To evaluate the diagnostic performance of ultrasound examination of the major salivary glands (US-SG) according to the 2019 OMERACT US scoring system for Sjogren's syndrome (SS).
This was a retrospective study based on a multicentric cohort of SS/sicca syndrome. ACR/EULAR 2016 (≥ 4 without OSS), AECG 2002 and clinician experts were considered as reference standards for SS diagnosis. An OMERACT score ≥ 2 according to 2 independent readers defined the diagnosis of SS based on US-SG assessment. Diagnostic performances and Inter-observer reproducibility of US-SG were assessed.
Forty-two patients fulfilling the ACR/EULAR 2016 criteria for SS were compared to 30 controls with sicca syndrome. Twenty-five patients were diagnosed with SS according to US-SG evaluation, they were more frequently included in the SS group (52.5%) than in controls (10.0%) (p < 0.001). US-SG showed AUC of 0.751 (0.621-0.882) for the diagnosis of SS (ACR/EULAR 2016 classification). The inclusion of USSG in the ACR/EULAR 2016 classification improved Se (91.5% vs 89.4%) with limited decrease of Sp (96.0% vs 100%) and with an AUC of 0.975 (0.945-1.00). Similar results were observed when USSG was included in the AECG 2002 classification. Inter-observer reproducibility of the 2019 OMERACT US scoring ≥ 2 for SS diagnosis was good (k =0.73 (0.64-0.81)). Histological lymphocyte infiltration of the minor salivary glands was associated with the OMERACT grading of US-SG.
This study confirms the good specificity of the 2019 OMERACT US classification of US-SG for the diagnosis of SS and its feasibility in daily practice.