Serum BAFF level and its correlations with various disease parameters in patients with systemic sclerosis and systemic lupus erythematosus

ABSTRACT

Interest in B-cells has been revived due to the description of new functions. Supporting a role for B-cells in the genesis of autoimmune diseases is the fact that the B-cell-activating factor of the TNF ligand family [BAFF] is essential in their physiology. The role of BAFF, a new cytokine, in autoimmune diseases has been highlighted. To assess serum BAFF level in systemic sclerosis [SSc] and systemic lupus erythematosus [SLE] to verify its role in these diseases and find any relation with the clinical manifestations, laboratory investigations, disease activity and damage. The study included 12 SSc and 40 SLE patients. The patients were subjected to full history taking and thorough clinical rheumatological and dermatological examinations and relevant investigations including autoantibodies and CT chest in SSc. In SSc, the total skin thickness score was scored according to the modified Rodnan skin score [MRSS] method. In SLE, the disease activity was assessed using the Systemic Lupus Activity Measure [SLAM] and organ damage using the Systemic Lupus International Collaborating Clinics/ACR [SLICC/ACR] index. The serum BAFF levels were measured using a specific ELISA. The BAFF level was remarkably elevated in SSc and SLE in a comparable percentage of patients, yet the level was highest in SLE and lower in the limited SSc subtype. The BAFF significantly correlated with the level with the MRSS in SSc and with both the SLAM and SLICC in SLE patients. The elevated level of BAFF in SSc further confirms the importance for new therapeutic targets for its inhibition to slow the disease progression, particularly skin fibrosis. The role of BAFF in the pathogenesis and disease activity in SLE is well-known and the novel noticeable correlation with the damage index high lightens on the utility of BAFF as an indicator of disease damage and predictor of poor outcome: