Single-cell profiling identifies pre-existing CD19-negative subclones in a B-ALL patient with CD19-negative relapse after CAR-T therapy

Abstract

CD19-negative relapses are observed in patients with B-cell acute lymphoblastic leukemia (B-ALL) treated with anti-CD19 CAR-T cells. Here, by single-cell RNA sequencing of leukemic cells in a patient with B-ALL, the authors show that pre-existing CD19 negative leukemic subclones are present before CAR-T cell therapy and can account for the relapse.