الملخص

ABSTRACT Background: Polycythemia Vera (PV) is a myeloproliferative neoplastic disorder involving uncontrolled red blood cell production resulting in elevated red blood cell (RBC) mass. There is a signaling defect leading to an abnormal response to growth factors, and the abnormal clonal line interferes with normal lineage proliferation. The Janus kinase-2 (JAK2) gene involved with intracellular signaling is mutated in 90% of cases of PV. It can occur in all age groups, but the median age of diagnosis is 60 years. Thrombosis considered as the most common cause for morbidity and mortality. Aim of study: To review the clinical characteristics of a sample of  PV patients and their current treatment in addition to assessment of frequency of development of thrombotic events while on treatment. Patients and method: A hospital based retrospective study was conducted in the hematology outpatient's clinic from different centers in Iraq over a period of 11months (from January 2020 till November 2020). Patient's age more than 18 years old with duration of the disease more than 6 months and all of them were positive for JAKII V617F mutations were included in this study while excluding those who were negative for this mutation. The patients were divided in to low and high risk based on age and leukocyte counts and history of previous thrombosis and presence of cardiovascular risk factors. The response and resistance to treatment with hydroxyurea were evaluated according to ELN definition. Result: Thirty patients were enrolled in this study. The median age was 60.6±11 years, ranging between 35-78 years. The mean duration of disease was 54± 5.5 months. Headache was the predominant symptom observed in 96.7%, pruritus was experienced in 63.3%.Splenomegaly was seen in 46.7% .Thrombosis at time of diagnosis happened in 13.4%of cases. The most common complication that occurred in this study group was thrombosis in 20% of patients ,16.6% progressed to myelofibrosis and 63.3% of patients were controlled by treatment. Conclusion: The demographic and some of characteristic of Iraqi PV patients are similar to those from other countries. A good number of patients were controlled with hydroxyurea. Thrombosis is still the commonest complication in patients with PV and occurred mainly in the first 4 years since diagnosis of polycythemia Vera. Median time for development of myelofibrosis was more than 10 year.