Systemic lupus erythematosus (SLE) is an autoimmune disease that is characterized by abnormal T and B cells. B-cell activating factor (BAFF) has been suggested to play a crucial role in lupus by promoting the proliferation, differentiation, and survival of B cells. Increased serum levels of BAFF have been found in patients with lupus. However, the expression of BAFF and its receptors on immune cells and in skin has not been systematically reported before. Here, we report that SLE patients showed increased levels of BAFF on circulating CD3⁺ T cells and B-cell maturation antigen (BCMA) on CD14⁺ monocytes and dramatically increased expression of BAFF in lupus skin lesions compared with those of healthy controls. TACI was undetectable on circulating immune cells. An increased serum level of BAFF was also confirmed in lupus patients in this study. Our findings may provide a better understanding of the pathogenesis and predictors of BAFF antibody treatment response, as well as potential targets for skin therapies.

系统性红斑狼疮（SLE）是一种自身免疫性疾病，其特征是T细胞和B细胞异常。B细胞活化因子（BAFF）被认为通过促进B细胞的增殖，分化和存活，在狼疮中起关键作用。在狼疮患者中发现BAFF的血清水平升高。然而，BAFF及其受体在免疫细胞和皮肤中的表达以前尚未系统报道。在这里，我们报道SLE患者的循环CD3 ⁺ T细胞BAFF水平升高，而CD14 ⁺ B细胞成熟抗原（BCMA）升高与健康对照组相比，狼疮皮肤病变中的单核细胞和BAFF的表达显着增加。在循环免疫细胞上无法检测到TACI。在这项研究中，狼疮患者的BAFF血清水平也得到了证实。我们的发现可能提供对BAFF抗体治疗反应的发病机制和预测指标以及皮肤疗法潜在靶标的更好理解。