AB0540 Role of B-Lymphocyte Activating Factor (BAFF) in the Pathogenesis of Systemic Lupus Erythematosus

Background B-lymphocyte activating factor (BAFF) is a new member of the tumor necrosis factor family that promotes B-cell survival, acting as an antiapoptotic factor and thus contributing to the development of autoimmune disease. Objectives The aim of the study was to investigate the role of BAFF in the pathogenesis ofsystemic lupus erythematosus (SLE) by correlating its serum levels to differentclinicopathological indices of disease activity. Methods The research carried out here with human subjects was in compliance with the Helsinki Declaration. This is a prospective study that was conducted on 20 female patients with SLE. Ten healthy controls of matching age and sex were also included in this study. All patients were subjected to full history taking and clinical examination upon presentation, and the following laboratory parameters were evaluated: complete blood picture, erythrocyte sedimentation rate, serum (creatinine, blood urea nitrogen), and complete urine analysis (anti nuclear antibody, anti-dsDNA, C3, C4 in serum). Serum BAFF levels were measured by enzyme-linked immunosorbent assay in all patients. Renal biopsy was performed whenever necessary. Results Serum BAFF levels were significantly higher in patients with active SLE than in controls (Po0.05). These levels also correlated positively with systemic lupus erythematosus disease activity index (SLEDAI) in a highly significant manner (Po0.001). Correlating serum BAFF among patients with photosensitivity and symptoms of central nervous system affection proved to be highly significant (Po0.001). In addition, within this study, serum BAFF levels correlated positively with ESR levels among patients and negatively with both C3 and C4 in a significant manner (Po0.05 and 0.001, respectively). Conclusions Serum BAFF levels were significantly higher among patients with active SLE thanamong controls. It correlated in a negative manner with both C3 and C4 – significantlywith C3 and highly significantly with C4. BAFF levels also correlated with SLEDAI in ahighly significant manner, implicating B-cell immunoglobulin production and immunecomplex formation in the disease activity of lupus patients. References Yoshimoto K, Tanaka M, Kojima M, Setoyama Y, Kameda H, Suzuki K, et al. Regulatory mechanims for the production of BAFF and IL-6 are impaired in monocytes of patients with primary Sjogren9s syndrome. Arthritis Res Ther 2011. Acknowledgements We are gratefull to Ain Shams Universiy hospital manager and Head of clinical pathology for facilitating this research. There are no conflicts of interest. Disclosure of Interest None declared DOI 10.1136/annrheumdis-2014-eular.1292