AB0468 COMPARISON OF THE DIAGNOSTIC PERFORMANCE OF SALIVARY GLAND SCINTIGRAPHY AND ULTRASOUND IN SJÖGREN’S SYNDROME

Abstract

BackgroundThe 2002 American-European Consensus Group (AECG) criteria included salivary gland scintigraphy (SGS) as one of the possible objective methods for assessing salivary gland involvement in primary Sjögren’s syndrome (pSS). However, this test as well as the sialography were not included in the 2016 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) criteria and considered obsolete. On the other hand, salivary gland ultrasound (SGUS) is a simple and non-invasive procedure that is readily available and provides important information on the major salivary glands. Several recent studies have assessed SGUS as a tool for diagnosing pSS.ObjectivesTo compare the diagnostic performance of SGS and SGUS for pSS patients.MethodsWe included 63 patients with sicca symptoms and suspected pSS. Diagnosis of pSS was established following the 2002 AECG criteria. The patients’ scintigraphic grade was determined according to Schall classification (I-IV scale) [1], establishing Schall grade ≥III (moderate functional impairment) as the cut-off. We considered SGUS score based on parenchymal homogeneity, presence of hypoechogenic areas, and clearness of posterior glandular border of salivary glands. The score of the highest graded gland was considered, and a score ≥2 was defined as a positive SGUS, according to OMERACT US-SG scoring [2]. The area under the receiver operating characteristic (ROC) curve was employed to evaluate the screening method’s performance.ResultspSS was diagnosed in 40 (63%) patients, and the remaining 23 sicca subjects (37%) constituted the control group. Abnormal SGS was established in 26/40 (65%) pSS patients and 10/23 (43%) controls. Positive SGUS was established in 24/40 (60%) pSS patients and 6/23 (26%) controls. Thus, the sensitivity and specificity of SGS were 65% and 57%, respectively, and 60% and 74% for SGUS, respectively. The area under the ROC curve (Figure 1) of scintigraphy was 0.73, while for the SGUS was 0.83.Figure 1.ROC curve comparison of SGS and SGUS for the diagnosis of pSS.ConclusionThe diagnostic accuracy of SGUS is not only comparable with scintigraphy in pSS patients but also results in a better performance. This result indicates that SGUS is a useful method for evaluating salivary gland involvement in pSS and could be an alternative tool to other diagnostic techniques, such as SGS.References[1]Schall GL, Anderson LG, Wolf RO, Herdt JR, Tarpley TM Jr, Cummings NA, et al. Xerostomia in Sjögren’s syndrome. Evaluation by sequential salivary scintigraphy. JAMA. 1971 28;216(13):2109-16.[2]Jousse-Joulin S, Coiffier G. Current status of imaging of Sjogren’s syndrome. Best Pract Res Clin Rheumatol. 2020;34(6):101592.Disclosure of InterestsNone declared