Beyond Hemoglobin: When and How to Work Up Possible Polycythemia Vera

Area of Science:

• Hematology
• Oncology
• Clinical Diagnostics

Background:

• The 2017 World Health Organization (WHO) guidelines lowered hemoglobin cutoffs for polycythemia vera (PV) diagnosis but were not intended for initial screening.
• Differentiating PV from secondary erythrocytosis (SE) is crucial for appropriate patient management.

Purpose of the Study:

• To evaluate the utility of clinical and laboratory parameters in guiding the diagnostic workup for PV.
• To explore the role of bone marrow morphology in distinguishing PV from SE.

Main Methods:

• Evaluated 200 patients using JAK2 V617F testing and WHO criteria to compare PV and SE.
• Assessed clinical features (age, obesity, smoking) and laboratory parameters (hemoglobin, platelets, RBC count, erythropoietin, MCV, ferritin).
• Examined bone marrow morphology in a subset of patients (111 cases).

Main Results:

• Myeloproliferative neoplasms (MPN) were uncommon in patients under 40 or with obesity (BMI ≥ 30 kg/m²).
• Current smoking history was more indicative of SE; these patients rarely had platelet counts ≥ 450 × 10³/µL.
• Laboratory indicators for PV included high RBC counts (men > 6.8 × 10⁶/µL, women > 5.9 × 10⁶/µL), low erythropoietin, low MCV, or low ferritin.
• Bone marrow in PV cases generally showed increased cellularity compared to SE, aiding disease progression assessment.

Conclusions:

• Accessible clinical and laboratory data can effectively aid in determining the need for a PV diagnostic workup.
• A preliminary diagnostic algorithm is proposed, highlighting the need for larger studies to develop a formal PV risk-scoring system.