Decreased Serum and Salivary Levels of Aquaporin 5 in Oral Lichen Planus

ABSTRACTObjectivesOral lichen planus (OLP) is an autoimmune disease with unknown etiology. Many OLP patients complain of xerostomia, and studies are still ongoing to find the reason for this manifestation. Aquaporin 5 has been expressed in salivary glands, and its physiological significance in transferring water as transcellular is properly identified. In this study, for the first time, we have investigated the serum and salivary levels of aquaporin 5 (as a salivary gland biomarker) in oral lichen planus patients with xerostomia.Material and MethodsThirty patients with OLP and xerostomia and 30 healthy individuals were chosen. The flow of stimulatory and non‐stimulatory saliva was calculated, and the serums, in addition to salivary levels of aquaporin 5, were determined.ResultsThe level of Aquaporin 5 in serum and its output in stimulatory, and non‐stimulatory saliva were significantly decreased, the stimulatory and non‐stimulatory saliva flow was reduced, and the degree of xerostomia was significantly higher in the OLP group.ConclusionsAquaporin 5 is implicated in OLP patients in several ways such as impaired salivary functioning, xerostomia or dry mouth, diminished repair ability of the mucosal lesion, increased apoptosis, and probable carcinogenesis in this premalignant lesion.