Immune thrombotic thrombocytopenic purpura (iTTP) is a rare, life-threatening autoimmune disorder caused by a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13 (ADAMTS13) deficiency. Caplacizumab, an anti–von Willebrand factor nanobody, is approved for iTTP treatment, reducing the need for therapeutic plasma exchange (TPE) and improving platelet count recovery and survival. We conducted a retrospective study on 42 acute iTTP cases in Austria and Germany, treated with a modified regimen aimed at avoiding TPE if platelet count increased after the first caplacizumab dose. Baseline characteristics and patient outcomes were compared with a control group of 59 patients with iTTP receiving frontline treatment with TPE, caplacizumab, and immunosuppression. The main outcome was the time to platelet count normalization. Secondary outcomes included clinical response, exacerbation, refractory iTTP, iTTP-related deaths, and the time to platelet count doubling. The median time to platelet count normalization was similar between the 2 cohorts (3 and 4 days; P = .31). There were no significant differences in clinical response, exacerbations, refractoriness, iTTP-related deaths, or time to platelet count doubling, reflecting the short-term treatment response. Four patients did not respond to the first caplacizumab dose, and TPE was subsequently initiated. Cytomegalovirus infection, HIV/hepatitis B virus coinfection, an ovarian teratoma with associated antiplatelet antibodies, and multiple platelet transfusions before the correct diagnosis may have impeded the immediate treatment response in these patients. In conclusion, caplacizumab and immunosuppression alone, without TPE, rapidly controlled thrombotic microangiopathy and achieved a sustained clinical response in iTTP. Our study provides a basis for TPE-free iTTP management in experienced centers via shared decision-making between patients and treating physicians.

中文翻译：

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不进行血浆置换治疗的免疫性血栓性血小板减少性紫癜的治疗


免疫性血栓性血小板减少性紫癜 (iTTP) 是一种罕见的危及生命的自身免疫性疾病，由具有血小板反应蛋白 1 型基序成员 13 (ADAMTS13) 的解整合素和金属蛋白酶缺陷引起。 Caplacizumab 是一种抗血管性血友病因子纳米抗体，已被批准用于 iTTP 治疗，减少对治疗性血浆置换 (TPE) 的需求并改善血小板计数恢复和存活。我们对奥地利和德国的 42 例急性 iTTP 病例进行了一项回顾性研究，这些病例采用改良方案进行治疗，旨在避免在首次服用 caplacizumab 后血小板计数增加时发生 TPE。将基线特征和患者结果与接受 TPE、caplacizumab 和免疫抑制一线治疗的 59 名 iTTP 患者组成的对照组进行比较。主要结果是血小板计数正常化的时间。次要结局包括临床反应、病情恶化、难治性 iTTP、iTTP 相关死亡以及血小板计数加倍的时间。两个队列之间血小板计数正常化的中位时间相似（3 天和 4 天；P = .31）。临床反应、病情加重、难治性、iTTP 相关死亡或血小板计数倍增时间没有显着差异，反映了短期治疗反应。 4 名患者对第一剂 caplacizumab 没有反应，随后开始 TPE。巨细胞病毒感染、HIV/乙型肝炎病毒合并感染、具有相关抗血小板抗体的卵巢畸胎瘤以及在正确诊断之前进行的多次血小板输注可能阻碍了这些患者的立即治疗反应。 总之，单独使用 caplacizumab 和免疫抑制剂（无需 TPE）可快速控制血栓性微血管病，并在 iTTP 中实现持续的临床缓解。我们的研究通过患者和治疗医生之间的共同决策，为经验丰富的中心的无 TPE iTTP 管理提供了基础。