POS0737 SICCA SYNDROME: A MULTIMODAL ASSESSEMENT TO CHARACTERIZE PATIENT COHORTS BEYOND SJÖGREN’S SYNDROME CLASSIFICATION CRITERIA

Abstract

BackgroundSicca syndrome represents a heterogeneous group of conditions, including Sjögren syndrome, causing xerophthalmia and xerostomia.ObjectivesThis study characterizes in depth patients with Sicca syndrome and evaluates salivary gland ultrasound (SGUS) in this cohort.MethodsPrincipal component analysis and hierarchical clustering of clinical parameters, including ESSPRI, ESSDAI and laboratory data were performed on all referrals for assessment of Sicca symptoms between October 2018 and March 2021. SGUS and labial gland biopsies were compared across groups.Results583 patients were assessed. Objective dryness was confirmed in 73% of patients. Cluster analysis identified 3 groups with post-hoc analysis confirming distinct phenotypes: Somatic Group (283/583; 49%) with higher reported symptoms but limited objective dryness; Dry Without Autoimmune Features (DAFneg, 206/532; 35%) and Dry With Autoimmune Features (DAFpos, 94/532; 16%). DAFpos patients had highest autoantibody titres (SSA 240 vs 3.6 vs 3.8; p<0.001), most extra-glandular manifestations (p<0.001) and highest median SGUS Score (DAFpos: 8 [IQR 4-10] vs SG: 2 [1-4] vs DAFneg 4 [2-5]; p< 0.001). No tangible correlation primary Sjögren syndrome criteria was observed.ConclusionSGUS score correlated with a subset of Sjögren syndrome patients, identified in the DAFpos cluster. This study highlights heterogeneity within Sicca and indeed Sjögren syndrome, highlighting the need for further studies.