Beyond Hemoglobin: When And How To Work Up Possible Polycythemia Vera

Background: World Health Organization (WHO) 2017 diagnostic criteria for hemoglobin levels in polycythemia vera (PV) were lowered from 185 g/L to 165 g/L for men and from 165 g/L to 160 g/L for women, but these cutoffs were not designed for screening.Objectives: The primary aim of this study was to assess the value of laboratory and clinical parameters in deciding whether to further pursue a diagnosis of PV. A secondary aim was to explore the diagnostic utility of bone marrow morphology.Methods: We evaluated clinical and laboratory parameters that may be useful when considering further diagnostic work-up, emphasizing PV vs. secondary erythrocytosis (SE). We classified 200 patients with JAK2 V617F testing using WHO criteria.Results: Patients with myeloproliferative neoplasms (MPN) were rarely under age 40 and uncommonly obese (BMI >= 30 kg/m(2)). Current smoking history favored SE, and these patients rarely had a platelet count >= 450 x 10(3)/uL. Laboratory parameters suggesting greater PV likelihood were: RBC > 6.8 x 10(6) for men or > 5.9 x 10(6) for women; low erythropoietin; and low MCV or low ferritin. Bone marrow morphology (available in 111 cases) was generally more cellular in PV vs. SE and assessed disease progression.Conclusions: Readily accessible clinical and laboratory data can assist in considering a PV workup, and a possible diagnostic algorithm is presented. These preliminary findings warrant larger studies to develop a more formal PV-risk scoring system with optimal cutoffs and weighting.