Clinical characteristics of stroke patients with essential thrombocytosis according to JAK2 mutation

초록

Backgrounds and Purpose: Essential thrombocytosis is a rare disorder and usually presents with either bleeding or thrombosis and splenomegaly. JAK2 mutation is one of the common causes of essential thrombocytosis. However, the clinical features of stroke patients with essential thrombocytosis, especially related to JAK2 mutation, remains unclear. Methods: We selected the patients with essential thrombocytosis from our stroke registry from 2005 to 2014 and analyzed the demographic and laboratory findings according to JAK2 mutation. Results: Among 7857 stroke patients in registry, only 40 (0.5%) patients had the essential thrombocytosis (mean age 66.8±11.2, male 18). Mean platelet count was 648±267 *103/μL. Among them, 18 (45%) had JAK2 mutation. In the etiologic evaluation, 21 patients (52.5%) was classified as cryptogenic stroke, followed by cardioembolism (17.5%). Transient ischemic attack was also frequently observed (15%). Three (7.5%) patients died within 3 months of stroke onset. There was no difference in the demographic profile and the frequency of risk factors such as hypertension, diabetes mellitus, and dyslipidemia between the patients with JAK2 mutation and those without. The platelet counts were not different either between two groups. In the etiology analysis, stroke patients without JAK2 mutation had more frequent accompanying cancer than those with JAK2 mutation (41% vs. 11%, P=0.04). Conclusion: Our results suggest that the essential thrombocytosis is rare condition in stroke population and is more commonly detected in the cryptogenic stroke. If a stroke patient with essential thrombocytosis had no JAK2 mutation, the possibility of hidden malignancy might be considered