Autologous T cells are engineered via lentiviral transduction to express fourth-generation chimeric antigen receptors targeting CD19 (B cells) and BCMA (plasma cells). Antigen engagement activates T-cell cytotoxicity and cytokine release, depleting autoreactive B cells and antibody-producing plasma cells to reduce pathogenic autoantibodies. An inducible caspase-9 safety switch allows controlled elimination of the CAR T cells if needed.