Due to the insidious nature of many of the myeloproliferative neoplasms, including PV, patients are diagnosed before symptoms appear. Abnormal laboratory results demonstrated in many patients with PV include:
- Erythrocyte count >6.0 x 1012/L
- Hemoglobin >16.5 g/dL (males) and >16.0 g/dL (females)
- Hematocrit >49% (males) and >48% (females)
- WBC count >12.0 x 109/L
- Platelet count >450 x 109/L
The WHO states that bone marrow morphology is a major diagnostic criterion (hypercellularity with prominent erythroid, granulocytic, and megakaryocytic proliferation), along with JAK2(V617F) or exon 12 mutation. At least 95% of patients with PV will possess the JAK2(V617F) gene mutation, which helps to distinguish PV from other causes of erythrocytosis, such as secondary polycythemia or relative polycythemia.
However, a patient may still be diagnosed with PV if the patient meets the previously established hemoglobin threshold of 18.5 g/dL in men or 16.5 g/dL in women and shows a JAK2 mutation, as well as a decreased serum erythropoietin level.
