Disease Description (Causes and Symptoms)
Myeloproliferative neoplasm (MPN) is a group of chronic blood disorders in which hematopoietic cells in the bone marrow proliferate abnormally, causing an increase in one or more cell lines among red blood cells, white blood cells, and platelets, or progression of bone marrow fibrosis. Known major causes include genetic mutations such as JAK2 V617F, CALR, and MPL (or chronic myeloid leukemia (CML), which is defined by BCR‑ABL1, etc.). These mutations cause persistent activation of proliferative signals in hematopoietic cells.
Main symptoms
- Thrombosis (vascular occlusion, cerebral infarction, myocardial infarction, deep vein thrombosis, etc.) or a tendency to bleed
- Splenomegaly (abdominal distension, early satiety)
- Anemia (fatigue, dizziness) — particularly common in myelofibrosis
- Polycythemia vera (PV): facial flushing, headache, pruritus (especially after bathing)
- Essential thrombocythemia (ET): easy bruising, coldness and pain in the hands and feet due to peripheral ischemia
- Primary myelofibrosis (PMF): weight loss, fever, night sweats, and symptoms related to anemia
The clinical course varies depending on the disease type and genetic mutations, and some patients are found to have the disease through abnormal blood test results while asymptomatic.
Treatment Methods
The goals of treatment are to prevent thrombosis/bleeding, relieve symptoms, and manage the risk of disease progression (myelofibrosis and leukemic transformation). Treatment varies according to the disease type and risk level (age, history of thrombosis, blood cell counts, genetic mutations, etc.).
General treatment principles
- Lifestyle management: Reduce the risk of thrombosis through adequate fluid intake, smoking cessation, and management of weight, blood pressure, and lipids
- Antiplatelet therapy: Low-dose aspirin (especially for the prevention of thrombosis in PV and high-risk ET)
- Risk-based blood cell count control (cytoreductive therapy)
- Transfusion and phlebotomy: Regular phlebotomy in PV to reduce excessive red blood cell volume
- Oral cytoreductive agent: Hydroxyurea — commonly used in older and high-risk patients
- Interferon (especially pegylated interferon-α): Used in patients of childbearing potential, those planning pregnancy, or younger patients
- Targeted therapy
- CML (BCR‑ABL1-positive): Tyrosine kinase inhibitors (TKIs; imatinib, dasatinib, nilotinib, etc.) — standard treatment
- Symptomatic MF or MF with severe splenomegaly or systemic symptoms: JAK inhibitors (ruxolitinib, fedratinib, etc.) — reduce symptoms and spleen size
- Bone marrow transplantation: In diseases such as primary myelofibrosis, young patients in the high-risk group may receive allogeneic hematopoietic stem cell transplantation for therapeutic purposes (with the possibility of a cure)
- Supportive care: Consider transfusion and use of ESAs (erythropoiesis-stimulating agents) for anemia, treatment of iron deficiency, etc.
Precautions
- When taking anticoagulants/antiplatelet agents, carefully evaluate the balance between bleeding risk and treatment effects
- Adjust treatment when planning pregnancy (e.g., preferentially consider interferon; some medications are contraindicated)
- Monitor treatment response and progression through regular blood tests and molecular tests
Checklist Before an Outpatient Visit (Items to Bring and Sample Questions)
Items to bring
- List of currently used medications (including prescription drugs, over-the-counter medications, and supplements) — including aspirin, anticoagulants, hormonal medications, etc.
- Records of past medical history, surgeries, and family history (thrombosis and blood disorders)
- Recent blood test results (if possible, blood cell counts, serum iron and ferritin, EPO, liver and kidney function, and molecular genetic test results)
- Records of when symptoms began, their frequency, aggravating factors, and relieving factors (e.g., pruritus, shortness of breath, abdominal distension)
- Pregnancy plans or whether of childbearing potential (for women), and a history of past thrombosis related to the need for anticoagulation
Items to check and report yourself during the outpatient visit
- Recent weight changes and whether fever or night sweats are present
- Bleeding (bruising, nosebleeds, bleeding gums) and symptoms suggestive of thrombosis (sudden pain, swelling, shortness of breath, etc.)
- Symptoms suspected to be medication side effects
Sample questions (questions for the doctor)
- "What are the side effects of this medication?"
- "How high is my risk of thrombosis?"
- "What is the target blood cell count range for treatment?"
- "I am planning a pregnancy; how should my treatment be adjusted?"
Examples of General Questions to Ask the Doctor
- What is my disease subtype (e.g., PV, ET, CML, or PMF), and what genetic mutation do I have?
- What are the goals and expected side effects of the currently recommended treatment?
- How much does treatment reduce the risk of thrombosis and bleeding?
- What are the schedule and items for regular testing and monitoring?
- What should I be careful about in daily life (exercise, employment, travel, and vaccinations)?
Examples of Disease-Specific Questions
- PV/ET patients: "In my case, am I in the low-risk group that can be monitored with aspirin alone, and when will cytoreductive therapy be needed?"
- MF (including CMF) patients: "My spleen is enlarged and causing discomfort; how much can it be reduced and how much can symptoms improve with a JAK inhibitor (e.g., ruxolitinib)? What are the indications for allogeneic hematopoietic stem cell transplantation?"
Additional information
- Regular blood tests and molecular genetic tests (JAK2/CALR/MPL, BCR‑ABL1, etc.) are essential for diagnosis, treatment decisions, and follow-up.
- If symptoms worsen (acute pain, shortness of breath, sudden severe bleeding, decreased consciousness, etc.), immediate evaluation at an emergency room is necessary.