Correlation of B-cell-activating Factor Levels and Diseases Activity in Systemic Lupus Erythematosus Patients

Background: B-cell hyperactivity is believed to have a central role in the pathogenesis of systemic lupus erythematosus (SLE). B-cell-activating factor (BAFF) is a cytokine that plays a role in accelerating maturation, differentiation, and survival of B-cells. The purpose of this study is to determine whether there is a significant association between the serum BAFF levels and disease activity in SLE patients. Subjects and Methods: This study uses bivariate analysis with a cross-sectional design. The statistical analysis test used is Pearson's and Spearman's correlation coefficient test, as well as Mann-Whitney test. Participants were 44 SLE patients with active disease (SLEDAI 2K >2) in the rheumatology clinic and in-patient wards of Hasan Sadikin General Hospital, Department of Internal Medicine, Bandung, during the period of December 2016-March 2017. Results: Forty-four participants of the study were women with a mean age of 28 +/- 8 years. Renal (93.2%) and mucocutaneous (93.2%) involvements were the most common manifestations. Median of disease activity based on SLEDAI-2K score was 8 (4-23). Median serum BAFF level was 1.218 ng/ml (0.476-10.835). There was a weak positive correlation between serum BAFF levels and SLEDAI-2K (r = 0.327, P = 0.015). There was also a significant correlation with weak relation found between serum BAFF levels and anti-dsDNA and complement C3 levels. Conclusion: There is a significant correlation between the serum levels of BAFF and SLE disease activity. However, the strength of the relationship is weak. Therefore, disease activity in lupus can be influenced by other factors.