Department of Medicine I, Medical University of Vienna, Vienna, Austria.
Karl Landsteiner Institute of Clinical Thrombosis Research, Vienna, Austria.
J Thromb Haemost. 2019 May;17(5):782-786. doi: 10.1111/jth.14415. Epub 2019 Mar 18.
Essentials Factor XI is a potential target for anticoagulation. The association between factor XI and venous thrombosis recurrence was tested in a cohort study. Low factor XI was associated with reduced risk of recurrent venous thrombosis. A sex-and age-adjusted linear association between D-Dimer and factor XI was found. SUMMARY: Background and objectives Low factor XI activity (FXIa) reduces the risk of venous thromboembolism (VTE), and FXI is regarded as a potential target for anticoagulation. Patients/methods We studied the relationship between FXIa and VTE in 851 patients with unprovoked VTE in whom anticoagulation had been stopped. Results Recurrent VTE was recorded in 265 patients. The sex-adjusted and age-adjusted hazard ratio (HR) of recurrence was 0.94 (95% confidence interval [CI] 0.89-0.99) for each decrease of 10 IU dL in FXIa. The HRs of recurrence were 0.73 (95% CI 0.54-0.99) for patients with FXIa below the 34th percentile, and 1.05 (95% CI 0.79-1.39) for patients with FXIa between the 34th and 67th percentiles, as compared with patients with higher FXIa. The probability of recurrence was lower among patients with FXIa below the 34th percentile than in patients with higher FXIa (P = 0.029). At 10 years, the probabilities of recurrence were 31%, 43% and 41% among patients with FXIa below the 34th percentile, with FXIa between the 34th and 67th percentiles, or with higher FXIa, respectively. We found a significant sex-adjusted and age-adjusted linear association between D-dimer levels, measured 3 weeks after anticoagulation, and FXIa. When patients' age and sex are taken into account, a patient with 10 IU dL lower FXIa is expected to have a 2.79% (95% CI 0.95-4.59%) lower D-dimer value (P = 0.003). Conclusions Our findings of a lower thrombosis risk and less pronounced hemostatic system activation among patients with low FXIa is in line with the concept that FXI is a promising target for anticoagulation.
因子 XI 是抗凝治疗的潜在靶点。在一项队列研究中，检测了因子 XI 与静脉血栓复发之间的关系。低因子 XI 与静脉血栓复发风险降低相关。发现 D-二聚体和因子 XI 之间存在性别和年龄调整的线性关联。
低因子 XI 活性（FXIa）可降低静脉血栓栓塞（VTE）的风险，FXI 被认为是抗凝治疗的潜在靶点。
患者/方法：我们研究了在 851 例无诱因 VTE 患者中停止抗凝治疗后，FXIa 与 VTE 之间的关系。
265 例患者发生复发性 VTE。每降低 10IU/dL FXIa，复发的性别调整和年龄调整的危险比（HR）为 0.94（95%置信区间 [CI] 0.89-0.99）。因子 XIa 低于第 34 百分位的患者的复发 HR 为 0.73（95%CI 0.54-0.99），而因子 XIa 在第 34 百分位至第 67 百分位之间的患者为 1.05（95%CI 0.79-1.39），与较高的 FXIa 相比。因子 XIa 低于第 34 百分位的患者的复发概率低于因子 XIa 较高的患者（P=0.029）。在 10 年时，因子 XIa 低于第 34 百分位的患者、因子 XIa 在第 34 百分位至第 67 百分位之间的患者和因子 XIa 较高的患者的复发概率分别为 31%、43%和 41%。
我们发现，在抗凝治疗后 3 周测量的 D-二聚体水平与 FXIa 之间存在显著的性别调整和年龄调整线性关联。当考虑到患者的年龄和性别时，预计 FXIa 降低 10IU/dL 的患者的 D-二聚体值将降低 2.79%（95%CI 0.95-4.59%）（P=0.003）。
我们发现低 FXIa 患者的血栓形成风险较低，止血系统激活程度较低，这与 FXI 是抗凝治疗有前途的靶点的概念一致。
