Objective: Salivary gland ultrasonography (SGUS) has been applied in the diagnosis of Sjögren's syndrome (SS). The aim of this study is to investigate the association of SGUS findings with clinical, histological, and serologic features of SS.
Methods: A total of 104 patients with suspected SS underwent SGUS for evaluation of salivary gland involvement. Patients with primary SS were determined according to the classification criteria for SS. The parenchymal inhomogeneity of bilateral parotid and submandibular glands was graded from 0 (homogeneity) to 4 (gross inhomogeneity). Receiver operating characteristic curve analysis was performed to compare the diagnostic performance of different SGUS scoring methods. Clinical and serologic features were compared between groups classified by SGUS score. The association between SGUS and these features of SS was explored by multivariable linear regression analysis.
Results: Study participants were predominantly women (96.2%) and had a mean age of 54.1 years. Eighty-seven patients and 88 patients with primary SS were identified based on AECG criteria and ACR/EULAR classification criteria for SS, respectively. Among the different scoring methods, the sum of the grades of four salivary glands (range 0-16) had the best diagnostic performance, with sensitivity of 77.3% and specificity of 87.5% (cutoff value, 7) for distinguishing primary SS from sicca non-SS. SGUS score was associated with focus score in labial salivary gland biopsy (β = 0.240, p = 0.033) and anti-Ro/SSA serology (β = 0.283, p = 0.016) and inversely associated with unstimulated whole salivary flow (β = -0.298, p = 0.011).
Conclusion: Ultrasonography of major salivary glands is associated with histopathology of minor salivary glands, serology of SS, and salivary gland function.