Profiling the serum cytokine B cell activating factor (BAFF),proliferation inducing ligand (APRIL), and BP180, BP230 antibodies in bullous pemphigoid patients before and after treatment: a prospective case-control study

• Recent findings have highlighted two molecules from the TNF superfamily, which are expressed by macrophages and dendritic cells, as key regulators of normal B cell function, differentiation, expansion, and even the onset of autoimmune diseases. These molecules are B cell-activating factor (BAFF) and A proliferation-inducing ligand (APRIL). • Overexpression of BAFF and APRIL is involved in the pathogenesis of autoimmune diseases and probable involvement in autoimmune blistering diseases too. • We performed a prospective case-control study on 32 patients with newly diagnosed BP and 24 healthy controls • Based on the obtained results, BAFF and APRIL levels were higher in the case group than the control group both before and after the treatment. Specifically, the changes in the BAFF index were statistically significant in both conditions: before treatment compared to controls ( P = 0.001) and after treatment compared to controls ( P = 0.015). • Similarly, significant changes were observed in the APRIL index for the cases when comparing before treatment to controls ( P < 0.001). • Interestingly, those who have been treated with rituximab experienced a high level of BAFF even after treatment and in comparison with the healthy group but a decline in APRIL, BP180, and BP230. • we suggested that adding an anti-BAFF after rituximab therapy might affect the repopulation of B cells and hence, might be a reasonable therapeutic approach especially in those patients relapsing after rituximab therapy. • This study is one step forward in elaborating the role of BAFF and APRIL in the pathogenesis and monitoring of patients with BP. Bullous pemphigoid is a subepidermal autoimmune blistering disease caused by auto-antibodies directed against specific components of the basement membrane molecules. It has been shown that T cell function and B cell survival depend on B-cell activating factor (BAFF), a member of the tumor necrosis factor superfamily. Its contribution to the formation of BP is yet unknown, though. To measure the serum level of cytokines B cell activating factor (BAFF) and proliferation inducing ligand (APRIL), as well as BP180 and BP230 antibodies in patients with bullous pemphigoid before and after treatment. New patients with a confirmed diagnosis of bullous pemphigoid from a tertiary care hospital were selected. After obtaining written consent, blood samples were taken according to the required standards, and the levels of the above indices were checked before and four months after treatment. This prospective case-control study recruited 32 patients with newly diagnosed BP and 24 healthy controls. Based on the obtained results, BAFF and APRIL levels were higher in the case group than the control group both before and after the treatment. Specifically, the changes in the BAFF index were statistically significant in both conditions: before treatment compared to controls ( P = 0.001) and after treatment compared to controls ( P = 0.015). Similarly, significant changes were observed in the APRIL index for the cases when comparing before treatment to controls ( P < 0.001). Interestingly, those who have been treated with rituximab experienced a high level of BAFF even after treatment and in comparison with the healthy group but a decline in APRIL, BP180, and BP230. The results of this study showed a decrease in APRIL, BP180, and BP230 indices in patients with Bullous pemphigoid after treatment in accordance with clinical improvement and remission. This study is one step forward in elaborating the role of BAFF and APRIL in the pathogenesis and monitoring of patients with BP.