Molecular Otolaryngology and Renal Research Laboratories, University of Iowa, Iowa City, IA, United States.
Front Immunol. 2019 Apr 4;10:668. doi: 10.3389/fimmu.2019.00668. eCollection 2019.
C3 Glomerulopathy (C3G) is a renal disease mediated primarily by dysregulation of the alternative pathway of complement. Complement is the cornerstone of innate immunity. It targets infectious microbes for destruction, clears immune complexes, and apoptotic cells from the circulation, and augments the humoral response. In C3G, this process becomes dysregulated, which leads to the deposition of complement proteins-including complement component C3-in the glomerular basement membrane of the kidney. Events that trigger complement are typically environmental insults like infections. Once triggered, in patients who develop C3G, complement activity is sustained by a variety of factors, including rare or novel genetic variants in complement genes and autoantibodies that alter normal complement protein function and/or regulation. Herein, we review two such autoantibodies, one to Factor B and the other to C4b2a, the C3 convertase of the classical, and lectin pathways. These two types of autoantibodies are identified in a small fraction of C3G patients and contribute marginally to the C3G phenotype.
C3 肾小球病（C3G）是一种主要由补体替代途径失调引起的肾脏疾病。补体是先天免疫的基石。它可以靶向感染微生物进行破坏，清除循环中的免疫复合物和凋亡细胞，并增强体液免疫反应。在 C3G 中，这个过程会失调，导致补体蛋白（包括补体成分 C3）沉积在肾脏的肾小球基底膜中。触发补体的事件通常是感染等环境损伤。一旦触发，在发生 C3G 的患者中，补体活性会被多种因素维持，包括补体基因中的罕见或新型遗传变异以及改变正常补体蛋白功能和/或调节的自身抗体。在此，我们回顾两种自身抗体，一种针对因子 B，另一种针对 C4b2a，即经典和凝集素途径的 C3 转化酶。这两种类型的自身抗体在一小部分 C3G 患者中被识别，并对 C3G 表型有轻微贡献。
