Real-World Diagnostic Performance of OMERACT Salivary Gland Ultrasound in Patients Evaluated for Sicca Symptoms.

Abstract

Sjögren disease (SjD) is a systemic autoimmune condition that frequently involves the salivary glands. Salivary gland ultrasound (SGUS) has emerged as a promising noninvasive tool, and the Outcome Measures in Rheumatology (OMERACT) group has proposed a standardized semiquantitative scoring system. The aim of this study was to evaluate the diagnostic accuracy of OMERACT SGUS in routine clinical practice, using the 2016 American College of Rheumatology/European Alliance of Associations for Rheumatology (ACR/EULAR) criteria as the gold standard for diagnosis, and to compare its performance with salivary flow and Schirmer test. A prospective study was conducted including 103 consecutive outpatients referred for dryness evaluation. Two blinded sonographers performed SGUS of parotid glands (PGs) and submandibular glands (SMGs), applying the OMERACT 0-3 scale. Positivity was defined as a score ≥ 2 in at least 1 gland. Among 103 participants, 51 fulfilled the 2016 ACR/EULAR criteria. Overall, SGUS achieved sensitivity of 66.7% and specificity of 76.9%. PG analysis showed high specificity (92.3%) but lower sensitivity (49%), whereas SMGs demonstrated higher sensitivity (58.8%) but lower specificity (78.8%). Schirmer test and unstimulated whole salivary flow rate (UWSFR) showed sensitivities of 49% and 52.9%, respectively. Stimulated whole salivary flow rate had very high specificity (94.2%) but poor sensitivity (17.6%). In patients aged < 40 years, UWSFR sensitivity dropped markedly to 20% (vs age ≥ 40 years: 57.1%), whereas SGUS maintained stable performance. In real-world settings, SGUS using the OMERACT score demonstrates high specificity, particularly in PGs, and moderate sensitivity, outperforming UWSFR in younger patients. These findings support SGUS as a practical adjunct to established diagnostic tests and reinforce its potential role in refining the diagnostic workup of suspected SjD.