This study investigates the potential of CD19-targeting chimeric antigen receptor (CAR) T cells in treating ANCA-associated vasculitides (AAV), a group of life-threatening autoimmune diseases. The researchers used a preclinical mouse model of anti-myeloperoxidase (MPO) ANCA-induced necrotizing crescentic glomerulonephritis (NCGN) to test the hypothesis that CD19 CAR T cells can deplete B cells, including MPO-ANCA-producing B cells, thereby protecting against NCGN. The study found that CD19 CAR T cells efficiently migrated to and persisted in various organs, depleted B cells and plasmablasts, and significantly reduced MPO-ANCA levels. Importantly, CD19 CAR T cell treatment protected mice from NCGN, as evidenced by reduced glomerular damage and improved kidney function. The results suggest that CD19 CAR T cells may be a promising therapeutic approach for AAV, offering a potential drug-free remission strategy. However, the study also highlights the need for further research to address long-term safety concerns and to explore antigen-specific CAR T cell approaches.This study investigates the potential of CD19-targeting chimeric antigen receptor (CAR) T cells in treating ANCA-associated vasculitides (AAV), a group of life-threatening autoimmune diseases. The researchers used a preclinical mouse model of anti-myeloperoxidase (MPO) ANCA-induced necrotizing crescentic glomerulonephritis (NCGN) to test the hypothesis that CD19 CAR T cells can deplete B cells, including MPO-ANCA-producing B cells, thereby protecting against NCGN. The study found that CD19 CAR T cells efficiently migrated to and persisted in various organs, depleted B cells and plasmablasts, and significantly reduced MPO-ANCA levels. Importantly, CD19 CAR T cell treatment protected mice from NCGN, as evidenced by reduced glomerular damage and improved kidney function. The results suggest that CD19 CAR T cells may be a promising therapeutic approach for AAV, offering a potential drug-free remission strategy. However, the study also highlights the need for further research to address long-term safety concerns and to explore antigen-specific CAR T cell approaches.