Leukocytosis and risk stratification assessment in essential thrombocythemia
Leukocytosis and risk stratification assessment in essential thrombocythemia
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DOI：
10.1200/jco.2007.15.3569
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发表时间：
2008-06-01
影响因子：
45.3
通讯作者：
Barbui, Tiziano
中科院分区：
文献类型：
--
作者：
Carobbio, Alessandra;Antonioli, Elisabetta;Barbui, Tiziano
目的已确定的原发性血小板增多症 (ET) 血栓形成的危险因素包括年龄和既往血管事件。我们的目的是通过增加基线白细胞增多来完善这种风险分层。患者和方法我们招募了 657 名 ET 患者，随访时间中位数为 4.5 年，其中 72 例出现严重血栓形成。采用Cox比例风险模型分析血栓风险，并采用多变量C统计指数来区分有或无血栓的ET患者。我们通过接受者操作特征曲线寻找具有最佳敏感性和特异性的白细胞截止值。结果结果证实年龄和既往事件是血栓形成的独立危险因素，并显示基线白细胞增多和血栓形成之间存在梯度。相反，JAK2(V617F) 等位基因负荷和其他实验室参数（包括血小板数量）均未发现显着关联。在仅包含常规危险因素的模型中，总血栓形成的C统计比为0.63，当添加白细胞增多时，变化很小（C = 0.67）。相反，在年轻且无症状的患者（低危类别）中，C统计值表明白细胞增多的患者血栓形成的风险较高，与传统定义的高危组的计算结果相似（C = 0.65）。预测事件的最佳白细胞截止值为 9.4 ( X 10(9)/L)。结论我们建议将基线白细胞增多纳入临床试验中 ET 患者的风险分层中。
PurposeEstablished risk factors for thrombosis in essential thrombocythemia ( ET) include age and previous vascular events. We aimed to refine this risk stratification by adding baseline leukocytosis.Patients and MethodsWe enrolled 657 patients with ET followed for a median of 4.5 years who developed 72 major thrombosis. Cox proportional hazard model was performed to analyze the thrombotic risk and to discriminate ET patients with or without thrombosis, multivariable C statistic index was used. We searched for leukocytes cutoff with the best sensitivity and specificity by a receiver operating characteristic curve.ResultsResults confirmed that age and prior events are independent risk factors for thrombosis and showed a gradient between baseline leukocytosis and thrombosis. On the contrary, no significant association was found either for JAK2(V617F) allele burden and for other laboratory parameters, including platelet number. In the model with conventional risk factors alone, C statistic ratio for total thrombosis was 0.63 and when leukocytosis was added, the change was small ( C = 0.67). In contrast, in younger and asymptomatic patients ( low-risk category), C statistic value indicated an high risk for thrombosis in patients with leukocytosis, similar to that calculated in conventionally defined high-risk group ( C = 0.65). The best leukocyte cutoff values for predicting the events was found to be 9.4 ( X 10(9)/L).ConclusionWe suggest to include baseline leukocytosis in the risk stratification of ET patients enrolled in clinical trials.