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

The immunophenotype of leukaemia cells from 60 patients with acute myeloid leukaemia (AML) was analysed with the APAAP technique using a panel of anti-myeloid and lymphoid associated monoclonal antibodies (McAb). Cells from all cases, including three with negative cytochemical features, were labelled by at least one of the anti-myeloid McAb CD13, anti-myeloperoxidase (anti-Mpo), and/or CD14. The most sensitive marker was CD13, since it was positive in 90% of cases. In two out of three AML cases defined as M0-AML, CD13 was expressed in the cytoplasm but not on the membrane; in these three cases peroxidase (Mpo) was not detected by conventional cytochemistry, but could be demonstrated in all of them using the McAb anti-Mpo. The simultaneous expression of CD14 and CD68 McAb was often confined to the M4 and M5 FAB AML subtypes (92% cases) as compared to the others: M1, M2, M3 (18% cases). Lymphoid antigens were rarely positive (TdT+: 13%, CD7+: 15%, CD19+: 5%) and none of the AML cases were CD3+ or CD10+. By contrast, CD4 was expressed in blasts from 44% of cases and this was not restricted to AML with a monocytic component (M4, M5) but also found in other subtypes. There were no significant differences in the clinical or prognostic features according to the positivity or negativity with TdT and CD4. By contrast, expression of CD7 was associated with refractoriness to the treatment or short complete remission duration, although the number of patients is too small to draw firm conclusions. Our findings support the clinical and diagnostic relevance of immunophenotypic studies in AML.
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PMID:The value of detecting surface and cytoplasmic antigens in acute myeloid leukaemia. 132 89

Between 1983-1988 bone marrow samples obtained from 195 peroxidase-negative leukemia patients were analyzed for their surface antigens. Thirteen of these patients (6.7%) had myelomonocytic-positive and lymphoid-negative antigens. These leukemic cells reacted with CD13 in eight patients, CD33 in seven, CD11 in six and CDw41 in two. In none of these patients did the leukemic cells react with CD1, CD2, CD3, CD4, CD5, CD8, CD10, CD19 or CD20. Leukemic cells from two patients were reactive with CD7. These leukemic cells demonstrated L2 morphology in 11 patients and L1 morphology in one patient. The leukemic cells from the final patient were diagnosed as those of leukemic transformation of myelodysplastic syndrome. Chromosomal abnormality was observed in approximately half of the patients examined (6/10). Cytochemical analysis revealed that the leukemic cells were negative for periodic acid Schiff stain but positive for acid phosphatase. The prognosis of these patients was markedly poor as compared to acute lymphocytic leukemia or typical peroxidase-positive nonlymphocytic leukemia. Complete remission was induced in only 30% of patients and duration of survival was short (4.7 months). This suggests that myelomonocytic antigen-positive peroxidase-negative acute leukemia is a distinct type of leukemia and may require more aggressive therapy to improve survival.
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PMID:Peroxidase-negative and myelomonocytic antigen-positive acute leukemia. 132 47

Philadelphia chromosome (Ph') was detected at presentation in 10 out of 110 patients with acute lymphoblastic leukemia (ALL) and five of 168 patients with acute myelogenous leukemia (AML). Two other ALL patients who had studies at relapse were also included in the analyses. One of the 12 Ph'-positive (Ph+) ALL patients had simultaneous expression of myeloid-associated antigen on the leukemic blasts, while all the five AML patients coexpressed markers of lymphoid cells. Double labeling of the cells with myeloperoxidase and CD10 on three Ph+ AML cases showed that most leukemic blasts expressed either myeloperoxidase activity or CD10 but not both. Cross-lineage gene rearrangements of T-cell receptor (TCR) beta-chain gene were detected in three of the eight Ph+ ALL patients tested. All the four Ph+ AML cases studied showed immunoglobulin heavy chain gene rearrangements, and three of them also had simultaneous rearrangements of TCR beta-chain gene. The results revealed that Ph+ acute leukemia in this study belonged either to ALL or mixed lineage leukemia, and none was pure AML. This finding is contrary to that of acute blast crisis of chronic myelogenous leukemia in which the majority of patients had myeloid transformation. Rearrangements of bcr were detected in four of the 10 Ph+ ALL and three of the four Ph+ AML patients tested. No significant difference was noted in the clinical or hematologic manifestations among Ph+ leukemia with or without bcr rearrangements.
Leukemia 1992 Sep
PMID:Characterization of Philadelphia-chromosome-positive acute leukemia by clinical, immunocytochemical, and gene analysis. 132 82

Expression of numerous genes encoding myeloid-specific proteins is tightly regulated during normal myeloid differentiation. This heterogeneous group of genes thus offers a tool for dissection of different maturational steps of myelopoiesis. We have previously shown that the human myeloperoxidase (MPO) gene is modified at numerous CpG residues in normal myeloid cells and in myeloid cell lines in a development-specific and expression-associated manner. In the present work, we have applied this type of methylation analysis to primary leukemia myeloid cell samples. We found that expression of MPO messenger RNA (mRNA) is grossly limited to leukemias of late myeloblastic and promyelocytic stages; expression is thus associated with progressive demethylation in the 5' region of the MPO gene. This modification was not global. Low-level induction of MPO mRNA expression in very immature leukemic cells using phorbol ester was not accompanied by progressive demethylation. This type of methylation analysis of a myeloid-specific gene may yield a molecular indicator for different types of myeloid leukemias.
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PMID:A switch toward demethylation is associated with the expression of myeloperoxidase in acute myeloblastic and promyelocytic leukemias. 132 88

Development of a fixation allowed flow cytometric analysis of nuclear and intracellular antigen in leukemic cells. In this paper the analyzing procedure of cytoplasmic myeloperoxidase by FCM was described. This procedure is more sensitive than cytochemical staining of fixed cell smears and more specific than cell surface immunophenotyping by CD13, CD14, CD33. So, this technique is useful for classification of myelogenous leukemic cells especially MO type leukemia by FAB classification. This technique also allowed two color analysis of cell surface antigens and cytoplasmic antigens. Mixed lineage leukemia can be easily and accurately classified by using of this procedure.
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PMID:[Quantitative analysis of cytoplasmic myeloperoxidase positive leukemic cells by FCM]. 133 19

A newly established human monocytic cell line, SKM-1, showed strong expression of myeloperoxidase mRNA, to the same extent as in HL-60 cells. We studied the cell morphology and myeloperoxidase expression of this cell line, which was established from a patient with myelodysplastic syndrome who had an abnormal chromosome on the upstream region of 17p13. Electron micrographs showed the cells to have a fragile and irregular cell surface. SKM-1 cells were peroxidase-positive. About 60% of myeloperoxidase (MPO) was released to the culture fluid from SKM-1 cells but only a few percent of MPO was released from HL-60 cells into the culture fluid. The predominant mRNA size of SKM-1 myeloperoxidase was 3.3 kb although there was a smaller size as well. Fluorescent in situ hybridization of MPO mRNA showed strong staining in 5% to 10% of SKM-1 cells and of bone marrow cells from patients with myelogenous leukemia, while all cells from HL-60 were positive.
Leukemia 1992 Dec
PMID:The monocytic cell line SKM-1 strongly expresses the myeloperoxidase gene. 133 56

Blood samples from 40 adult patients with untreated acute leukaemia were processed through the Technicon H*1 blood autoanalyser which gives a complete white cell differential count using flow cytochemistry and provides white cell cytograms as well. We examined the differences in the percentage differential counts and the white cell cytograms of various FAB types of acute leukaemia in an attempt to estimate the usefulness of this easily obtainable data for the identification of acute leukaemias. Differentiation of the 33 acute myeloid leukaemia (AML) cases from the 7 acute lymphoblastic leukaemia (ALL) cases was possible on the basis of lymphocyte percentage (AML mean 29.6 vs. ALL mean 67.1, p < 0.01), monocyte percentage (AML mean 12.5 vs. ALL mean 3.3, p < 0.001), mean peroxidase activity value (AML mean -12.6 vs. ALL mean -0.6, p < 0.01) and the absence of IG flag (circulating immature granulocytes) in ALL. Interestingly, the FAB subtypes of AML could be distinguished from each other on the basis of characteristic patterns of cell distribution in the peroxidase cytogram when the total white cell count was over 10 x 10(9)/l. Even with lower counts the differences were distinctive providing that circulating blasts were present.
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PMID:Use of flow cytochemistry via the H*1 in FAB identification of acute leukaemias. 133 11

Merocyanine 540 (MC540) is a photosensitizing dye that has been used in several preclinical models and in a phase I clinical trial for the extracorporeal purging of tumor cells from autologous bone marrow grafts. The mechanism of the cytotoxic activity of MC540 is not yet fully understood, and the subcellular targets of MC540-mediated photodynamic damage remain to be identified. The human neutrophil provides an attractive model with which to study the effects of photoactivated MC540 on several well-defined cellular functions. As we report in this paper, simultaneous exposure of neutrophils to MC540 and light inhibited phagocytosis, random migration, chemotaxis, hydrogen peroxide production, and oxygen consumption. By contrast, the ability of neutrophils to kill engulfed bacteria and to produce superoxide radical was not compromised. Intracellular ATP levels and the activities of the cytosolic enzymes superoxide dismutase, catalase, and myeloperoxidase were only slightly reduced. Even in HL-60 leukemia cells, which bind more dye and are more readily killed by MC540-mediated photodynamic therapy than neutrophils, superoxide dismutase, catalase, and myeloperoxidase activities remained at normal or near-normal levels. These results are compatible with the view that plasma membrane components are primary targets of MC540-mediated photodynamic damage.
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PMID:Photodamaging effects of merocyanine 540 on neutrophils and HL-60 cells. 133 24

Cytochemical analysis of leukemic blasts from 46 patients with acute myeloblastic M2 leukemia (according to the FAB classification) was performed before and after cytostatic therapy, and compared with findings obtained in 20 age- and sex-matched control subjects. Cytochemical findings for myeloperoxidase (MPO), Sudan black B, acid phosphatase and alpha-naphthyl-acetate esterase (ANAE) were related to the achievement of the first complete remission (CR), i.e. data were compared after the patients had been divided into CR and non-CR groups. The analysis clearly showed that a high proportion of myeloperoxidase- and, to a lesser extent, Sudan black B-positive blasts before treatment may have constituted a significantly unfavourable prognostic factor.
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PMID:Prognostic significance of cytochemical analysis of leukemic M2 blasts. 134 19

FAB Cooperative Group has cited 3 or higher percentage in the peroxidase (PO) activity as one of criteria for the diagnosis of acute myeloid leukemia. We have previously reported in two cases of acute myelomonocytic leukemia (M4) that there was a great difference between 3,3'-diaminobenzidine (DAB) and 3-amino 9-ethyl carbazole (3AC) as substrates for PO reaction. In order to confirm the previous result, we extended the cases and compared the PO activities in blood films taken from several leukemic subjects, which were fixed with various kinds of fixatives, using DAB and 3AC as substrates. Their peroxidase activities were also determined through electron microscopy (EM-PO). There were no differences among fixatives and substrates in staining normal granulocytic cells (neutrophils and monocytes) and cells in 13 cases of leukemia, except for two cases, one with M4 and the other with relapse of M2. These showed the highest PO activity with 3AC staining and 10% formaldehyde acetone buffer for fixation. Besides, all types manifested the highest positivity in EM-PO, except for the relapse of M2 that showed a higher positivity in the peroxidase stain by 3AC staining, 10% formaldehyde acetone buffer fixation than the EM-PO. Unlike other leukemic blasts PO reaction products of blast cells of the two cases showed a scattered distribution of microscopic granules. These findings suggested the difference, which was seen in the previous reports, of the PO stain between two substrates might be due not only to sensitivity for staining but to the presence of some heterogeneity such as isoenzyme in the myeloperoxidase.
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PMID:[The sensitivity and specificity of various peroxidase stains--the difference between DAB and 3AC stainings]. 137 54


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