title: Infection and rheumatoid arthritis: still an open question.
abstract: OBJECTIVE
  This review focuses on recent research that explores the role of infectious organisms in the development of autoimmunity and rheumatoid arthritis (RA).
  
  
  RESULTS
  Human and animal studies provide further evidence supporting a role for the periodontal pathogen, Porphyromonas gingivalis, in the development of RA. The microbiome plays a key role in the developing immune system. Alterations in the bowel microbiome lead to altered innate and adaptive immune responses potentially relevant to the development or persistence of RA.
  
  
  CONCLUSIONS
  Microbes and the host response to microbes are important factors in the maintenance of health. Abnormalities or imbalances in these responses can lead to the development of autoimmune inflammatory conditions such as RA.
authors.affiliation: University of Manitoba, Winnipeg, Manitoba, Canada.
authors.forename: Carol A
authors.initials: CA
authors.lastname: Hitchon
authors.forename: Hani S
authors.initials: HS
authors.lastname: El-Gabalawy
mesh_terms: D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D001424:Bacterial Infections / Q000150:complications / Q000276:immunology / Q000382:microbiology; D003141:Communicable Diseases / Q000150:complications* / Q000276:immunology / Q000382:microbiology; D006801:Humans; D010510:Periodontal Diseases / Q000150:complications / Q000276:immunology / Q000382:microbiology