Immunohistochemical analysis demonstrates long-term presence of bone marrow PCs and B-cell aplasia after CTL019 treatment. (A) Bone marrow core biopsies from subject UPN-1 at baseline and serial time points post-CTL019 infusion were stained, separately, for CD138, CD20, and CD19 by IHC. Representative regions at ×20 magnification are shown. (B-E) The frequency of CD138⁺ (B), CD20⁺ (C), and CD19⁺ cells (D) among total nucleated cells in bone marrow biopsies from adult (red curves) and pediatric (blue curves) patients was determined by digital image analysis for the indicated time points pre- and post-CTL019.