Griesshammer M, Bangerter M, van Vliet H H, Michiels J J
Department of Internal Medicine III, Hematology, Oncology, Clinical Immunology, and Infectious Diseases, University of Ulm, Germany.
Semin Thromb Hemost. 1997;23(4):371-7. doi: 10.1055/s-2007-996111.
Aspirin has a well established role in the prevention of arterial thrombosis. Discussion on the efficacy and safety of aspirin in the treatment and prophylaxis of thrombosis in essential thrombocythemia (ET) has become an important issue. The rationale for its use in ET comes from the observation that arterial thrombosis and platelet-mediated microcirculatory disturbances are the major causes of morbidity and mortality in ET. Experimental data have shown persistently elevated levels of thromboxane A2 (TXA2) in ET patients probably reflecting an enhanced in vivo platelet activation. Increased TXA2 biosynthesis and platelet activation in vivo in ET are selectively suppressed by repeated low doses of aspirin. ET-related symptoms such as erythromelalgia, transient neurologic and ocular disturbances are sensitive to aspirin. However, the benefit of low-dose aspirin is still uncertain in the primary prevention of thrombosis in ET. Furthermore, aspirin may unmask a latent bleeding diathesis frequently present in ET which may result in severe hemorrhagic complications. Thus, aspirin is contraindicated in ET patients with a bleeding history or a very high platelet count (> 1500 x 10(9)/L) leading to the acquisition of von Willebrand factor deficiency. If indicated, aspirin is presently used in the widely accepted low-dose regimen of 100 mg daily. However, an optimal effective dose has not yet been established. To further evaluate the efficacy and safety of aspirin in ET, prospective clinical trials are needed.
阿司匹林在预防动脉血栓形成方面具有公认的作用。关于阿司匹林在原发性血小板增多症（ET）血栓形成的治疗和预防中的疗效与安全性的讨论已成为一个重要问题。其在ET中使用的理论依据源于以下观察结果：动脉血栓形成和血小板介导的微循环障碍是ET发病和死亡的主要原因。实验数据表明，ET患者体内血栓素A2（TXA2）水平持续升高，这可能反映了体内血小板活化增强。重复给予低剂量阿司匹林可选择性抑制ET患者体内TXA2生物合成增加和血小板活化。ET相关症状如红斑性肢痛症、短暂性神经和眼部障碍对阿司匹林敏感。然而，低剂量阿司匹林在ET血栓形成一级预防中的益处仍不确定。此外，阿司匹林可能会暴露ET患者中经常存在的潜在出血素质，这可能导致严重的出血并发症。因此，有出血史或血小板计数非常高（>1500×10⁹/L）导致血管性血友病因子缺乏的ET患者禁用阿司匹林。如果有指征，目前阿司匹林采用每日100mg这一广泛接受的低剂量方案使用。然而，尚未确定最佳有效剂量。为进一步评估阿司匹林在ET中的疗效和安全性，需要进行前瞻性临床试验。
