Periodontitis and Porphyromonas gingivalis in preclinical stage of arthritis patients

Abstract

Purpose: To determine whether the presence of periodontitis (PD) and Porphyromonas gingivalis (Pg) in the subgingival biofilm associates with the development of rheumatoid arthritis (RA) in treatment naïve preclinical stage of arthritis patients.

Methods: We conducted a prospective cohort study of 72 consecutive patients with arthralgia who had never been treated with any anti-rheumatic drugs or glucocorticoids. Periodontal status at baseline was assessed by dentists. PD was defined stringently by the maximal probing depth≧4 mm, or by the classification by the 5th European Workshop in Periodontology (EWP) in 2005 using attachment loss. Up to eight plaque samples were obtained from each patient and the presence of Pg was determined by Taqman PCR. The patients were followed up for 2 years and introduction rate of methotrexate (MTX) treatment on the diagnosis of RA was compared in patients with or without PD or Pg.

Results: Patients with PD (probing depth≧4mm) had higher arthritis activity (p = 0.02) and higher risk for future introduction of MTX treatment on the diagnosis of RA during the follow up than patients without PD (Hazard ratio 2.68, p = 0.03). Arthritis activity and risk for MTX introduction increased with the severity of PD assessed by EWP, although not statistically significant. On the other hand, presence of Pg was not associated with arthritis activity (p = 0.72) or the risk for MTX introduction (p = 0.45).

Conclusion: In treatment naïve arthralgia patients, PD, but not the presence of Pg, associates with arthritis activity and future requirement of MTX treatment on the diagnosis of RA.

Fig 1. Hazard ratio for methotrexate treatment introduction during the follow up period.

The patients were divided into two groups based upon the diagnosis of PD (maximal probing depth ≧ 4 mm) (a), three groups based upon the severity of PD (EWP) (b), or two groups based upon the presence of P. gingivalis in subgingival biofilm (c). MTX treatment introduction in each groups were compared by cumulative hazard method. X axis indicates days for MTX treatment introduction after the first visit. Y axis indicates the cumulative hazard ratio for MTX introduction. Hazard ratio of positive PD (probing depth≧4mm) vs negative PD was 2.68 (95% CI, 1.11–6.50), p = 0.03. Hazard ratio of severe PD (EWP) vs non PD (EWP) was 7.26 (95% CI, 0.75–69.9), p = 0.09, and hazard ratio of moderate PD vs non PD was 4.42 (95% CI, 0.60–32.4), p = 0.15. Hazard ratio of positive Pg vs negative Pg was 0.77 (95% CI, 0.39–1.53), p = 0.45.