Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm (MPN), a rare blood disorder that causes an increase in the number of blood cells. Some symptoms include headaches, dizziness, and nosebleeds.
ET causes an overproduction of platelets, which are the blood cells responsible for clotting.
Although many cases of ET do not cause symptoms for years, the condition can lead to complications such as blood clots or bleeding. This makes timely diagnosis and management essential.
ET can affect people of any age. However, it usually affects middle-aged and older people, with the average age at diagnosis being 65 years.
ET is a type of MPN, a rare group of blood cancers that affect bone marrow function.
ET produces an excess combination of white blood cells, red blood cells, and platelets. This is often due to mutations in specific genes, such as JAK2, CALR, or MPL. These genes are “driver mutations” due to their role in developing an MPN.
The JAK2 gene makes a protein that controls how many blood cells the stem cells produce. This gene change causes too much protein production, which causes the stem cells to make more platelets.
Each year, ET affects approximately
Many people with ET discover the condition during routine blood tests. This is because ET usually develops slowly and does not cause symptoms at first.
Symptoms may occur as a result of blood clots forming or bleeding problems that develop because the platelets are not fully mature and do not work normally.
When symptoms do occur, they may include:
If a blood clot occurs, symptoms may include:
- headaches
- dizziness
- weakness or numbness on one side of the body
- blurred or double vision
- slurred speech
- pain, swelling, and discoloration in the arms or legs
If bleeding occurs, symptoms may include:
- nosebleeds or bleeding gums
- bruising more easily
- gastrointestinal bleeding
- blood in stool
- blood in urine
- burning and tingling in the hands and feet, or erythromelalgia
- purplish mottled skin changes, usually on the legs
- heavy menstrual periods or unexpected vaginal bleeding
The severity and type of symptoms can vary widely among individuals.
A person should seek medical attention if they experience any symptoms of ET or any symptoms that suggest blood clots or bleeding. A blood clot is serious, but a doctor can treat it with medication.
Early diagnosis can help reduce the risk of complications and guide appropriate treatment strategies.
ET can develop when genetic mutations alter the function of bone marrow cells responsible for platelet production. These mutations occur in adulthood, and people are not born with them. They include:
- JAK2 mutation: Present in
around 55%Trusted Source of ET cases, this mutation causes bone marrow cells to overproduce platelets. - CALR mutation: This mutation primarily affects younger people, who often have a lower risk of complications.
- MPL mutation: This mutation is rare and affects the thrombopoietin receptor, which regulates platelet production.
In about 10% of ET cases, the exact cause remains unknown. This condition is known as triple-negative ET. Environmental and lifestyle factors, such as exposure to toxins or radiation over time, may also contribute to genetic mutations. However, researchers need to conduct more studies.
In rare cases, individuals may have a family history of MPNs. This might mean that a faulty gene increases the risk of developing MPNs.
The goals of treatment in ET are to
Treatment plans depend on several factors, including:
- age
- previous history of blood clots or bleeding
- any current symptoms
- other medical conditions
- results from genetic tests showing specific gene changes
A doctor may prescribe one or more treatments depending on individual need.
People at low risk
Individuals under 60 years old with no history of blood clots and a lower platelet count may not require active treatment. Instead, a doctor may recommend regular monitoring and lifestyle modifications, such as quitting smoking, if necessary.
A doctor can also recommend management strategies for other cardiovascular risk factors or conditions that may increase the risk of blood clots, such as:
People at high risk
Treatments for people with a high risk of developing blood clots include:
- Aspirin: Low-dose aspirin helps reduce clotting risk by preventing platelets from sticking together.
- Hydroxycarbamide: This is a type of chemotherapy drug and is the primary treatment for ET. It lowers platelet levels and is the first-line treatment for those at high risk.
- Anagrelide: An alternative to hydroxycarbamide, anagrelide comes in capsule form and specifically targets platelet production. Side effects can include headaches and changes to heart rate.
- Busulfan: This is another type of chemotherapy drug. Doctors usually prescribe it for people who cannot take hydroxycarbamide. Long-term use may
increase the riskTrusted Source of developing other types of cancer, such as leukemia. - Peginterferon alfa 2a: This is a type of immunotherapy that a doctor administers with an injection. It stimulates immune system cells to attack the cancer and can also help control the number of platelets.
Some medications can cause side effects and may not be suitable for everyone, so it is crucial to consult a healthcare professional.
Without treatment, ET can lead to serious health issues, including:
- Blood clots: High platelet levels increase the risk of clots in veins or arteries, potentially causing stroke, heart attack, or deep vein thrombosis.
- Bleeding: Extremely high platelet counts can impair clotting, leading to excessive bleeding.
- Progression to other conditions: Some cases may progress to myelofibrosis or acute myeloid leukemia, both of which are severe conditions.
- Pregnancy complications: Pregnant individuals with ET face higher risks of miscarriage, preeclampsia, or intrauterine growth restriction.
Going to regular follow-ups with a hematologist can help detect and manage these risks early.
ET is not yet curable, but it is treatable. Individuals can manage their symptoms over a long period. Also, with appropriate treatment and monitoring, most people with ET live typical or near-normal life spans.
ET requires ongoing research to better understand the factors influencing progression and to develop more effective treatments.
Currently, there is no way to prevent ET, as it often arises from genetic mutations. However, people can reduce their risk of complications by adopting a heart-healthy lifestyle, including:
- maintaining a balanced diet and moderate weight
- exercising regularly
- avoiding smoking
- limiting alcohol consumption
- managing any chronic conditions
Early detection through routine blood tests is also critical for those with a family history of MPNs or other risk factors.
ET is a chronic blood disorder that causes the overproduction of platelets. Although it often does not cause symptoms at first, the condition can lead to severe complications without treatment. These may include blood clots or bleeding.
People experiencing symptoms and those with a family history of ET should consult a healthcare professional to ensure timely intervention.
Early diagnosis, regular monitoring, and targeted treatment can help people manage the disorder effectively and maintain a good quality of life.
