Saliva: Contribution to Disease Status in Bechet's Disease

Introduction: Severe oral ulceration is a primary manifestation of Behcet's disease (BD), affecting 97-100 % of patients. It is likely that inflammatory cytokines present in the saliva may reflect the inflammatory status of the disease. Objective: To examine the role of saliva in the inflammatory response to BD. Methods: Patients with BD were recruited, under local research ethical approval, from a specialist tertiary clinic run jointly by the Medical Eye Unit, St. Thomas' Hospital and the Dept of Oral Medicine, Royal London Hospital, London. The study was funded by Queen Mary University of London. All patients fulfilled the diagnosis of BD according to International Study Group Criteria (Lancet, 1990). Cellular assays were performed using fifteen patients with BD (F/M: 7/8) and 16 healthy controls (HC) (F/M: 8/8). Effects of fresh serum and saliva on mucosal epithelial (SVpgC2a) and inflammatory monocyte cell lines (MM6) were measured by cellular proliferation (MTT assay) and cytokine responses (ELISA). Multiplex analysis for intrinsic expression of cytokines and growth factors was also performed on 40 BD patients and 10 healthy controls. Further analysis are surrently being carried out by this method. Results: Saliva, but not serum, dramatically stimulated epithelial cell proliferation, with HC producing marked increases over BD saliva (p<0.0001). Of all cytokines assayed (IL-1£\, IL-6, IFNƒ×, IL-12, IL-15), IL-1£\ and IL-6 showed the most striking results. IL-1£\ expression was significantly higher in BD than HC saliva in MM6 cells (p=0.002). IL-6 expression was increased by saliva compared to serum (P< 0.0001). Endogenous IL-6 levels were significantly greater in saliva than serum of BD patients (P<0.001). Multiplex analysis demonstrated increases in inflammatory cytokines (specifically IL-6), with significant decreases in growth factor expression (VEGF, PDGF) in BD patients. Conclusion: The saliva may be crucial to understanding oral immunity in BD and other systemic diseases.