Up-regulation of transcription factor Blimp1 in systemic lupus erythematosus.

•Blimp1 expression level increased in the SLE patients.•The increased expression of Blimp1 related to SLE disease activity, ANA antibody titer, and the CD138+ plasma cells.•In MRL/lpr lupus mice, Blimp1 was strongly expressed in the kidneys, lymph nodes and spleen, was much higher than normal mice.•Blimp1 is closely related to differentiation of B-lymphocytes, antibody production and renal lesions.•Blimp1 may play a role in SLE disease development.