Polycythemia vera is a blood disorder in which the bone marrow produces excess blood cells (erythrocytes, platelets and leukocytes). Excess blood cells causes a thickening of the blood leading to increased coagulation risk, which in turn can lead to stroke, myocardial infaction and other complications. The exact cause of polycythemia is unknown, but it is assumed that development of the disease is influenced by certain genetic changes. Polycythemia or polycythemia vera gene evolves slowly and is especially common in older people, and quite rare in young children. Although polycythemia vera is a result of a genetic mutation, these genetic abnormalities are usually acquired during the life of an individual and are not transmitted generally from parents to children. The condition is more common in adults over 60 years
In the first phase of polycythemia vera, symptoms are mild and include flushing, dizziness and impaired senses. In more severe cases thrombosis can occur (blood clotting), which leads to more serious manifestations. In later stages of polycythemia vera, long-term presence of oxygen deprivation signs are present (as in the case of chronic smokers or people who spend long periods at high altitudes) due to increased production of red blood cells and blood thickening. This form of polycythemia disappears when the oxygen deprivation cause is treated.
However, in all cases of polycythemia, improvements can be achieved by removing a quantity of blood periodically until the number of erythrocytes in blood is reduced (phlebotomy) or administering drugs that reduce the number of blood cells. Unfortunately a permanent cure for the disease does not exist.
Although polycythemia is quite rare and can be controlled, sometimes serious complications can occur such as a heart attack or stroke, in case of lack of treatment. Emergency medical intervention will be required for any symptoms that occur suddenly like weakness, confusion, vision problems or chest pain that persists.In early stages, polycythemia vera produces no symptoms. However as the disease progresses one or more polycythemia vera symptoms may be present
- Itching especially after bathing with hot water
- Skin redness
- Shortness of breath
- Shortness of breath while lying down
- Numbness, tingling, burning or weakness in hands, feet, arms
- Feeling of fullness or bloating in the left upper abdomen due to splenomegaly
Polycythemia Vera Causes
Polycythemia vera develops when a mutation in a cell in the bone marrow causes blood cell production problems. Normally, the body carefully regulates the number of existing blood three cell types but in polycythemia vera, the mechanism used by the body to control blood cell production is impaired and the bone marrow produces too many blood cells. Mutation that causes polycythemia vera role affects a protein that signals cells to grow (JAK2 V617F mutation). Most people with polycythemia vera have this mutation.
Physicians and researchers could not fully determine the role of this mutation and its implications during studies that searched for a treatment. Scientists believe that the mutation occurs after conception therefore is acquired rather than inherited.
Polycythemia Vera Risk Factors
Factors that may increase the risk of developing polycythemia vera are:
- Advanced age – chances of developing polycythemia vera increases with age, being more common in adults over the age of 60 years and quite rare in people who are under 20 years
- Males – polycythemia vera effects with predilection men
- Medical history – family history of polycythemia vera (especially relatives) increases the risk for developing the disease.
Any person should consult a physician if any specific signs or symptoms of polycythemia vera are present. Because polycythemia vera causes a thickening of the blood it increases the risk of developing blood clots. If a clot reaches the blood vessels of the head, it can cause a stroke. Immediately seek emergency care if any of the signs or symptoms of a stroke are present such as:
- Sudden numbness, weakness, paralysis of the face, limbs – usually on one side
- Difficulty in understanding speech
- Sudden dizziness, loss of balance or coordination
- Sudden pain, headache that might be accompanied by stiff neck, facial pain, vomiting or altered consciousness
- Confusion or impaired memory, poor spatial orientation or perception.
Polycythemia Vera Treatment
Polycythemia vera is treated using blood thinners to prevent clots formation. This can be done by periodic blood collection to reduce red blood cell count. In some cases, drugs that suppress the action of the bone marrow like hydroxyurea and interferon can be administered. To prevent blood clots formation aspirin can be also used, but less frequently as it may be a triggering factor for a bleeding stomach.
Polycythemia Vera Complications
Progression of polycythemia vera is usually slow and most patients do not suffer complications if the disease is well treated. In some rare complication can occur unfortunately and are serious enough to cause strokes and heart attacks.
In addition to bone marrow dysfunction, polycythemia vera can lead to myelofibrosis (scarring of the bone marrow) or in very rare cases, to leukemia. These consequences can be life threatening and the patient should be treated immediately. The risk of serious complications can be minimized by following a correct treatment plan.
Complications of polycythemia vera include: