High expression of B lymphocyte stimulator in lesional keratinocytes of patients with cutaneous lupus erythematosus

Belimumab, an anti‐B lymphocyte stimulator (BLyS) monoclonal antibody, is approved for systemic lupus erythematosus; however, it is unclear if it can be used to treat specific skin lesions in this disease. In this analysis, we investigated the expression of BLyS and its receptors in skin lesions of different subtypes of cutaneous lupus erythematosus (CLE) using immunohistochemistry and gene expression analyses. Compared to healthy controls, the expression of BLyS was significantly higher in skin lesions of all included CLE subtypes. Similar results were seen for the BLyS receptors BAFF‐R and BCMA. Moreover, CLE‐typical pro‐inflammatory mediators (immunostimulatory DNAs) significantly enhanced the BLyS expression of keratinocytes in vitro. This study suggests a potential role for BLyS as therapeutic target in the treatment of CLE skin lesions.