Minor salivary glands Ultra High-Frequencies Ultrasonography (UHFUS): a new tool for improving the diagnostic work-up in Sjögren’s syndrome

The purpose of this study is to evaluate the role of High-Frequencies Ultrasonography (UHFUS) of minor salivary glands in the diagnosis of Sjögren’s syndrome (SS). 32 consecutive patients with suspected SS were enrolled between January and June 2018. All patients underwent to antibodies Ro/SSA, Unstimulated Salivary Flow Rate (USFR), Schirmer’s test and Lissamine green test, conventional major salivary glands ultrasound by using 10 MHz probe, UHFUS by using VEVO MD ultrasound equipped with a 70 MHz probe, and marked biopsy of minor salivary glands. In 14 out of 32 subjects the diagnosis of SS was confirmed. The remaining 18 subjects represented symptomatic controls. Statistically significant difference in central and peripheral UHFUS inhomogeneity in SS versus symptomatic controls was observed (p=0.04), with a fair concordance between the two (Cohen’s k=0.396). The glandular inhomogeneity detected by UHFUS was characterized by a sensitivity, specificity, PPV and NPV that were comparable to the anti-Ro/SSA antibodies, although conventional ultrasound of major salivary glands showed a higher specificity than UHFUS. By using UHFUS, moreover, the percentage of biopsies with an area ≥ 4 mm² raised from 50% up to 100% during the study period. Conclusion: UHFUS of minor salivary glands represents a new and promising tool to optimize the diagnosis of SS