CD19 and systemic lupus erythematosus: SLE is associated with the dysregulation of B cells,43 mainly characterized by abnormal homeostasis and hyperactivation.8, 9 In this study, we first showed an increased mortality of CD19+CD27− and CD19+IgM+ B-cell subsets from active SLE patients and a differential expression profile correlated to signaling pathways including IFN, TLR and BCR as well as the apoptosis, necroptosis and immune pathways.