Background:Oral microbiome (OM) seems to be significant in the pathogenesis of some immune-mediated diseases, such as rheumatoid arthritis (RA), psoriasis or inflammatory bowel disease.1 Some microorganisms, as Porphyromonas gingivalis have been related with the production of autoantibodies. Also it has been suggested that composition of OM could change RA disease course, being more difficult-to-treat and having higher disease activity scores.2Objectives:To identify which variables could predict the appearance of altered OM and its implications in clinical practice.Methods:Patients were recruited if they were diagnosed of RA and were at active treatment (biological, classical or targeted synthetic disease modifying anti-rheumatic drugs [b/cs/tsDMARDs]). Patients performed a dental review with a specialized odontologist that made an OM test (semiquantitative PCR), and oral health standards were instructed (following criteria of American Academy of Periodontology). Recruitment was made during 2020 in the Clinical University Hospital in Santiago de Compostela, Spain. Disease activity reevaluation was made 2 months later.Treatment, demographic and clinical data were collected from participants.Univariable logistic and linear regression were performed to identify predictors of OM. Variables with p<0.20 were selected for multivariable analysis.Stata 15.1 was used to perform statistical analysis.Results:47 patients were selected of whom 40 were female. Mean age was 55.43 years (SD 14.42). 30.77% were current or ex-smokers. Mean time since RA diagnosis was 14.89 years (SD 8.47). 63.83% were anti-citrullinated peptide autoantibody (ACPA) positive and 70.21% were rheumatoid factor (RF) positive, letting only 6 patients double negative. 46.81% had moderate/severe periodontal disease (PD). 32.61% of patients had any comorbidity. Mean DAS28 at the OM test was 2.67 (SD 1.28) and after 2 months 2.37 (SD 1.03). Mean C-reactive protein (CRP) was 0.64 mg/dl (SD 1.48) and median erythrocyte sedimentation rate (ESR) was 13 mm (IQR 7;27). All patients were under glucocorticoid treatment, 46 with bDMARD, 1 with tsDMARD and 46 with csDMARD. Treponema denticola was detected in 44.68% of patients, P. gingivalis in 29.79%, Actinomyces spp in 8.51%, Tanerella forsythia in 36.17% and Prevotella intermedia in 25.53%. Only 15 patients were full-negative for OM test.Univariable analysis identified RF positive, double autoantibody positive (RF and ACPA) and moderate/severe PD as potential predictors of the presence of at least one oral microorganism (p<0.20). Multivariable testing pointed out moderate/severe PD as predictor of the presence of at least one oral microorganism (OR 22.91 [CI95% 2.38-220.4] p=0.007).Univariable analysis identified higher age, presence of any comorbidity, RF positive, higher CRP, treatment with anti-tumour necrosis alpha (aTNF) and moderate/severe PD as potential predictors of the presence of multiple species in OM (p<0.20). Multivariable testing pointed out moderate/severe PD as predictor of the presence of multiple species in OM (ß 0.39 [95%CI 0.19-0.58] p=0.000).Conclusion:Oral microbiome is closely related with periodontal disease, added to our results, a relationship between OM and disease activity has been exposed. In this analysis the role of OM and autoantibody profile is manifest, as being double positive or RF positive is associated with the presence of altered OM. Also patients with high acute-phase reactants, active disease and under aTNF treatment could delineate a specific RA population under risk of altered OM, where intensive strategies for changing oral microbiome could have any repercussion in the disease course.References:[1]Chen, B., Zhao, Y., Li, S. et al. Variations in oral microbiome profiles in rheumatoid arthritis and osteoarthritis with potential biomarkers for arthritis screening. Sci Rep8, 17126 (2018).[2]R Bodkhe, B Balakrishnan, V Taneja. The role of microbiome in rheumatoid arthritis treatment. Ther Adv Musculoskelet Dis. 2019;11:1759720.Disclosure of Interests:None declared
Variations in oral microbiome profiles in rheumatoid arthritis and osteoarthritis with potential biomarkers for arthritis screening
