SAT0205 Blys up-regulation and salivary clonal B-cell expansion characterize sjögren’s syndrome-related lymphoproliferative disorders and correlate with the new ESSDAI score

Background Primary Sjogren’s syndrome (SS) is characterized by an increased risk of lymphoma in patients with prelymphomatous manifestations (i.e., myoepithelial sialadenitis (MESA) or mixed cryoglobulinemia). Increased levels of B-lymphocyte stimulator (BLyS) characterize different autoimmune diseases, and in particular SS. Objectives Serum BLyS levels in SS-related B-cell lymphoproliferative disorders were studied, by integrating the results with the disease activity score and molecular analyses of B-cell expansion on the salivary glands. Methods 76 primary SS patients were studied. SS patients were distributed into four groups: a) SS without any lymphoproliferative disorder (n=34); b) SS with cryoglobulinemic vasculitis (CV) without overt lymphoma (n=14); c) SS with MESA (n=12); d) SS with overt lymphoma (n=16). Serum BLyS and molecular analyses of B cells in the salivary gland tissues, when available, were performed. Patients with SS and persistent parotid swelling underwent parotid biopsy. Results BLyS differed between SS subgroups, higher levels being documented in patients with B-cell lymphoproliferative disorders (as a whole group) versus SS without (1.85 (0.45-4.12) ng/ml vs 1.12 (0.56-1.98) ng/ml; p Conclusions Higher BLyS levels and clonal B-cell expansion characterizes SS with B-cell lymphoproliferative disorders, even at pre-lymphomatous stages. This subgroup of SS patients showed the highest ESSDAI scores. This is the biologic rationale for targeting both the clonal B-cell expansion and the BLyS overproduction in SS patients with a B-cell lymphoproliferative disorder and high disease activity. Disclosure of Interest None Declared