New developments in Sjögren's syndrome.

Sjögren's syndrome is an autoimmune exocrinopathy with characteristics of both organ-specific and generalized autoimmune disease. The main features are keratoconjunctivitis sicca and xerostomia, but patients may also show signs of extraglandular involvement. Sjögren's syndrome can occur in the absence (primary Sjögren's syndrome) or in the presence of other connective tissue disease (secondary Sjögren's syndrome). Sjögren's syndrome has often been considered a link in the spectrum between autoimmune disease and lymphoproliferative disorders. The cause of Sjögren's syndrome is still unknown, although the role of viruses in the pathogenesis is disputed. There is still no consensus about the diagnostic criteria, due to lack of specificity and sensitivity of the diagnostic procedures performed thus far. Recent studies using immunohistochemical and molecular biologic techniques highly suggest that disturbances in the target organs, such as salivary glands, are the consequence of local processes, rather than the reflection of systemic alterations. This underlines the importance of implementing these techniques for diagnostic purposes. Based on increasing understanding of the pathogenetic processes, new therapeutic possibilities will come into the picture. Over the past few years, interesting studies have contributed to our knowledge of the disease.