What is Polycythemia Vera?
Polycythemia Vera (PV) is a type of chronic cancer of the blood, which starts in the bone marrow which is the soft center of the bone where the production of new blood cells takes place. In persons affected by polycythemia vera, there is excessive production of red blood cells, and other cells, such as platelets and white blood cells in the bone marrow, which makes the blood very thick in consistency resulting in increased likelihood of a person having blood clots, heart attack or a stroke. Polycythemia vera is a rare condition, which develops slowly, often over a period of many years. With proper treatment and care, patients suffering from Polycythemia vera can live for many years; however, if treatment is not started, then it can become a life threatening condition. There is also a risk of development of other more fatal blood cancers, such as acute leukemia or myelofibrosis. Polycythemia vera tends to develop in individuals who are 60 years of age or more; however, people of any age can be affected by it. Men are more susceptible to it than women. Patient may experience some warning signs, such as weakness, tiredness and dizziness. Polycythemia vera often is discovered during a routine blood test where the increased count of blood cells is revealed.
There is no cure for Polycythemia vera. Treatment for Polycythemia vera depends on the patient’s age, general health and each individual’s case. Treatment focuses on decreasing the blood cell count and alleviating the symptoms. If the patient is not having lot of symptoms, then he/she may only be observed on a regular basis without any treatment being done.
Causes & Risk Factors of Polycythemia Vera
Polycythemia vera is not a contagious disease. It does not pass from one person to another like a common cold. It occurs when there is a problem in the gene known as JAK2, which is responsible for keeping a check on the excessive production of blood cells. Rarely, this faulty gene can be passed to the children from the parents.
There are three types of blood cells made by the bone marrow, red blood cells, white blood cells and platelets. The red blood cells are responsible for carrying oxygen, the white blood cells fight infections, and the platelets are responsible for clotting the blood so bleeding is stopped. In majority of cases, there is excessive production of red blood cells in polycythemia vera, however, there can also be excessive production of platelets and white blood cells.
The risk of Polycythemia Vera is more as a person ages. Individuals over the age of 60 are at an increased risk for having this condition. Men are more likely to develop Polycythemia Vera than women.
Signs & Symptoms of Polycythemia Vera
Initially, the patient may not experience any symptoms of polycythemia vera and the disease gets detected during routine blood tests. If patient does not seek treatment, then the excessive red blood cells increase the risk of blood clots, which in turn hinders the blood circulation. This leads to increase in the risk for stroke and heart attack along with causing chest pain (angina).
Common symptoms of Polycythemia Vera include:
- Double vision.
- Blind/dark spots which come and go.
- Sweating, particularly at night.
- Generalized itching in the body, particularly after the patient has been in warm/hot water or shower.
- There is redness of the face, which resembles blushing or sunburn.
- Loss of weight.
- Shortness of breath.
- Numbness, burning or tingling in the arms/legs.
- Pain and swelling in the joint, especially in the big toe.
- Feeling of fullness or pressure beneath the ribs in the left upper abdomen due to spleen enlargement. The function of the spleen is filtering the blood.
Diagnosis of Polycythemia Vera
- Physical exam is done where the spleen is checked. The doctor also checks the patient’s face to see if it is exceptionally red.
- Blood tests to include CBC (Complete Blood Count ) are done where a sample of the blood is taken to check for an increase in red blood cells and also white blood cells and platelets which indicates Polycythemia Vera. There is also increase in hemoglobin and hematocrit level in Polycythemia Vera. Blood tests are also done to rule out other diseases, which can be associated with Polycythemia Vera.
- Blood test is also done to check the EPO level i.e. erythropoietin level, which is a hormone which helps in production of new red blood cells by the bone marrow. There is very low level of EPO in patients having polycythemia vera.
- Bone marrow biopsy/aspiration is done to check if the bone marrow is making excessive blood cells, which is an indication of polycythemia vera. The bone marrow sample is commonly taken from the posterior side of the hip bone. This is done on an outpatient basis.
Treatment for Polycythemia Vera
There is no cure for Polycythemia Vera. Treatment for it depends on patient to patient and is aimed at reducing the blood cell count, relieving the signs and symptoms and trying to prevent complications from polycythemia vera. If the patient is not experiencing any symptoms, then treatment may not be started and the patient is only monitored or observed on a regular basis. Treatment for Polycythemia Vera consists of:
- Phlebotomy: This is usually the first line of treatment for polycythemia vera. In this procedure, the blood is removed from the veins. The aim of this procedure is bringing down the blood cell count so that the consistency of the blood is thinner and it circulates and functions better. Phlebotomy also helps in relieving symptoms like dizziness and headaches. The frequency of undergoing phlebotomy depends on the severity of the disease. In some patients, this is the only treatment required for many years.
- Low-dose aspirin is prescribed to prevent the platelets from sticking to each other, so that the risk of getting blood clots is reduced. This in turn will decrease the risk of strokes and heart attacks. Low-dose aspirin also helps in alleviating the burning sensation in the hands and feet.
- Medicines, which will reduce the number of blood cells, are prescribed when the phlebotomy and aspirin do not work sufficiently for the patient. Hydroxyurea is a medicine, which helps in lowering the red blood count and relieving the symptoms by suppressing the function of the bone marrow for producing cells. Interferon Alfa is a medicine which boosts the body’s immune system to halt the overproduction of blood cells. Ruxolitinib can also be used in patients who are not responding to hydroxyurea or who are not able to tolerate the side effects of this medicine.
- Antihistamines are prescribed for relief from itching. Ultraviolet light therapy also provides relief from discomfort. Antidepressants, such as SSRIs (Selective Serotonin Reuptake Inhibitors), also can provide relief from itching.
Lifestyle Modifications for Polycythemia Vera
- Smoking and chewing tobacco should be avoided as tobacco constricts the blood vessels thus increasing the likelihood of formation of blood clots.
- It is important to get some type of exercise daily, such as walking, as it will help in improving the blood circulation and keeps the heart healthy. Ankle and leg exercises help in preventing the formation of clots in the leg veins.
- Exposure to extreme temperatures should be avoided, as poor blood circulation makes the body more prone to injury in hot and cold weathers. Warm clothing should be worn in cold weather and measures for sun protection should be undertaken in the hot weather. Plenty of fluids should be consumed during the hot weather.
- If warm water is causing itching, then showering or bathing in cool water should be done for relief. Other things to avoid include heated whirlpools and hot tubs. Resist the urge to scratch, as it causes skin damage and increases the risk of infection. Moisturizers should be used to keep the skin moist and reduce the dryness and it also alleviates itching.
Prognosis & Life Expectancy of Polycythemia Vera
There is no cure for Polycythemia Vera; however, with proper treatment, patients can live for many years with this disease and are able to lead an active life. It should also be borne in mind that each patient has different course of disease and the prognosis can vary from patient to patient. In rare cases, Polycythemia Vera can lead to other fatal blood cancers, such as myelofibrosis or acute leukemia. About 15% of patients suffering from PV may develop a serious and advanced stage of polycythemia vera, which is known as myelofibrosis. In this condition, bone marrow transplantation may be required. With regular treatments and monitoring, patient can live with Polycythemia Vera for around 35 to 40 years. It is important to seek support of family and friends and try to keep a positive attitude to fight this disease.