POS0782 FOLLICULAR DENDRITIC CELL NETWORKS IN MINOR SALIVARY GLAND BIOPSIES: A MARKER OF DISEASE ACTIVITY AT BASELINE AND DURING THE FOLLOW-UP IN SJÖGREN’S SYNDROME

Background: Minor salivary gland biopsy (MSGB) has been increasingly recognized as an important tool for the stratification of patients with primary Sjögren’s syndrome (pSS). Recently, presence follicular dendritic cell (FDC) networks in inflammatory infiltrate associated more severe biological and serological abnormalities compared less organized infiltrates. Objectives: To investigate associations between number FDC foci pSS glandular extra-glandular disease activity at baseline during follow-up. Methods: Consecutive MSGBs performed daily practice clinically suspected from January 2017 to October 2020 were reviewed. Patients’ demographic, clinical, data obtained medical records. The ESSDAI was used measure end follow-up patients. For histopathology, 3 µm sections cut each formalin-fixed paraffin-embedded block stained haematoxylin eosin (H&E). Immunohistochemical stainings on additional μm order detect T lymphocytes (CD3), B (CD20) cells (CD21). Glandular tissue areas, foci, focus score (FS) assessed. Results: We reviewed 330 consecutive pSS: out them 146/330 (44%) classified nonspecific chronic sialadenitis (NSCS) whereas 184/330 (56%) focal lymphocytic (FLS). According ACR/EULAR criteria diagnosis confirmed 130 (117 F:13 M, age 56±13 yrs). mean (S.D) surface area 7.8 (3.9) mm 2 . FLS samples ranged 1 12 (mean (S.D)=3.1 (2.6)), FS 0.3 9.0 = 1.4 (1.2)).The documented 106/330 (32%) samples; 54/106 (51%) these 8 (1.4)). significantly correlated (r=0.721**) (r=0.707**). Patients presented (i.e anti-Ro/SSA, anti-LA/SSB, Rheumatoid factor) elevated IgG levels (p<0.001). In patients, slightly also C4 (r=-0.216*), peripheral lymphocyte count (r=-0.274**) (r=0.213*), (r=0.230**) domains baseline. After a 21(13) months, still final total (r=0.312**). Conclusion: represent useful histopathological parameter able reflect follow-up, thus allowing personalized interventions. Disclosure Interests: None declared