Department of Hematology, Children's Hospital of Orange County, Orange, CA, USA.
Br J Haematol. 2009 Sep;146(6):585-96. doi: 10.1111/j.1365-2141.2009.07717.x. Epub 2009 May 14.
Chronic immune thrombocytopenia (ITP) is a haematological disorder in which patients predominantly develop skin and mucosal bleeding. Early studies suggested ITP was primarily due to immune-mediated peripheral platelet destruction. However, increasing evidence indicates that an additional component of this disorder is immune-mediated decreased platelet production that cannot keep pace with platelet destruction. Evidence for increased platelet destruction is thrombocytopenia following ITP plasma infusions in normal subjects, in vitro platelet phagocytosis, and decreased platelet survivals in ITP patients that respond to therapies that prevent in vivo platelet phagocytosis; e.g., intravenous immunoglobulin G, anti-D, corticosteroids, and splenectomy. The cause of platelet destruction in most ITP patients appears to be autoantibody-mediated. However, cytotoxic T lymphocyte-mediated platelet (and possibly megakaryocyte) lysis, may also be important. Studies supporting suppressed platelet production include: reduced platelet turnover in over 80% of ITP patients, morphological evidence of megakaryocyte damage, autoantibody-induced suppression of in vitro megakaryocytopoiesis, and increased platelet counts in most ITP patients following treatment with thrombopoietin receptor agonists. This review summarizes data that indicates that the pathogenesis of chronic ITP may be due to both immune-mediated platelet destruction and/or suppressed platelet production. The relative importance of these two mechanisms undoubtedly varies among patients.
慢性免疫性血小板减少症（ITP）是一种血液系统疾病，患者主要表现为皮肤和黏膜出血。早期研究表明，ITP 主要是由于免疫介导的外周血小板破坏所致。然而，越来越多的证据表明，这种疾病的另一个组成部分是免疫介导的血小板生成减少，无法与血小板破坏保持同步。血小板破坏增加的证据包括：ITP 患者血浆输注后血小板减少、体外血小板吞噬作用、对预防体内血小板吞噬作用的治疗有反应的 ITP 患者血小板存活率降低；例如，静脉注射免疫球蛋白 G、抗-D、皮质类固醇和脾切除术。大多数 ITP 患者的血小板破坏原因似乎是自身抗体介导的。然而，细胞毒性 T 淋巴细胞介导的血小板（和可能的巨核细胞）裂解也可能很重要。支持血小板生成受抑制的研究包括：超过 80%的 ITP 患者血小板周转率降低、巨核细胞损伤的形态学证据、自身抗体诱导的体外巨核细胞生成抑制以及大多数 ITP 患者在接受血小板生成素受体激动剂治疗后血小板计数增加。这篇综述总结了表明慢性 ITP 的发病机制可能是由于免疫介导的血小板破坏和/或血小板生成受抑制所致的数据。这两种机制的相对重要性无疑在患者之间存在差异。
