Persistence pays off. A century-long question akin to – what comes first the chicken or the egg – as it pertains to a suspected common denominator for periodontal disease and rheumatoid arthritis, has been puzzled together by researchers at Johns Hopkins.
Both gum disease and rheumatoid arthritis (RA) are known to be remarkably similar. Each manifests pain and swelling that can lead to chronic inflammation and bone destruction.
Published in the journal Science Translational Medicine, the researchers point to a bacterium called Aggregatibacter actinomycetemcomitans (Aa) as a probable root cause for rheumatoid arthritis (RA).
Aa is one of many pathogens involved in the microbiology of periodontal disease and has only recently displaced 10-year interest in the bacterium Porphyromonas gingivalis as a possible common trigger for gum disease and RA.
But what is the link exactly? In one word: Hypercitrullination. Or more specifically, Aa-induced hypercitrullination that no other bacteria studied to date has been shown to induce.
Felipe Andrade, M.D., Ph.D., who is the senior study investigator and associate professor of Medicine at the Johns Hopkins University School of Medicine, explains Aa causes “normal” citrullination (a process for regulating protein functions) to go into overdrive and results in an overproduction of antibodies that cause inflammation and destruction of a person’s own tissues. Both are hallmarks of autoimmune disorders like RA.
Despite the breakthrough of a probable root cause for RA, the researchers caution that more than 50 percent of the RA-affected study participants showed no evidence of infection with Aa, and conclude that other bacteria in the gut, lung or elsewhere could be using a similar mechanism to induce hypercitrullination.
Written by: MaryAnne Pankhurst
http://stm.sciencemag.org/content/8/369/369ra176 Maximilian F. Konig et. Al