Background/Purpose: Rheumatoid arthritis (RA)
outcomes have improved substantially due to the development of new drug
therapies, but also due to emphasis on early aggressive MTX therapy. Although
MTX monotherapy is highly effective in approximately one-third of patients, a
majority require additional treatment to achieve optimal disease control. Despite
growing evidence suggesting a link between periodontitis (PD) and RA
pathogenesis there are limited investigations examining whether PD impacts
treatment response. This study explores the relationship between PD, smoking,
and treatment response to MTX in early RA.

Methods: This is a 16-week, open-label prospective
study of RA patients with active disease defined as ≥ 4 swollen and
tender joints.  Patients completed a questionnaire at enrollment that included
items detailing their history of PD: 1. Have you been told you have periodontal
disease? 2. Have you required deep cleaning or scaling? 3. Have you been seen
by a periodontist? At the initial visit, patients were started on MTX 15 mg
weekly. Repeat evaluation at 8 weeks was performed; if patients were not in remission
as defined by a DAS28- ESR < 2.6, MTX was increased to 20 mg weekly for the
remainder of the study. The primary outcome of this analysis was achievement of
low disease activity, defined as a DAS-28 < 3.2 at week 16. For this pilot
study, associations of patient factors with treatment response were examined
using unadjusted-logistic regression.

Results: Eighty-five RA patients have completed the
study and were included in this analysis; 89% were Caucasian and 75% were
women. After 16 weeks, 43 (51%) patients achieved a DAS-28 < 3.2. Factors
associated with better MTX response included male gender (OR 4.4; 95% CI
1.4-13.8) and prior evaluation by a periodontist (OR 4.0; 95% CI 1.3-13.4)
(Table). There was no association of MTX treatment response with other factors
examined including age, disease duration, and known PD risk factors including
smoking or diabetes. There was no association of “known PD” or “a requirement
of deep cleaning” with treatment response.

Conclusion: Results of this pilot study suggest a
potential correlation between periodontal disease evaluation and RA treatment
response with those reporting prior care from a periodontist being more than
4-times as likely to achieve low disease activity with MTX use. These
preliminary findings suggest that PD treatment could be an important component
in a comprehensive approach to treating early RA with MTX. Further information
is required to confirm these results in a larger patient population and to
evaluate if the timing of PD treatment or whether specific oral pathogens or
other factors that may be affected by periodontal disease alter MTX response.

Baseline Patient Characteristics and Associations with
Achieving Low Disease Activity (n = 90)