What is anaemia?
Our body is made up of blood cells. These blood cells have a component called red blood cells which carry oxygen and supply it to various parts of the body. The component in the red blood cell that is responsible for this is haemoglobin.
The abnormal reduction in either the number of red blood cells or the quality of haemoglobin is called anaemia.
what is sickle celled anaemia?
It is a type o anaemia in which there is low oxygen tension which leads to deformation of the red blood cells into a sickle shape. It is an autosomal recessive disease which means that only if both the parents have the disease, the child will inherit the disease.
What causes sickle-cell anaemia and what happens in the body?
The gene which is responsible for haemoglobin synthesis is defective making it rigid and sticky.
“Glutamine”, an amino acid is replaced by “valine”.
This gives rise to defective haemoglobin (haemoglobin S).
This defective haemoglobin distorts the RBC( red blood cell) membrane and forms the characteristic sickle-shaped cells.
This defective shape leads to an increase in viscosity of the blood and reduces the flow of blood leading to infarction.
Since these cells are defective, the body’s natural mechanism destroys it causing haemolysis.
Sickling of cells may be precipitated by dehydration, infections, and chills.
What are the clinical symptoms of sickle cell anaemia?
- Tiredness, weakness and fatigue: since the sickle cells undergo haemolysis, the amount of oxygen transported is very less, leaving the patient weak and tired.
- Pain: episodes of pain is a common feature of sickle cell anaemia. It is called as sickle cell crises. This occurs because of the increase in viscosity of blood leading to the occlusion of blood vessels causing pain. Pain may occur in the chest, abdomen, muscle, joints and even in bones. It lasts from a few hours to weeks and sometimes even the whole year.
- Haematuria: breakdown of RBC’s leads to haemoglobin in the urine which gives a distinct reddish hue to the urine.
- Swelling: due to the obstruction of blood vessels, and blockage of blood flow, there is painful swelling of arms and feet.
- Hyperplasia of bone marrow: this means the increased growth of bone marrow. to compensate for the destruction of blood cells, the body over stimulates the bone marrow. if this occurs in the developmental years, it leads to changes in the shape of the skull, bossing of the skull, protrusive teeth, etc.
- Infections: increased production and destruction directly affects the spleen. Since the spleen is also responsible for fighting infections, this makes the patient more prone to infections.
- Pallor: paleness or pallor is seen on palms.
- Heart changes: due to the viscosity of blood, there is an increase in the size of the heart and a murmur is distinguishable in the heartbeat.
- Thrombosis: obstruction to important vessels leads to severe neurological disorders like stroke, convulsions, coma, drowsiness and speech and visual disturbances.
- Osteomyelitis: the patients are more prone to develop osteomyelitis.
- Facial changes: mongoloid features like high cheekbones, protrusion of the upper jaw (bimaxillary protuberance) are common features.
How is sickle celled anaemia diagnosed?
What do the x-rays show?
- Osteoporosis: this is due to bone marrow hyperplasia
- Ground glass appearance: the parts of the bone which are less mineralised appear darker than the other parts which appear whiter. This gives a ground glass appearance.
- The hair on end appearance: the skull shows a hair on end appearance
These features, along with the cell picture and clinical symptoms help in the diagnosis of the disease.
What is the treatment available for sickle celled anaemia?
- Prevention: preventing the triggering factors is one of the key elements as there is no complete cure for it.
- Folic acid supplements: the doctor may prescribe folic acid supplements of 5mg/day to stimulate new blood cell formation.
- Antibiotics: prophylactic antibiotics are prescribed as the body’s immunity is weak.
- Analgesics: Analgesics are painkillers. This is to manage the pain in sickle cell crises. Usually, a non-addictive painkiller is advised as the pain is recurrent.
- Blood transfusion: in severe cases, a blood transfusion may be given. It should not be done frequently as it increases the viscosity of blood.
- Genetic counselling: it is one of the most important preventive measures to be taken by the parents.
What are the complications of sickle cell anaemia?
If the disease is not managed properly, it could lead to various adverse effects:
- Stroke: one of the main adverse effects of this disease is stroke due to obstruction of blood vessels of the brain which could lead to permanent damage. This is mainly due to the increased viscosity of blood.
- Acute chest syndrome: it is an emergency condition of sickle cell crisis in which there are acute respiratory infections which is due to blockade in the pulmonary blood vessels and an increased tendency for infections.
- Pulmonary hypertension: there is an increase in the blood pressure of the lungs leading to pulmonary hypertension. This usually affects the adults and is a fatal condition. It is characterised by shortness of breath and difficulty in breathing.
- Organ damage: due to ischaemia and reduced oxygen supply, the vital organs may get permanently damaged.
- Gallstone: breakdown of the RBC’s lead to a release of a substance called bilirubin. This is responsible for jaundice and formation of gallstones.