Polycythemia Vera

It is caused by a mutation in a hematopoietic stem cell, and 90% of patients affected by the disease have a mutation in the tyrosine kinase gene  (V617F).

In our country, the incidence of Polycythemia Vera is four to six cases per million inhabitants per year, with the median age of diagnosis being 60 years. This disease is rare before the age of 40.

Symptoms

In most cases it is a disease that does not present symptoms at the time of diagnosis, and is frequently diagnosed incidentally in a

Polycythemia can be vera or secondary to other causes. For example, smoking and sleep apneas cause a drop in oxygen in the blood, and the body compensates for this by making more red blood cells so there are more oxygen carriers.

If there are clinical manifestations, they can be:

• Nonspecific symptoms (50%): weakness or fatigue, night sweats, weight loss, gout flare, stomach upset, generalized itching (itching).
• Thrombotic phenomena (50%): cerebrovascular accidents (stroke), angina pectoris, heart attacks, intermittent claudication of the lower extremities and thrombosis of abdominal veins.
• Peripheral vascular insufficiency: redness and pain / burning in the fingers and soles of the feet that worsens with heat (shower) and improves with exposure to cold.
• Bleeding: nasal bleeding, gingivorrhagia, digestive bleeding (15-30%).
• Neurological manifestations (60%): headaches, tingling in hands and feet, vertiginous sensation, visual disturbances.
• Hemodynamic repercussions of myocardial hypoxia.
• Dyspnea (feeling short of breath).
• Arterial hypertension.
• Angor (angina pectoris).
• Splenomegaly (large spleen), in 80-90% of cases.

Diagnosis

It uses a table for diagnosis that distinguishes between major and minor criteria. A major criterion A together with a minor B or the presence of the first criterion A and two of the minor ones are diagnostic:

A. Major criteria

• Hemoglobin> 18.5 g / dL in men, 16.5 g / dL in women, or other evidence of increased red cell mass.
• Presence of the JAK2V617F mutation or another activating JAK2 mutation, such as those in exon 12.

B. Minor criteria

• Bone marrow biopsy demonstrating trilinear hypercellularity (panmyelosis), for the age of the patient, with prominent erythroid, granulocytic, and megakaryocytic proliferation.
• Serum erythropoietin below normal reference value.
• Endogenous growth of erythroid colonies in the in vitro culture of hematopoietic progenitors.

C. Measurements of the concentration of red blood cells

• Hematocrit: greater than 51% in men and 48% in women. Hematocrit is the blood cell volume in relation to total blood; It is expressed as a percentage. The normal hematocrit value is normally between 40 and 50%.
• Hemoglobin: higher 18.5 g / dl in men and 16.5 g / dl in women. Hemoglobin is a blood protein that carries oxygen from the respiratory organs to the tissues.
• Red blood cells or erythrocytes (values ​​greater than 5-6 million). He frequently shows, in addition, an increase in the values ​​of white blood cells (leukocytosis) and platelets (thrombocytosis).

Treatment

In patients without a history of thrombosis, bleeding or phlebotomy they are the treatment of choice in most cases. Initially, they are carried out every three or four days and draw 300 to 500 ml of blood to reduce hematocrit up to 45% in men or 42% in women in order to eliminate the risk of, once stable every one or three months.

Unless contraindicated, it is recommended that patients receive 100 mg daily of acetylsalicylic acid (aspirin). The treatment does not cure polycythemia will see, but controls and can decrease the likelihood of complications.

When phlebotomies or bleeding are insufficient, doctors can use ruxolitinib, a drug that inhibits the activity of, or other drugs, such as interferon alfa-2, anagrelide, or hydroxyurea. Interferon alpha-2 specifically targets the affected cell and not normal stem cells.

Thebone marrow transplant it is the only cure for PV, but it is recommended only when PV is complicated by myelofibrosis and bone marrow failure.

Prognosis of polycythemia

Even if it is not a curable diseaseDue to its chronic nature, it is customary to drive effectively for long periods of time.

Over the years, patients with PV can evolve into one with spinal cord exhaustion (deficit of all the normal elements of the blood). Similarly, and especially after many years of treatment with hydroxyurea, a evolution toacute myeloblastic leukemia. Despite all this, well-treated patients have a median survival exceeding 15 years.

The offers patient and ex-patient forums where you can find people who support and advise each other to live this situation in the best possible way.

What you should know:

• It is produced by an excess of red blood cells that increases the volume of the blood and thickens, which moves with less fluidity favoring poor circulation and thrombosis.
• In most cases it is a disease that does not present symptoms at the time of diagnosis, and it is frequently diagnosed incidentally in a routine analysis.
• Treatment does not cure polycythemia vera, but it controls it and can reduce the likelihood of complications, always carrying one.

Family Medicine Specialist