CD19-L is the first CD19-specific recombinant human protein with potent anti-leukaemic activity against B-lineage acute lymphoblastic leukaemia (ALL), the most common form of childhood cancer and the second most common form of acute leukaemia in adults.
A minimal primary panel of nine antibodies consisting of three myeloid markers (CD13, CD33, and CD117), B-cell lymphoid marker (CD19), T-cell marker (CD7), with CD45, CD10, CD34, and HLADR could assign lineage to 92% of AL.
Joint Modeling of Immune Reconstitution Post Haploidentical Stem Cell Transplantation in Pediatric Patients With Acute Leukemia Comparing CD34<sup>+</sup>-Selected to CD3/CD19-Depleted Grafts in a Retrospective Multicenter Study.
There were no significant differences in karyotypic pattern between the CD19-positive and CD19-negative leukemic cells, raising the concern that therapeutically targeting CD19 for acute leukemia may not eradicate all malignant clones.
These data suggest that a small population of acute leukemia patients with distinct phenotype, CD13/CD33+CD7+CD19+ acute leukemia, may originate from hematopoietic stem cells.
Two cases were classified by immunological phenotyping as acute null-AL(L), one case as pre B-cell ALL (CD10+) and two cases expressed both immature B-cell markers CD19 and CD24 and myelomonocytic markers CD15 and CD14, suggesting mixed lineage leukemia.