Do infectious agents cause rheumatoid arthritis?

Although rheumatoid arthritis (RA) has been widely suspected to have an infectious etiology, this hypothesis has remained difficult to prove. Epstein-Barr virus, parvoviruses, and retroviruses are considered by some investigators to be the primary candidates. An increasing body of data, on the other hand, appears to implicate bacteria or their products in the syndrome. Important evidence has surfaced in support of this view. Lyme arthritis, a disease caused by a bacterium, can mimic RA. Bacteria and their products have been conclusively linked to many forms of inflammatory "reactive" arthropathies. RA-like diseases can be induced in certain inbred strains of rats with bacterial cell-wall fragments, e.g., streptococcal and other bacterial peptidoglycans. Immunologic relationships between host and bacterial peptidoglycans, relevant to RA, have been well documented, e.g., heat shock proteins, bacterial IgG Fc binding proteins, and rheumatoid factors. These data not only support the hypothesis that bacteria may play an important role in RA but also indicate that current concepts of infection and autoimmune disease are broadening and overlapping.

虽然类风湿性关节炎（RA）一直被广泛怀疑具有感染病因，但这一假说仍然难以证实。一些研究者认为爱泼斯坦 - 巴尔病毒、细小病毒和逆转录病毒是主要的候选病原体。另一方面，越来越多的数据似乎表明细菌或其产物与该综合征有关。支持这一观点的重要证据已经出现。莱姆关节炎是一种由细菌引起的疾病，其症状可类似于类风湿性关节炎。细菌及其产物已被确凿地与多种形式的炎症性“反应性”关节病联系起来。用细菌细胞壁片段，例如链球菌和其他细菌的肽聚糖，可以在某些近交系大鼠中诱发类似类风湿性关节炎的疾病。与类风湿性关节炎相关的宿主和细菌肽聚糖之间的免疫学关系已有充分的文献记载，例如热休克蛋白、细菌IgG Fc结合蛋白和类风湿因子。这些数据不仅支持细菌可能在类风湿性关节炎中起重要作用的假说，还表明当前关于感染和自身免疫性疾病的概念正在扩大且相互重叠。