Diagnostic performance of salivary gland ultrasonography using the OMERACT scoring system in Sjögren disease: A cross-sectional diagnostic accuracy study.
Hossain Md Ismail MI, Choudhury Minhaj Rahim MR, Majumder Muhammad Shoaib Momen MSM, Shazzad Md Nahiduzzamane MN et al.
Sjögren disease (SjD) is an autoimmune disorder characterized by salivary and lacrimal gland dysfunction. Salivary gland ultrasonography (SGUS) is a non-invasive, accessible imaging modality for assessing glandular structural changes, although its diagnostic performance compared with conventional diagnostic tests requires further evaluation. To evaluate the diagnostic accuracy of OMERACT-scored salivary gland ultrasonography in patients with suspected primary or secondary SjD. This is a cross-sectional diagnostic accuracy study of salivary ultrasonography. This study was conducted in the Department of Rheumatology, Bangladesh Medical University, from February 2023 to February 2024. Patients presenting with sicca symptoms were classified according to the 2016 ACR/EULAR classification criteria, which served as the reference standard. All participants underwent clinical evaluation, Schirmer's test, unstimulated whole salivary flow rate (UWSFR), anti-SSA/anti-SSB antibody testing, and SGUS of the parotid and submandibular glands. SGUS images were scored using the OMERACT semiquantitative grayscale scoring system (0-3 per gland) by a blinded examiner. Diagnostic performance was assessed using sensitivity, specificity, and receiver operating characteristic (ROC) curve analysis. Among 100 participants, 50 fulfilled the 2016 ACR/EULAR classification criteria for SjD. Patients with SjD had significantly higher mean SGUS scores and lower mean UWSFR compared with those without SjD (p < 0.001). An OMERACT SGUS grade ≥2 in at least one gland demonstrated 84% sensitivity and 92% specificity. A total SGUS score ≥4 showed 88% sensitivity and 86% specificity, whereas a score ≥6 provided 100% specificity with reduced sensitivity (64%). SGUS showed excellent diagnostic performance with an area under the ROC curve (AUC) of 0.94 (95% CI: 0.90-0.99). Compared with SGUS, Schirmer's test demonstrated lower diagnostic accuracy (sensitivity 65.3%, specificity 52%), while UWSFR showed high sensitivity (92%) but limited specificity (48%). SGUS score showed a weak positive correlation with disease duration (r = 0.33, p < 0.05). OMERACT-scored salivary gland ultrasonography demonstrated excellent diagnostic accuracy and superior specificity compared with conventional functional tests. SGUS may serve as a valuable non-invasive adjunctive tool in the diagnostic evaluation of patients with suspected SjD.