The clinicopathological features of these cases were analyzed to determine the influence of age, secondary karyotype abnormalities, and expression of the lymphoid marker CD19 on event free survival, and presence of extramedullary leukemia on overall survival.
Four hematological groups could be distinguished: (i) 13 cases of acute lymphoblastic leukemia (ALL) of B lineage, mostly CD19+; (ii) eight cases of biphenotypic leukemia: CD19+ (most often) ALL but with simultaneous or inducible expression of differentiation marker of monocytic lineage.
Effective immunochemotherapy of human t(4;11) leukemia in mice with severe combined immunodeficiency (SCID) using B43 (anti-CD19)-pokeweed antiviral protein immunotoxin plus cyclophosphamide.
We show that a highly aggressive subclone of murine BCL-1 B-lineage leukemia expresses a single 2.4-kb transcript hybridizing to the human CD19 cDNA probe and reacts strongly with the anti-human CD19 monoclonal antibodies (MoAb) B43, B4, Leu-12, and J3-119.
The anti-CD19(B43)-pokeweed antiviral protein immunotoxin selectively inhibited clonogenic RS4;11 cells in vitro, markedly reduced the burden of disseminated leukemia of severe combined immunodeficient mice, and, most importantly, resulted in the long-term survival of treated animals.