Definition of Essential Thrombocythemia: Essential thrombocythemia (ET) is an uncommon disorder in which your body produces too many blood platelets (thrombocytes). It's also known as primary thrombocythemia (throm-bo-sigh-THE-me-uh). Essential thrombocythemia is one of a group of diseases of the blood and bone marrow known as myeloproliferative neoplasms.
Symtoms: Many people with essential thrombocythemia have no signs or symptoms. The first indication you have the disorder may be the development of a blood clot (thrombus). Although clots can develop anywhere in your body, with ET, they occur most often in your brain, hands and feet.
- Dizziness or lightheadedness
- Chest pain
- Temporary vision changes
- Numbness or tingling of the hands and feet
- Redness, throbbing and burning pain in the hands and feet (erythromelalgia)
- Mildly enlarged spleen
- Pregnancy complications. Uncontrolled thrombocythemia can cause miscarriage, premature delivery, high blood pressure (preeclampsia), early separation of the placenta from the uterine wall (placental abruption) and slow fetal growth. If you have ET and become pregnant, be sure your doctor monitors you carefully throughout your pregnancy.
- Stroke. A clot that blocks blood flow to your brain can cause a stroke. If you develop signs and symptoms of a stroke, get immediate medical attention.
- Heart attack. A clot that obstructs blood flow to your heart can cause a heart attack. If you develop signs and symptoms of a heart attack, such as pressure, fullness or a squeezing pain in the center of your chest lasting more than a few minutes; pain extending to your shoulder, arm, back, teeth or jaw; shortness of breath; and sweating or clammy skin, get immediate medical attention.
- Acute leukemia. Acute myelogenous leukemia is a type of blood and bone marrow cancer that progresses rapidly.
- Myelofibrosis. This progressive bone marrow disorder results in bone marrow scarring, severe anemia, and enlargement of your liver and spleen.
If you're at risk of blood clots, your doctor may recommend low-dose aspirin, particularly if you're pregnant. Aspirin makes the platelets less sticky and your blood less likely to form clots. If you take aspirin during pregnancy, stop taking it at least one week before delivery to lower your risk of bleeding complications during delivery.
- Hydroxyurea (Droxia, Hydrea). This drug suppresses bone marrow production of blood cells, including platelets. Also used to treat cancers, it's the most commonly prescribed platelet-lowering drug for ET. It's often used in combination with low-dose aspirin. If you take hydroxyurea, your doctor will monitor your blood counts closely. There's some concern that long-term use may increase the risk of developing acute myelogenous leukemia.
- Anagrelide (Agrylin). Unlike hydroxyurea, anagrelide isn't associated with an increased risk of leukemia. But it's not considered as effective as hydroxyurea. Side effects may include fluid retention, heart problems, headaches, dizziness, nausea and diarrhea.
- Interferon alfa-2B (Intron A). Given by injection, this drug is less convenient to administer than hydroxyurea or anagrelide, may be more expensive and may cause less tolerable side effects. Side effects may include flu-like symptoms, confusion, nausea, depression, diarrhea, seizures, irritability and sleepiness.
Used only in emergencies, such as after a stroke or other dangerous blood clotting, a medical procedure known as plateletpheresis can be used to rapidly lower platelet count. During the procedure, an intravenous (IV) needle connected to a tube is inserted into one of your blood vessels. Your blood flows through the tube and into a device that removes platelets from your blood. The remaining portion of your blood (plasma) and your red cells are then returned to you through an IV line. The effect is temporary.
Essential thrombocythemia — Comprehensive overview covers symptoms, causes, treatment of this blood clotting disorder.