C5a是3条补体途径共同裂解产生的活性产物，它具有广泛的生物学功能。目前对于它的研究主要集中在促炎活性上。然而，研究发现C5a与凝血异常亦有很重要的关系。在多种疾病中，常同时存在补体系统和凝血系统的异常。作为有着相同来源的两个生物活性系统，他们直接或间接的相互作用关系到疾病的发生、发展和转归。凝血系统的异常可以表现为凝血激活亢进、抗凝物质的削弱、纤溶系统的失衡。C5a与它们均存在一定的联系。

Complement 5a, as a common cleave product of 3 complement activation pathways, possesses wide biological activities. Current studies mainly focused on its pro-inflammatory properties. However,some studies have been shown that complement 5a was associated with coagulation disorders.Disorders of complement and coagulation system coexist in many diseases. The 2 systems share same origins and the interactions (directly or indirectly) between them are related to the occurrence, progression and prognosis of the disease. The disorders of coagulation are as follows: hyper-coagulation activation, impaired anticoagulation system, and unbalanced fibrinolytic system, which all correlatet with complement 5a.

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