Fig 3.

Chimeric antigen receptor (CAR) –expressing T cells were detected in regressing lymph node mass of patient with chronic lymphocytic leukemia (CLL). (A) Computed tomography scans show regression of large cervical lymph node mass in patient No. 13. (B) Fine-needle aspiration of lymph node mass shown in (A) was performed 19 days after infusion of anti-CD19 CAR T cells. Aspirated cells were analyzed by flow cytometry with CAR-specific monoclonal antibody. Among lymphoid cells from mass, 70% were T cells, and 31% of T cells expressed anti-CD19 CAR. Plot gated on CD3⁺ lymphocytes. (C) Before treatment, flow cytometry of blood of patient No. 3 revealed large population of CLL cells as indicated by aberrant CD19⁺CD5⁺ phenotype; 91% of pretreatment blood B cells were CLL cells. (D) Ten weeks after treatment, all B cells were absent from blood of patient No. 3, as shown by complete lack of CD19⁺ cells. CD20⁺ and CD22⁺ cells were also absent, which confirmed lack of B cells. (E) One year after treatment, recovering B cells with normal CD19⁺CD5⁻ phenotype were detected in blood of patient No. 3. (F) Polyclonality of recovering B cells was confirmed by kappa/lambda staining on CD19⁺ population from (E). In (C), (D), and (E), plots gated on lymphocytes.