People with increased levels of gum disease are at risk of developing rheumatoid arthritis (RA) as a new study suggests that it could be a key initiator of RA-related autoimmunity.

The researchers explained that it is because autoimmunity in RA is characterised by an antibody response to citrullinated proteins and the oral bacterium Porphyromonas gingivalis (Pg) is the only human pathogen known to express an enzyme that can generate citrullinated proteins.