Salivary IL-6 levels in chronic periodontitis patients with and without oral squamous cell carcinoma: A comparative cross-sectional study at khartoum dental teaching hospital, 2016–2017

Periodontal disease is an inflammatory disease that affects periodontal tissue, such as the gingiva, periodontal ligament and alveolar bone. Recently, a link between periodontal disease, oral cancer and inflammation has been suggested. In this study, the concentration of the inflammatory cytokine salivary IL-6 was measured to determine its role in the inflammatory process of periodontitis and oral squamous cell carcinoma. An analytical cross-sectional study was conducted at the Khartoum Dental Teaching Hospital, Sudan. Three study groups were enrolled with their consent: patients diagnosed with chronic periodontitis with at least two interproximal sites showing clinical attachment loss > 4 mm and pocket depth > 5 mm. (n = 32); patients with chronic periodontitis and oral squamous cell carcinoma (OSCC) pathology reports of OSCC at the time of saliva collection (n = 22); and matched healthy controls (n = 30). Patients were excluded if they had any chronic inflammatory condition or disease; had a history of recent trauma, acute infection, burns, laceration, previous surgery, chemotherapy, or radiotherapy; had used antibiotics within the previous three months; had a history of periodontal treatment within the previous three months; were pregnant or lactating; were taking drugs that induce hyposalivation; or had a history of previous radiation therapy to the head and neck area. A trained dentist clinically examined the participants. Periodontal parameters (plaque index, bleeding on probing, probable pocket depth and clinical attachment level) were measured, and the IL-6 concentration in the saliva samples was measured via enzyme-linked immunosorbent assay. A statistically significant difference in periodontal parameters was observed between the OSCC patient group and the other groups. OSCC patients had significantly greater IL-6 concentrations in their saliva (log 2.40 ± 0.37) pg/ml) than did chronic periodontitis patients (CP) (log 1.42 ± 0.418 pg/ml) and healthy controls (log 1.25 ± 0.13 pg/ml) (P < 0.001). High salivary IL-6 levels suggest potential utility as a biomarker for OSCC unconfounded by chronic periodontitis.