Current and future challenges in primary Sjögren's syndrome

Sjögren's syndrome (SS) is an autoimmune inflammatory disorder of exocrine glands. SS particularly affects the lacrimal and salivary glands. Dry mouth and dry eyes are frequently proffered as presenting symptoms, but nonspecific symptoms such as malaise and fatigue, and extraglandular manifestations like purpura, polyneuropathy and arthritis are also often present. Moreover, lymphomas develop in about 7.5% of SS patients, mostly marginal zone B-cell lymhomas. Futhermore, SS has a very substantial impact on the patients' quality of life and their daily activities. Recently, many breakthroughs have been seen in salivary diagnostics, which not only can be used for diagnosis but also for monitoring of disease activity and disease progression as well as for objectively scoring the effect of intervention treatment with biologicals. In addition, salivary proteomics, genomics and system biology have been shown to be very promising tools in unravelling the pathophysiology of SS, thus providing in depth insight in its underlying mechanisms which could give clues for intervention therapies with biologicals. The latter is of particular interest as B cell depletion therapy has been shown a very promising therapy for a subgroup of SS patients. When applying salivary diagnostics in combination with instruments to rate disease activity and progression in SS, one might be able to select those SS patients who respond to a particular type of biological. These topics are addressed in this review and promises for the near future are described.