Arterial and venous thromboses are major clinical events in patients with Philadelphia-negative myeloproliferative neoplasms (MPNs) including essential thrombocythemia (ET) and polycythemia vera (PV) [1 2]. Some MPN patients suffer from vascular complications even prior to diagnosis . In some cases, MPN is evident in individuals newly diagnosed with cerebral infarction (CI) which is a type of thrombosis .
The World Health Organization (WHO) revised the MPN diagnostic criteria in 2016 . Most notably, in the revised criteria, the hemoglobin/hematocrit threshold values for the diagnosis of PV were lowered. This has markedly changed the diagnostic landscape, and consequently, the treatment options and outcome of this disorder. However, the revised criteria were not widely used to evaluate patients with CI until recently. Thus, we retrospectively evaluated the likelihood of MPN in CI patients using the revised criteria. The medical records of CI patients admitted to the Chungnam National University Hospital from January 2016 to December 2017 were retrospectively reviewed. Patients with erythrocytosis or thrombocytosis were divided into those with a reactive case and possible, probable, or proven MPN. “Possible MPN” indicates that a reactive increase in RBC or platelet level is not evident, but the increase is resolved during follow-up. “Probable MPN” indicates that the increase in RBC or platelet level continues during follow-up. “Proven MPN” is diagnosed with PV or ET based on the WHO criteria. In total, 1,729 CI patients (1,003 men; 726 women) of median age 73 years (range, 19–96 yr) were reviewed. Thrombocytosis (platelets ≥450×109/L) was evident in 69 (4.0%) patients at diagnosis or during follow-up. Reactive thrombocytosis was the most common form of thrombocytosis (N=62, 3.6%). Three (0.2%) patients were considered to exhibit possible ET, and four (0.2%) had proven ET. The causes of reactive thrombocytosis (N=62 patients) included infection (N=59, 95.2%), bleeding (N=1, 1.6%), and iron-deficiency (N=1, 1.6%). Erythrocytosis was evident in 79 (4.6%) patients at diagnosis or during follow- up. Reactive erythrocytosis was the most common form of erythrocytosis (N=50, 2.9%), followed by possible PV (N=21, 1.2%), probable PV (N=6, 0.3%), and proven PV (N=2, 0.1%). None of the 27 patients with possible or probable PV underwent further investigations. Particularly, the
These results showed that many CI patients with erythrocytosis did not undergo further evaluation in terms of a PV diagnosis and that
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