Department of Medicine, University of Florida, FL 32610-0221, USA.
Adv Exp Med Biol. 2013;768:45-59. doi: 10.1007/978-1-4614-5107-5_4.
Like many other classical autoantibodies in systemic rheumatic diseases, anti-Su antibodies were originally defined by the double immunodiffusion assay in the early 80s. However, despite its high prevalence, only a few reports on anti-Su were published in the following years and the progress in characterizing the target antigens and clinical significance was slow, probably due to its inconsistent or poor reactivity in other standard immunoassays. In 2006 the target antigen was identified as the microRNA (miRNA)-binding protein Argonaute 2 (Ago2). Ago2 is a key component of the RNA-induced silencing complex enriched in cytoplasmic foci called GW bodies. Due to preferential reactivity of human autoantibodies with native antigens, immunoprecipitation is the only method to reliably detect anti-Su/Ago2 antibodies. Anti-Su/Ago2 does not appear to have disease specificity since it is found in 10-20% of patients with various rheumatic diseases, including systemic lupus erythematosus, scleroderma, polymyositis/dermatomyositis, and Sjögren's syndrome, as well as apparently healthy individuals at lower prevalence. The clinical significance and the mechanism of production of anti-Su/Ago2 remains to be clarified.
与系统性风湿病中的许多其他经典自身抗体一样，抗 Su 抗体最初是在 80 年代初的双免疫扩散测定中定义的。然而，尽管其患病率很高，但在接下来的几年中，仅有少数关于抗 Su 的报道发表，并且在表征靶抗原和临床意义方面进展缓慢，这可能是由于其在其他标准免疫测定中的反应不一致或较差所致。2006 年，靶抗原被鉴定为 microRNA（miRNA）结合蛋白 Argonaute 2（Ago2）。Ago2 是富含细胞质焦点的 RNA 诱导沉默复合物的关键组成部分，这些焦点称为 GW 体。由于人类自身抗体优先与天然抗原反应，因此免疫沉淀是可靠检测抗 Su/Ago2 抗体的唯一方法。抗 Su/Ago2 似乎没有疾病特异性，因为它存在于 10-20%的各种风湿病患者中，包括系统性红斑狼疮、硬皮病、多发性肌炎/皮肌炎和干燥综合征，以及患病率较低的明显健康个体中。抗 Su/Ago2 的临床意义和产生机制仍有待阐明。
