Essential Thrombocythemia

Essential thrombocythemia, or primary thrombocythemia, is a rare blood cancer that affects your platelets. These cells make blood clots that slow or stop bleeding. With this disease, your bone marrow makes more platelets than your body needs. The abnormal platelets may be larger than normal.

High levels of abnormal platelets may increase your risk of a life-threatening heart attack or stroke. This can happen if a clot blocks blood flow to your heart and brain.

Essential thrombocythemia (pronounced “thraam-bow-sai-THEE-mee-uh”) may also cause you to bleed more than usual when you’re hurt. That may sound odd, as this disease usually makes your blood clot, so you don’t bleed. Your body drains your platelet supply when it makes many blood clots. When that happens, you don’t have enough platelets to control how much you bleed.

Essential thrombocythemia affects 2 out of 100,000 people in the U.S. It typically affects people aged 60 to 80. It’s an acquired genetic disorder that happens when certain genes change (mutate) during your lifetime.

There’s no cure for this disease. But treatment can reduce your risk of serious complications.

Symptoms of essential thrombocythemia

You may not have symptoms until your platelet levels increase and your body makes many blood clots. The clots cause different symptoms depending on the part of your body they affect. For example, a clot that blocks blood flow to your brain may cause stroke symptoms, like:

• Changes in your pattern of speech
• Dizziness
• Loss of coordination or muscle control
• Sudden severe headaches

A clot that blocks blood flow to your heart may cause heart attack symptoms, including:

• Chest pain that may spread to your arms, back, jaw, neck or shoulder
• Dizziness
• Feeling short of breath (dyspnea)
• Nausea

This condition can also cause unusual or heavy bleeding. Symptoms may include:

• A bloody nose that won’t stop bleeding
• Bleeding gums
• Blood in your poop (stool)
• Blood in your pee (urine)
• Bruising that happens for no obvious reason
• Heavy menstrual periods

Essential thrombocythemia causes

Essential thrombocythemia is an acquired genetic disease. This means you aren’t born with it. Instead, it happens when genes inside certain cells mutate, or change. In this case, the genes that mutate affect stem cells in your bone marrow that make blood cells. Those genes are:

• The JAK2 gene affects stem cells so they constantly make abnormal platelets.
• The CALR gene causes stem cells to make more platelets than your body needs. 
• The MPL gene is an oncogene. Oncogenes are genes that may cause cancer.

Experts aren’t sure why these genes change.

Essential thrombocythemia risk factors

Some issues may increase your risk for this disease, including your:

• Age: This disease typically affects people aged 60 to 80.
• Health: Having a history of blood clots increases your risk.
• Sex: Women are more likely to have it.

How doctors diagnose essential thrombocythemia

A healthcare provider will do a physical exam and ask about your symptoms. They may do tests, including:

• Complete blood count (CBC)
• Peripheral blood smear
• Bone marrow aspiration and biopsy
• Genetic tests

How is it treated?

Healthcare providers may use medications to lower your platelet levels, prevent blood clots or keep platelets from multiplying. Medications include:

• Aspirin: Aspirin may prevent blood clots.
• Chemotherapy: You may take hydroxyurea or busulfan (Busulfex®, Myleran®). These medications lower platelet levels.
• Immunotherapy: The medication interferon alfa (Multiferon®) targets abnormal platelets in bone marrow so they don’t multiply.
• PDE-3 inhibitors: Anagrelide (Agrilyn®) is a type of phosphodiesterase inhibitor that helps lower platelet levels.
• Targeted therapy: Ruxolitinib (Jakafi®) targets the changed JAK2 genes.

When should I see my healthcare provider?

Your healthcare provider will schedule regular checkups. They may do blood tests to check your platelet levels. But remember that essential thrombocythemia increases your risk of heart attack and stroke. You may have unusually heavy bleeding or bleed for no obvious reason. Call 911 or go to the emergency room if you have these symptoms:

• Chest pain
• Difficulty speaking or seeing clearly
• Heart palpitations
• Severe headache or dizziness
• Shortness of breath
• Sudden weakness on one side of your face or body
• Bleeding that you can’t control

What is the life expectancy for someone with essential thrombocythemia?

Medication can reduce blood clot risk, as well as risk for life-threatening complications, like a heart attack or stroke. But people with this disease may not live as long as people who don’t have it. One study found people lived eight to 33 years after diagnosis, with people diagnosed before age 60 living the longest with this disease.

Many things affect how long you may live. If you have essential thrombocythemia, ask your healthcare provider what you can expect. They know you and your situation and are your best resource.

What’s the difference between essential thrombocythemia and thrombocytosis?

If you have essential thrombocythemia, you have a high platelet count that isn’t related to another medical condition. If you have reactive thrombocytosis, your platelet count is high because you have another disease or condition. Thrombocytosis is more common than thrombocythemia.