Rheumatoid arthritis (RA) and periodontitis are chronic inflammatory diseases that share common risk factors. Researchers conducted periodontal exams on patients with rheumatoid arthritis to determine what bacteria were present and how these patients might benefit from periodontal treatment.
They found that patients who were taking anti-inflammatory medicines for rheumatoid arthritis generally had a healthier microbiome. They hope their research will lead to the development of personalized treatments, they wrote in a study published on September 19 in PLOS One.
"In RA patients with active disease, anti-inflammatory medication as part of RA therapy was associated with better oral health status and healthier subgingival microbiome compared to that of RA patients in remission," the authors wrote.
The study was led by Kathrin Beyer, a doctoral candidate in the department of clinical dentistry at the University of Bergen Faculty of Medicine in Norway, and Egija Zaura, PhD, of the department of preventive dentistry at the Academic Centre for Dentistry Amsterdam at the University of Amsterdam and Free University Amsterdam in the Netherlands.
The more researchers know about patients' subgingival microbiome, the better the understanding of the biological mechanisms behind the association between rheumatoid arthritis and periodontitis. This, in turn, will help with the development of personalized therapies. Beyer, Zaura, and colleagues wanted to identify the bacterial component of the subgingival microbiome in patients with different degrees of periodontal disease and relate this to rheumatoid arthritis disease activity and periodontal status.
They conducted periodontal examinations on 78 patients with chronic, established rheumatoid arthritis (either active or in remission). Active disease was diagnosed in 45 patients and periodontitis in 64 patients, with seven of these patients having mild periodontitis, 43 with moderate periodontitis, and 14 having severe periodontitis. The rest were diagnosed with gingivitis. Of the patient cohort, 90% reported they brushed their teeth twice a day, and 95% said they performed some sort of interdental cleaning daily.
During the exams, the researchers also collected subgingival plaque samples and obtained the patients' clinical and laboratory data on rheumatoid arthritis status and medication use.
They found that different levels of gingival bleeding, periodontal probing depth, disease status, prednisolone use, and smoking were associated with significantly different microbiome compositions.
Of the demographic and behavioral variables tested (age, gender, body mass index, and smoking status), only smoking status showed a significant association with the microbiome profile of subgingival plaque (p = 0.0017). Microbiomes of current smokers differed significantly from patients who never smoked (p = 0.0033) and those who were former smokers (p = 0.0048).
Compared with patients whose rheumatoid arthritis was in remission, patients with active disease and those who used prednisolone had lower bacterial diversity and a higher proportion of taxa (a group of one or more populations of an organism or organisms), which usually has been associated with supragingival plaque and periodontal health.
Since patients with active disease had significantly higher use of prednisolone than those in remission, the effect on the oral microbiome could be related to this drug's use and not disease activity, the researchers noted.
The authors noted as a limitation that their study had a "very heterogeneous" patient population with considerable variety in terms of disease activity, medication, smoking status, and oral health.
Nevertheless, they advocated that patients with rheumatoid arthritis in remission who are current smokers may benefit from a systematic periodontal treatment program. They also pushed for more studies on the role of microbial community types in patient stratification and personalized therapy.
"Our study suggests that RA therapy and lifestyle factors such as smoking influence subgingival microbiome," the authors concluded.