Sjogren Syndrome (SS) is a chronic inflammatory systemic autoimmune disease characterized by lymphocytic infiltration of the exocrine glands leading to sicca symptoms of the eyes and mouth. Several systemic and extraglandular manifestations can develop, including fatigue, arthritis, and involvement of organs such as the skin, lungs, and kidneys. SS may occur as a primary disorder or in association with other systemic autoimmune diseases, traditionally defined as secondary SS, such as rheumatoid arthritis, and systemic lupus erythematosus. Salivary secretions from these patients exhibit elevated levels of antibodies and cytokines. This is accompanied by a reduction in oral phosphate levels and xerostomia due to reduced salivary flow, which can lead to infections, progressive caries, dysphagia and oral pain. Current tests for SS include sialometry, salivary scintigraphy, sialography, serological tests or minor salivary gland biopsies. Recently, salivary biomarkers of SS has been investigated. The etiology of SS is still unclear. Since there is a familial aggregation of primary SS, however, genetic factors have been suspected for a long time. Initially, HLA haplotypes were shown to be associated with primary SS. Recently, polymorphisms in the genes IRF5 and STAT4 have been convincingly identified and replicated in several studies as susceptibility factors.
