Abstract
Polycythemia is a hematological condition characterized by an elevated red blood cell (RBC) mass that exceeds the normal range for a specific age and gender; it can be classified as either primary or secondary. This study aimed to estimate the prevalence of primary and secondary polycythemia among adult blood donors in the West Bank and characterize potential risk factors. This cross-sectional study included 674 adult Palestinian male blood donors, aged 18 to 62 years, at An-Najah National University Hospital. Data were collected through face-to-face interviews. Eligible donors underwent complete blood count (CBC) analysis, and samples meeting the latest World Health Organization (WHO) diagnostic criteria for polycythemia, hemoglobin > 16.5 g/dL or hematocrit > 49% in men, were sent for DNA sequencing. Among the participants, 16.6% met the diagnostic criteria for polycythemia; however, none had the JAK2 p.V617F mutation, indicating a potential lack of polycythemia vera (PV). Risk factor analysis revealed an increased risk of polycythemia in moderate (p = 0.039, OR 2.223, [95% CI 1.041-4.746]), heavy cigarette smoking (p = 0.008, OR 2.301, [95% CI 1.246-4.249]), and heavy waterpipe smoking (p ≤ 0.001, OR: 5.019, [95% CI 2.364-10.653]), whereas heavy coffee consumption had a protective effect against polycythemia (p = 0.013, OR 0.444 [95% CI 0.234-0.843]). The absence of the JAK2 p.V617F mutation among participants suggests that secondary polycythemia predominance is driven by smoking and other modifiable lifestyle factors. These findings emphasize the importance of public health efforts focused on lifestyle modification to reduce the risk of polycythemia.