Polycythemia vera is a blood disorder in which theÂ bone marrow produces excessÂ blood cellsÂ (erythrocytes, platelets and leukocytes). Excess blood cells causes aÂ thickeningÂ of the blood leading toÂ increased coagulation risk, whichÂ in turnÂ canÂ lead toÂ stroke, myocardial infaction and other complications. The exact cause of polycythemia is unknown, but it is assumed that development of the disease isÂ influenced by certainÂ genetic changes. Polycythemia or polycythemia vera gene evolves slowly and is especially common in older people, and quiteÂ rare in young children. AlthoughÂ polycythemia vera is aÂ result of aÂ genetic mutation, these genetic abnormalities are usually acquired during the life of an individual andÂ are notÂ 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 casesÂ thrombosis can occurÂ (blood clotting), which leads to more serious manifestations. In later stages of polycythemia vera,Â long-term presence of oxygen deprivation signs are presentÂ (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 polycythemiaÂ disappearsÂ whenÂ the oxygen deprivation cause is treated.
However, in all cases of polycythemia, improvements can be achievedÂ by removing a quantity of blood periodically until the number of erythrocytes in bloodÂ is reducedÂ (phlebotomy) or administering drugsÂ that reduce the number of blood cells. UnfortunatelyÂ a permanent cure for the disease does not exist.
Although polycythemia is quite rare and can be controlled, sometimes serious complications can occur such asÂ a heart attack or stroke,Â in case of lack ofÂ treatment. Emergency medical intervention will be requiredÂ for any symptoms that occurÂ suddenly like weakness, confusion, vision problems or chest pain that persists.In early stages, polycythemia vera produces no symptoms. However as the disease progressesÂ one or more polycythemia vera symptoms may be present
- Itching especially after bathing with hot water
- Skin redness
- Shortness of breath
- Shortness of breath whileÂ lying down
- Numbness, tingling, burning or weakness in hands, feet, arms
- Feeling of fullness or bloating in the left upper abdomen due toÂ splenomegaly
PolycythemiaÂ VeraÂ Causes
Polycythemia vera develops when a mutation in a cellÂ in the bone marrowÂ causesÂ blood cell production problems. Normally, the body carefully regulates the number of existingÂ 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 thatÂ 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 VeraÂ 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 andÂ quite rareÂ in people who are under 20 years
- Males – polycythemia vera effectsÂ with predilection men
- Medical history – family history ofÂ polycythemia veraÂ (especially relatives) increases the risk for developing the disease.
Any personÂ should consult a physicianÂ if Â any specific signs or symptoms of polycythemia vera are present. BecauseÂ polycythemia veraÂ causes a thickening of the bloodÂ it increases the risk of developing blood clots. If a clot reaches the blood vessels of the head, it can cause a stroke.Â ImmediatelyÂ seek emergency care if any ofÂ the signsÂ 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,Â poor spatial orientation or perception.
Polycythemia VeraÂ Treatment
Polycythemia veraÂ is treatedÂ usingÂ blood thinners to preventÂ clots formation. This can be done by periodic blood collection to reduce red blood cell count. In some cases, drugs that suppress the action ofÂ the bone marrowÂ like hydroxyurea and interferon can be administered. To prevent blood clots formation aspirin can be also used, but less frequentlyÂ as it may be a triggering factor for aÂ bleeding stomach.
Polycythemia VeraÂ Complications
Progression of polycythemia vera is usuallyÂ slow and most patients do not suffer complications if the disease is wellÂ treated. In some rareÂ complication can occur unfortunately andÂ are serious enoughÂ toÂ causeÂ strokes and heart attacks.
In addition to bone marrow dysfunction, polycythemia vera canÂ lead to myelofibrosis (scarring of the bone marrow) or in very rare cases, toÂ 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: