Diagnostic Performances of Ultrasound Evaluation of Major Salivary Glands According to the 2019 Outcome Measures in Rheumatology Ultrasound Scoring System.

Objective: To evaluate the diagnostic performance of ultrasound examination of the salivary glands (US-SG) according to the 2019 Outcome Measures in Rheumatology (OMERACT) US scoring system for Sjögren's syndrome (SS).

Methods: The present work was a retrospective study based on a multicentric cohort with SS/sicca syndrome. The American College of Rheumatology (ACR)/European Alliance of Associations for Rheumatology (EULAR) 2016 classification criteria for SS (a score of ≥4 without ocular staining score), the American-European Consensus Group (AECG) 2002 classification criteria, and clinician experts were considered as reference standards for diagnosis of SS. An OMERACT score of ≥2 according to 2 independent readers defined the diagnosis of SS based on US-SG assessment. Diagnostic performances and interobserver reproducibility of US-SG were assessed.

Results: Forty-two patients fulfilling the ACR/EULAR 2016 criteria for SS were compared to 30 control subjects with sicca syndrome. Twenty-five patients were diagnosed as having SS according to US-SG evaluation, and they were more frequently observed in the SS group (52.5%) than in the control group (10.0%) (P < 0.001). US-SG showed an area under the curve (AUC) of 0.751 (95% confidence interval [95% CI] 0.621, 0.882) for the diagnosis of SS (ACR/EULAR 2016 classification). The inclusion of US-SG in the ACR/EULAR 2016 classification improved sensitivity (91.5% versus 89.4%) with limited decrease of specificity (96.0% versus 100%) and with an AUC of 0.975 (95% CI 0.945, 1.00). Similar results were observed when US-SG was included in the AECG 2002 classification criteria. Interobserver reproducibility of a score of ≥2 according to the 2019 OMERACT US scoring system for SS diagnosis was good (κ = 0.73 [95% CI 0.64, 0.81]). Histologic lymphocyte infiltration of the minor salivary glands was associated with the OMERACT grading of US-SG.

Conclusion: The present study confirms the good specificity of the 2019 OMERACT US classification measures of US-SG for the diagnosis of SS and its feasibility in daily practice.