Cytokines in gingivocrevicular fluid of rheumatoid arthritis patients: A review of the literature

OBJECTIVE: Rheumatoid arthritis (RA) and periodontitis share several pathological features including bone and soft tissue destruction and high levels of circulating inflammatory proteins. Studies related to cytokines in the periodontal inflammatory exudate (gingivocrevicular fluid, GCF) of RA patients might provide insight into the association between periodontitis and RA. The aim of our study was to review the literature on cytokines in GCF of RA patients including the effect of anti‐rheumatic treatment with biological disease‐modifying anti‐rheumatic drugs (DMARDs) and periodontal treatment on these cytokines. MATERIALS AND METHODS: MedLine/PubMed searches with different combinations of keywords “rheumatoid arthritis or RA” and “crevicular fluid or GCF” until June 2019 revealed 64 articles. Ten cross‐sectional observational studies and nine treatment studies fulfilled the inclusion criteria. RESULTS: Rheumatoid arthritis patients have increased circulating and GCF levels of pro‐inflammatory cytokines and proteins, despite anti‐rheumatic treatment with biological DMARDs. Presence of periodontitis was accompanied by higher cytokine and protein levels. Treatment of periodontitis resulted in a decrease of these levels. CONCLUSION: Analysis of GCF of RA patients reveals that the relationship between periodontitis and RA is bidirectional, probably caused by a non‐specific inflammatory burden. Data for a specific relationship are barely present in GCF.