Interleukin-6, -17, and -35 levels in association with clinical status in stage III and stage IV periodontitis: a cross-sectional study.

Background: This study compared the concentrations of interleukin (IL)-6, IL-17, and IL-35 in the gingival crevicular fluid of periodontally healthy participants with individuals who had stage III and IV periodontitis.

Methods: In total, 60 participants with stage III grade B-C (n = 12)-stage IV grade C (n = 18) periodontitis and 30 healthy controls were included in this cross-sectional study. Full-mouth clinical periodontal measurements were performed. Concentrations of IL-6, IL-17, and IL-35 were determined using enzyme-linked immunosorbent assays. Parametric/nonparametric methods, Pearson's/Spearman's correlation, and logistic regression methods were used for data analyses.

Results: The periodontitis group exhibited significantly higher levels of IL-6, IL-17, and IL-35 compared with the healthy group (p < 0.001). IL-17 levels had a positive correlation with pocket depth (PD) (r = 0.395; p = 0.031) in the periodontitis group. IL-6, IL-17, and IL-35 levels were associated with periodontitis (odds ratio [OR] = 1.344, 95% confidence interval [CI] = 1.159-1.56; OR = 1.063, 95% CI = 1.025-1.102; OR = 1.261, 95% CI = 1.110-1.434, respectively) (p < 0.001, p = 0.001, p < 0.001, respectively). Full-mouth and sampling sites PD and clinical attachment loss (CAL) values were significantly higher in the periodontitis group than in the healthy group (p < 0.001).

Conclusions: This study revealed upregulated levels of IL-6, IL-17, and IL-35 in periodontitis patients compared to healthy individuals. IL-17 shows a correlation with increased PD. These findings suggest a potential association between these cytokines and severe and advanced periodontitis.

Trial Registration: The trial was registered in ClinicalTrials.gov with this identifier NCT05306860 on 24/01/2022.