Sickle-cell Anaemia

What is Sickle Cell Anaemia?

Normal haemoglobin is called haemoglobin A. In sickle disease, this is replaced genetically by haemoglobin S. This produces a typical deformity of the red blood cell. The cells are unable to carry oxygen at the same rate. Small blood vessels become blocked by clumping up of the deformed cells, and tissue infarction can occur. This means the tissues being supplied by the jammed-up vessel simply die. In key areas, this may be extremely damaging. Due to their deformed pattern, the sickled cells have a much shorter life span. They fragment more rapidly, resulting in a severe haemolytic anaemia. The disease is very common, and a huge belt embracing the middle third of Africa is involved. It is claimed that around 80,000 infant deaths occur annually as a result.

Between 10 and 30 per cent of the population may carry the gene that produces the defect to the next generation. It also occurs to a lesser extent in parts of Italy, Greece, the Middle East and India.

Sickle Cell Anaemia Symptoms

These often set in during the third or fourth month of life. There may be painful swelling of the hands and feet (the “hand-and-foot syndrome”). The child appears to be pale and slightly jaundiced. The usual telltale symptoms of anaemia become established and gradually worsen with age.

There is general ill health, interspersed with typical crises. Often the child is thin and gangling, with narrow shoulders and hips. Ulcers on the legs and shins with scarring are very common. The spleen enlarges and may be felt jutting below the left, lower margin of the rib cage. When the blood is examined under the microscope, it shows changes characteristic of the disease, which are diagnostic. There is a marked anaemia, and the red cells are irregular in size, shape and colour.

Infections are very common, affecting the lungs, brain and bowel. These often precipitate crises. A high fever occurs, accompanied with severe pain in the back, limbs and abdomen. The condition may produce prostration. During these bouts, death may occur from infarction of the liver, brain or lungs. (This means blood vessels going to vital areas become jammed by the abnormal aggregations of sickle cells and the blood flow is stopped.)

Sickle Cell Anaemia Treatment

Treatment is a major problem, and if possible it is best carried out in specialised centres where the doctors have an intimate knowledge of the disease and its course. Between crises, the patient is given folic acid. Unlike the treatment of other iron anaemias, blood transfusions and iron supplements are not given, for this may aggravate the condition. It could further increase the viscosity (thickness) of the blood and precipitate more crises and possible risk of premature death.

Efforts are made to prevent crises by reducing the risk of infections. Crises are managed symptomatically, with warmth, analgesics (for the relief of pain and to help reduce elevated temperatures), oxygen and antibiotics. Often patients may become profoundly anaemic, sometimes within a few hours. Often crises settle with or without therapy, even though many different lines of treatment have been advocated in different centres. Sometimes complete exchange transfusions may be attempted if severe crises recur. This means the whole blood of the body is replaced with new blood – a major undertaking.

As anaesthesia is a major problem and hazard, any at-risk person (such as negroes or those from sickle-disease lands) may have a check made before surgery for the disease, as special precautions are necessary. The disease carries a special risk to the mother and infant in the event of pregnancy. The outlook depends largely on the socioeconomic background of the individual. In Africa, the chances of surviving childhood are remote. However, as early diagnosis and treatment facilities are improving, more are reaching adult years. In Westernised lands such as the United States, many reach adulthood, but few live longer than 50 years. Infection usually ultimately kills the person, or else cardiac failure sets in and brings premature death.