Polycythemia

Polycythemia is a type of blood cancer that’s marked by an increase in red blood cells. This thickens the blood and leads to other maladies. Some of them are life-threatening, such as stroke or heart attack.

Definition & Facts

There are three main forms of polycythemia. In polycythemia vera, the white blood cells and platelets are overproduced along with the red blood cells. White blood cells are part of the body’s immune system while platelets are tiny cell fragments that are crucial in clot formation.

Secondary polycythemia, or pseudopolycythemia is a complication of other diseases that do not involve the patient’s red blood cells. In stress polycythemia, the liquid part of the blood, or plasma is decreased.

Symptoms & Complaints

• Fatigue
• Drowsiness
• Dizziness
• Headache
• Itchy skin
• Flushed skin
• Bleeding that can’t be explained
• Hyperhydrosis, or excessive sweating
• Painful gout-like joint swelling (arthritis)
• Shortness of breath
• Difficulty breathing when the patient lies down
• Tingling, numbness, and burning in the extremities
• Peptic ulcer
• Enlarged liver (hepatomegaly)

An enlarged spleen (splenomegaly) is also a sign of polycythemia. The spleen is part of the immune system. It filters and purifies red blood cells and stores blood cells. It becomes enlarged because it has to work especially hard to do this with polycythemia. People with an enlarged spleen sometimes have abdominal bloating.

The patient may have one, some or all of these symptoms. The complications of polycythemia include blood clots in both the arteries and the veins, gout, heart attack or stroke, ulcer or kidney stones.

Untreated polycythemia can deteriorate into chronic or acute leukemia, myelofibrosis, a condition where the bone marrow that creates blood cells is replaced with scar tissue or myelodysplastic syndrome, where stem cells don't grow into normal blood cells.

Causes

Polycythemia seems to be caused by a genetic mutation of the Janus kinase 2 (JAK2 protein). Most people with polycythemia vera have this mutation, though some do not. Research is ongoing into finding out why these people have the disease without the JAK2 mutation.

The mutation isn’t inherited, but is acquired after conception. It’s most common in people over 60 but can strike a person of any age. 

The causes of pseudopolycythemia are chronic lung disease or heart disease, smoking, and living at high altitudes. Stress polycythemia can be a side effect of taking diuretic drugs, smoking or dehydration. 

Diagnosis & Tests

Polycythemia is diagnosed through the doctor taking the patient’s medical history and the patient telling the doctor of their symptoms. They should be careful to tell the doctor if they are suffering from any other disease that can lead to pseudopolycythemia. The doctor orders tests of the patient’s bone marrow through a fine-needle aspiration biopsy.

The complete blood count, or CBC is also taken, as is the red blood cell count through the hematocrit test. The hematocrit is about 40 to 45 percent in healthy people, but in people with polycythemia it can be as high as 70 to 80 percent.

Tests also show elevated levels of hemoglobin, which is a protein in the red blood cells that carry oxygen. The patient has a low erythropoietin, or EPO levels. Erythropoietin is a chemical that tells the bone marrow to make red blood cells.

Treatment & Therapy

The treatment depends on how the patient responds. Some patients need more than one type of therapy to improve.

Some asymptomatic patients do not need treatment, so the doctor adopts a posture of watchful waiting. Other patients are treated by phlebotomy, or having their blood drawn to keep the hematocrit in normal range and to prevent hemorrhaging or blood clots. How often the patient needs a phlebotomy depends on their particular needs. Some patients can have their blood drawn once and not have to have it drawn again for years.

The doctor prescribes anti-itching medicines called antihistamines if itchy skin is a problem. Doctors believe people with polycythemia have itchy skin because the disease releases histamines into the blood stream. Other patients with itchy skin benefit from being exposed to ultraviolet light. For some, taking selective serotonin reuptake inhibitors (SSRI) antidepressants such as citalopram relieves their itching.

Patients take low-dose aspirin to prevent clots and cardiovascular problems. They take hydroxyurea, a drug given to people with sickle-cell anemia, to lower their red blood cell count. 

Home remedies include mild exercise and avoiding bathing in hot water, which stimulates the release of histamines. The patient should wash with cool water and pat their skin dry. They should avoid very hot or very cold temperatures because their skin is more susceptible to being damaged by extreme temperatures. They should be careful to tend to any sores, as the thickened blood does not circulate well. This causes wounds to heal poorly.

Interferon alpha helps the body lower its production of blood cells. Ruxolitinib is given to patients who can’t tolerate the side effects of hydroxyurea, which include nausea, vomiting, diarrhea, constipation, and mouth sores. 

Chemotherapy drugs are sometimes given to polycythemia patients, but this puts them at risk for developing acute leukemia. In the past, patients who were given radioisotope therapy, where they were treated with radioactive isotopes of elements such as carbon, were also at risk for leukemia. This treatment is rarely resorted to now.

Polycythemia is not curable, but with treatment the patient can live a normal life span. Pseudopolycythemia and stress polycythemia can be cured if the underlying cause is found and treated.

Prevention & Prophylaxis