Polycythaemia (Rubra) Vera
What is Polycythaemia (Rubra) Vera?
Polycythaemia (Rubra) Vera, also known as primary polycythaemia vera, is a disorder where too many red cells are produced in the bone marrow, without any identifiable cause. These cells accumulate in the bone marrow and in the blood stream where they increase the blood volume and cause the blood to become thicker, or more ‘viscous’ than normal. In many people with polycythaemia vera, too many platelets and white cells are also produced.
Polycythaemia vera is a rare chronic disease diagnosed in an estimated 2 to 3 people per 100,000 population. Although it can occur at any age, polycythaemia vera usually affects older people, with most patients diagnosed over the age of 55. Polycythaemia vera is rare in children and young adults. It occurs more commonly in males than in females.
Symptoms and Complications
Many people have no symptoms when they are first diagnosed with polycythaemia vera. The disease is often discovered during a routine blood test or physical examination.
If symptoms do develop, they tend to do so over time. They are mainly due to the increased thickness (hyperviscosity) and abnormally high numbers of blood cells in the circulating blood. Common symptoms include headaches, blurred vision, fatigue, weakness, dizziness, itchy skin and night sweats.
Enlargement of the spleen (splenomegaly) is also common and occurs in around 75 per cent of cases. Symptoms include feelings of discomfort, pain or fullness in the upper left-side of the abdomen. An enlarged spleen may also cause pressure on the stomach causing a feeling of fullness, indigestion and a loss of appetite. In some cases the liver may also be enlarged.This is called hepatomegaly.
Some people experience gout, which usually presents as a painful inflammation of the big toe or foot. This can result from a build up of uric acid, a byproduct of the increased production and breakdown of blood cells. Some individuals may develop erythromelalgia, a rare condition that primarily affects the feet and, less commonly, the hands. It is characterised by intense, burning pain of affected extremities, and increased skin temperature that may be episodic or almost continuous in nature.
In many cases, people with polycythaemia vera have a ruddy (red) complexion, and a reddening of the palms of the hand and soles of the feet, ear lobes, mucous membranes and the eyes. This is due to the high numbers of red cell in the circulation. A raised blood pressure (hypertension) is also common.
Bleeding and easy bruising can also occur. This is usually minor and occurs in around one quarter of all patients.
Occasionally bleeding into the gut can be prolonged or severe.
How is Polycythaemia Vera diagnosed?
Polycythaemia vera is diagnosed using a combination of laboratory tests and a physical examination.
Full blood count
People with polycythaemia vera have a high red cell count, haemoglobin level and haematocrit (>52 % in men or >48% in females) due to the excessive production of red cells. The haematocrit is the percentage of the whole blood that is made up of red cells. A raised white cell count (especially a raised neutrophil count) and a raised platelet count are also common findings.
The red cell mass is the total number of red cells circulating in your blood. Polycythaemia vera may be diagnosed when the red cell mass is 25% greater than the average normal expected value. Other findings that help confirm the diagnosis of polycythaemia vera include an enlarged spleen (splenomegaly) and the presence of the JAK2 mutation or other cytogenetic abnormalities in your blood or bone marrow cells.
JAK2 Mutation testing
JAK2 mutations (particularly the V617F mutation) can be found in more than 95% of people with Polycythaemia vera. This test can be performed on a blood sample and will help to confirm the diagnosis of a myeloproliferative neoplasm. It doesn’t help distinguish polycythaemia vera from essential thrombocythaemia or primary myelofibrosis.
Bone marrow examination
In polycythaemia vera the bone marrow is often very active with abnormally high numbers of normal cells. Iron stores may be depleted since iron is being used to make more and more red cells.
- Other possible blood tests: serum vitamin B-12 levels; uric acid levels; erythropoietin levels; coagulation studies (to see if your blood is clotting normally); blood oxygen levels
- Other possible tests: chest x-ray – to rule out lung disease; abdominal ultrasound and/or CT scan – to rule out kidney disease and measure spleen/liver size.
How is Polycythaemia Vera treated?
The goal of treatment for polycythaemia vera is to reduce the number of cells in your blood and help you to maintain a normal blood count. This helps control any symptoms of your disease and reduces the risk of complications due to blood clotting, or bleeding. The treatment, or combination of treatments chosen for you will depend on several factors including the duration and severity of your disorder, whether or not you have a history of blood clots, your age and your general health.
Venesection (or phlebotomy) is a procedure in which a controlled amount of blood is removed from your bloodstream. This procedure is commonly used when people are first diagnosed with polycythaemia vera because it can help to rapidly reduce a high red cell count. In a process similar to a blood donation, 450mls to 500mls of your blood is removed, usually from a large vein in the arm, inside the elbow bend. This is usually done in the outpatient’s department of the hospital. It takes about 30 minutes to complete. You will need to have a blood test before to check your blood count, and you must make sure you drink plenty of water before and after the procedure.
This procedure may need to be repeated frequently at first, usually every few days, until your haematocrit is reduced to the desired level. After this, you may need to have the procedure repeated periodically, for example at monthly intervals, to help maintain a normal blood count.\For many people, particularly younger patients and those with mild disease, regular venesection (every few months) may be all that is needed to control their disease for many years.
Many people with polycythaemia vera also need other treatments in addition to, or instead of venesection, to help control their blood count.
- Myelosuppressive and other drugs
Myelosuppressive (bone marrow suppressing) drugs, chemotherapy, biotherapy, radioactive isotopes, cytokines and anticoagulant (anti clotting) drugs are commonly used to reduce blood cell production in the bone marrow. These drugs are commonly used for people with an extremely high platelet count, complications due to blood clotting or bleeding, or symptoms of an enlarged spleen. They are also used for some people who are unable to tolerate venesection or whose disease is no longer responding to venesection.
You should report any side-effects you are experiencing to your doctor as many of them can be treated to reduce any discomfort to you. You need to contact your doctor immediately if you experience the following symptoms: shortness of breath or difficulty breathing, swollen ankles, fast or irregular heartbeat, and/or chest pain.
You should not stop taking any medication for polycythaemia vera unless instructed by your doctor. Stopping these medications suddenly can be harmful.
In addition to the treatments described above, your doctor will advise you on ways to stay healthy and reduce any ‘life-style’ factors that might increase your risk of thrombosis. For example you may be advised to stop smoking, and/or take a series of steps to maintain a healthy weight range and blood pressure.
A prognosis is an estimate of the likely course of a disease. It provides some guide regarding the chances of curing the disease or controlling it for a given time.
The natural course of polycythaemia vera can vary considerably between individuals. In many patients, with treatment, the disease remains stable for long periods of time, often many years. In around 10% of all cases, polycythaemia vera transforms over time into another type of myeloproliferative neoplasm called myelofibrosis, and less commonly, in up to 3% of cases into acute myeloid leukaemia.
In some people, polycythaemia progresses over time despite treatment. The spleen may become increasingly enlarged. Anaemia and thrombocytopenia (low numbers of circulating platelets) is common as the bone marrow is no longer able to produce adequate numbers of red cells or platelets. In addition, abnormal immature blood cells, known as blast cells may start to appear in the blood.
Treatment during this time is supportive and involves making every effort to improve the patient’s quality of life, by relieving any symptoms they might have and by preventing and treating any complications that arise from their disease or its treatment. This may involve blood transfusions if required, pain relief and careful myelosuppression.
In selected cases, surgical removal of the spleen, or low dose radiation to the spleen may be required to relieve symptoms.
Your doctor is the best person to give you an accurate prognosis regarding your disease as he or she has all the necessary information to make this assessment.
Last updated on June 19th, 2019
Developed by the Leukaemia Foundation in consultation with people living with a blood cancer, Leukaemia Foundation support staff, haematology nursing staff and/or Australian clinical haematologists. This content is provided for information purposes only and we urge you to always seek advice from a registered health care professional for diagnosis, treatment and answers to your medical questions, including the suitability of a particular therapy, service, product or treatment in your circumstances. The Leukaemia Foundation shall not bear any liability for any person relying on the materials contained on this website.