Nomura Shosaku
First Department of Internal Medicine, Kansai Medical University, Hirakata, Osaka, Japan.
Clin Med Insights Blood Disord. 2016 Jul 17;9:15-22. doi: 10.4137/CMBD.S39643. eCollection 2016.
Immune thrombocytopenia (ITP) is an acquired hemorrhagic condition characterized by the accelerated clearance of platelets caused by antiplatelet autoantibodies. A platelet count in peripheral blood <100 × 10(9)/L is the most important criterion for the diagnosis of ITP. However, the platelet count is not the sole diagnostic criterion, and the diagnosis of ITP is dependent on additional findings. ITP can be classified into three types, namely, acute, subchronic, and persistent, based on disease duration. Conventional therapy includes corticosteroids, intravenous immunoglobulin, splenectomy, and watch-and-wait. Second-line treatments for ITP include immunosuppressive therapy [eg, anti-CD20 (rituximab)], with international guidelines, including rituximab as a second-line option. The most recently licensed drugs for ITP are the thrombopoietin receptor agonists (TRAs), such as romiplostim and eltrombopag. TRAs are associated with increased platelet counts and reductions in the number of bleeding events. TRAs are usually considered safe, effective treatments for patients with chronic ITP at risk of bleeding after failure of first-line therapies. Due to the high costs of TRAs, however, it is unclear if patients prefer these agents. In addition, some new agents are under development now. This manuscript summarizes the pathophysiology, diagnosis, and treatment of ITP. The goal of all treatment strategies for ITP is to achieve a platelet count that is associated with adequate hemostasis, rather than a normal platelet count. The decision to treat should be based on the bleeding severity, bleeding risk, activity level, likely side effects of treatment, and patient preferences.
免疫性血小板减少症(ITP)是一种获得性出血性疾病,其特征是抗血小板自身抗体导致血小板清除加速。外周血血小板计数<100×10⁹/L是诊断ITP的最重要标准。然而,血小板计数并非唯一的诊断标准,ITP的诊断还取决于其他检查结果。根据病程,ITP可分为三种类型,即急性、亚慢性和持续性。传统治疗方法包括使用糖皮质激素、静脉注射免疫球蛋白、脾切除术以及观察等待。ITP的二线治疗包括免疫抑制治疗[如抗CD20(利妥昔单抗)],国际指南将利妥昔单抗列为二线治疗选择。ITP最新获批的药物是血小板生成素受体激动剂(TRA),如罗米司亭和艾曲泊帕。TRA可使血小板计数增加,并减少出血事件的发生次数。对于一线治疗失败后有出血风险的慢性ITP患者,TRA通常被认为是安全有效的治疗方法。然而,由于TRA费用高昂,患者是否更倾向于使用这些药物尚不清楚。此外,目前一些新型药物正在研发中。本文总结了ITP的病理生理学、诊断和治疗方法。ITP所有治疗策略的目标是使血小板计数达到足以实现充分止血的水平,而非达到正常血小板计数。治疗决策应基于出血严重程度、出血风险、活动水平、治疗可能产生的副作用以及患者偏好。