Session Information
Date: Sunday, November 5, 2017
Title: Rheumatoid Arthritis – Human Etiology and Pathogenesis Poster I
Session Type: ACR Poster Session A
Session Time: 9:00AM-11:00AM
Background/Purpose:
The mouth is the second most abundantly colonized mucosal surface in the human body. Periodontitis, a polymicrobial infectious and inflammatory disease of tooth-supporting structures, is associated with rheumatoid arthritis (RA) and may be caused by oral microbial dysbiosis, with shift toward pathogenic commensal species. Particular pathogens such as Porphyromonas gingivalis (Pg), and Aggregatibacter actinomycetecomitans (Aa) have been implicated, but few studies have analyzed oral microbiota composition in RA patients.
Methods: 73 subjects, 33 RA patients, the majority with new-onset RA, all meeting 2010 ACR/EULAR criteria, 20 age- and gender-matched healthy subjects (HS) without periodontitis or RA, and 20 patients with chronic periodontitis who lacked RA (non-RA CP) completed standardized periodontal examination. Subgingival plaque samples (2 per subject) were evaluated for the presence of 40 bacterial taxa associated with periodontitis biofilms by checkerboard DNA-DNA hybridization.
Results: Typical of RA cohorts, the 33 patients were mainly female (85%) with median age of 51; 23 had DMARD-naive early disease, 58% had rheumatoid factor (RF) or anti-citrullinated protein antibody (ACPA). Only one currently smoked. The majority (91%) received regular dental care with cleanings every 6 months.
Of the RA patients, 10 (30%) had periodontal health, 13 (39%) had gingivitis, and 10 (30%) had periodontitis. Pocket depth, clinical attachment loss, and bleeding on probing were all increased in the 33 patients compared with HS (P<0.002).
The RA patients had a significantly higher total bacterial load in dental plaque (111.8 x 105) compared with HS (58.9 x 105, P=0.01) and non-RA CP (70.5 x 105, P=0.03). RA patients with periodontal health had lower bacterial burden than those with gingivitis and periodontitis (P=0.03). Seropositive RA patients also tended to have a higher oral bacterial load than seronegative patients. By phylum, RA patients had particularly higher levels of Actinobacteria, Proteobacteria, and Firmicutes compared to both HS and non-RA CP (P≤0.03), whereas Fusobacteria, Spirochaetes, and Bacteroidetes were elevated compared to HS (P≤0.03) but similar to non-RA CP.
Accounting for multiple comparisons, 21 of 40 individual microbes had higher DNA probe counts (levels) in RA patients versus HS (P ≤0.01), this included only 1 red-complex classic pathogen, Tannerella forsythia. Notably, levels of Pg, detected in 5 RA patients, were not significantly different from HS. Aa was detected in only one RA patient who also had periodontitis.
While none of the 40 organisms correlated directly with ACPA, 4 correlated with RF levels, particularly Eubacterium saburreum (R=0.549, P≤0.001), and 9 organisms correlated with swollen joint counts, 6 of which were Actinobacteria species.
Conclusion: Despite routine dental care and lack of smoking, new-onset RA patients had an abundance of oral bacteria, with expansion of pathogenic species seen in non-RA CP. Thus dysbiosis is a feature of the oral, as well as gut microbiome, in RA. Besides pathogens such as Pg and Aa, other oral microbes here were associated with RA autoantibodies and will require further study.
To cite this abstract in AMA style:
Arvikar S, Hasturk H, Strle K, Nguyen D, Bolster MB, Collier D, Kantarci A, Steere A. The Oral Microbiome Is Altered in Patients with Rheumatoid Arthritis [abstract]. Arthritis Rheumatol. 2017; 69 (suppl 10). https://acrabstracts.org/abstract/the-oral-microbiome-is-altered-in-patients-with-rheumatoid-arthritis/. Accessed .« Back to 2017 ACR/ARHP Annual Meeting
ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-oral-microbiome-is-altered-in-patients-with-rheumatoid-arthritis/