Increased risk of periodontitis occurrence in patients with rheumatoid arthritis and its association with the levels of IL-1β and TNF-α in gingival crevicular fluid

Background: Periodontitis (PD) is a chronic inflammatory disease caused by infection of the periodontal supporting tissues. Clinical studies have reported that rheumatoid arthritis (RA) patients have a higher prevalence of PD. This study aimed to explore the correlation between RA and PD. Methods: A total of 307 RA patients (RA group) and 324 healthy individuals (control group) who received physical examinations during the same period were recruited to this study. The incidence of PD in the two groups was analyzed, and the periodontal disease index (PDI) and bleeding on probing (BOP) were recorded. Then, 42 RA patients with PD and 56 control group patients with PD were selected for further analysis. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of interleukin 1 beta (IL-1 beta) and tumor necrosis factor-alpha (TNF-alpha) in the gingival crevicular fluid (GCF) of the two groups. For patients with both RA and PD, the level of serum C-reactive protein (CRP) and the duration of morning stiffness were also recorded. Results: The prevalence of PD in the RA group (51.5%) was significantly higher than that in the control group (31.2%), and the prevalence of PD also increased notably with the increase of age and the duration of the disease in RA patients. The levels of TNF-alpha and IL-1 beta in the PDI and the GCF in the concurrent RA and PD group were significantly higher than those in the PD group (P<0.05). Partial correlation analysis showed that TNF-alpha in the GCF positively correlated with the BOP of patients with RA and PD. Multiple linear regression analysis showed that the level of TNF-alpha in the GCF and serum CRP were independent influencing factors of the level of IL-1 beta in the GCF (the r values were 1.074 and 3.851, respectively; P<0.01). Conclusions: The presence of RA can increase risk of PD occurrence and is positively correlated with the levels of IL-1 beta and TNF-alpha in the GCF.