Serum Cytokine and Periodontal Profiles in Relation to Disease Activity of Rheumatoid Arthritis in Japanese Adults

Abstract

Background: Rheumatoid arthritis (RA) and periodontitis are common chronic inflammatory conditions and share many pathologic features. A similar profile of cytokines is involved in the pathogenesis of the two diseases. The relationship between the disease activity of RA and the periodontal condition remains unclear. This study examines whether the disease activity of RA affects serum cytokine and periodontal profiles. Methods: The study subjects consisted of 84 Japanese adults with RA and 22 race‐matched control individuals. After periodontal and rheumatologic examination, the disease activity of RA was determined with the Disease Activity Score including 28 joints using C‐reactive protein (DAS28‐CRP). Serum levels of cytokines including interleukin (IL)‐1β, IL‐6, IL‐12, IL‐12 p40, IL‐18, and tumor necrosis factor‐α (TNF‐α) were determined by an enzyme‐linked immunosorbent assay. High‐sensitive CRP was also measured with a latex particle‐enhanced nephelometric method. Results: Of 84 patients with RA, 28 and 56 patients exhibited low and moderate to high disease activity, respectively. Serum levels of IL‐6, TNF‐α, and CRP were significantly different between the two groups (P <0.05). Additionally, a significant correlation was observed between DAS28‐CRP and percentage of sites with bleeding on probing (BOP) (P = 0.008) and between serum TNF‐α levels and percentage of sites with BOP (P = 0.01) in 56 patients with RA with moderate to high activity. Conclusion: These results suggest that the disease activity of RA correlated with serum levels of IL‐6, TNF‐α, and CRP, and it might influence BOP in the patients with moderate to high disease activity.