Polycythemia vera (PV) is a chronic blood disorder observed by an unusual increase in three types of blood cells produced by bone marrow: red blood cells, white blood cells, and platelets. PV is called a myeloproliferative disorder because the bone marrow is producing too many cells too rapidly.
Polycythemia vera (PV) usually develops over a time span of 10-20 years. In the United States PV affects about one person in every 200,000. PV mostly affects middle-aged adults and the male/female ratio is 2:1.
Polycythemia vera (PV) is often a diagnosis of exclusion, meaning that the doctor will first rule out other possible causes of the patient’s symptoms. Accurate diagnosis of PV is critical because treatment may require the use of drugs with the potential to cause leukemia.
In the initial phase, the symptoms of polycythemia vera are related to the increased volume of the patient’s blood and it’s greater thickness (high viscosity). Common symptoms are bone pain, headaches, ringing in the ears, tiring easily, memory problems, difficulty breathing, lightheadedness, hypertension, visual difficulties, tingling or burning sensation in the hands and feet, itching (often worse after a warm bath or shower), unusually heavy bleeding from minor cuts, nose bleeds, and stomach ulcers. As the disease progresses, patients can experience episodes of hemorrhage or thrombosis (thrombosis being the most frequent cause of death). In the late stages of PV the bone marrow eventually fails and the patient becomes severely anemic, requiring repeated blood transfusions. The spleen and liver become greatly distended and the patient’s spleen may occupy the entire left side of the abdomen.
The principle treatment of polycythemia vera is phlebotomy. Phlebotomy is used to bring down the ratio of red blood cells to fluid volume (the hematocrit) in the patient’s blood to a level below 45%. Other treatments are myelosuppression therapy to slow down the body’s production of blood cells, investigational drugs, and antihistamines (for itching).
The cause of polycythemia vera (PV) remains unclear. The prognosis for untreated PV is poor; 50% of patients die within 18 months after diagnosis. Patients being treated for PV can expect to live between 11 and 15 years on average after diagnosis. Death usually results from heart failure, leukemia, thrombosis, or hemorrhage.
Frey, R., & Longe, J. (2006). Polycythemia vera. The Gale Encyclopedia of Medicine 5(3).
Retrieved October 9, 2011 from Gale database.
