■当抗原阴性红细胞(RBC)被补体系统裂解时,会发生旁观者溶血。许多临床实体,包括乘客淋巴细胞综合征,输血后溶血过度,阵发性夜间血红蛋白尿症并发旁观者溶血。
■该综述提供了有关补体系统在旁观者溶血发病机理中的作用的数据。此外,描述了对这种综合症的理解和管理的未来观点。
■补体系统可以通过经典激活,另类,和凝集素途径。经典途径激活是由抗原抗体(自身抗体和针对自体红细胞的同种抗体,传染原)复合物。旁路启动是由血红素引发的,红细胞微泡,血管内溶血导致的内皮损伤。因此,C5b形成,与C6-C9复合体结合,MAC(C5b-9)配制在旁观者红细胞膜中,导致细胞裂解。血管内溶血,导致替代途径的激活,在补体激活和旁观者溶血之间建立恶性循环。C5抑制剂已有效用于患有过度溶血综合征和其他以旁观者溶血为特征的实体的患者。
UNASSIGNED: Bystander hemolysis occurs when antigen-negative red blood cells (RBCs) are lysed by the complement system. Many clinical entities including passenger lymphocyte syndrome, hyperhemolysis following blood transfusion, and paroxysmal nocturnal hemoglobinuria are complicated by bystander hemolysis.
UNASSIGNED: The review provides data about the role of the complement system in the pathogenesis of bystander hemolysis. Moreover, future perspectives on the understanding and management of this syndrome are described.
UNASSIGNED: Complement system can be activated via classical, alternative, and lectin pathways. Classical pathway activation is mediated by antigen-antibody (autoantibodies and alloantibodies against autologous RBCs, infectious agents) complexes. Alternative pathway initiation is triggered by heme, RBC microvesicles, and endothelial injury that is a result of intravascular hemolysis. Thus, C5b is formed, binds with C6-C9 compomers, and MAC (C5b-9) is formulated in bystander RBCs membranes, leading to cell lysis. Intravascular hemolysis, results in activation of the alternative pathway, establishing a vicious cycle between complement activation and bystander hemolysis. C5 inhibitors have been used effectively in patients with hyperhemolysis syndrome and other entities characterized by bystander hemolysis.