Polycythemia Vera

• Polycythemia Vera is a myeloproliferative neoplasm characterized by the bone marrow producing too many red blood cells, and sometimes white blood cells and platelets.
• Common symptoms include fatigue, headaches, dizziness, and itching, often linked to thickened blood and an enlarged spleen.
• The primary cause is typically a mutation in the JAK2 gene, which is crucial for blood cell production.
• Diagnosis involves blood tests, bone marrow biopsy, and genetic testing for the JAK2 mutation.
• Treatment focuses on managing symptoms and preventing complications through methods like phlebotomy, low-dose aspirin, and targeted medications.

What is Polycythemia Vera?

Polycythemia Vera (PV) is a rare, chronic myeloproliferative neoplasm (MPN) where the bone marrow produces too many red blood cells. In some cases, it also leads to an overproduction of white blood cells and platelets. This excess of blood cells thickens the blood, making it flow less efficiently and increasing the risk of blood clots, which can lead to serious cardiovascular events such as strokes or heart attacks. According to the National Cancer Institute, PV is considered a slow-growing cancer, but it requires lifelong management.

The condition primarily affects adults, with the median age of diagnosis typically around 60 years old, though it can occur at any age. While the exact prevalence varies by region, it is estimated to affect approximately 2.8 per 100,000 people in the United States, as reported by the American Society of Hematology.

Polycythemia Vera Symptoms, Causes & Diagnosis

Understanding polycythemia vera symptoms and causes is crucial for early detection and management. The primary cause of Polycythemia Vera is almost always a mutation in the Janus kinase 2 (JAK2) gene, specifically the JAK2 V617F mutation, which is found in over 95% of patients. This genetic mutation leads to uncontrolled blood cell production in the bone marrow, independent of normal regulatory signals.

Symptoms often develop gradually and can be non-specific, making initial diagnosis challenging. They typically arise from the increased blood viscosity and reduced blood flow. Common symptoms include:

• Fatigue and weakness
• Headaches and dizziness
• Shortness of breath
• Itching (pruritus), especially after a warm bath or shower
• Reddened skin, particularly on the face
• Enlarged spleen (splenomegaly), causing abdominal discomfort or fullness
• Burning or tingling in the hands and feet (erythromelalgia)

The process of polycythemia vera diagnosis involves a combination of tests. A complete blood count (CBC) will typically show elevated red blood cell count, hemoglobin, and hematocrit levels. Platelet and white blood cell counts may also be elevated. Further diagnostic steps include a bone marrow biopsy, which can reveal hypercellularity (increased cell production) and abnormal cell morphology, and genetic testing to confirm the presence of the JAK2 mutation. Blood tests for erythropoietin (EPO) levels, which are usually low in PV, also aid in distinguishing PV from secondary polycythemia.

Polycythemia Vera Treatment Options

The goal of polycythemia vera treatment is to reduce the risk of complications, alleviate symptoms, and improve quality of life. Treatment plans are individualized based on the patient’s age, symptoms, and risk factors for thrombosis. There is currently no cure for Polycythemia Vera, so management is lifelong.

The cornerstone of treatment for most patients is phlebotomy, a procedure similar to blood donation, to reduce the red blood cell count and blood viscosity. This helps to maintain hematocrit levels below 45%, significantly lowering the risk of blood clots. Low-dose aspirin is also commonly prescribed to reduce the risk of thrombosis by inhibiting platelet aggregation. For patients with higher risk factors or those whose symptoms are not controlled by phlebotomy and aspirin, medications may be necessary.

Medications used to manage Polycythemia Vera include:

• Hydroxyurea: A myelosuppressive agent that reduces the production of all blood cells in the bone marrow.
• Ruxolitinib: A JAK inhibitor that targets the JAK2 pathway, effective in reducing spleen size and alleviating symptoms like itching and fatigue.
• Interferon alfa: A biological agent that can reduce blood cell counts and may be considered for younger patients or those who cannot tolerate other treatments.

Regular monitoring through blood tests and clinical evaluations is essential to adjust treatment as needed and to watch for potential complications or disease progression. While some supportive care options may help manage symptoms, they are not a substitute for medical treatment and should always be discussed with a healthcare professional.