Sakai Kazuya
Department of Blood Transfusion Medicine, Nara Medical University.
Rinsho Ketsueki. 2025;66(6):481-487. doi: 10.11406/rinketsu.66.481.
Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic disorder. Immune-mediated TTP is caused by autoantibodies against ADAMTS13, an enzyme responsible for cleaving von Willebrand factor (VWF). Therapeutic plasma exchange (TPE) combined with corticosteroids has historically been the standard treatment, and has significantly improved patient survival. Caplacizumab, a nanobody targeting the VWF A1 domain, inhibits platelet-VWF interactions. Addition of caplacizumab to standard therapy has led to rapid platelet count recovery and prevention of thrombotic events in acute phases. Caplacizumab combined with immunosuppressive therapy has been effective in patients unable to undergo TPE due to clinical or logistical challenges, such as anaphylaxis to fresh frozen plasma or religious restrictions. A retrospective study in 2024 reported that 90.5% of patients achieved clinical response without TPE, highlighting the potential for plasma exchange-free management of acute immune-mediated TTP. These findings underscore the growing importance of caplacizumab in modern TTP therapy. Currently, a phase 3 clinical trial (MAYARI) is evaluating the efficacy of caplacizumab and immunosuppressive therapy without TPE in treating acute immune-mediated TTP. This trial aims to validate a simplified treatment paradigm, potentially transforming the management of TTP by offering safe and effective alternatives to TPE.
血栓性血小板减少性紫癜(TTP)是一种罕见且危及生命的血栓性疾病。免疫介导的TTP由针对ADAMTS13的自身抗体引起,ADAMTS13是一种负责裂解血管性血友病因子(VWF)的酶。治疗性血浆置换(TPE)联合皮质类固醇一直是标准治疗方法,并显著提高了患者生存率。卡泊珠单抗是一种靶向VWF A1结构域的纳米抗体,可抑制血小板与VWF的相互作用。在标准治疗中添加卡泊珠单抗可使血小板计数迅速恢复,并预防急性期的血栓事件。对于因临床或后勤挑战(如对新鲜冰冻血浆过敏或宗教限制)而无法进行TPE的患者,卡泊珠单抗联合免疫抑制治疗已显示出疗效。2024年一项回顾性研究报告称,90.5%的患者在未进行TPE的情况下实现了临床缓解,凸显了无血浆置换管理急性免疫介导TTP的潜力。这些发现强调了卡泊珠单抗在现代TTP治疗中日益重要的地位。目前,一项3期临床试验(MAYARI)正在评估卡泊珠单抗和无TPE的免疫抑制治疗在治疗急性免疫介导TTP中的疗效。该试验旨在验证一种简化的治疗模式,通过提供安全有效的TPE替代方案,可能改变TTP的管理方式。