Proteomic analysis of the saliva: a clue for understanding primary from secondary Sjögren's syndrome?

The clinical entity of secondary Sjögren's syndrome (SS) is controversial and the relationship with primary SS and other systemic autoimmune diseases is still far from being completely understood. In the last few years, proteomic approaches have been applied with a growing interest in the search for diagnostic biomarkers for many rheumatic diseases and it is possible that, in the near future, proteomic analysis of human saliva could help in distinguishing also primary from secondary SS. This review summarizes the state of the art of proteomic analysis of human saliva in the diagnosis of connective diseases focusing its advantages, limits and future perspectives.