Infections: a double-edge sword in autoimmunity

PURPOSE OF REVIEWInfections play a role in the pathogenesis of autoimmune diseases (AID). Several bacterial and viral pathogens play a double role, as both inducers and inhibitors of AID. In this review, we will present current evidence and discuss different aspects of this notion. RECENT FINDINGSInfectors that both inhibit and induce AID include Helicobacter pylori, Klebsiella pneumoniae, hepatitis B virus, group B Coxsackieviruses, Epstein–Barr virus and Lymphocytic choriomeningitis virus. Numerous AID are affected by infections, including polyarteritis nodosa, inflammatory bowel disease, and type 1 diabetes. Some pathogens, such as group B Coxsackieviruses, may induce and inhibit the development of the same AID. This reveals a complex role of infections in autoimmunity pathogenesis. SUMMARYElucidating the exact role of each pathogen on each specific AID is important, as this will enable evaluating the manipulation of these infections in the treatment of AID.