AB0864 USEFULNESS OF SALIVARY GLAND ULTRASONOGRAPHY IN SJÖGREN’S SYNDROME: THE TUNISIAN EXPERIENCE
Authors: R. Bourguiba, S. Bellakhal, M. Boudokhane, W. Helali, M. Charfi, K. Bouzaidi
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Primary Sjögren's syndrome (pSS) is characterized by the presence of sicca syndrome. Confirmation of pSS requires immunological testing and biopsy of the accessory salivary glands. Sjögren's syndrome is classified according to weighted criteria (ACR/EULAR 2016): salivary gland biopsy and laboratory immunological testing are the most weighted criteria. Salivary gland ultrasonography (SGUS) allows the detection of structural changes in the salivary glands and has been proposed as a reliable tool to assess major salivary gland involvement in patients with pSS. Recently, a new semi-quantitative score has been validated by experts: The OMERACT US score to assess salivary gland involvement in pSS [1] <h3>Objectives:</h3> The aim of our study was to evaluate the usefulness of the SGUS as a tool for the diagnosis of pSS using the OMERACT score in a Tunisian cohort. <h3>Methods:</h3> All patients referred for sicca syndrome during the last period June 2022-December 2023 were enrolled. All underwent measurement of salivary flow, minor salivary gland biopsy, ophthalmological examination for dry eye syndrome, SSA antibody. SGUS was performed for all included patients. Both parotid glands and submandibular glands were exanimated using the scoring system 0-3 (OMERACT). Numeric variables were expressed as mean (±SD) and discrete outcomes as absolute and relative (%) frequencies. We created 2 groups according to the values of Sjögren. Discrete outcomes were compared with chi-squared or Fisher's exact test accordingly. Statistical analysis was performed with EasyMedStat (version 3.30.2; www.easymedstat.com). We used Receiver-Operating-Characteristic curves to assess the ability to predict Sjögren's syndrome according to the highest ultrasonography score. The area under the curve and 95% confidence intervals were calculated. <h3>Results:</h3> We enrolled 94 patients with suspected pSS. Women made up 83% of the cohort. The median age was 59 years [Q1 52-Q3 65]. Primary SS (pSS) was diagnosed in 50 patients, all of whom met the 2016 American College of Rheumatology (ACR)/EULAR classification criteria. Thirty-one patients had a focus score &gt; 1 on minor salivary gland biopsy. All patients had ultrasound of the four glands. Of the 94 patients, heterogeneous parotid gland was found in 28 (30%) patients and heterogeneous submandibular gland in 29 (30%) patients. We performed subgroup analysis: group 1: pSS (n=50) versus group 2: control group (n=44). Positive antinuclear antibodies were found in 31 patients in group 1 versus 8 patients in group 2 (p&lt;0.001). Anti-SSA/RO52 was positive in 26 patients in group 1 versus 2 patients in group 2 (p&lt;0.001). On salivary gland ultrasound, heterogeneous parotid gland was reported in 22 patients in group 1 versus 6 patients in group 2 (p&lt;0.002). Heterogeneous submandibular gland was found in 19 patients in group 1 versus 3 patients in group 2 (p&lt;0.001). An OMERACT score &gt;2 was observed in 26 patients in group 1 versus 5 patients in group 2 (p&lt; 0.001). The area under the curve was 0.743 (95% CI: [0.656; 0.829]) for the highest ultrasound score to predict pSS. An ultrasound score ≥ 2 was associated with a sensitivity of 62% and specificity of 97%. <h3>Conclusion:</h3> More patients with pSS compared to no pSS had a score ≥2 in at least one gland (22 pSS vs 6 no pSS). An ultrasound cut-off of &gt;2 is associated with a sensitivity of 67% and a specificity of 88%, suggesting that SGUS may be a useful tool for the diagnosis of pSS. Our data support what has been reported in several previous studies. Recently, Mossel et al. reported that SGUS correlated with histopathological findings in 41 patients with pSS[2]. Further studies are needed to try to integrate SGUS into the classification criteria for pSS. <h3>REFERENCES:</h3> [1] Finzel S, Jousse-Joulin S, Costantino F, <i>et al.</i> Patient-based reliability of the Outcome Measures in Rheumatology (OMERACT) ultrasound scoring system for salivary gland assessment in patients with Sjögren's syndrome. <i>Rheumatology</i>. 2021;60:2169–76. [2] Mossel E, Van Ginkel MS, Haacke EA, <i>et al.</i> Histopathology, salivary flow and ultrasonography of the parotid gland: three complementary measurements in primary Sjögren's syndrome. <i>Rheumatology</i>. 2022;61:2472–82. <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>