Polycythemia veraDefinition: Polycythemia vera is an abnormal increase in blood cells (primarily red blood cells) resulting from excess production by the bone marrow.
Alternative Names: Primary polycythemia; Polycythemia rubra vera; Myeloproliferative disorder; Erythremia; Splenomegalic polycythemia; Vaquez's disease; Osler's disease; Polycythemia with chronic cyanosis - Myelopathic polycythemia; Erythrocytosis megalosplenica; Cryptogenic polycythemia
Causes, incidence, and risk factors: Polycythemia vera is an acquired disorder of the bone marrow that causes the overproduction of all three blood cell lines: white blood cells, red blood cells, and platelets. It is a rare disease that occurs more frequently in men than women, and rarely in patients under 40 years old. It is not known what causes polycythemia vera. The disease usually develops slowly, and most patients do not experience any problems related to the disease after being diagnosed. However, the abnormal bone marrow cells may begin to grow uncontrollably in some patients leading to acute myelogenous leukemia. Patients with polycythemia vera also have an increased tendency to form blood clots that can result in strokes or heart attacks. Some patients may experience abnormal bleeding because their platelets are abnormal.
Symptoms: Note: Symptoms are due to increased blood viscosity (thickness) and clotting. Additional symptoms that may be associated with this disease:
Signs and tests: This disease may also alter the results of the following tests:
Treatment: The objective of treatment is to reduce the high blood viscosity (thickness of the blood) due to the increased red blood cell mass and to prevent hemorrhage and thrombosis. Phlebotomy is one method used to reduce the high blood viscosity. In phlebotomy, 1 unit (pint) of blood is removed weekly until the hematocrit is less than 45, then phlebotomy is continued as necessary. Occasionally, chemotherapy may be given to suppress the bone marrow. Other agents such as interferon may be given to lower blood counts. Anegrelide may be given to lower platelet counts. The use of anti-platelet therapy (such as aspirin) is controversial because it may cause stomach bleeding. Allopurinol is given for hyperuricemia (gout).
Expectations (prognosis): Polycythemia vera usually develops slowly, and most patients treated appropriately do not experience any problems related to the disease. However, the abnormal bone marrow cells may begin to grow uncontrollably leading to acute myelogenous leukemia.�This occurs in a minority of cases. Patients with polycythemia vera also have an increased tendency to form blood�clots that can result in strokes or heart attacks. Some patients may experience abnormal bleeding because their platelets are abnormal.
Calling your health care provider: Call your health care provider if symptoms of polycythemia vera develop.
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