Polycythemia vera is a rare type of blood cancer that involves excessive red blood cell production. It often develops slowly and one might not even know about it until a blood test is done. The red blood cells are produced within the soft tissues inside the bone – bone marrow. When the bone marrow produces too many blood cells, the blood becomes thicker. This results in a slow blood flow and many other serious complications including blood clots.
In a normal state, nearly 40 – 50% of the total blood is made up of red blood cells also known as erythrocytes. This volume percentage of RBC to the total blood volume is known as the hematocrit of PCV (Packed Cell Volume). The main function of the RBC is to carry oxygen to the tissues and carbon dioxide back to the lungs. In polycythemia vera, because of excessive RBC production, the hematocrit or PCV will be more than 50%, thereby making the blood thicker.
What Causes Polycythemia Vera?
Polycythemia vera is caused by a hematopoietic stem cell mutation, which produces red blood cells, white blood cells, and platelets. In 90% of the affected individuals, there is a Janus Kinase 2 (JAK2) gene mutation that causes excessive production of RBCs.
RBC Production Mechanism
Kidneys produce a hormone called erythropoietin which binds to the receptors on the hematopoietic stem cell. This hormone activates the JAK2 gene which results in the production of more blood cells.
Also, read about Kidney Health & Lifestyle Modifications
However, when the mutation occurs, the JAK2 gene is always kept activated even in the absence of the erythropoietin, resulting in the production of more blood cells. As a result the mutated cells rapidly become the predominant hematopoietic cells in the bone marrow.
In time these hematopoietic stem cells die out forming scar tissues. As a result, the bone marrow may no longer be able to produce blood cells which cause low red blood cell level (anaemia), low platelet levels (thrombocytopenia), low white blood cell level (leucopenia). This is known as the spent phase and this situation is called myelofibrosis.
The cause for this gene mutation in polycythemia vera is unknown and is not genetic.
Risk factors of Polycythemia Vera
This condition can happen at any age but adults between the ages of 50-75 are more prone. Even though women tend to get this at a younger age, it is often noticed that men are more likely to get this mutation problem.
Symptoms of Polycythemia
There are no noticeable symptoms for Polycythemia Vera. Vague symptoms like Headache, dizziness, fatigue, blurred vision, redness in the face, increased sweating, etc might be developed due to this issue.
More specific symptom includes:
- Itchiness of the skin, especially after a hot water shower. This happens because of increased basophils and mast cells which releases histamine
- Numbness, weakness, burning or tingling sensation in arms or legs
- Splenomegaly or spleen enlargement that leads to bloating or pain in the left abdomen. The spleen helps in removing the excess red blood cells.
- Unusual bleeding (nose bleed or bleeding gums)
- Swelling of the big toe
- Difficulty in respiration or shortness of breath while lying down.
Complications of Polycythemia
Blood Clots – As the blood thickens the blood flow decreases racing the risk of blood clots. Stroke, heart attack, pulmonary embolism (blockage in an artery in the lungs), clots in the vein of leg muscle or the abdomen (deep vein thrombosis), or even Budd- Chiari syndrome (when liver veins are blocked by the blood clot), etc are some of the risks of blood clots impacting other organs in the body.
Enlarged Spleen – Spleen filters the unwanted RBCs such as old or damaged blood cells and also helps in fighting infections. The increase in red blood cells causes excess strain on the spleen, making it work harder than normal causing spleen enlargement. Enlargement of the spleen is also known as Splenomegaly
Problems due to high red blood cell levels – it may cause inflammation in the joints that are gout or result in an open sore on the inside lining of the stomach, small intestine, or esophagus.
Gout – High turnover of red blood cells can increase the serum uric acid levels. This can lead to gout (inflammation of small joints), uric acid stones in the kidney.
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Other disorders – it may cause cancer of the blood and bone marrow (acute leukaemia). A progressive disorder happens when bone marrow is replaced with scar tissues.
Diagnosis of Polycythemia vera
Polycythemia vera is often diagnosed during a blood analysis report that tests the CBC (Complete blood count) Increased levels of haemoglobin, hematocrit (PCV), white blood cells, or even platelets can be a sign of this disease. It is also seen that most individuals with polycythemia vera have decreased erythropoietin levels – a hormone secreted by the kidney that promotes RBC production. But in some cases, it was found to be normal and even elevated. Bone marrow tissue examination/biopsy can be performed to check for fibrosis. To check for a JAK2 mutation, genetic testing can be performed to confirm polycythemia vera
Treatment for polycythemia vera
Treatment of polycythemia vera primarily involves reducing the thickness of blood by removing blood at regular intervals, medications to reduce the new blood cell formation and prevention of blood clots
Phlebotomy or bloodletting – blood is drawn out through a vein every few months to bring the PCV levels to normal. This blood is not donated but it can be used by the donor in the future if necessary.
Myelosuppressive Medication – like hydroxyurea and Ruxolitinib which is a JAK 2 Inhibitor, may be prescribed by the haematologist, to lower red blood cell formation. Ruxolitinib is also particularly helpful in relieving itching and discomfort
Other medications such as antihistamine, hydroxyzine, aspirin (to prevent clotting) may also be prescribed by the doctor to relieve the symptoms and prevent the complications of polycythemia
In the spent phase, where the bone marrow fibrosis has lead to scar tissue and reduced RBC production, the patient may also need a blood transfusion at regular intervals.
Lifestyle and home remedies for Polycythemia
Exercise – Moderate exercise like walking can increase blood circulation and decrease the risk of blood clots
Avoid Smoking – Nicotine is a vaso-constrictor – ie, it constricts the blood vessels. This shrinkage of the blood vessels increases the risk of blood clots leading to heart attack or stroke.
Avoid a low oxygen environment – any activity such as skiing or mountaineering or residing in high altitudes may result in the reduction of oxygen levels in the blood. It is hence best avoided, especially in the case where the disease has progressed to the spent phase.
Skincare – using a gentle cleanser with cool water to reduce itching. Adding starch (corn starch) to the bath and avoiding hot tubs, hot showers, etc is found to be useful. Keeping the skin moist with a lotion and not scratching unnecessarily is advisable.
Avoid extreme temperature – extreme temperatures can increase the risk of injury when the blood flow is poor due to polycythemia vera. Protecting from the sun, drinking plenty of liquids, and wearing warm clothes on hands and feet in cold weather is a must
Checking for sores – Poor circulation can result in unhealed sores on the hands and feet. One must consult a doctor immediately if the sores are not healed.
Diet for Polycythemia vera
There is no specific diet or exercise that reverses polycythemia vera. However, maintaining a healthy lifestyle that includes a well balanced and nutrient-rich diet and exercises can improve many body vitals and overall health. A healthy body is less prone to complications of any disease.
As far as the diet goes, reduce the intake of high-calorie foods – especially junk food. Include a lot of antioxidant-rich vegetables and fruits and fibre. Maintain a well-balanced diet, with moderate exercise levels to keep the body healthy and fit