From the Guidelines
Essential thrombocythemia (ET) can lead to several serious complications, including thrombotic events, bleeding problems, and transformation into more aggressive blood disorders, and management typically involves aspirin for low-risk patients and cytoreductive therapy for high-risk patients. The main complications of ET include:
- Thrombotic events such as deep vein thrombosis, pulmonary embolism, heart attack, stroke, and transient ischemic attacks, which occur due to excessive platelet production causing blood clots 1
- Bleeding problems including nosebleeds, easy bruising, and gastrointestinal bleeding because the abnormal platelets may not function properly
- Vasomotor symptoms like headaches, dizziness, and erythromelalgia (burning pain and redness in extremities)
- Transformation into more aggressive blood disorders such as myelofibrosis or acute myeloid leukemia
- Pregnancy complications, including miscarriage and placental insufficiency, with a live birth rate estimated at 70% and a first trimester fetal loss rate of 30% 1 Risk stratification is based on age (>60 years), history of thrombosis, and cardiovascular risk factors, and regular monitoring of blood counts and prompt treatment of symptoms are essential to prevent these complications 1. Aspirin is recommended for ET patients, especially those with JAK2 mutation or cardiovascular risk factors, while cytoreductive therapy with interferon alpha is mandated in all high-risk ET patients with prior thrombosis history 1.
From the Research
Essential Thrombocytopenia Complications
- The principal risks of essential thrombocythemia include thrombosis, major hemorrhage, and conversion to leukemia or myelofibrosis 2.
- Risk factors for thrombosis include age and prior thrombosis, as well as smoking and obesity in some cases 2.
- Patients with essential thrombocythemia are at increased risk of arterial thrombosis (11%), venous thrombosis (7%), and hemorrhagic complications (8%) 3.
- Thrombosis risk is increased among those with a history of thrombosis, age older than 60 years, a JAK2 gene variant, and cardiovascular risk factors (eg, hypertension, diabetes mellitus, hyperlipidemias, tobacco use) 3.
Management of Essential Thrombocytopenia
- A risk-oriented therapeutic approach is recommended to avoid inappropriate exposure to cytotoxic drugs or suboptimal treatment 4.
- Low-dose aspirin (81-100 mg/d) is suggested for most patients with essential thrombocythemia to lower thrombosis risk 3.
- Cytoreductive therapy, such as hydroxyurea, is advised for high-risk patients and optional for intermediate-risk disease 5.
- Recombinant interferon-alfa (IFNα)-2a/2b and pegylated (PEG)-IFN-α-2a/2b are alternative treatment options, with high rates of complete haematological responses and good tolerability and safety 6.
Risk Stratification
- Patients with essential thrombocythemia can be stratified into four risk categories: very low, low, intermediate, and high, based on age, thrombosis history, and JAK2 mutation status 5.
- The triple A survival risk model, based on Age, Absolute neutrophil count, and Absolute lymphocyte count, can effectively delineate high-, intermediate-1-, intermediate-2-, and low-risk disease 5.