Tracy Alexander, Buckley Christopher D, Raza Karim
Department of Rheumatology, Sandwell and West Birmingham Hospitals NHS Trust, Dudley Road, Birmingham, B18 7QH, UK.
Rheumatology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, B15 2TT, UK.
Semin Immunopathol. 2017 Jun;39(4):423-435. doi: 10.1007/s00281-017-0620-6. Epub 2017 Mar 23.
It is well recognised that a state of autoimmunity, in which immunological tolerance is broken, precedes the development of symptoms in the majority of patients with rheumatoid arthritis (RA). For individuals who will later develop seropositive disease, this manifests as autoantibodies directed against proteins that have undergone specific post-translational modifications. There is evidence that the induction of this autoantibody response occurs at peripheral extra-articular mucosal sites, such as the periodontium and lung. In addition to their utility as diagnostic markers, these autoantibodies may have a pathogenic role that helps localise disease to the synovium. Alongside the development of autoantibodies, other factors contributing to pre-symptomatic autoimmunity may include dysbiosis of the gastrointestinal tract, abnormal development of lymphoid tissue, and dysregulated autonomic and lipid-mediated anti-inflammatory signalling. These factors combine to skew the balance between pro-inflammatory and anti-inflammatory signalling in a manner that is permissive for the development of clinical arthritis. We present data to support the concept that the transitions from at-risk states to systemic autoimmunity and then to classifiable RA depend on multiple "switches". However, further prospective studies are necessary to define the molecular basis of these switches and the specific features of pre-symptomatic autoimmunity, so that preventative treatments can be targeted to individuals at high risk for RA. In this review, we analyse mechanisms that may contribute to the development of autoimmunity in at-risk individuals and discuss the relationship between this pre-symptomatic state and subsequent development of RA.
人们普遍认识到,在大多数类风湿关节炎(RA)患者中,自身免疫状态(即免疫耐受被打破)先于症状出现。对于后来会发展为血清阳性疾病的个体,这表现为针对经过特定翻译后修饰的蛋白质的自身抗体。有证据表明,这种自身抗体反应的诱导发生在外周关节外黏膜部位,如牙周组织和肺部。除了作为诊断标志物的用途外,这些自身抗体可能具有致病作用,有助于将疾病定位到滑膜。除了自身抗体的产生外,导致症状前自身免疫的其他因素可能包括胃肠道微生物群失调、淋巴组织异常发育以及自主神经和脂质介导的抗炎信号失调。这些因素共同作用,以一种有利于临床关节炎发展的方式改变促炎和抗炎信号之间的平衡。我们提供数据支持这样的概念,即从风险状态到全身性自身免疫再到可分类的RA的转变取决于多个“开关”。然而,需要进一步的前瞻性研究来确定这些开关的分子基础以及症状前自身免疫的具体特征,以便预防性治疗能够针对RA高危个体。在这篇综述中,我们分析了可能导致风险个体自身免疫发展的机制,并讨论了这种症状前状态与随后RA发展之间的关系。