AN ARTHRITOGENIC STRAIN OF SUBDOLIGRANULUM SPECIFICALLY DETECTABLE IN THE FECES OF INDIVIDUALS AT-RISK FOR AND WITH RHEUMATOID ARTHRITIS IS BOUND BY ACPA AND STIMULATES TH17 CELL ACTIVATION IN THOSE WITH RHEUMATOID ARTHRITIS
Authors: Meagan Chriswell et al.
In this study from the US, the researchers were able to demonstrate that ACPAs (anti-CCP antibodies) are specifically targeting certain intestinal bacteria in individuals at-risk for RA (“pre-RA”). When these bacteria («Subdoligranulum») are then transferred into the intestine of mice, the mice develop RA-related autoantibodies and arthritis.
This bacteria («Subdoligranulum») was detectable in the feces of ~16% of individuals at-risk for and with early RA, but not at all in healthy individuals (0%). The bacteria also induced a specific T cell activation in individuals with RA, but not in controls.
Chronic mucosal inflammation is known to be involved in the pathogenesis of rheumatoid arthritis (RA), whether in the lung (cf. tobacco smoke, COPD), in the intestine (cf. chronic diarrhea) or in the oral cavity (cf. periodontitis). The precise etiopathogenic mechanisms linking chronic mucosal inflammation and the development of RA are poorly understood. The findings of this research supports the idea that an arthritogenic bacterium may be involved in the pathogenesis of the disease in a subset of patients. Furthermore, it suggests that bacterial protein may be stimulating the human immunity and lead to the development of RA through molecular mimicry.