What is thrombocythemia?
Essential thrombocythemia, or ET, is a chronic bone marrow disorder in which the production of platelets is abnormally high. Platelets are important for the body's clotting and help stop bleeding. However, in ET, thrombocytes are produced in excessive amounts, which can make the blood more prone to forming clots.
Thrombocythemia is most often caused by acquired mutations in bone marrow stem cells, such as in the JAK2, CALR, or MPL genes. These mutations lead to increased and uncontrolled production of platelets.
ET is closely related to other MPN diseases such as polycythemia vera and myelofibrosis. The condition is chronic but often develops slowly.
Symptoms of essential thrombocythemia?
Many people with ET have no obvious symptoms and discover the disease through routine blood tests. When symptoms occur, they are often linked to altered blood circulation or increased clotting tendency.
- Headache
- Dizziness
- Visual disturbances
- Tingling or numbness in the hands and feet
- Redness and burning pain in the fingers or toes
- Easily bruising
- Nosebleeds or other minor bleeding
- Fatigue
In some cases, both increased clot formation and increased bleeding tendency can occur at the same time, especially with very high platelet levels.
The most common complication
The most common and most serious complication of ET is blood clot (thrombosis). Clots can occur in both arteries and veins and can lead to, for example, stroke, heart attack or deep vein thrombosis. The risk of thrombosis is affected by several factors, including age, previous blood clot, smoking, high blood pressure and the presence of a JAK2 mutation. Therefore, an individual risk assessment is always made after diagnosis.
Prognosis and course of the disease
Essential thrombocythemia is a chronic disease that often has a slow course. Many people live a long time with the condition without major symptoms. The prognosis is often good, especially in younger people without other risk factors for blood clot.
In some cases, the disease can develop over time into myelofibrosis or, more rarely, acute myeloid leukemia (AML). Therefore, regular follow-up with blood tests and specialist assessment is important.
How is essential thrombocythemia diagnosed?
The detection of elevated platelets in a blood test does not automatically mean that you have ET. High platelet levels can also be due to infection, inflammation, iron deficiency or another underlying disease. This is called secondary (reactive) thrombocytosis.
If ET is suspected, an investigation is performed that may include:
- Repeated analyses of blood status to confirm persistently high platelet levels.
- Assessment of inflammation markers and iron status.
- Genetic testing for mutations in JAK2, CALR, or MPL.
- Bone marrow biopsy in some cases to confirm the diagnosis.
The diagnosis is made according to international criteria and requires specialist assessment in hematology.
Treatment of ET
Treatment is adapted to the individual risk of blood clots. The goal is to reduce the risk of thrombosis and relieve symptoms.
- Low-dose acetylsalicylic acid can be given to reduce the tendency to clot in low-risk patients.
- Cytoreductive treatment (drugs that lower platelet levels), such as hydroxyurea, can be given in cases of higher risk.
- Interferon is sometimes used, especially in younger patients or during pregnancy.
- Regular follow-up with blood tests is a central part of treatment.
With the right follow-up and treatment, many people can live a long time with essential thrombocythemia and have a good quality of life.