POS1265 ULTRA HIGH-FREQUENCY ULTRASOUND (UHFUS) OF LABIAL GLANDS IN PRIMARY SJÖGREN’S SYNDROME: ASSOCIATIONS AMONG SONOGRAPHIC PATTERNS, HISTOLOGY AND AUTOANTIBODIES SPECIFICITIES AND TITER
Authors: G. Fulvio, R. Izzetti, V. Donati, C. Porciani, S. Fonzetti, G. La Rocca, I. C. Navarro García, F. Ferro, M. Mosca, C. Baldini
Journal: Annals of the Rheumatic Diseases (2024)

<h3>Background:</h3> Last-generation ultra-high-frequency ultrasound (UHFUS) transducers are highly sensitive tools potentially able to visualize the echo structure abnormalities of labial salivary glands (LSG) with a good diagnostic accuracy in differentiating patients with Sjögren's disease (SD) from no-SD sicca. Little is known about the correspondence between LSG-UHFUS, LSG histology and anti-Ro/SSA and anti-La/SSB antibodies levels and specificities. <h3>Objectives:</h3> 1. to assess the association between UHFUS scoring and LSG histology in patients with established SD; 2. to explore the association between LSG-UHFUS scoring and anti-Ro/SSA and anti-La/SSB antibodies specificities and titers. 3. To explore whether pathological UHFUS (grade 3 and 2) may allow the identification of different phenotypes of SD. <h3>Methods:</h3> Out of a cohort of consecutive patients undergoing a UHFUS guided LSG biopsy for suspected SD (Jan 2018-Nov 2022), SD patients who fulfilled the ACR/EULAR classification criteria and had available the quantitative titer of anti-Ro/SSA and anti-La/SSB antibodies at baseline were included. Patients' clinical, serological, and histological features were collected. UHFUS of LSG was performed by using VEVO MD, equipped with a 70 MHz probe, evaluating parenchymal inhomogeneity (grade 0-3, with grade 2 and 3 defined as pathological, Figure 1). For each of the LSG specimens' number of foci, focus score (FS) and ectopic lymphoid structures (ELS) were assessed. Serum from each patient was tested for anti-Ro52, anti-Ro60, and anti-SSB/La antibodies with commercially available immunoblot (EUROIMMUN srl), analyzing the quantitative titer of the autoantibodies with band densitometry. The positive control value of the immunoblot strips, obtained in an automatized way, was used to normalize the value of each autoantigen tested. With the formula value of the autoantigen/ (positive control value/100) we calculated a ratio that was used for the analysis. Descriptive statistics and logistic regression were performed with SPSS software. <h3>Results:</h3> We included a total of 117 SD patients, 107 (91.5%) were female, median age was 57 years (IQR 48.5-66)). UHFUS grade 0 was detected in 3/117 (2.6%) patients, grade 1 in 52/117 (44.4%), grade 2 in 30/117 (25.6%) and grade 3 in 32 (27.4%). We found a significant positive correlation between UHFUS scoring and LSG histology parameters (number of foci, FS and ELS) (p&lt;0.001) Patients presenting a pathological UHFUS (grade 2 and 3) had a higher FS (2 (1.7-2.5) vs 1(0.7-1.1)), number of foci (4.5(4.5-6.5) vs 2(1.5-2.5)) and number of ELS (2 (2-4) vs 1(0-1) compared to patients with milder UHFUS (grade 0 and 1) (p&lt;0.01). Similarly, when compared to the latter, the former presented more frequently a combined positivity for anti-Ro52 and anti-Ro60 or a triple positivity for anti-Ro52 and anti-Ro60 and anti-La/SSB (p=0.004). Moreover, titers of anti-Ro52 (p=0.01), anti-Ro60 (p&lt;0.001) and anti-La/SSB (p&lt;0.001) were significantly higher in patients with UHFUS grade 2 and 3 than in patients with UHFUS score 0 and 1. Finally, patients with UHFUS grade 2 and 3had a significantly higher ESSDAI score. Age at inclusion, anti-Ro60 titer and FS were independent factors associated with pathological UHFUS scores. <h3>Conclusion:</h3> UHFUS of LSG appeared significantly associated with serological and histological findings in SD. Pathological UHFUS grading may have a role in patients' stratification. <h3>REFERENCES:</h3> <b>NIL.</b> <h3>Acknowledgements:</h3> <b>NIL.</b> <h3>Disclosure of Interests:</h3> <b>None declared.</b>