Level of Interleukin‐35 in Gingival Crevicular Fluid, Saliva, and Plasma in Periodontal Disease and Health

Background: A novel member of the interleukin (IL)‐12 family, IL‐35 is an important inhibitory cytokine released by regulatory T cells. The aim of this study is to evaluate gingival crevicular fluid (GCF), saliva, and plasma levels of IL‐35 in periodontal disease and health. Methods: Samples of GCF, whole saliva, and plasma were obtained from systemically healthy, non‐smoking individuals with gingivitis (n = 20) or chronic periodontitis (CP) (n = 20) and periodontally healthy individuals (n = 20). Full‐mouth clinical periodontal measurements, including probing depth (PD), bleeding on probing, gingival index, and plaque index (PI), were also recorded. Enzyme‐linked immunosorbent assay was used to determine IL‐35 levels in the samples. Data were tested statistically by analysis of variance and Pearson rank correlation test. Results: All clinical parameters were significantly higher in the CP group than the healthy and gingivitis groups (P