Department of Hematology and Oncology L. e A. Seràgnoli, St. Orsola-Malpighi Hospital, University of Bologna, Bologna, Italy.
Ann Hematol. 2011 Aug;90(8):933-8. doi: 10.1007/s00277-010-1154-3. Epub 2011 Feb 2.
Established risk factors for thrombosis in essential thrombocythemia (ET) include age (≥ 60 years) and previous vascular events. Recently, also leukocytosis has been proposed in risk stratification of ET patients. We report a retrospective study on 532 ET patients followed for a median of 7.6 years. Sixty-four patients (12%) developed 95 thrombotic events during follow-up. Together with the high-risk condition, a white blood cell (WBC) value above 11 × 10⁹/L, corresponding to the fourth percentile value, significantly correlated with a higher thrombotic risk (p = 0.033) by Cox proportional hazards. Moreover, the cumulative risk of thrombosis was significantly higher in high-risk patients with WBC >11 × 10⁹/L. JAK2 V617F mutation did not correlate with thrombosis. Overall, 123 (23%) patients died. Three independent parameters were noted as prognostic factors for survival in multivariate analysis: age > 60 years, leukocytosis >11 × 10⁹/L, and hemoglobin level below normal values. Based on these parameters, three groups of risk were defined, with significantly different survivals. Baseline leukocytosis correlated with a higher thrombotic risk in high-risk patients and identified a cohort of patients with worse survival.
原发性血小板增多症（ET）中已确定的血栓形成危险因素包括年龄（≥60 岁）和先前的血管事件。最近，白细胞增多也被提出用于 ET 患者的风险分层。我们报告了一项对 532 例 ET 患者进行的回顾性研究，中位随访时间为 7.6 年。64 例患者（12%）在随访期间发生了 95 例血栓事件。与高危情况一起，白细胞（WBC）值高于 11×10⁹/L，对应第四百分位值，与更高的血栓形成风险显著相关（p = 0.033），通过 Cox 比例风险。此外，在 WBC >11×10⁹/L 的高危患者中，血栓形成的累积风险显著更高。JAK2 V617F 突变与血栓形成无关。总体而言，123 例（23%）患者死亡。在多变量分析中，有三个独立的参数被认为是生存的预后因素：年龄>60 岁、白细胞增多>11×10⁹/L 和血红蛋白水平低于正常值。基于这些参数，定义了三组风险，生存率有显著差异。基线白细胞增多与高危患者的更高血栓形成风险相关，并确定了一组生存较差的患者。
