A bacterium known to cause inflammatory gum infection is also associated with the autoimmune response that triggers rheumatoid arthritis (RA), according to findings from new research conducted at Johns Hopkins University. The bacterium, Aggregatibacter actinomycetemcomitans, initiates the development of RA by promoting the overproduction of immune-activating citrullinated proteins. The discovery sheds new light on the known clinical association of periodontal disease and RA, and may lead to further advances in RA treatment and prevention, according to the authors. The findings are published this month in Science Translational Medicine.
Previous efforts at identifying the common driver for periodontal disease and RA had focused in a different bacterium, Porphyromonas gingivalis found in patients with gum disease, but a causal link could not be proven. The current study focused on abnormally high levels of citrullinated proteins that stimulate the production of inflammatory antibodies that can attack the body’s tissue, as occurs in RA. The team found that A. actinomycetemcomitans was the common pathogen that induced this hypercitrullination. Senior author Felipe Andrade, MD, associate professor of medicine at Johns Hopkins, commented, "This is like putting together the last few pieces of a complicated jigsaw puzzle that has been worked on for many years."
Read a news story about the findings here.
The journal abstract may be read here.
Posted on December 16, 2016