Anti-CCP Positive Early Rheumatoid Arthritis Clinical Trial
Official title:
Assessment of the Effect of an Intervention (Periodontal Scaling + Mouthwash + Toothpaste) to Reduce the Load on Oral Bacterial Activity of Rheumatoid Arthritis: a Randomized Trial Nested in the Cohort ESPOIR
The purpose of this study is to assess the impact of an intervention (scaled every 06 months associated with the use of mouthwash with essential oils (toothpaste and Listerine® 2 times / day containing polymer Triclosan (Colgate Total®)) on the activity of rheumatoid arthritis
Introduction: Several epidemiological studies have suggested that a link between periodontal
disease and rheumatoid arthritis. In cohorts, the risk of development of rheumatoid arthritis
is increased in subjects with periodontal disease. The main bacterium implicated in chronic
periodontal disease is Porphyromas gingivalis, a commensal microorganism of the mouth. P.
gingivalis is the only microorganism with a deiminase capable of transforming arginine into
citrulline, and is suspected of to play a major role in the production of anti-citrulline
antibodies, the principal diagnostic marker of rheumatoid arthritis.
Hypotheses: The regular professional and individual plaque control in patients with
rheumatoid arthritis (standard of care) - i.e. decreasing oral bacterial load, including P.
gingivalis - reduces the activity of rheumatoid arthritis Principal objective: To assess the
impact of professional periodontal scaling every 6 months combined with the individual plaque
control, i.e. toothbrushing plus the use of mouthrinses on rheumatoid arthritis activity.
Methodology: The trial design is innovative and based on random selection of a sample of
patients in an observational cohort of patients as described in the recent publication
"Cohort Multiple Randomised Controlled Trials Design" (Ref.: BMJ 2010; 340: c1066). A
randomly selected sample of eligible patients from the cohort will be asked to take part in
the study. Changes in the randomised sample will be compared to those of other potentially
eligible patients from the cohort. The cohort used will be the ESPOIR cohort, a cohort
including 813 patients who initially presented with early undifferentiated polyarthritis that
developed into rheumatoid arthritis with anti-citrulline antibodies in approximately 40 to
50% of cases.
Procedures studied: Periodontal scaling every 6 months and twice daily use of a mouthwash
containing essential oils (Listerine®) plus a triclosan/copolymer toothpaste (Colgate
Total®).
Sample size calculation: The principal assessment criterion is DAS variations at 1 year. The
expected statistical power is 80% (the type I risk being set at 5%) and the standard
deviation common to the two samples for DAS variation is evaluated at 1.5. With these
hypotheses, the inclusion of 100 patients in the study group and 100 patients in the control
group will produce an effect size of 0.40 (i.e. a difference in DAS between the two groups
equal to 0.6).
Statistical analysis: A linear, mixed-effects model will be used to compare DAS variations
between the two groups. In addition, the Mixed Model for Repeated Measurements (MMRM) based
on a linear mixed model will include two other random effects, i.e.: the centre effect and
the centre*treatment interaction effect, which will be used to measure heterogeneity between
the centres and heterogeneity of the effect of the procedure. Finally, propensity scores with
adjustment by weighting will be used to take into account any potential imbalances between
the two study arms.
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