In oncology, polycythemia vera (PV) is an uncommon myeloproliferative neoplasm in which the bone marrow makes too many red blood cells. of PV patients have a JAK2 gene mutation in their blood-forming cells (compared with 0.1-0.2% of the general population).

Most of the health concerns associated with PV, such as thrombosis, are caused by the blood being thicker as a result of the increased red blood cells.

PV may be asymptomatic. Possible symptoms, if any do occur, include fatigue, itching (pruritus), particularly after exposure to warm water, and severe burning pain in the hands or feet that is usually accompanied by a reddish or bluish coloration of the skin.

Treatment consists primarily of blood withdrawals (phlebotomy) and oral meds.

PV is more common in the elderly.

Classification

PV is code 2A20.4 in the ICD-11.

It is a myeloproliferative neoplasm (MPN).

It is a primary form of polycythemia.

Pathophysiology

Approximately 98%

While the mutation is a JAK2 V617F in 95% of patients, JAK2 exon 12 mutations have also been observed.

Possible symptoms of PV that may aid identification include;

  • pruritus (itching), particularly after exposure to warm water (such as when taking a bath), which may be due to abnormal histamine release or prostaglandin production. Such itching is present in 40–55% of patients with PV.
  • erythromelalgia, a burning pain in the hands or feet, usually accompanied by a reddish or bluish coloration of the skin. Erythromelalgia is caused by an increased platelet count or increased platelet "stickiness" (aggregation), resulting in the formation of tiny blood clots in the vessels of the extremity; it responds rapidly to treatment with aspirin.

Other possible symptoms of PV include night sweats and fatigue. and may cause the spleen to be palpable in some patients. This may be associated with both the V617F mutation and the development of myelofibrosis.

  • Swollen joints (Gout)

There are 3 major criteria for PV diagnosis:

  1. A very high red blood cell count, which is usually identified by elevated levels of hemoglobin or hematocrit;
  2. A bone marrow biopsy that shows hypercellularity and abnormalities in megakaryocytes; and
  3. The presence of a mutation in the Janus kinase 2 (JAK2) gene.

A minor diagnostic feature is that patients usually have a very low level of erythropoietin (EPO), a growth factor that increases the production of red blood cells. This is used to detect cases which are negative for JAK2 mutation.

Reviews 2023–25

As of 2025, reviews state diagnosis can be based on

  • the presence of a JAK2 mutation and
  • hemoglobin/hematocrit levels of >16.5 g/dL/49% in men or 16 g/dL/48% in women.

Bone marrow morphologic confirmation is advised but not mandated.

Outlook and prognosis

Prognosis

PV may remain stable for many years, with no effect on life expectancy, particularly if managed effectively. Studies show the median survival rate of controlled PV ranges from 10 to 20 years but most observations are of people diagnosed in their 60s. Patients live close to a normal life expectancy, Factors predicting this may include age and detailed genetic differences. with the two main risk factors being a previous clot or clots, and age (60 years or older). If PV is untreated, there is a substantial risk of Budd-Chiari syndrome (a hepatic vein thrombosis).

PV may develop into myelofibrosis (a rare bone marrow cancer) or acute myeloid leukemia.

A secondary treatment goal is to alleviate symptoms, for instance of pruritus (itching). and helps to keep haematocrit levels low. This might be done weekly initially, and less often over time.

  • Ropeginterferon alfa-2b (Besremi) reduces the rate of blood cell production, and can be used regardless of treatment history.
  • Anagrelide with other cytoreductive drugs may be used to manage platelet levels.

Erlotinib may be an additional treatment option for those with certain genetic markers.

Allopurinol may be used to manage gout.

Managing emotional and practical effects

Patient education and patient forums can help patients practically and emotionally manage a PV diagnosis, symptoms and other practical considerations.

Epidemiology

Polycythemia vera occurs in all age groups, although the incidence increases with age.

One study found the median age at diagnosis to be 60 years, and another that the highest incidence was in people aged 70–79 years.

10% of PV patients are below age 40 years.

While the JAK2 V617F mutation is generally sporadic (random), a certain inherited haplotype of JAK2 has been associated with its development.

Notable cases

Notable people living with PV include:

  • Juan Alderete
  • Will Self

Few notable deaths have been attributed to PV. Instances (all aged 56 or older) are

  • Alessandro Di Fiore (1965–2021), Italian entrepreneur.
  • Phyllis George (1949–2020), American sportscaster and former First Lady of Kentucky
  • Chet Lemon (1955–2025), American baseball player
  • Ron Miles (1963–2022), American jazz trumpeter
  • Nell Rankin (1924–2005), American mezzo-soprano
  • Lee Korzits - Israeli 4 time wind surfing world champion

History

Figures in the discovery of and development of treatment for PV include William Osler and Louis Henri Vaquez. Historically PV was called Osler–Vaquez disease.

References

  • Polycythemia Vera at the National Heart, Lung, and Blood Institute