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

During the diagnostic investigation of 750 acute leukemias, nine cases were morphologically, cytochemically, and phenotypically undifferentiated. In seven of these cases the blasts were class II+, CD34+ and TdT+, in one were class II+, TdT+, CD7+ while in the remaining leukemia blasts expressed class II only. Cytoplasmic and membrane CD22, CD3, CD13, and Ig as well as membrane CD19, CD10, CD37, CD2, CD33, CD14, glycophorin C, and CD61 were absent. The further characterization of these rare leukemias yielded the following results. The TCR-beta, -gamma and -delta genes were in germline configuration in seven cases studied while IgH genes were rearranged on both alleles in two cases and germline in the other five. By ultrastructural analysis peroxidase activity was detected on unfixed cells in a minority of blasts from four of seven cases. In two of the peroxidase-positive cases a small proportion of blasts also reacted with an anti-myeloperoxidase monoclonal antibody. In one of the peroxidase-negative cases, 7% of blasts were labeled by the antibody, suggesting the presence of peroxidase in its proenzyme form. Importantly, the two cases with Ig gene rearrangements did not have cytochemically or immunologically detectable peroxidase. Three of the nine patients were treated as ALL while six received AML chemotherapy. In five patients complete remission was achieved while the other four died from infections during remission induction. Four patients are still in remission 7, 12, 24, and 30 months after diagnosis while one patient relapsed after 12 months. In conclusion, we have characterized the genotypic and ultrastructural features of subtype of acute leukemia in which blasts expressed immaturity markers and lacked lineage associated antigens. In contrast to previously reported "unclassifiable" cases, the leukemias were phenotypically homogeneous and showed a good response to chemotherapy.
Leukemia 1990 Sep
PMID:Phenotypic, genotypic, cytochemical, and ultrastructural characterization of acute undifferentiated leukemia. 239 82

DNA/RNA flow cytometry studies were performed on the spinal fluid samples of thirty patients with acute leukemia or lymphoma at the time of clinical central nervous system relapse, and compared with similar studies of 56 patients (98 specimens) who had leukemia in remission with no evidence of CNS disease. Twelve of the 30 patients with CNS involvement had cells with abnormal DNA content in the spinal fluid (40%); the remaining eighteen had cells with diploid DNA content. In the group of 18 with diploid DNA, 10 had other abnormalities detected by flow cytometry. These included eight patients with acute leukemia who had cells with high RNA content, and two patients with non-Hodgkin's lymphoma who had markedly increased proliferation. Of the 22 patients studied by conventional cytology nine were negative for malignant cells, and in eight of these patients flow cytometry studies of DNA/RNA demonstrated abnormalities. Common ALL antigen was demonstrated by flow cytometry in three out of five cases studied. Thus, abnormal DNA content, increased RNA content, increased proliferation and/or expression of the cell surface antigen CALLA identified CNS relapse by flow cytometry in 22 of 30 patients with acute leukemia or lymphoma. The technique appears to be at least as sensitive as conventional cytology and identifies CNS relapse in some patients with negative cytology.
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PMID:Detection of central nervous system relapse in acute leukemia by multiparameter flow cytometry of DNA, RNA, and CALLA. 242 87

A monoclonal immunocytochemical method with 25 monoclonal antibodies was used to study the distribution in human tonsil of determinants expressed on T cells (mature and immature), Langerhans cells, B cells, killer/natural killer cells, macrophages, immature myeloid and lymphoblastic leukemia cells. Many of the respective determinants were found to have a discrete topographic distribution in normal reactive tonsil. The common acute lymphoblastic leukemia antigen and a determinant found on myeloblastic leukemia cells (My10) were not found in the specimens of the tonsil examined.
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PMID:Tonsillar mapping of determinants found on normal lymphoreticular (T,B,K, immature and macrophage) and myeloblastic leukemia cells. 243 59

In the present study we have generated four new monoclonal antibodies (mAbs), termed SN5, SN5a, SN5b, and SN5c, which are directed toward the human common acute lymphoblastic leukemia antigen (CALLA). SN5 and SN5c were generated separately by immunizing two mice with a leukemia antigen preparation isolated from uncultured non-T-/non-B-acute lymphoblastic leukemia cells whereas SN5a and SN5b were generated by immunizing a third mouse with intact KM-3 (a cultured non-T-/non-B-acute lymphoblastic leukemia cell line) cells. It was found that the binding activities of mAbs SN5 and SN5c generated by using an isolated leukemia antigen preparation were approximately twice as large as those of mAbs SN5a and SN5b generated by using intact leukemia cells. All four of the present mAbs induced antigenic modulation of CALLA on the leukemia cells in vitro; subclasses of mAbs appear to be an important factor which influences the kinetics of antigenic modulation. SN5, SN5a, and SN5c immunoprecipitated a distinct Mr 100,000 component from detergent-solubilized cell membrane antigens but SN5b failed to do so. These four mAbs together with J5, another anti-CALLA mAb, were individually tested in a solid phase radioimmunoassay for reactivity with the detergent extracts of various human tissues, i.e., kidney, lymph node, spleen, brain, liver, pancreas, lung, and heart. SN5, SN5a, SN5c, and J5 showed reaction only with kidney whereas SN5b did not show significant reaction with any tissues including kidney. However, SN5b as well as SN5 showed a significant reaction with kidney in an immunoperoxidase-staining test. These results indicate that the interaction of SN5b with a unique epitope on the CALLA moleucle is strongly disturbed by relatively mild detergents (deoxycholate, taurocholate, and Nonidet P-450). These detergents did not significantly disturb the reaction between other mAbs (SN5, SN5a, and SN5c) and the corresponding epitopes on the CALLA molecule. Competitive binding experiments show that the three epitopes recognized by SN5, SN5b, and SN5c are sufficiently close to each other to allow complete or nearly complete reciprocal inhibition of binding to CALLA present on leukemia cells. Peculiar inhibition patterns, however, were observed between SN5a and the other three mAbs. SN5, SN5b, and SN5c inhibited only partially the subsequent binding of SN5a to the leukemia cells. Conversely, SN5a inhibited nearly fully the subsequent bindings of SN5, SN5b, and SN5c. These results suggest another unique epitope defined by SN5a.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Unique epitopes of common acute lymphoblastic leukemia antigen detected by new monoclonal antibodies. 243 7

Lymphocyte subpopulations in human cord blood have been examined using monoclonal antibodies, visualized with immunogold. The proportions of T11, T4, T8, and B1 cells in cord blood are very similar to values in adult peripheral blood. Some evidence of lymphocyte immaturity in cord blood is suggested by the presence of 12% CALLA-positive cells and the sum of T4 and T8 cells significantly exceeding the number of T11 cells; however, there were no TdT-positive cells. The presence of CALLA-positive lymphocytes in normal cord blood should be borne in mind when investigating blood smears from neonates for congenital leukemia.
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PMID:Characterization of lymphocyte subpopulations in human cord blood using the immunogold staining technique. 244 85

Thirty-one cases of acute leukemia with blast cells greater than or equal to 70% positive for the hematopoietic stem cell Ag, CD34 (MY10, HPCA-1), were identified from the University of Nebraska Medical Center and The Johns Hopkins Oncology Center over an 18-month period. Fourteen of the cases were classified as early B-lineage ALL, 3 cases were other ALL subtypes, and 14 of the cases were ANLL. Five of the 17 cases of ALL expressed one or more myeloid-associated surface Ags, 3 ANLL cases expressed CD10 (CALLA, J5), and T-lymphoid Ags were present in 12 of 31 cases (1 T-cell ALL, 3 of 16 B-lineage ALL cases, and 8 of 14 ANLL cases). Eleven of 12 CD34+ ALL cases studied had abnormal karyotypes; only 7 of 12 CD34+ ANLL cases studied had abnormal karyotypes, and 3 of these were CD10+ ANLL. Six cases were Ph1 positive, including the one mature B cell ALL, 4 early B-lineage ALL, and 1 CD10+ ANLL case. Good and poor prognosis subgroups of high frequency of expression of CD34 leukemias could be identified, generally, as would have been predicted by previously defined criteria. Thus, of the 10 Ph1-negative early B-lineage ALL patients, 9 achieved CR (90%). At the other extreme, the CR rate of CD10- ANLL was 4 of 11 (36%). The leukemias characterized by greater than or equal to 70% of cells positive for CD34 form a relatively undifferentiated subset of the leukemias which may show features associated with more than one lineage, and if CD10- and myeloid morphology, may respond poorly to therapy.
Leukemia 1988 Oct
PMID:Acute leukemia expressing the normal human hematopoietic stem cell membrane glycoprotein CD34 (MY10). 245 68

Terminal deoxynucleotidyl transferase (TdT) is a useful marker for normal lymphocyte precursors and acute lymphoblastic leukemia (ALL). Our previous studies, however, have shown that for monitoring minimal residual disease in the circulation, assay for TdT alone is not sufficiently specific to distinguish leukemia cells from the background of rare normal blood TdT+ cells. In an attempt to increase specificity for leukemic cells, we have used double and triple immunophenotypic analysis to characterize normal circulating and bone marrow TdT+ cells. Overall, normal TdT+ cells were about 1000-fold more frequent in the marrow than in the blood. More than 75% of TdT+ cells in both the blood and marrow expressed the CD34, CD22, and HLA-DR antigens. However, circulating TdT+ cells infrequently expressed CD19 (4.5%) and CD9 (2.3%), compared with their marrow counterparts (74% and 47%, respectively). The brightly staining CD10+ phenotype, frequently associated with ALL blasts, was significantly less common among normal blood (5.7%) than marrow (31%) TdT+ cells. Although T-lineage markers were rarely expressed on TdT+ cells in either site, CD7+ cells were far more prevalent within the circulating TdT+ subset (4%) than among the marrow population (less than 0.2%). The results suggest a selective release of lineage-uncommitted and/or thymus-destined TdT+ cells from the marrow into the circulation. Moreover, since CD19, CD9, and high-density CD10 are frequently found on ALL blasts, staining for these markers on TdT+ cells in the circulation should improve the specificity of assay for residual common ALL cells. Likewise, assay for CD5+ and possibly CD7+ TdT+ cells in either marrow or blood should provide a very sensitive method of detection of T-ALL blasts.
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PMID:Phenotypic heterogeneity of TDT+ cells in the blood and bone marrow: implications for surveillance of residual leukemia. 233 29

Seventeen patients with acute myeloid leukaemia (AML) whose blasts co-expressed the T-cell associated CD7 antibody were identified among 160 consecutive AML cases. Fourteen had FAB defined AML according to morphocytochemical criteria, whereas three patients were classified as 'MO' on the basis of immunophenotype. The incidence of CD7 positively was particularly significant in the less differentiated subtypes M0 and M1 compared with other FAB groups (P less than 0.001). In all cases the myeloid determinants CD13 and/or CD33 were associated with CD7 expression. Other B-lymphoid (CD10, CD19) or T-lymphoid (CD2, surface and cytoplasmic CD3) markers were analysed and found to be negative. Five out of 15 cases examined were TdT+. Clonal rearrangements of the immunoglobulin heavy chain (IgH) and/or T-cell receptor (TcR) beta chain genes were identified in only three out of 13 cases. Among these, one out of five co-expressing TdT showed IgH rearrangement when analysed at the DNA level. Clinical features at presentation and response to induction therapy did not allow us to consider CD7+ AML patients as a distinct subgroup with prognostic significance. Our data indicate that CD7 expression is a common finding in immature AML, being generally found in the absence of other T-cell features. Rather than suggesting the occurrence of 'mixed leukaemia', such cases confirm a broader spectrum of CD7 reactivity and its possible identification of a particular subset of myeloid progenitors.
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PMID:CD7 positive acute myeloid leukaemia: a subtype associated with cell immaturity. 248 63

Even though much is known about the presence of the common acute lymphoblastic leukemia antigen (CALLA) with respect to its distribution in hematopoietic and non-hematopoietic tissues, its functional role in lymphoid cells is as yet unknown. Given the fact that CALLA is completely modulated on the surface of lymphoid cells, we have employed pre-embedding immunogold techniques at electron-microscopical level and demonstrated that J5 monoclonal antibody (MoAb)-mediated modulation of CALLA expression on the lymphoblastic cell line NALM-6 is a specific, rapid process, closely resembling receptor-mediated endocytosis. Furthermore, it was found that CALLA was internalized through plasmalemmal pits and cytoplasmic vesicles and processed intracellularly in multivesicular bodies and secondary lysosomes. In contrast, HLA-DR antigen remained at the cell surface upon contact with specific MoAb. These data suggest that CALLA might be a receptor for a hitherto unknown signal molecule.
Leukemia 1989 Feb
PMID:Immunoelectron microscopy studies on the modulation of common acute lymphoblastic leukemia antigen (CALLA) on NALM-6 cells: delineation of intracellular transport. 252 68

We have previously reported that the amino acid sequence of the common acute lymphoblastic leukemia antigen (CALLA, CD10) translated from a normal human kidney cDNA clone is identical to that of neutral endopeptidase (NEP, EC 3.4.24.11). In this study, we show that by flow cytometry, a monoclonal antibody (135A3) produced against rabbit NEP reacted selectively with leukemia and melanoma cell lines expressing CALLA on their surface. A glycoprotein of apparent Mr 100,000 was immunoprecipitated from surface labeled NALM-1 leukemia or Mel-1477 melanoma cells with monoclonal antibodies to NEP (135A3) or CALLA (44C10). mRNAs hybridizing to a NEP-specific probe were present in CALLA+ leukemia and melanoma cell lines, but absent from CALLA- lines. NEP enzymatic activity was detected on intact cells from CALLA+ lines, but not CALLA- lines. The activity was blocked by two selective inhibitors of NEP, thiorphan and phosphoramidon. CALLA antigen purified from the NALM-6 leukemic cell line by affinity to 44C10-IgG Sepharose retained a peptidase activity that was completely blocked by thiorphan and phosphoramidon. Thus the CALLA antigen present at the surface of leukemia and melanoma cell lines is an enzymatically active neutral endopeptidase.
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PMID:Common acute lymphoblastic leukemia antigen expressed on leukemia and melanoma cell lines has neutral endopeptidase activity. 252 92


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