[The incidence and risk factors for thrombosis in primary immune thrombocytopenia]

Objective: To probe the incidence and risk factors for thrombosis in Chinese immune thrombocytopenia through a retrospective analysis of the inpatients referred to the Blood Disease Hospital, CAMS & PUMC. Methods: A retrospective survey of 3 225 patients with ITP from October 2005 to December 2017 was performed, the clinical data of the patients with thrombosis were collected to analyze the causes, diagnosis, treatment and prognosis. Results: A total of 46 patients experienced a thrombotic event with a prevalence of 1.43%(46/3 225 cases) with the median age of thrombosis as 54 years (26-83) years, the prevalence of thrombosis was 3.37% (40/1 187 cases) in>40 years old, which was significantly higher than 0.58% (6/1 030 cases) in those under 40 years old, in adults (P=0.00). There were 20 males and 26 females, there was no statistical difference in the incidence of thrombosis between males and females[1.53% (20/1 309) vs 1.36% (26/1 916), P=0.187]; The prevalence of arterial thrombosis was 1.12% (36/3 225) higher than venous thrombosis[0.22% (7/3 225), P=0.00]when 82.61%(38/46 cases) of patients with PLT<100×10(9)/L. Post-splenectomy are risk factors for thrombosis in ITP patients, P values was 0.022, There was no statistical difference in the presence or absence of thrombotic events whether received glucocorticoid or TPO/TPO-Ra treatment, the P values were 0.075 and 0.531, respectively. Conclusions: In Chinese population, ITP disease maybe with a higher risk of thrombosis, there was no positive correlation between thrombosis and platelet level; and had obvious age distribution characteristics. The history of tobacco, hypertension, diabetes and post-splenectomy are risk factors for thrombosis in ITP patients.