Multiple sclerosis and autoimmunity: learnings from post-streptococcal autoimmunity.

Group A streptococcus (GAS) or Streptococcus pyogenes, which typically causes a purulent pharyngitis, is the established cause of acute rheumatic fever (ARF) and several other autoimmune diseases. Primary prevention, achieved by treating acute pharyngitis with antibiotics, prevents ARF. After an initial attack of ARF, secondary prevention, using long-term prophylactic antibiotics, prevents further attacks and chronic end-organ damage or chronic rheumatic heart disease. Infection with the Epstein-Barr virus (EBV) is the likely cause of multiple sclerosis (MS). EBV-associated infectious mononucleosis (IM) is a significant risk factor for developing MS. Reasoning by analogy, similar to the role of GAS in ARF, we hypothesise that treating IM with effective antivirals will prevent or at least reduce the incidence of MS. Similarly, once MS is established, the chronic administration of effective EBV antivirals will prevent further MS attacks and prevent end-organ damage or disability in people with MS. Treating IM and preventing EBV latent-lytic cycling in patients with MS needs to be explored as strategies to prevent and treat MS, respectively.