Polycythemia Vera - What You Need to Know

Polycythemia is a rare condition where the count of red blood cells in the body increases. The normal count of red blood cells ranges from 4.9-5.2 million cells per cmm. People having polycythemia witness an increase in the count of hemoglobin, hematocrit or red blood cells as compared to the normal level.

Women with hemoglobin levels higher than 16.5g/dL and hematocrit value higher than 48, are believed to have polycythemia. In case of men, hemoglobin levels higher than 18.5g/dL and hematocrit value greater than 52 are suggestive of polycythemia.

A myeloproliferative disorder that involves an uncontrolled red blood cells formation in the bone marrow is called as polycythemia vera. It is a slow growing cancer involving the blood cells. The cells growing in an excess quantity cause a thickening of blood and cause a reduction in the flow rate of blood. Thickening or clot formation can lead to a stroke or a cardiac arrest. This condition can develop and progress without any symptoms and go undiagnosed for a long period of time. Lack of prompt diagnosis and treatment can cause the condition to become life-threatening. It may also progress to other forms of cancers like acute leukemia.

The two main types of polycythemia are primary and secondary. Polycythemia vera is symptomless usually. When symptoms appear, the commonly seen ones are as follows – constant headache of mild to moderate intensity, itchy rashes on skin, bruises with bleeding points, lethargy, blurring of vision, excess sweating, joint swelling and excessive pain, unexpected weight loss, neuropathy in limbs, low to moderate grade fever and even shortness of breath. There is no specific age group predilection for its incidence, it can occur at any age. However, the prevalence rate is common in adults over 60 years of age. The male to female ratio of occurrence is also even, with no gender predilection.

Polycythemia vera is not completely curable, with the treatment being focused on reduction of red blood cell count. Symptomatic treatment allows for reducing the complications related to the presenting signs and symptoms. Phlebotomy is done where the blood volume is decreased by drawing out of blood from the veins. Thrombolytic drugs like low dose aspirin is given to break clots. Anti-cancer drug Ruxolinitib helps in the destruction of cancer cells to some extent.

What are the possible causes of polycythemia?

1. Polycythemia occurs due to a genetic mutation of the protein called Janus kinase 2 or JAK2. This results in increased production of red blood cells.
2. Another condition known as Primary Familial and Congenital Polycythemia (PFCP) is related to the mutation in the Erythropoietin Receptor (EPOR) which escalates the production of red blood cells in response to EPO.
3. Deficiency of 2, 3-Bisphosphoglycerates (BPG) can increase red blood cell production in your body. Under this condition, hemoglobin develops an increased affinity to hold on to the oxygen, and is less likely to discharge it to the tissues. As a result more red blood cells are produced in response to insufficient oxygen levels.

Look out for the symptoms!
The usual symptoms of polycythemia include the following-

• Headache
• Dizziness
• Minor bruising or bleeding
• Fatigue and weakness
• Blurred vision
• Unintentional weight loss
• Abdominal pain
• Bloating or a feeling of fullness due to an enlarged spleen
• Numbness in the hands and feet
• Painful swelling of a joint
• Itching after a warm shower

The symptoms may vary from mild to severe. If left untreated, polycythemia can lead to severe health complications like scarring of the bone marrow, acute leukemia or myelodysplastic syndrome. Recognizing the symptoms at an early stage can help prevent the complications.

This disorder can cause various complications, formation of blood clots in the body being the most common of them. Formation of such blood clots in organs like lungs can cause an embolism or in the blood vessels can cause an obstruction to the blood flow. Deep vein thrombosis is a common complication caused by the presence of a thrombus formation due to blood clot in the veins of lower limbs. Polycythemia also causes splenomegaly due to increased exertion on the spleen by the uncontrolled growth of red blood cells. Other complications include formation of ulcers in the intestines, joint inflammation and development of more severe blood disorders.

How is polycythemia treated?
Treatment of polycythemia depends on its cause and severity.

Phlebotomy is the procedure whereby the doctor uses a needle to remove a tiny amount of blood from the vein. This decreases the volume and count of red blood cells so that excess blood cells are not formed, and oxygen is carried to different organs in the body.

People who are at high-risk, or have reached an advanced stage, require more specialized treatment. Certain medications used in the treatment of polycythemia include-

1. Hydroxycarbamide- Prevents over production of red blood cells in the body.
2. Interferon alpha- Helps combat the overactive bone marrow cells which are related to polycythemia vera.
3. Busulfan- Although this drug is prescribed for the treatment of leukemia, it can also be used off- label to cure polycythemia.
4. Ruxolitinib- This drug is usually prescribed when other medications like hydroxyurea have failed to lower the blood count. Ruxolitinib inhibits the growth factors which are responsible for producing red blood cells.

Other treatment procedures for easing symptoms like persistent itching may include antihistamines, Selective Serotonin Reuptake Inhibitors (SSRIs) and phototherapy.