From the Guidelines
The hematology workup for polycythemia vera should include a complete blood count with differential, peripheral blood smear, serum erythropoietin level, and molecular testing for JAK2 mutations (particularly JAK2 V617F, which is present in about 95% of cases) 1.
Key Components of the Workup
- Complete blood count with differential to assess for erythrocytosis, leukocytosis, and thrombocytosis
- Peripheral blood smear to evaluate for morphological abnormalities
- Serum erythropoietin level to help distinguish primary from secondary polycythemia
- Molecular testing for JAK2 mutations, which is a key diagnostic criterion for polycythemia vera 1
Additional Testing
- Comprehensive metabolic panel to assess for underlying metabolic disorders
- Iron studies to evaluate for iron deficiency or overload
- Bone marrow aspiration and biopsy with cytogenetic analysis to assess for bone marrow morphology and cytogenetic abnormalities
- Arterial blood gas analysis to rule out secondary causes of polycythemia
- Abdominal ultrasound to assess spleen size, as splenomegaly is common in polycythemia vera
Importance of JAK2 Mutation Testing
- JAK2 V617F mutation is present in about 95% of cases of polycythemia vera 1
- Testing for exon 12 mutations should be considered if JAK2 V617F is negative
- JAK2 mutation testing is included in the World Health Organization diagnostic criteria for polycythemia vera
Bone Marrow Examination
- Typically shows hypercellularity with trilineage growth (erythroid, myeloid, and megakaryocytic proliferation) and characteristic megakaryocyte morphology 1
- Helps confirm the diagnosis and exclude other myeloproliferative disorders
- Cytogenetic analysis may disclose abnormalities, but has limited diagnostic value in polycythemia vera 1
From the Research
Hematology Workup for Polycythemia Vera
The hematology workup for polycythemia vera (PV) typically involves several diagnostic tests and criteria, including:
- Erythrocytosis, characterized by an elevated hemoglobin or hematocrit level 2, 3, 4
- Bone marrow biopsy to distinguish PV from other myeloproliferative neoplasms (MPNs) 5, 6
- Presence of the Janus kinase 2 (JAK2) genetic mutation, which is present in approximately 98% of cases 3, 4
- Subnormal erythropoietin level to differentiate PV from common causes of secondary erythrocytosis 4
- Leukocytosis and thrombocytosis, which are common in PV patients 2, 3
Diagnostic Criteria
The World Health Organization's major diagnostic criteria for PV include:
- Elevated hemoglobin or hematocrit level
- Abnormal results on bone marrow biopsy
- Presence of the JAK2 genetic mutation
- Subnormal erythropoietin level (minor criterion) 4
Treatment and Management
The main goal of therapy in PV is to prevent thrombohemorrhagic complications, and treatment typically involves: