It is as early as the 1900's that scientists have discovered the link between periodontal disease and rheumatoid arthritis, but just recently, scientists have uncovered new evidence to support the old belief.
Early scientists who worked on the link between the gum disease and rheumatoid arthritis have been barking up the wrong tree on the bacterium responsible for activating the joint disease. They have been putting their efforts on the Porphyromonas gingivalis
bacterium found in patients with gum disease.
The intriguing links between the two disease caused the investigators at Johns Hopkins University School of Medicine to pursue the search for the common driver of the disease. The scientists found the new evidence by the common denominator of the two diseases which is hypercitrullination.
Citrullination is a normal process that helps regulate the functions of proteins. For people with rheumatoid arthritis, this process becomes hyperactive which results to abnormal accumulation of citrullinated proteins that cause inflammation and attack the person's own tissues. This also results to the overproduction of antibodies that attack the said proteins.
The most abundant inflammatory cells found in the joints and the gums of patients with RA and periodontal disease are neutrophils which are rich in peptidylarginine deiminase (PAD) enzymes for citrullination. The scientists found that the bacterium, A. actinomycetemcomitans
, which is involved in periodontal disease was the only pathogen responsible in inducing hypercitrullination in neutrophils.
activates pore-forming toxins which is the same in the hypercitrullination in the joints of patients with RA.
Osteoarthritis and Rheumatoid Arthritis are the 2 most common types of arthritis. Rheumatoid arthritis is a result of an autoimmune disorder.
The scientists found that 92 out of 196 samples from a large study of patients with RA had evidence of infection by A. actinomycetemcomitans
. The data substantially matched by 60 percent to patients with periodontal disease.
The group of scientists are open to the fact that they still have to perform additional studies to prove the cause and effect pf A. actinomycetemcomitans
The findings of the study are reported on Science Translational Medicine
See: Nose Cells Repair Knee Joints and Cartilage in Human Trial