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Query: UMLS:C0023418 (leukemia)
 93,477 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Immunophenotypic and immunogenotypic changes in 23 patients with Ph positive chronic myelogenous leukemia in blast crisis were determined using a panel of monoclonal antibodies and gene probes. According to the immunophenotypes, 9 patients were considered to be in lymphoid blast crisis, including 7 patients with lymphoblastic crisis and 2 patients with lymphoid/myeloid mixed blast crisis. Leukemia cells from the remaining 14 patients showed myeloid phenotypes and 10 of these had platelet-associated antigens. Rearrangement of the immunoglobulin (Ig) gene was observed in all the 9 patients with lymphoid blast crisis, and Ig gene rearrangement was associated with the expression of CD19 antigen. Two patients with myeloid blast crisis showed rearrangements of T-cell-receptor gene, but, dissociation between phenotypes and genotypes was not frequently observed in patients with blast crisis.
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PMID:[Immunogenotypes and surface marker analysis in Ph1 positive chronic myelogenous leukemia in the blastic crisis]. 151 43

Twenty-five patients with B-cell chronic lymphocytic leukemia (B-CLL) were investigated to correlate the immunological phenotype with the description of the Ig gene rearrangements of the B-cell clone. All patients were positive for the CD19 antigen and one pan B-antigen, markers of late cells (CD20, CD37 or Y2955). Twenty-four of the 25 patients tested expressed monoclonal cell surface immunoglobulin (SIg). The CD5 antigen was present in 21 of the 25 tested patients. Immunoglobulin gene rearrangements were detected by hybridization of the BamHI, EcoRI, BgIII, and HindIII digested genomic DNAs to the IGHJ, IGKC, IGLC, and IGLJ2 probes. Twenty-four of 25 patients had two rearranged IGH loci. The IGKC rearrangements were observed in 20 patients. In four patients, the IGK loci were deleted on both chromosomes. One patient without SIg displayed a germline pattern. All six patients with lambda producing B-CLL showed a lambda gene rearranged band, although the use of IGL polymorphism to investigate IGL rearrangements must be noted. These clonal rearrangements of IGL genes, together with the detection of either the kappa or lambda light chain of SIg, confirm that patients with B-CLL meet the developmental scheme of ordered light chain gene rearrangements.
Leukemia 1991 Nov
PMID:Rearrangements of immunoglobulin light and heavy chain genes and correlation with phenotypic markers in B-cell chronic lymphocytic leukemia. 196 Oct 33

Extensive immunologic surface marker analyses and binding competition assays demonstrated that B43 monoclonal antibody (MoAb) is a new member of the CD19 cluster that recognizes the same surface epitope as several other anti-CD19 MoAbs. We used B43 MoAb to test for CD19 expression on neoplastic cells from 340 leukemia and 151 malignant lymphoma patients and on nonneoplastic cells in normal lymphohematopoietic and nonlymphohematopoietic tissues. Our study more than doubles the total number of cases with classified hematologic malignancies that have been examined for CD19 antigen expression. The data presented confirm that CD19 is the most reliable B lineage surface marker and support our view that this B lineage-restricted surface determinant may be an important functional receptor. Our findings provide unique and direct evidence that (a) CD19 is expressed on leukemic B lineage lymphoid progenitor cells freshly obtained from B lineage acute lymphoblastic leukemia patients but not on normal myeloid, erythroid, megakaryocytic, or multilineage bone marrow progenitor cells; (b) ligation of CD19 with B43 MoAb induces sustained increases in [Ca2+]i when crosslinked and inhibits high-molecular weight B cell growth factor (HMW-BCGF)-induced proliferation of activated B cells without affecting their low-molecular weight B cell growth factor (LMW-BCGF) response; therefore CD19 may be a unique signal receptor; (c) HMW-BCGF and LMW-BCGF augment expression of CD19, which suggests that CD19 and BCGF receptors may be under coordinate regulatory control; (d) approximately two million B43 MoAb molecules per cell can be bound to target B lineage lymphoma cells with a Ka of 1.9 x 10(8)/mol/L; (e) CD19 can undergo B43 MoAb-induced internalization; and (f) the opportunity is thus provided for using anti-CD19 MoAb to deliver toxins to B lineage neoplastic cells for more effective treatment of high-risk leukemia/lymphoma patients.
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PMID:Detailed studies on expression and function of CD19 surface determinant by using B43 monoclonal antibody and the clinical potential of anti-CD19 immunotoxins. 325 43

Antibodies that recognize antigens restricted to leukemia, lymphoma, and normal hematopoietic cells represent a unique opportunity to develop therapeutics, because they have the potential for relatively selective treatment of these diseases. Antibodies that recognize the CD19 antigen found on normal and malignant B cells, but not on stem cells, have been used to develop immunoconjugates. However, these conjugates are large and might be suboptimal in tumor penetration when compared to molecules using smaller single chain Fv (scFv) antibody fragments. scFv has the advantage of being a molecularly engineered homogeneous molecule. In this report, we demonstrate the cloning, expression, and binding of three anti-CD19 antibodies as scFvs. All three scFvs were successfully cloned and expressed. FVS191, derived from cell line B43, and FVS192, derived from SJ25C1, were properly refolded and bound CD19 antigen in FACS competition assays. These anti-CD19 scFv should be useful in the further development of diagnostic and therapeutic molecules.
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PMID:Development and characterization of three recombinant single chain antibody fragments (scFvs) directed against the CD19 antigen. 753 1

Bone marrow is the primary site of disease in patients with acute lymphoblastic leukemia (ALL) and is frequently involved in patients with non-Hodgkin's lymphoma (NHL). At the time of autologous bone marrow transplantation, marrow grafts from patients with leukemia and lymphoma are often still contaminated by malignant cells, even when such patients achieve complete clinical remission. In this study, we evaluated the potential of anti-B4-blocked-ricin (anti-B4-bR) immunotoxin to eliminate residual ALL and NHL cells from bone marrow. Anti-B4-bR binds to the CD19 antigen, which is B-lineage specific, and, at concentrations of 5 x 10(-9) M or greater, could eliminate more than 3 logs of CD19+ Nalm-6 or Namalwa cells in a 20-fold excess of normal irradiated bone marrow after only 5 hr of incubation. This activity was abrogated by the addition of anti-B4 but not by the presence of galactose, which is the natural ligand for native ricin. Also, when used at these high concentrations, anti-B4-bR showed little nonspecific toxicity against normal hematopoietic progenitors. In conclusion, a single short exposure to anti-B4-bR is capable of inducing high levels of depletion of CD19+ leukemia and lymphoma cells without significant nonspecific toxicity against normal marrow progenitors. Therefore, anti-B4-bR offers an interesting approach to the elimination of B-lineage malignant cells prior to autologous bone marrow transplantation.
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PMID:Elimination of B-lineage leukemia and lymphoma cells from bone marrow grafts using anti-B4-blocked-ricin immunotoxin. 753 11

We have investigated the value of both conventional and quantitative flow cytometry to detect minimal residual disease in 21 CLL patients in remission including bone marrow histology: eight in complete remission (CR), 11 in nodular partial remission (nPR) and two in PR. The techniques used were double immunostaining with CD5 and CD19 and quantitative estimation of the number of both antigens with standard microbeads. Reference values were established on normal peripheral blood and bone marrow controls. Patients were considered in 'immunological' remission when the percentage of CD5+ CD19+/total CD19+ cells was <25% in PB and <15% in BM. In six of the eight patients in CR, CLL cells were still detectable by flow cytometry. Only two patients, that underwent allogeneic bone marrow transplant, achieved immunological remission. CLL samples showed significantly higher CD5 and lower CD19 antigen density than normal controls (P < 0.001). Persistence of residual disease was a predictor of time to progression. None of the two patients in immunological remission relapsed within a period of 13 and 33 months, whilst two of the six patients in CR with positive flow cytometry relapsed 3 and 6 months after achieving CR. This study demonstrates that flow cytometry contributes to increase the sensitivity of the clinicohematological criteria to detect residual malignant cells in CLL patients and may be useful to monitor disease status following treatment.
Leukemia 1997 Nov
PMID:Analysis of residual disease in chronic lymphocytic leukemia by flow cytometry. 936 25

We have conjugated the murine monoclonal anti-CD19 antibody B43 to the tyrosine kinase inhibitor genistein to construct an effective immunoconjugate against CD19 antigen positive hematologic malignancies. The scaled-up production and purification of B43 antibody, genistein, and B43-Genistein immunoconjugate permitted the manufacturing of a highly purified clinical-grade B43-Genistein preparation. In clonogenic assays, B43-Genistein elicited selective and potent cytotoxicity against CD19 antigen positive human leukemia cells. To our knowledge, this work represents the first effort of producing a clinical-grade genistein immunoconjugate for treatment of B-lineage leukemia and lymphoma.
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PMID:Large scale manufacturing of B43(anti-CD19)-genistein for clinical trials in leukemia and lymphoma. 968 30

Phenotypic conversion from acute myeloid leukemia (AML) to acute lymphoblastic leukemia (ALL) is rare. A 38-year-old man was initially diagnosed as having AML (FAB-M2) associated with the t(8;21)(q22;q22) chromosomal abnormality. The blasts showed myeloperoxidase (MPO) activity and CD13 antigen expression. He showed complete remission after standard chemotherapy for AML. However, the patient relapsed with blasts showing ALL morphology (FAB-L1), MPO negativity, and CD19 antigen expression 33 months after cessation of AML therapy. Cytogenetic analysis at relapse was unsuccessful. Molecular analysis of ALL blasts revealed immunoglobulin heavy-chain gene and MLL gene rearrangements but no AML1 gene. MLL gene rearrangement or the 11q23 chromosomal abnormality has been associated with therapy-related leukemia. The subsequent ALL in our patient may have been induced by the chemotherapy including daunorubicin, known as a topoisomerase II inhibitor.
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PMID:Phenotypic conversion from t(8;21) acute myeloid leukemia to MLL gene rearrangement-positive acute lymphoblastic leukemia. 984 25

B-chronic lymphocytic leukemia (B-CLL) is the most common adult leukemia. Molecular genetic characterization of B-CLL has made significant progress and typical chromosomal anomalies have been assessed. The most frequent chromosomal abnormalities are deletions at 13q14, 17p13, and 11q22 approximately q23 and trisomy 12. The aim of this study was to establish incidence of chromosomal changes in bone marrow or peripheral blood cells (or both) of B-CLL patients using a molecular cytogenetic method, interphase fluorescence in situ hybridization (I-FISH), and to evaluate the prognostic implications. We performed I-FISH on bone marrow and blood smears from 217 B-CLL patients (124 male, 93 female). Trisomy 12 was found in 35 of the 217 (16%); deletion 13q14 was analyzed in 207 patients and found in 112 (54%). Deletion 17p13 was found in 34 (16%) out of 206 examined. Deletion of 11q23 was analyzed in 56 patients and was present in 7 (12%). Statistical analyses were performed to correlate the molecular-cytogenetic findings with disease status (stable versus progressive), Rai stage, CD38/CD19 antigen coexpression, immunoglobulin variable heavy chain (IgV(H)) mutational pattern, and other clinical and laboratory parameters. No apparent differences in distribution were noted for anomalies +12, del(13)(q14), or del(17)(p13) among patients with stable and progressive disease, and no consistent pattern in the distribution of type of genomic changes were found among various Rai stages and in CD38/CD19-positive or -negative patients. Patients without IgV(H) mutation had a worse prognosis; however, distribution of chromosomal abnormalities identified with FISH was the same for patients with and without IgV(H) mutations.
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PMID:Incidence of chromosomal anomalies detected with FISH and their clinical correlations in B-chronic lymphocytic leukemia. 1594 67

T lymphocytes expressing a chimeric antigen receptor (CAR) targeting the CD19 antigen (CAR.19) may be of value for the therapy of B-cell malignancies. Because the in vivo survival, expansion and anti-lymphoma activity of CAR.19(+) T cells remain suboptimal even when the CAR contains a CD28 costimulatory endodomain, we generated a novel construct that also incorporates the interleukin-15 (IL-15) gene and an inducible caspase-9-based suicide gene (iC9/CAR.19/IL-15). We found that compared with CAR.19(+) T cells, iC9/CAR.19/IL-15(+) T cells had: (1) greater numeric expansion upon antigen stimulation (10-fold greater expansion in vitro, and 3- to 15-fold greater expansion in vivo) and reduced cell death rate (Annexin-V(+)/7-AAD(+) cells 10+/-6% for iC9/CAR.19/IL-15(+) T cells and 32+/-19% for CAR.19(+) T cells); (2) reduced expression of the programmed death 1 (PD-1) receptor upon antigen stimulation (PD-1(+) cells <15% for iC9/CAR.19/IL-15(+) T cells versus >40% for CAR.19(+) T cells); and (3) improved antitumor effects in vivo (from 4.7- to 5.4-fold reduced tumor growth). In addition, iC9/CAR.19/IL-15(+) T cells were efficiently eliminated upon pharmacologic activation of the suicide gene. In summary, this strategy safely increases the anti-lymphoma/leukemia effects of CAR.19-redirected T lymphocytes and may be a useful approach for treatment of patients with B-cell malignancies.
Leukemia 2010 Jun
PMID:Engineering CD19-specific T lymphocytes with interleukin-15 and a suicide gene to enhance their anti-lymphoma/leukemia effects and safety. 2042 7


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