P055 CXCL13 as biomarker for histological involvement in sjogren’s syndrome

Career situation of first and presenting author Post-doctoral fellow. Introduction Sjogren’s syndrome (SS) is an autoimmune condition characterised by systemic B cell activation, autoantibody production and ectopic germinal centers (GC) formation within salivary gland (SG). The extent of SG infiltrate has been proposed as biomarker of disease severity. Plasma levels of CXCL13 correlate with GC activity in animal models and disease severity in SS, suggesting its potential use as a surrogate serum marker to monitor local B cell activation. Objectives To evaluate the potential role of CXCL13 as biomarker of SG pathology in two independent SS cohorts. Methods 109 patients with SS were recruited at Sapienza University of Rome (Italy) (n=60), or at Queen Elizabeth Hospital in Birmingham and Barts Health NHS Trust in London (n=49). Both sera and matched paraffin-embedded minor SG biopsy were available. Sicca (n=57) and healthy subjects (HS) (n=19) sera were used as control. CXCL13 gene expression was also assessed in 25 frozen SGs. Results CXCL13 serum levels were higher in SS patients [90.3 (84.2) pg/ml], compared to both sicca [61.9 (38.6) pg/ml), p=0.0005] and HS [36.5 (40.18) pg/ml, p Conclusions Our data foster the use of CXCL13 to monitor the extent of local pathology in SS and its validation in longitudinal clinical studies. Both serum and tissue expression of CXCL13 correlate with SS histological severity, suggesting a major role of this chemokine in SG lymphocytes recruitment and organization. Disclosure of Interest None declared.