SLE is a heterogeneous B cell driven disease with characteristic features such as the presence of autoantibodies and increased Interferon signature. Five patients with SLE refractory to immunosuppressive drug treatments were treated with anti-CD19 chimeric antigen receptor (CAR) T cell therapy and single cell analysis was performed. Single cell RNA-sequencing and Repertoire Analysis was performed before induction of therapy and after the reappearance of B cells. Transcriptional analysis showed a decrease in Interferon dependent genes in whole PBMCs and T cells. Diminished Interferon signature could not be detected in whole B cells but in memory B cell subsets. Repertoire Analysis showed a statistically common non-Isotype switched naïve and memory B celll repertoire after anti-CD19 CAR T cell therapy. T cell repertoire shown no significant difference after reappearance of B cells. Together with clinical Data previously showed, this suggests a reset of B cell immunity and a balancing of the Interferon signature.