Scurvy

Disease Description (Causes and Symptoms)

• Definition summary: Myeloproliferative neoplasms (MPNs) are a group of disorders in which hematopoietic stem cells in the bone marrow undergo clonal overproliferation, causing abnormally increased numbers of red blood cells, white blood cells, and/or platelets, or progressive bone marrow fibrosis. Major subtypes include polycythemia vera (PV), essential thrombocythemia (ET), primary myelofibrosis (PMF), and BCR‑ABL1-positive chronic myeloid leukemia (CML).
• Causes/genetic background: Representative driver mutations include JAK2 (V617F), CALR, and MPL mutations; JAK2 mutations are observed particularly frequently in PV. These mutations activate the JAK-STAT signaling pathway, resulting in abnormal hematopoiesis.
• Key pathophysiology: Increased clonal hematopoiesis → increased peripheral blood cell counts (or hematopoietic failure due to bone marrow fibrosis) → increased blood viscosity and elevated thrombotic risk, splenomegaly (extramedullary hematopoiesis), peripheral circulatory impairment, anemia/fatigue, etc.
• Main symptoms: Asymptomatic (detected through abnormal blood test results) → thrombosis (arterial and venous thrombosis), bleeding (especially acquired vWD with extreme thrombocytosis), splenomegaly, pruritus (particularly worsening after a hot bath), facial flushing (plethora), erythromelalgia (burning sensation and redness in the extremities), fatigue and anemia-related symptoms, weight loss and night sweats (with progression).

Treatment Methods

• Treatment principles: Personalized treatment is based on subtype, age, thrombotic risk factors (history, age, platelet/hematocrit and white blood cell counts, etc.), presence or absence of symptoms, and genetic mutations and treatment resistance. The primary goal is to prevent complications (thrombosis, bleeding, and progression).
• Polycythemia vera (PV)
  • Standard: Target hematocrit (Hct) <45% (recommended without regard to sex), with hematocrit controlled through regular phlebotomy (200–500 mL).
  • Prevention of thrombosis with low-dose aspirin (e.g., 75–100 mg/day), determined after assessing bleeding risk.
  • Cytoreductive agents (hydroxyurea) are used in high-risk patients (older adults or those with a history of thrombosis) or when the condition is unstable. Interferon (peg‑IFN) may be considered for patients planning pregnancy or younger patients.
  • If hydroxyurea is intolerable or ineffective, a JAK2 inhibitor (ruxolitinib: effective for symptoms and splenomegaly) may be used.
• Essential thrombocythemia (ET)
  • Low-risk group (age <60 and no history of thrombosis): Observation or low-dose aspirin (depending on symptoms and thrombotic risk).
  • High-risk group (age ≥60 or history of thrombosis): Hydroxyurea (primary first-line agent) or interferon (e.g., during pregnancy or childbearing years) or anagrelide (an alternative when platelet reduction is needed).
  • With extreme thrombocytosis (e.g., >1,000×10^9/L), assessment of bleeding risk (acquired vWD) is necessary — consider vWF testing before administering aspirin.
• Primary myelofibrosis (PMF)
  • Symptom relief and spleen reduction: JAK1/2 inhibitor (ruxolitinib) — improves splenomegaly and systemic symptoms.
  • Management of anemia: Conservative treatment such as transfusions, erythropoietin, androgens, and corticosteroids.
  • Definitive treatment: Allogeneic hematopoietic stem cell transplantation for young, high-risk patients eligible for transplantation (the only curative treatment).
  • Conservative management for asymptomatic, low-risk patients who can be monitored.
• Chronic myeloid leukemia (CML, BCR‑ABL1-positive)
  • Standard: Tyrosine kinase inhibitors (TKIs; imatinib, nilotinib, dasatinib, etc.). The goal is a complete molecular response.
• General supportive and lifestyle management
  • Actively manage cardiovascular risk factors (smoking, hypertension, diabetes, and hyperlipidemia).
  • Avoid dehydration and excessive alcohol consumption; regular exercise is recommended.
  • Consult a doctor when using medications with a high bleeding risk (caution is needed when combining NSAIDs and anticoagulants).
• Precautions during treatment
  • There is a risk of bleeding with extremely high platelet counts (acquired vWD) — testing is needed before using aspirin.
  • Hydroxyurea may cause adverse effects such as infertility and skin reactions; interferon may cause toxicity and depression.
  • Anticoagulant or antiplatelet treatment is determined based on the balance between thrombotic and bleeding risks.

Checklist Before an Outpatient Visit (Including Items to Bring and Sample Questions)

• Items to prepare/bring
  • Recent blood test results (CBC, platelet, hematocrit, and white blood cell counts), with the test dates indicated.
  • Copies of genetic test results (JAK2, CALR, MPL, BCR‑ABL, etc.), if available.
  • A list of all medications and dietary supplements currently being taken (including directions and dosages).
  • Records of any history of thrombosis or bleeding, transfusions, surgeries, and pregnancies.
  • Records of symptom changes (redness, pain, night sweats, weight changes, etc.), including onset, frequency, and triggers.
• Points to show the doctor during the outpatient visit
  • Recent CBC trends (time series) and test dates.
  • Whether medications have caused side effects or been effective (e.g., bleeding after aspirin, skin lesions while taking hydroxyurea).
  • Pregnancy plans and breastfeeding status (these have a major impact on treatment selection).
• Symptoms to monitor yourself during the outpatient visit period (items to report to the doctor immediately)
  • Symptoms suggestive of thrombosis, such as sudden limb pain, numbness, visual disturbances, or dizziness.
  • Unexplained bleeding (frequent nosebleeds, gum bleeding, or heavy menstrual bleeding).
  • High fever, rapid weight loss, or persistent night sweats (signs of progression).

General Sample Questions to Ask the Doctor

• "What exactly is my disease (subtype), and what is the long-term prognosis?"
• "What standard medication should I take, and what are its major side effects?"
• "Should I take aspirin to prevent thrombosis? How will my bleeding risk be assessed?"
• "I am planning a pregnancy; which treatment options are safe?"
• "What regular tests (interval and test items) will be performed, and what target values should I aim for?"

Sample Questions Tailored to the Disease

• Regarding JAK2/CALR/MPL:
  • "What are the results of my genetic tests (JAK2/CALR/MPL), and how will they affect treatment selection and prognosis?"
• Regarding thrombotic/bleeding risk assessment:
  • "How is my thrombotic risk classified (high risk/low risk), and what specific treatment recommendations follow from that classification (e.g., aspirin, anticoagulation, or cytoreductive agents)?"
• (Additional optional question) Regarding myelofibrosis:
  • "What are the indications for allogeneic hematopoietic stem cell transplantation, and how will my eligibility for transplantation be assessed?"

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Note: Treatment selection and monitoring depend greatly on the subtype, age, comorbidities, past medical history (especially thrombosis and bleeding), and molecular genetic test results. The indications, contraindications, and side effects of each treatment vary from person to person, so please consult your treating doctor during an outpatient visit based on specific test results.