Polycythemia vera is a chronic progressive disorder characterized by an excess of red blood cells, causing the blood to thicken and putting the affected person at risk of thrombosis. It is also referred to as primary polycythemia or polycythemia vera and belongs to the group of myeloproliferative syndromes. It usually occurs after the age of 50 and affects 10 to 15 people in 100 every year. Proper treatment allows the patient to lead a normal life. (000)

It is often by chance of a blood test that the disease is detected, because few of the symptoms of polycythemia vera are specific and its evolution is slow and progressive:

• Areas of the skin and mucous membranes turn red, often on the face and hands, mouth and eyelids. We speak of cutaneous erythrosis. Very painful “erythromelalgia” attacks can occur, with the affected person suffering from a burning sensation in the red hands and feet. Skin contact with hot water can cause itching.
• Headaches, headaches, dizziness, tinnitus, blurred vision and tingling in the tips of the fingers are some of the non-specific symptoms of polycythemia vera, linked to poor oxygen supply to the organs.

95% of polycythemia vera cases are caused by a mutation in the JAK2 gene, identified by a blood test. This gene plays a particularly important role in the production of blood cells from stem cells located in the bone marrow. Due to this genetic mutation, the bone marrow begins to produce red blood cells in excess (hence its name “polycythemia”) and with a longer lifespan. If the concentration of red blood cells is too high for the total volume of the blood, the blood thickens, which flows more slowly, does not supply enough oxygen to the organs and increases the risk of blood clots forming. A person with polycythemia vera is therefore at risk of deep vein thrombosis, heart attack, stroke and pulmonary embolism, caused by blood clots in the heart, brain and lung.

It is important to note that the mutation in the JAK2 gene mentioned above is acquired during life and that Polycythemia vera is therefore not hereditary. It is not contagious either. The disease is a little more common in men than women (without the reason being known) and usually occurs between the ages of 50 and 70.

Polycythemia cannot be cured, but treatments allow the patient to lead a normal life and limit the associated vascular risks. Regular bleeding (phlebotomies) aims to reduce the total volume of blood in the body to improve blood circulation. Red blood cell counts are reduced by so-called “myelosuppressive” drugs, the most widely used of which is hydroxyurea. Low-dose aspirin helps reduce the risk of blood clots.

Polycythemia vera can cause serious long-term complications such as an enlarged spleen (splenomegaly), heart disease, leukemia, and idiopathic myelofibrosis.