Immune Thrombocytopenia (ITP) is the commonest acquired thrombocytopenia after chemotherapy-induced thrombocytopenia. Existing guidelines describe the management and treatment of most patients who overall do well, even if they present with chronic disease, and are usually not at high risk of bleeding. However, a small percentage of patients is refractory and difficult to manage. Patients classified as refractory either have a diagnosis that is not really ITP or have disease that is difficult to manage. ITP is a diagnosis of exclusion; no specific tests exist to confirm the diagnosis. Response to treatment is the only affirmative confirmation of diagnosis. However, refractory patients do not respond to front-line or other treatments, and thus, no confirmation of diagnosis exists. This review carefully evaluates the diagnostic considerations in patients with refractory ITP. The second section describes combination treatment for refractory cases of ITP. The reported combinations are divided into the era before thrombopoietin(TPO) and rituximab and the current era. Current therapy appears to have increased effectiveness. However, the definition of refractory, if it includes insufficient response to TPO agents, describes a group with more severe and difficult to treat disease. The biology of refractory ITP is largely unexplored and includes oligoclonality, lymphocyte pumps, and other possibilities. Newer treatments, especially rapamycin, fostamatinib, FcRn and BTK inhibitors, may be useful components of future therapy given their mechanisms of action but TPO agents, notwithstanding failure as monotherapy, appear to be critical components. In summary, refractory ITP is a complicated entity in which precise, specific diagnosis is as important as development of effective combination treatments.

中文翻译：

---

难治性 ITP 的识别和治疗：诊断困难和联合治疗的作用

免疫性血小板减少症（ITP）是继化疗引起的血小板减少症之后最常见的获得性血小板减少症。现有指南描述了大多数总体状况良好的患者的管理和治疗，即使他们患有慢性疾病，并且通常出血风险不高。然而，一小部分患者是难治性且难以管理的。被归类为难治性患者的诊断要么不是真正的 ITP，要么患有难以治疗的疾病。ITP 是一种排除性诊断；没有具体的测试来确认诊断。对治疗的反应是诊断的唯一肯定确认。然而，难治性患者对一线治疗或其他治疗没有反应，因此不存在诊断确认。本综述仔细评估了难治性 ITP 患者的诊断注意事项。第二部分介绍难治性 ITP 病例的联合治疗。已报道的组合分为血小板生成素（TPO）和利妥昔单抗之前的时代和当前时代。目前的治疗似乎已经提高了疗效。然而，如果难治性的定义包括对 TPO 药物的反应不足，则描述的是疾病更严重且难以治疗的群体。难治性 ITP 的生物学在很大程度上尚未被探索，包括寡克隆性、淋巴细胞泵和其他可能性。较新的治疗方法，尤其是雷帕霉素、福斯塔替尼、FcRn 和 BTK 抑制剂，鉴于其作用机制，可能是未来治疗的有用组成部分，但 TPO 药物尽管作为单一疗法失败，但似乎是关键组成部分。总之，难治性 ITP 是一个复杂的疾病，精确、特异性的诊断与开发有效的联合治疗同样重要。