CD19 and systemic lupus erythematosus: The development of neutralizing antibodies to the chimeric compound might also undermine the durability of B cell depletion.[31] Finally, the failure of depletion of pathological B cells in tissues may contribute to treatment failure and disease relapse in some SLE patients.[7] This is supported by the observation that with more profound depletion of the CD19+ B cells by chimeric antigen receptor T cell therapy (CAR-T), the efficacy in SLE could be prolonged.[32]