Background: Major salivary glands ultrasound (SGU) is a promising tool in the diagnosis of Sjögren syndrome (SS) and has demonstrated good sensitivity and specificity in previous studies [1]. However, its usefulness in daily rheumatology practice has not been completely established.

Objectives: To assess the performance of SGU for diagnose of SS in routine clinical practice.

Methods: This was a cross-sectional single center observational study. Patients with clinical suspicion (due to xerostomia, xerophthalmia or positive anti-Ro) or confirmed diagnosis of SS were included in the study. All patients underwent sialometry, Schirmer test and blood samples, including autoantibodies, as part of the routine clinical practice. SGU was performed in all patients by a rheumatologist who was unaware of clinical data. OMERACT semi-quantitative scoring system for SGU that grades each gland from 0 to 3 (parotid and submandibular) was evaluated. A cutoff of ≥2 in any of the four glands was selected because has shown good performance for the diagnosis of SS in previous studies.

Demographic data and clinical history were collected, including minor salivary gland biopsy when available. Fulfilment of 2016 ACR/EULAR criteria for SS [2] was evaluated in each patient. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated for sialometry and SGU.

Results: 81 patients were included, of which 76 (93.8%) were women. Of the total, 41 (50.6%) met the 2016 ACR/EULAR SS criteria. Anti-Ro/SSA antibody was positive in 54/81 (66.7%) and minor salivary gland biopsy was performed in 8 (9.9%) patients, being pathological in 6 (7.4%). Of the 40 patients who did not meet criteria for classification as SS, 13 (32.5%) had a Schirmer test <5 mm, 7 (15.5%) had a basal sialometry < 1.5 mL in 15 minutes and 7 (17.5%) had an SGU with OMERACT ≥2. Of the 41 patients classified as SS, 22 (53.7%) had pathological Schirmer, 21 (51.2%) had a basal sialometry <1.5 mL in 15 minutes and 29 (70.7%) had an SGU with OMERACT ≥ 2.

Sialometry had a sensitivity of 51.2% (36.5-65.7%) and a specificity of 82.5% (68.0-91.3%) for classification as SS, and SGU (OMERACT ≥2) had a sensitivity of 70.7% (55.5-82.4%) and a specificity of 82.5% (68.0-91.3%). The positive predictive value of the SGU was 80.6% (65.0-90.2%) and the negative predictive value was 73.3% (59.0-84.0%).

Conclusion: In our routine clinical practice, the diagnostic performance of SGU is good, superior to sialometry, although the latter is included in the ACR/EULAR criteria for SS and the SGU not.

REFERENCES: [1] Fana V, Dohn U, Krabbe S, Terslev L. Application of the OMERACT Grey-scale Ultrasound Scoring System for salivary glands in a single-centre cohort of patients with suspected Sjögren’s syndrome. RMD Open. 2021 Apr;7(2):e001516.

[2] Shiboski CH, Shiboski SC, Seror R, et al: 2016 American College of Rheumatology/European League Against Rheumatism classification criteria for primary Sjögren’s syndrome: A consensus and data-driven methodology involving three international patient cohorts. Arthritis Rheumatol 69(1):35–45, 2017.

Acknowledgements: The study was supported by a research grant from Asociación para la Investigación en Reumatología de la Marina Baixa (AIRE-MB).

Disclosure of Interests: José Miguel Senabre Gallego Abbvie, Amgen, Bristol Myers Squibb, Celgene, Gebro Pharma, GlaxoSmithKline, Janssen, Lilly, Merck Sharp and Dohme, Novartis, Pfizer, Roche, Rubio and UCB pharma., Abbvie, Celgene., Abbvie., José Antonio Bernal: None declared, Lara Pons-Canet: None declared, Ana Pons-Bas: None declared, Juan Carlos Cortés-Quiroz: None declared, Carmen Raya-Santos: None declared, Rocio Gallego-Campuzano: None declared, Gregorio Santos Soler: None declared, Jose Rosas Gómez de Salazar: None declared.