PURPOSE: This study evaluates the effectiveness of lacrimal gland ultrasonography (LGUS) and shear wave elastography (SWE) in distinguishing primary Sjögren's syndrome (PSS) patients from healthy controls and examines their role in assessing disease activity and prognosis. METHODS: A total of 35 PSS patients and 23 age- and gender-matched healthy controls were included. LGUS was used to grade lacrimal gland structure, while SWE assessed gland elasticity. Disease activity and prognosis were evaluated using european league against rheumatism sjögren's syndrome disease activity index (ESSDAI) and serologic markers. RESULTS: Compared with healthy controls, LGUS, Emean, and shear wave velocity (SWV) were significantly higher in PSS patients. The optimal cut-off value of LGUS for diagnosis of PSS was 2 (area under the curve [AUC]: 0.832, sensitivity: 80.0%, specificity: 69.6%), the optimal thresholds for diagnosis of PSS using Emean and SWV values are 9.4 kPa (AUC: 0.768, sensitivity: 65.7%, specificity: 82.6%) and 1.7 m/s (AUC: 0.823, sensitivity: 71.4%, specificity: 91.3%), respectively. There are statistical differences in Emean and SWV between subgroups based on european league against rheumatism sjögren's syndrome disease activity index (ESSDAI)
there are statistical differences in LGUS, Emean, and SWV between subgroups based on IgG levels and complement titers. CONCLUSION: LGUS and SWE are accurate, noninvasive diagnostic tools for PSS and may serve as indicators of disease activity and prognosis.