From the Guidelines
The current guidelines for thrombocytosis evaluation and treatment recommend a risk-stratified approach, with low-risk patients (age ≤60 years, no prior thrombosis) being monitored for new thrombosis, acquired VWD, and/or disease-related major bleeding, while high-risk patients (age ≥60 years, history of thrombosis) should receive cytoreductive therapy with hydroxyurea and low-dose aspirin. The initial evaluation should include complete blood count, peripheral blood smear, bone marrow biopsy, and molecular testing for JAK2, CALR, and MPL mutations to confirm essential thrombocythemia (ET) and exclude reactive thrombocytosis 1. For very low-risk patients (age ≤60 years, no JAK2 mutation, no prior history of thrombosis), observation alone is appropriate, while low-risk patients (age ≤60 years, with JAK2 mutation, no prior history of thrombosis) should be managed with aspirin (81–100 mg/d) for vascular symptoms or observation 1. Some key points to consider in the management of ET include:
- Monitoring for new thrombosis, acquired VWD, and/or disease-related major bleeding
- Managing cardiovascular risk factors
- Using aspirin for vascular symptoms
- Initiating cytoreductive therapy for symptomatic thrombocytosis or progressive disease-related symptoms
- Performing bone marrow aspirate and biopsy to rule out disease progression to myelofibrosis prior to the initiation of cytoreductive therapy 1. It is also important to note that cytoreductive therapy is not recommended as initial treatment for low-risk patients, and aspirin should be used with caution in patients with acquired VWD 1. Regular monitoring should occur every 3-6 months with CBC and assessment of symptoms, and treatment aims to prevent thrombotic and hemorrhagic complications, as thrombocythemia increases risk for both arterial and venous thrombosis due to platelet dysfunction and hypercoagulability, while paradoxically also increasing bleeding risk at very high platelet counts.
From the Research
Evaluation and Treatment of Thrombocytosis (Essential Thrombocythemia)
The evaluation and treatment of thrombocytosis (essential thrombocythemia) involve several key considerations, including:
- Risk assessment: Patients are categorized into different risk groups based on factors such as age, platelet count, and history of thrombosis 2, 3, 4.
- Treatment goals: The primary goal of treatment is to prevent thrombosis and other complications 2, 4.
- Treatment options: Treatment options include low-dose aspirin, hydroxyurea, anagrelide, interferon-alpha, and other cytoreductive agents 2, 3, 5, 4, 6.
Risk Stratification
Risk stratification is a critical step in the evaluation and treatment of essential thrombocythemia. The risk categories include:
- Low-risk: Patients under 60 years old with no history of thrombosis and a platelet count < 1,500 x 10(9)/L 2, 3.
- Intermediate-risk: Patients under 60 years old with a platelet count > 1,500 x 10(9)/L or significant cardiovascular risk factors 3.
- High-risk: Patients over 60 years old or those with a history of thrombosis 2, 3, 4.
Treatment Recommendations
Treatment recommendations vary based on the risk category:
- Low-risk patients: Observation or low-dose aspirin may be recommended 2, 3.
- Intermediate-risk patients: Treatment may include low-dose aspirin, anagrelide, hydroxyurea, or interferon-alpha 3, 4.
- High-risk patients: Hydroxyurea plus aspirin is often the treatment of choice, although other options such as anagrelide and interferon-alpha may be considered 2, 3, 4.
Special Considerations
Special considerations include:
- Pregnancy: Interferon-alpha may be used in high-risk pregnant women who need treatment 3.
- Extreme thrombocytosis: Specific treatment strategies may be required in cases of extreme thrombocytosis 4.
- Splanchnic vein thrombosis: Specific treatment strategies may be required in cases of splanchnic vein thrombosis 4.