A role for these proteins of potential biomarkers for pSS and sSS has been already many hypothesised by previous proteomic studies. In particular, Ryu et al. demon strated a significant increase of b 2 microglobulin and IGKC protein and a reduction of a amylases Inhibitors,Modulators,Libraries precursor and carbonic anhydrase VI in the stimulated parotid sal iva obtained from 41 primary SS patients. A significant reduction of a amylases in pSS was also reported by Peluso and co workers. In the present work, we confirmed the significant decrease of the main spot of a amylases precursor in pSS and sSS with respect to healthy volunteers and non SS sicca syndrome. We also found that the pSS salivary profile was characterised by a peculiar abundance of a amylases precursor frag ments.

We concluded that to a certain extent, the decrease of this acinar protein might be explained by pSS fragmentation processes which have been previously reported as related to an unbalanced expression of pro teases and proteases inhibitors. We also documen ted an increase of IGKC protein, rheumatoid factor D5 light Inhibitors,Modulators,Libraries chain and b 2 microglobulin. As far as b 2 micro globulin is related, Hu S and coworkers identi fied and preclinically validated b 2 microglobulin, cathepsin D, and a enolase as potential biomarkers for pSS. In the current study we were unable to identify cathepsin D. However, in line with the studies by Hu S et al. we found that b 2 microglobulin was sig nificantly increased in pSS. WB and ELISA tests con firmed a trend in the expression of the protein with the highest levels in pSS and the lowest levels in healthy volunteers and a significant association between b 2 microglobulin and antiRo SSA positivity was also found.

The increased expression of this protein in pSS whole saliva might Inhibitors,Modulators,Libraries thus reflect both the systemic B cells activa tion and the increased intra glandular immunoglobulin Inhibitors,Modulators,Libraries synthesis, which are peculiar aspect of the disease. Finally, we also documented an increase in the salivary expression of a enolase in pSS in comparison to healthy controls. In addition, we also found that a enolase was significantly higher in patients with RA sSS with respect to pSS and significantly associated to the positivity for rheumatoid factor. Similar trends were Inhibitors,Modulators,Libraries also reported for lipocalin and for many spots of calgranulin B which showed the highest levels in RA sSS patients. Intriguingly, since increased levels of all these proteins have been already reported in biological fluids of patients with RA without sSS, we speculated that proteomic analysis of whole saliva could represent a novel technique not only for the diagnosis of disorders Vandetanib chemical structure involving salivary glands but also for systemic autoimmune disorders even in the absence of any salivary exocrinopathy.