Cortelazzo S, Finazzi G, Ruggeri M, Vestri O, Galli M, Rodeghiero F, Barbui T
Division of Hematology, Ospedali Riuniti di Bergamo, Italy.
N Engl J Med. 1995 Apr 27;332(17):1132-6. doi: 10.1056/NEJM199504273321704.
Abnormalities in the number and function of platelets may contribute to thromboembolic complications in patients with essential thrombocythemia. We assessed whether maintaining the platelet count below 600,000 per cubic millimeter with hydroxyurea reduces the incidence of thrombosis in patients with essential thrombocythemia and a high risk of thrombosis.
A total of 114 patients with essential thrombocythemia (77 women and 37 men; median age, 68 years; range, 40 to 85) and a median platelet count of 788,000 per cubic millimeter (range, 533,000 to 1,240,000 per cubic millimeter) were randomly assigned to receive hydroxyurea (56 patients) or no myelosuppressive therapy (58 patients). Ninety-seven (85 percent) were over 60 years old, and 52 (46 percent) had had thrombosis. The two groups were matched for age, sex, and platelet count at randomization. Antiplatelet prophylaxis with aspirin or ticlopidine was not stopped. Follow-up lasted a median of 27 months in both groups.
Two patients (3.6 percent) treated with hydroxyurea had thrombotic episodes (one stroke and one myocardial infarction), whereas 14 patients (24 percent) in the control group had thrombotic episodes (one stroke, five transient ischemic attacks, five peripheral arterial occlusions, one deep-vein thrombosis, and two cases of superficial thrombophlebitis). The difference (20.4 percentage points; 95 percent confidence interval, 8.5 to 32 percent) was statistically significant (chi-square with Yates' correction, 8.3; 1 df; P = 0.003).
Hydroxyurea is effective in preventing thrombosis in high-risk patients with essential thrombocythemia.
血小板数量和功能异常可能导致原发性血小板增多症患者发生血栓栓塞并发症。我们评估了使用羟基脲将血小板计数维持在每立方毫米600,000以下是否能降低原发性血小板增多症且有高血栓形成风险患者的血栓形成发生率。
总共114例原发性血小板增多症患者（77例女性和37例男性；中位年龄68岁；范围40至85岁），中位血小板计数为每立方毫米788,000（范围为每立方毫米533,000至1,240,000），被随机分配接受羟基脲治疗（56例患者）或不进行骨髓抑制治疗（58例患者）。97例（85%）年龄超过60岁，52例（46%）曾发生过血栓形成。两组在随机分组时按年龄、性别和血小板计数进行匹配。未停用阿司匹林或噻氯匹定的抗血小板预防治疗。两组的随访中位时间均为27个月。
接受羟基脲治疗的2例患者（3.6%）发生血栓事件（1例中风和1例心肌梗死），而对照组有14例患者（24%）发生血栓事件（1例中风、5例短暂性脑缺血发作、5例外周动脉闭塞、1例深静脉血栓形成和2例浅表性血栓性静脉炎）。差异（20.4个百分点；95%置信区间，8.5%至32%）具有统计学意义（经Yates校正的卡方检验，8.3；1自由度；P = 0.003）。
羟基脲对预防原发性血小板增多症高危患者的血栓形成有效。
