Tong Louis, Koh Vanessa, Thong Bernard Yu-Hor
Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore.
Corneal and External Eye Disease, Singapore National Eye Centre.
J Inflamm Res. 2017 Aug 7;10:97-105. doi: 10.2147/JIR.S137024. eCollection 2017.
Primary Sjögren's syndrome (pSS) is an autoimmune disease characterized by inflammation in exocrine glands, resulting in reduced secretion of tears and saliva, manifesting as xerophthalmia and xerostomia, respectively. It is commonly associated with Sjögren's syndrome type A (Ro) and Sjögren's syndrome type B (La) antigens. However, in most patients, the identity of the triggering antigen is not known. Factors such as genetics of histocompatibility, dysregulation of T-cells, B-cells and viral infections have been implicated. Several important studies on autoantigens in pSS have been published since a review in 2012, and the aim of this review is to provide an update on further peer-reviewed original articles in this field. Oxidative damage of Ro60 antigen may explain the epitope spreading during the immune activation in pSS. Immune-mediated destruction of the muscarinic receptor-3-expressing cells has been associated with a reduction in parasympathetic function, which could cause reduced secretory function of exocrine glands. Such a process also activates reactive oxidative species and antioxidants, which are linked to the triggering of inflammatory responses. Elevated levels of kallikrein, yet another antigen present in the lacrimal gland and other tissues, are similarly involved in triggering an autoimmune T-cell response against target glands. Studying additional antigens, the platelet-selectin and vasoactive intestinal peptides, in patients with pSS can help to elucidate the origin and process of autoimmunity, or even lead to potential biomarkers. In conclusion, the understanding of autoantigens has led to exciting major advances in the biology of pSS and may influence diagnosis and management of pSS in future.
原发性干燥综合征（pSS）是一种自身免疫性疾病，其特征为外分泌腺炎症，导致泪液和唾液分泌减少，分别表现为干眼症和口干症。它通常与干燥综合征A（Ro）抗原和干燥综合征B（La）抗原相关。然而，在大多数患者中，引发抗原的身份尚不清楚。诸如组织相容性遗传学、T细胞、B细胞失调以及病毒感染等因素都被认为与之有关。自2012年的一篇综述以来，已经发表了几项关于pSS自身抗原的重要研究，本综述的目的是提供该领域进一步经过同行评审的原创文章的最新情况。Ro60抗原的氧化损伤可能解释了pSS免疫激活过程中的表位扩展。免疫介导的表达毒蕈碱受体-3的细胞破坏与副交感神经功能降低有关，这可能导致外分泌腺分泌功能降低。这样的过程还会激活活性氧化物质和抗氧化剂，它们与炎症反应的触发有关。激肽释放酶水平升高，它也是泪腺和其他组织中存在的另一种抗原，同样参与触发针对靶腺的自身免疫性T细胞反应。研究pSS患者中的其他抗原，如血小板选择素和血管活性肠肽，有助于阐明自身免疫的起源和过程，甚至可能产生潜在的生物标志物。总之，对自身抗原的理解已在pSS生物学领域带来了令人兴奋的重大进展，并可能在未来影响pSS的诊断和管理。
