• sedation

• pain medication

• blood transfusion

• oxygen therapy

• large amounts of oral or intravenous (IV) fluids.

Routine clinical visits are needed to establish baseline data and clinical laboratory findings for comparison at times of clinical exacerbations. Treatment may also include periodic counseling regarding the disease, genetics, and psychosocial issues. There is no known cure for the condition.

• There may be repeated periodic hospitalizations for transfusion of packed RBCs.

• The person may experience side effects from the antisickling medication.

• The person will have chronic anemia, exacerbations of anemia, and repeated acute painful episodes.

• Long-term counseling may be needed to prevent depression, low self-esteem, poor family relationships, and social isolation.

• The person should avoid or restrict activities such as strenuous activities and conditions related to high altitudes and cold temperatures that might provoke hypoxia. Residuals include the impairment of circulation with periodic crises due to the sickled cells, and long-term complications involving multiple systems that often result in premature death.

• Specific complications include shrinkage of the spleen, which results in increased risk of infection with encapsulated bacteria and salmonella, and complications associated with the eye, e.g., hemorrhage.

• None.

• Sickle cell trait alone, without a history of directly attributable pathological findings, is not a ratable disability. Cases of symptomatic sickle cell trait will be forwarded to the Director, Compensation Service, for consideration under 38 CFR 3.321(b)(1).