Association of Human Interleukin-35 Level in Gingival Crevicular Fluid and Serum in Periodontal Health, Disease, and after Nonsurgical Therapy: A Comparative Study

BACKGROUND: Innovating newer methods to diagnose a multifactorial disease such as periodontitis is always challenging for a clinician. Gingival crevicular fluid (GCF) which is closely associated with the periodontal tissue environment has been used a viable alternative to saliva for the diagnosis of periodontitis. AIM: The aim of the present study was to estimate and compare the interleukin-35 (IL-35) levels in GCF and serum among healthy, gingivitis, and chronic periodontitis (CP) individuals as well as to evaluate the effect of nonsurgical periodontal treatment (NSPT) on IL-35 level among patients with CP. SETTINGS AND DESIGN: The study was conducted at the Department of Periodontics, Srirama Chandra Bhanja Dental College and Hospital, Cuttack, Odisha, India. It is a comparative study. MATERIALS AND METHODS: A total of 60 participants were divided into healthy (Group I; n = 20), gingivitis (Group II; n = 20), and CP (Group IIIA; n = 20). GCF samples collected from each individual at baseline and 6 weeks after NSPT for Group III individuals (Group IIIB; n = 20) were quantified for IL-35 levels using enzyme-linked immunosorbent assay. STATISTICAL ANALYSIS: All analyses were performed using Shapiro–Wilk test, analysis of variance, Tukey's honestly significant difference post hoc test, and multiple regression analysis. RESULTS: The mean IL-35 concentration in GCF was significantly high (P < 0.05) for Group IIIA (70.26 ± 4.0 pg/ml), as compared to Group I (54.81 ± 22.3 pg/ml) and Group IIIB (55.72 ± 10.2 pg/ml). CONCLUSION: In the present study, GCF and serum IL-35 concentration among CP individuals was highest among all the groups. Individuals receiving NSPT showed a significant reduction in IL-35 levels as compared to CP individuals.