604例低危原发性血小板增多症患者的临床特征及血栓危险因素分析

Clinical characteristics and risk factors for major thrombosis in 604 Chinese patients with low-risk essential thrombocythemia

目的 分析低危原发性血小板增多症（ET）患者的临床特征和血栓危险因素,探讨其治疗策略.方法 对1982年3月至2012年5月诊断的604例低危ET患者的临床资料进行回顾性分析.结果 全部604例患者中,男214例,女390例,中位发病年龄44（18～59）岁.中位随访时间49（0～338）个月.43例（7.1％）患者发生严重血栓事件.COX风险模型表明总体缸栓事件的危险因素为JAK2V617F突变（HR=2.279,P=0.035）及心血管危险因素（CVF） （HR=2.541,P=0.006）,动脉血栓事件的危险因素为CVF（HR=2.633,P=0.008）.同时存在JAK2 V617F突变及CVF两种危险因素患者的无血栓生存率低于仅有JAK2 V617F突变（P=0.002）或CVF的患者（P=0.040）.抗血小板治疗降低了仅存在1种危险因素患者的血栓发生率（P=0.016）,而降低血小板治疗可减少JAK2 V617F突变和CVF两种危险因素并存患者的血栓事件发生（P=0.018）.结论 JAK2V617F突变和CVF是低危ET患者血栓事件的两大危险因素.低危ET患者应按照不同的危险因素选择合适的治疗措施.

Objective To analyze clinical and molecular characteristics of low-risk essential thrombocythemia （ET） in a large cohort of Chinese patients and to explore risk factors for major thrombosis and treatment strategies.Methods Medical records of patients with an initial diagnosis of ET from March 1982 to May 2012 in our hospital were retrospectively analyzed.Results A total of 604 low-risk ET patients were enrolled with a median follow-up of 49 months （range：0-338）.43 （7.1％） patients experienced major thrombotic events.Cox proportional hazards regression revealed JAK2 V617F mutation （HR=2.279; P=0.035） and cardiovascular risk factors （CVF） （HR=2.541; P=0.006） to be risk factors for total thrombotic events,while only CVF （HR=2.633; P=0.008） was risk factor for arterial thrombosis.None of the evaluated factors was related to venous thrombosis.Patients with both JAK2 V617F mutation and CVF had a worse thrombosis-free survival than those with only one risk factor （P＜0.05）.In patients with JAK2 V617F or CVF alone,antiplatelet treatment （P=0.016） significantly decreased the risk of thrombosis,while those with both JAK2 V617F and CVF could benefit from cytoreductive agents （P=0.018）.Conclusions Chinese low-risk ET patients have a lower risk of thrombosis than Caucasian low-risk ET patients.JAK2 V617F mutation and CVF are the most significant risk factors for thrombosis.Existence of both risk factors further increases the thrombotic risk.Treatment strategies on low-risk ET patients should be made based on presence or absence of risk factors.