title: Infectious diseases and autoimmunity.
abstract: BACKGROUND
  Autoimmunity occurs when the immune system recognizes and attacks host tissue. In addition to genetic factors, environmental triggers (in particular viruses, bacteria and other infectious pathogens) are thought to play a major role in the development of autoimmune diseases.
  
  
  METHODS
  We searched PubMed, Cochrane, and Scopus without time limits for relevant articles.
  
  
  RESULTS
  In this review, we (i) describe the ways in which an infectious agent can initiate or exacerbate autoimmunity; (ii) discuss the evidence linking certain infectious agents to autoimmune diseases in humans; and (iii) describe the animal models used to study the link between infection and autoimmunity.
  
  
  CONCLUSIONS
  Besides genetic predisposition to autoimmunity, viral and bacterial infections are known to be involved in the initiation and promotion of autoimmune diseases. These studies suggest that pathogens can trigger autoimmunity through molecular mimicry and their adjuvant effects during initiation of disease, and can promote autoimmune responses through bystander activation or epitope spreading via inflammation and/or superantigens.
authors: Department of Drug Science, University of Sassari, Italy. lgdelogu@uniss.it
authors: Lucia Gemma
authors: LG
authors: Delogu
authors: Silvia
authors: S
authors: Deidda
authors: Giuseppe
authors: G
authors: Delitala
authors: Roberto
authors: R
authors: Manetti
mesh_terms: D001327:Autoimmune Diseases / Q000453:epidemiology* / Q000209:etiology*; D001419:Bacteria / Q000276:immunology; D003141:Communicable Diseases / Q000150:complications* / Q000276:immunology*; D020022:Genetic Predisposition to Disease; D006801:Humans; D014780:Viruses / Q000276:immunology