Salivary Expression of S100A7/Psoriasin and Oral Damage in Primary Sjögren's Syndrome and Overlapping Disorders.

S100A7/psoriasin, a protein belonging to the S100A family of Ca2+ binding proteins, is known to exhibit an antimicrobial activity but it has also been implicated in the regulation of cell proliferation, differentiation, invasion and metastasis. By using a proteomic approach, S100A7/psoriasin has been recently identified in the whole saliva of patients with Systemic Sclerosis as a potential disease biomarker. The aim of the present study were : 1) to compare the expression of salivary S100A7/psoriasin in patients with Sjogren's Syndrome associated to anti-centromere antibodies (ACA) positive Systemic Sclerosis (SS-SSc) versus patients with primary Sjogren's Syndrome (pSS) and 2) to explore any correlation between salivary S100A7/psoriasin and oral damage. S100A7/psoriasin levels were significantly higher in SS-SSc subjects; S100A7/psoriasin salivary levels negatively correlated with the unstimulated salivary flow (USF) rate; The salivary expression of the protein was significantly associated with the Sjogren's Syndrome disease damage index and specifically with the complete loss of teeth. In conclusion, salivary S100A7/psoriasin might be useful in differentiating pSS from SS-SSc and seems to be able to reflect oral damage in both pSS and SS overlapping disorders.