Salivary electrophoresis in the diagnosis of Sjögren's syndrome

Objective. The purpose of this study was to investigate the potential use of salivary electrophoresis for the diagnosis of Sjögren's syndrome. Methods. Salivary protein profiles of 43 patients and 39 healthy control subjects were compared on three different gel electrophoresis systems: sodium dodecylsulfate-polyacrylamide gel electrophoresis, anionic polyacrylamide gel electrophoresis, and immobilized pH gradient gel electrophoresis (isoelectric point, 3.5-5.0). Results. Most of the patients with Sjögren's syndrome exhibited an electrophoretic profile that was different from that of the healthy control subjects. Among the three gel electrophoresis systems examined, the immobilized pH gradient system appeared to be the most reliable for Sjögren's syndrome. Tests of accuracy revealed that the immobilized pH gradient system exhibits high specificity (97%), sensitivity (95%), positive predictive value (97%), and negative predictive value (95%) in the diagnosis of Sjögren's syndrome. Conclusions. Our results suggest that salivary electrophoresis is a potentially useful test for the diagnosis of Sjögren's syndrome.