Introduction: Systemic lupus erythematosus (SLE) is a multi-system autoimmune disease, characterized by the production of autoantibodies. Numerous mechanisms contribute to the pathogenesis and autoimmunity in SLE. One of the most important mechanisms is the defective function of the early complement components that are involved in clearing the immune-complexes and apoptotic debris. Major evidence supporting this hypothesis is the development of severe lupus in individuals with monogenic defects in any one of the early complement components such as C1q, C1 s, C1 r, C2, or C4.Areas covered: In this review, we discuss hereditary defects in classical complement components and their clinical manifestations, acquired defects of complements in lupus, the role of complements in the pathogenesis of antiphospholipid antibody syndrome and lupus nephritis, and laboratory assessment of complement components and their functions. Articles from the last 20 years were retrieved from PubMed for this purpose.Expert opinion: Complements have a dual role in the pathogenesis of SLE. On one hand, deficiency of complement components predisposes to lupus, while, on the other, excess complement activation plays a role in the organ damage. Understanding the intricacies of the role of complements in SLE can pave way for the development of targeted therapies.

中文翻译：

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重新审视系统性红斑狼疮的补体系统。

简介：系统性红斑狼疮（SLE）是一种多系统自身免疫性疾病，以产生自身抗体为特征。许多机制有助于 SLE 的发病机制和自身免疫。最重要的机制之一是参与清除免疫复合物和凋亡碎片的早期补体成分的功能缺陷。支持这一假设的主要证据是在任何一种早期补体成分（如 C1q、C1 s、C1 r、C2 或 C4）中具有单基因缺陷的个体发展严重狼疮。经典补体成分及其临床表现，狼疮补体获得性缺陷，补体在抗磷脂抗体综合征和狼疮性肾炎发病机制中的作用，补体成分及其功能的实验室评估。为此，从 PubMed 检索了过去 20 年的文章。 专家意见：补体在 SLE 的发病机制中具有双重作用。一方面，补体成分的缺乏易患狼疮，而另一方面，补体过度激活在器官损伤中起作用。了解补体在 SLE 中作用的复杂性可以为靶向治疗的发展铺平道路。过量的补体激活在器官损伤中起作用。了解补体在 SLE 中作用的复杂性可以为靶向治疗的发展铺平道路。过量的补体激活在器官损伤中起作用。了解补体在 SLE 中作用的复杂性可以为靶向治疗的发展铺平道路。