Infectious agents breaking the immunological tolerance: The holy grail in rheumatoid arthritis reconsidered

Multiple Sclerosis (MS) has been shown to be linked to Epstein Barr Virus (EBV) infection, a virus that infects B cells inside the CNS. The seminal study raises a key interest into the infectious origin of several other autoim-mune inflammatory diseases.We will discuss here the infectious agents that have been studied over the years in Rheumatoid Arthritis (RA), a crippling arthritis that was treated a century ago with gold salts (anti mycobacterial agent), chloroquine (anti malarial agent), or sulphasalazine (an antibacterial-antiinflammatory agent). Several infectious agents have been taken into consideration, i.e. Streptococcus group A, Proteus, Mycobacterium tuberculosis-MTB, Parvovirus B19, Epstein Barr virus, Porphyromonas gingivalis-Pg, Aggregatibacter actino-mycetescomitans, and finally Haemophilus-Glaesserella parasuis-Hps. Of these agents only three satisfy the Witebski's criteria as possible pathogenetic causes of an autoimmune disease, i.e. MTB, Pg, Hps. We will discuss here how the immune tolerance might be broken, which could be the neoantigen or autoantigen involved, how the infectious agent was studied as a trigger capable of inducing arthritis in animal models. The preventive measures that should be adopted to lessen the impact of the infections, to prevent the burden and the severity of the illness are described.

Automated summary

Multiple Sclerosis (MS) is associated with Epstein Barr Virus (EBV) infection, and there may be a link between other autoimmune inflammatory diseases and infection. In the study of Rheumatoid Arthritis (RA), various infectious agents have been considered, but only a few meet the criteria for possible pathogenic causes of autoimmune diseases. This article discusses the breakdown of immune tolerance and the role of infectious agents in triggering arthritis in animal models. Additionally, preventive measures are described.