Polycythemia vera is a myeloproliferative disorder associated with overproduction of all blood cells and, as a result, an increased risk of thromboembolism. With an incidence of 1 to 2 cases per 100,000 inhabitants per year, polycythemia vera is a rare syndrome.
What is polycythemia vera?
Polycythemia vera is a chronic myeloproliferative disease in which there is an increased synthesis of all blood cells, especially erythrocytes, in the bone marrow.
As a result of this progressive and irreversible overproduction, an increase in hematocrit (cellular blood components) and blood viscosity (tightness) is caused, which leads to microcirculation disorders and an increased risk of thromboembolic events. See polyhobbies for Meanings of Plague.
In addition, two clinical stages are differentiated in polycythemia vera. The first phase is characterized by increased erythrocyte synthesis and erythrocytosis (increased erythrocyte count) and can be completely asymptomatic. The progressive late phase is characterized by secondary marrow fibrosis (marrow tissue fibrosis) with extramedullary hematopoiesis (blood formation outside the bone marrow) and splenomegaly (enlargement of the spleen).
Likewise, polycythemia vera can develop into myelodysplasia, in which blood formation is increasingly taken over by mutated stem cells, or acute myeloid leukemia.
The exact etiology of polycythemia vera has not yet been clarified and is probably based on an as yet incompletely understood mutative transformation of stem cells, which can profile themselves into different specific cell types.
A so-called JAK2V617F point mutation was found in about 95 percent of those affected, which leads to an exchange of the amino acid valine with phenylalanine and thus to an increased rate of division of the specifically affected cells. A functionally comparable JAK2 mutation in exon 12 (DNA section coding for amino acids) was also observed in 2 to 3 percent.
Since these mutations also occur in other myeloproliferative syndromes such as essential thrombocythemia and primary myelofibrosis, possible triggering factors such as noxae (including benzene), ionizing radiation and the involvement of another, as yet unknown gene mutation are discussed.
Symptoms, Ailments & Signs
Polycythemia vera is characterized by an excessive production of red blood cells (erythrocytes). As a result, the blood thickens and the flow properties deteriorate. The associated circulatory disorders can cause various symptoms. Polycythemia vera often begins insidiously, so that many patients initially show few symptoms.
Circulatory problems in the hands and feet are among the more common symptoms. A lack of oxygen supply also causes the lips to turn blue (cyanosis). On the other hand, reddened skin appears on the face, arms and legs. Many patients with polycythemia vera complain of itching, especially after contact with water.
This is also referred to as aquagenic pruritus. The so-called erythromelalgia is also a characteristic symptom of the malignant blood disease. It is characterized by painful and sudden warmth and redness of the feet and/or hands. The increased amount of erythrocytes can also lead to dizziness, nosebleeds, blurred vision or ringing in the ears.
Due to the changed flow properties of the blood, there is also an increased risk of vascular occlusions due to blood clots (thrombosis) or embolisms. Reduced blood flow to the coronary arteries, on the other hand, leads to a feeling of tightness in the chest (angina pectoris) and also increases the risk of a heart attack.
Diagnosis & History
In many cases, an initial suspicion of polycythemia vera arises from an increased erythrocyte, hematocrit or hemoglobin value in the context of a blood test.
In addition, in many cases of the disease there is an increased number of leukocytes and thrombocytes with a simultaneously reduced erythropoietin level (EPO level). In the advanced stage of the disease, the suspicion can be strengthened by splenomegaly. The diagnosis is additionally secured by the detection of the JAK2(V617F) point mutation.
In the differential diagnosis, polycythemia vera (primary erythrocytosis) must be differentiated from secondary erythrocytosis such as stress erythrocytosis, smoking erythrocytosis, and erythrocytosis as a result of hypoxia or EPO-producing tumors in the liver or kidneys, which are characterized by an elevated EPO level.
With early diagnosis and controlled therapy, the disease has a good prognosis with an almost normal life expectancy despite the chronic progressive course. If left untreated, polycythemia vera is associated with a significantly increased risk of thromboembolic events (including stroke, thrombosis, heart attack).
In this disease, patients primarily suffer from a significantly increased volume of blood. This also leads to reddening of the skin, which can be particularly unpleasant on the face and thus significantly reduce the patient’s quality of life. The blood itself is viscous, so that coagulation is usually disturbed. The blood supply to the brain is also incorrect, which can lead to personality disorders or mood swings.
In many cases, those affected suffer from severe headaches or dizziness. Due to illness, the risk of a stroke or a heart attack increases enormously, so that the life expectancy of the patient can also be significantly reduced. In most cases, polycythemia vera is treated with medication.
Those affected are often dependent on long-term intake in order to minimize the risk of thrombosis. There are no particular complications or side effects. The life expectancy of the person affected may also be reduced due to polycythemia vera. Furthermore, a healthy lifestyle has a very positive effect on the course of this disease.
When should you go to the doctor?
Disorders and irregularities in blood flow should be presented to a doctor. If there is a racing heart, dizziness, an inner warmth or an unusual feeling of cold in some areas of the body, the person concerned needs help. A doctor should be consulted in the event of impaired perception, a tingling sensation in the limbs, numbness or hypersensitivity. Changes in the complexion, itching or redness should be presented to a doctor. If open wounds appear, sterile wound care is required.
If the person concerned cannot do this adequately, a doctor should be consulted. Otherwise, germs can get into the organism and trigger further diseases or sepsis. This threatens a life-threatening condition. Bleeding nose or gums, a feeling of tightness in the organism and general functional disorders must be examined and treated. In the case of visual impairments and ringing in the ears, the symptoms should be clarified. If an acute health-threatening situation arises, an emergency service must be alerted.
In the case of disorders of consciousness or loss of consciousness, an emergency doctor is required. A sharp decrease in internal forces, a collapse, as well as sudden overheating are alarm signals from the body. A blood clot can form in polycythemia vera. In severe cases, this can lead to a stroke or a reduction in heart activity. Without emergency medical care for the person concerned, there is a risk of premature death.
Treatment & Therapy
So far, polycythemia vera can only be treated causally or curatively by stem cell transplantation. Since such an intervention is associated with a high risk of secondary diseases and increased mortality, it is usually only considered when the disease is very advanced.
In contrast, palliative therapy measures aimed at reducing the risk of thromboembolic events, alleviating symptoms and preventing complications are the main focus of treatment for polycythemia vera. For this purpose, blood-letting therapy (phlebotomy) is usually initiated to reduce the hematocrit value, which ensures a quick and effective reduction in blood volume.
At the beginning, depending on the specific hematocrit value, a phlebotomy is performed at two to three-day intervals, with the interval between the individual treatments increasing as the treatment progresses. To minimize the risk of thrombosis and to treat the microcirculatory disorders, a thrombosis aggregation inhibitor (low-dose ASA) is used at the same time.
If long-term short intervals between the necessary phlebotomy sessions or high platelet counts can be determined, a drug-based reduction of the cell count value with active ingredients such as hydroxyurea or cytokines, which inhibit the synthesis of all blood cells in the bone marrow, is also sought as part of a cytoreductive therapy.
In some cases, in which a targeted reduction in platelet count is indicated, anagrelide, which has a suppressive effect on platelet maturation, can be applied to treat polycythemia vera.
Since polycythemia vera can most likely be traced back to a mutation in stem cells whose trigger factors (initiating factors) have not yet been clearly clarified, the disease cannot be prevented. However, weight reduction, regular exercise, avoidance of long periods of sitting and consistent therapy for cardiovascular diseases minimize the increased risk of thromboembolism in polycythemia.
In most cases, patients with polycythemia vera have only very few and only limited follow-up measures available. The most important thing here is quick and, above all, very early diagnosis, so that other complications or further symptoms cannot occur. Therefore, those affected should consult a doctor at the first symptoms or signs of the disease in order to prevent further complications or complaints.
As a rule, self-healing cannot occur. The treatment itself is carried out with a minor surgical intervention. After that, those affected should rest and rest. Efforts and physical or stressful activities should be avoided in order not to unnecessarily burden the body. The medication should also be checked regularly and adjusted by a doctor.
If anything is unclear or you have questions about the medicines, you should always contact a doctor first. Regular check-ups by a doctor are also very important in order to monitor the blood count permanently. It cannot be universally predicted whether polycythemia vera will lead to a reduced life expectancy for those affected.
You can do that yourself
Opportunities for self-help are generally not available to those affected by polycythemia vera. In any case, the patient is dependent on treatment by a doctor, which involves a transplantation of stem cells. In some cases, despite treatment, the patient dies.
In general, those affected by polycythemia vera must take care of their bodies and not expose themselves to unnecessary stress. Sporting activities should also be avoided as they strain the body. Stressful situations should also be avoided. In case of itching, the affected area should not be scratched to avoid a rash. Due to the increased risk of a heart attack, regular check-ups with a doctor are very useful to avoid a heart attack. Examinations for tumors in the kidneys or liver are also useful, since these can also occur favorably due to polycythemia vera.
In some cases, contact with other people affected by the disease makes sense, as this leads to an exchange of information, which can be helpful in everyday life and make life easier. In most cases, the patient’s life expectancy is reduced by polycythemia vera.