低危原发性血小板增多症和真性红细胞增多症患者诊断时的白细胞增多与随后发生血栓的风险。

Leukocytosis at diagnosis and the risk of subsequent thrombosis in patients with low-risk essential thrombocythemia and polycythemia vera.

机构信息

Division of Hematology, Mayo Clinic, Rochester, Minnesota 55905, USA.

出版信息

Cancer. 2009 Dec 15;115(24):5740-5. doi: 10.1002/cncr.24664.

DOI:10.1002/cncr.24664

PMID:19806641

Abstract

BACKGROUND

Advanced age and a history of thrombosis were well-established risk factors for thrombosis in essential thrombocythemia (ET) and polycythemia vera (PV); cytoreductive therapy was indicated in their presence. Recent studies have suggested leukocytosis as an additional risk factor; however, such an association would be treatment-relevant in the context of low-risk disease.

METHODS

In this retrospective study, a Cox proportional hazards model was used to determine the impact of various clinical and laboratory variables, including leukocytosis, on thrombosis-free survival (TFS). Arterial-specific or venous-specific TFS curves for different leukocyte count-defined risk groups were constructed by the Kaplan-Meier method and compared using the log-rank test.

RESULTS

A total of 407 low-risk patients (254 with ET and 153 with PV) were considered. After a respective median follow-up of 104 months and 130 months, respectively, 47 (19%) patients with ET and 41 (27%) with PV experienced a total of 55 (41 arterial and 14 venous) and 46 (22 arterial and 24 venous) thrombotic events, respectively. Leukocytosis at the time of diagnosis, defined by a cutoff level of either 15 or 9.4x10(9)/L, did not appear to be predictive of either arterial or venous thrombosis during follow-up; similar results were obtained when analysis was restricted to patients with platelet counts of <1000x10(9)/L. Instead, advanced age was found to be significantly associated with arterial thrombosis in patients with PV and higher hemoglobin level with venous thrombosis in patients with ET.

CONCLUSIONS

In the current retrospective study, leukocytosis at diagnosis did not appear to influence the risk of thrombosis in either ET or PV. However, a prospective study is required before leukocytosis is taken into account during treatment decisions in these disorders.

摘要

背景

高龄和血栓病史是原发性血小板增多症（ET）和真性红细胞增多症（PV）发生血栓的既定危险因素；存在这些因素时，需要进行细胞减少治疗。最近的研究表明白细胞增多也是一个额外的危险因素；然而，在低危疾病的背景下，这种关联与治疗相关。

方法

在这项回顾性研究中，使用 Cox 比例风险模型来确定各种临床和实验室变量（包括白细胞增多）对无血栓生存（TFS）的影响。通过 Kaplan-Meier 方法构建不同白细胞计数定义的风险组的动脉特异性或静脉特异性 TFS 曲线，并使用对数秩检验进行比较。

结果

共考虑了 407 例低危患者（254 例 ET 和 153 例 PV）。分别中位随访 104 个月和 130 个月后，47 例 ET 患者（19%）和 41 例 PV 患者（27%）共发生 55 例（41 例动脉和 14 例静脉）和 46 例（22 例动脉和 24 例静脉）血栓事件。诊断时的白细胞增多，用 15 或 9.4x10(9)/L 的截止水平定义，似乎并不能预测随访期间的动脉或静脉血栓形成；当分析仅限于血小板计数<1000x10(9)/L 的患者时，也得到了类似的结果。相反，在 PV 患者中，高龄与动脉血栓形成显著相关，而在 ET 患者中，血红蛋白水平较高与静脉血栓形成相关。