Relationship between interleukin-6 levels in gingival crevicular fluid and periodontal status in patients with rheumatoid arthritis and adult periodontitis

Background: The aim of this study was to determine and compare interleukin-6 (IL-6) levels in gingival crevicular fluid (GCF) and clinical periodontal findings in patients with rheumatoid arthritis (RA) and adult periodontitis (AP). Methods: A total of 45 patients divided into 3 groups (15 patients with RA and AP, 15 patients with AP, and 15 periodontally healthy subjects) were included in this study. Plaque index (PI), gingival index (GI), sulcus bleeding index (SBI), probing depth (PD), and attachment level (AL) values for each patient were recorded. Enzyme-linked immunosorbent assay for quantitative detection of IL-6 in each GCF sample was employed. Results: No significant difference could be detected between the RA and AP groups in the mean clinical parameter data except PI. Although the mean GCF IL-6 level in the RA group was the highest, no significant difference could be found among the groups. There was only a strong negative correlation between GCF IL-6 levels and GI scores in the RA group. Conclusions: In the patients with RA, despite increased local tissue destruction potential due to autoimmunity and higher PI levels than in the AP patients, our findings suggest that medication including corticosteroid and non-steroidal anti-inflammatory drugs may decrease gingival inflammation, but the synthesis and degradation of IL-6 in gingival tissue of RA patients may be different. To our knowledge, this study is the first report determining GCF IL-6 levels in RA patients.