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

A 72-year-old man with refractory anemia (RA) developed overt megakaryoblastic leukemia after the course of RA with excess of blasts. The blasts were positive for platelet peroxidase activity and had platelet glycoproteins (GPs) such as GPIIb/IIIa and GPIIIa. The bone marrow biopsy at terminal stage disclosed marked fibrosis. The nature of the megakaryoblasts was investigated. The blasts did not differentiate morphologically into mature megakaryocytes with TPA addition. In vitro colony assay showed the failure of colony-forming unit, megakaryocyte growth in peripheral blood. The pathogenesis of myelofibrosis in our patient is discussed.
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PMID:Refractory anemia terminating in acute megakaryoblastic leukemia (M7). 249 48

A case of acute leukemia with atypical malignant cells is reported. The clinical picture and coagulation studies were consistent with a disseminated intravascular coagulation syndrome. Morphologically, the leukemic cells from the peripheral blood and bone marrow showed azurophilic granules. More than 80% of cells were hypergranulated, resembling the macrogranular type of promyelocytes. Ultrastructural studies and the pattern of endogenous peroxidase were consistent with the microgranular type of promyelocytes in about 20% of the leukemic cells. Auer bodies were present in both types of atypical promyelocytes. Cytochemically, the whole malignant population exhibited intense peroxidase activity. Studies with monoclonal antibodies showed that about 45% of the proliferating cells expressed T-cell markers T3, T4, T8 and T11, but the cells were not reactive with OKM1 monoclonal antibodies. The chemotherapy for acute promyelocytic leukemia was inefficient, and the prompt disappearance of the blood abnormalities was observed only when chemotherapy for acute lymphoblastic leukemia was started. Therefore, it seems that in some cases of leukemia with hybrid types of malignant cells the morphological features determine the clinical picture, while the patient's response to the therapy is conditioned mainly by the cell surface phenotype.
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PMID:Acute promyelocytic leukemia with T-cell markers and particular response to treatment. Report of a case. 249 88

A new megakaryoblastic cell line (CMK), which also exhibits erythroid and myeloid markers, was established from a Down's syndrome patient suffering from acute megakaryoblastic leukaemia. The CMK cells were found to be positive in reactions with anti-platelet antibodies (anti-glycoproteins IIb/IIIa and Ib, and Plt-1). Platelet peroxidase (PPO) reactivity was found to be associated with the nuclear envelope and the endoplasmic reticulum but not with the Golgi apparatus. Some cells possessed cytoplasmic granules with the characteristics of alpha-granules and demarcation membranes. Karyotyping revealed near-tetraploidy (modal chromosome number of 95; ranging 87-98) and a translocation der(17)t(11;17), also found in the original leukaemic cells, confirming that the cells were derived from the patient's malignant blasts. The CMK cells were also found to be positive in reaction with anti-glycophorin A antibody, as well as with anti-myeloid antibodies (MY4, MY7 and MY9). Treatment of CMK cells with phorbol ester 12-O-tetradecanoylphorbol-13-acetate (TPA) greatly enhanced the reactivity with anti-platelet antibodies, increased the number of cells in which cytoplasm was dissociated into numerous segments and suppressed the reactivity with anti-glycophorin A. The proliferation of CMK cells was stimulated by interleukin-3 (IL-3) and granulocyte-macrophage colony stimulation factor (GM-CSF). This cell line should be a useful tool for analysing the basis of the afferent association between megakaryoblastic leukaemia and Down's syndrome, as well as for further study of megakaryocytic differentiation.
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PMID:Establishment of a human leukaemic cell line (CMK) with megakaryocytic characteristics from a Down's syndrome patient with acute megakaryoblastic leukaemia. 252 57

We analyzed the clinical and laboratory features of eight children (median age, 20 months; range, 13 months to 11 years) with acute megakaryocytic leukemia (M7) and compared the findings with those reported in the literature. The diagnosis was supported by ultrastructural examination for platelet peroxidase or immunophenotyping for glycoprotein IIb/IIIa or the von Willebrand factor protein. Two patients had Down's syndrome. Initial findings included anemia (in all patients), thrombocytopenia (in six), myelofibrosis (in three), lytic bone lesions (in two), and pronounced leukocytosis (in one). Stem cell culture studies of peripheral blood specimens revealed an aberrant phenotype of the megakaryocytes in one patient and reversal to a normal pattern after successful therapy. Remission was achieved in seven of the eight patients after aggressive chemotherapy, and four patients remained in remission 27 to 57 months after diagnosis. Three of these four patients underwent allogeneic bone marrow transplantation. M7 leukemia is not infrequent in children younger than 3 years of age, especially in those with Down's syndrome. The availability of monoclonal antibodies specific to restricted antigens of the megakaryocytic lineage has made the diagnosis of M7 leukemia both possible and practical.
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PMID:Acute megakaryocytic leukemia (M7) in children. 259 24

Ultrastructural and ultracytochemical studies were performed on blast cells from 12 Down's syndrome neonates with transient myeloproliferative disorder (TMD) and 13 Down's syndrome patients with megakaryoblastic leukaemia (MKL), in order to clarify the cytological characteristics of these cells. Average platelet peroxidase-positivity in blast cells of TMD patients was similar to that found in cases of MKL. Blast cells from subjects with TMD contained a number of different granules, namely, alpha granules, those that were myeloperoxidase (MPO)-positive, electron-lucent or basophil-like, and those containing membrane components or ferritin particles. On the other hand, granules found in the blast cells of MKL patients with Down's syndrome included the electron-lucent variety, those with membrane components and a few that were basophil-like, but not alpha and MPO-positive granules nor those containing ferritin particles. A demarcation membrane system was observed in blasts from the TMD group, but not in the MKL group. These findings suggest that blast cells in TMD patients differentiate to megakaryocytes, neutrophils, basphils and erythroblasts, while those in cases of MKL show limited differentiation to immature megakaryocytes, erythroblasts and, sometime, basophils. Such results correspond well with those of culture studies, in which TMD blasts were found to be precursors of various types of blood cells.
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PMID:Ultrastructural and ultracytochemical differences between transient myeloproliferative disorder and megakaryoblastic leukaemia in Down's syndrome. 253 35

A case of acute leukaemia is reported in which blast cells expressed some B-related antigens (namely the CALLA antigen) and no peroxidase activity at the optical level; however, some mature granular cells contained Auer rods. Simultaneous characterization of ultrastructural morphology, cytochemistry and immune phenotype was performed. There was an apparent mutual exclusion in the expression of myeloperoxidase activity and the CALLA antigen, and a heterogeneity in the CALLA expression among the blastic population. These results disagree with the hypothesis of a true biphenotypic leukaemia and demonstrate a complete heterogeneity between the lymphoblastoid cells and the myeloid ones. The interest of such a simple combined method in a case of putative hybrid acute leukaemia is emphasized.
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PMID:Interest of simultaneous ultrastructural characterization of morphology, cytochemistry and immune phenotype in a case of putative hybrid acute leukaemia. 253 24

Myeloperoxidase (MPO) is a heme containing enzyme involved in the oxygen-dependent microbicidal activity of human polymorphonuclear leukocytes (PMN). Complete hereditary and acquired MPO deficiencies are defined as lack of peroxidase activity in PMN. Using this criterion, we studied a patient with complete hereditary MPO deficiency, and a MPO deficient variant cell line of HL-60 (HL-60-A7), which we used as a model for acquired MPO deficiency. Western blot analysis showed complete absence of mature and precursor protein of MPO both in PMN from the patient and in HL-60-A7 cells. PMN from both parents had one half of normal levels of these proteins. To study further the molecular basis of this defect, we isolated an intron specific probe for MPO and used it and a cDNA probe. Both normal human bone marrow cells and the promyelocytic HL-60 leukemia cells contained MPO mRNA species of 2.8, 3.3, approximately 4, and greater than 8 kilobase (kb). The transcripts of greater than 8 and approximately 4 kb contained sequences hybridizing to a probe specific for intron 7 of the MPO gene. Bone marrow cells of the MPO deficient patient contained two species of heterogeneous nuclear (hn) RNA of greater than 8 and approximately 4 kb, but only trace amounts of the normal sized 3.3 kb MPO mRNA and undetectable 2.8 kb MPO mRNA. HL-60-A7 cells contained both greater than 8 and approximately 4 kb hnRNA, but only small amounts of normal sized 2.8 kb MPO mRNA and undetectable levels of the 3.3 kb mRNA. Southern blot analyses revealed no gross alteration of the MPO gene in both cases. Our results suggest that a pretranslational defect is one mechanism leading to MPO deficiency.
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PMID:Evidence for a pretranslational defect in hereditary and acquired myeloperoxidase deficiency. 254 Aug 60

Acute megakaryoblastic leukemia (FABM7) is an unusual but well recognized form of acute myelogenous leukemia in which the bone marrow blast cells are phenotypically recognized by the demonstration of cytoplasmic platelet peroxidase or surface staining for the IIb/IIIa platelet-specific glycoprotein. Herein, the authors report a case of acute megakaryoblastic leukemia that satisfies the accepted French-American-British criteria and in which the blast cells also exhibit evidence of myeloid differentiation, including surface MY7 (CD13) by flow cytometry and immunocytochemical positivity for myeloperoxidase. These findings suggest that megakaryoblasts may be closely related to myelomonoblasts, that they have the potential to partially differentiate along multiple phenotypic lines, and that aberrant phenotypes can occur that do not correspond to known stages of normal maturation. The authors illustrate the difficulty in classification of these aberrant phenotypes by standard cytochemical and morphologic criteria.
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PMID:Myeloperoxidase-positive acute megakaryoblastic leukemia. 254 7

Nine cases of acute leukemia presenting unusual phenotype were studied by light microscopy (LM) cytochemistry and transmission electron microscopy (TEM) immunocytochemistry with the immunogold staining (IGS) method; in addition, cytogenetic and molecular analyses were performed. The presence of myeloperoxidase (MPO) was studied at TEM in combination with immunophenotype to identify minor populations not characterizable at LM. Four of nine cases had no TEM/MPO reactivity, whereas the remaining five showed variable percentages of positive cells. Of the MPO negative cases, one was a megakaryoblastic leukemia with a positive platelet peroxidase (PPO) reaction, and three were lymphoid. Among the peroxidase positive cases, the percentage of MPO reactive cells was higher at TEM than at LM examination. In case 5 TEM analysis indicated that cells with some MPO reactivity at LM were non neoplastic myeloid cells. With this combined technique in cases 1 and 2 we excluded the presence of the MPO enzyme in CD15 positive lymphoid cells and, in another case, we documented the existence of CD19/MPO positive cells. The value of cytochemistry and immunology at the ultrastructural level for the characterization of blast cells and for the precise diagnosis of leukemia with "unusual" phenotype is illustrated.
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PMID:Relevance of ultrastructural immunocytochemistry in the characterization of unclassifiable leukemias: correlation with phenotypic and genic studies. 254 74

A 60-year-old female with fever and general lymphadenopathy was admitted to our hospital in 1979. By histological examination of cervical lymph node, she was diagnosed as B-cell malignant lymphoma, diffuse, large, stage IV B (Ann Arbor classification). In 1984, the complete remission of malignant lymphoma was observed after MOPP, COPP and VAPP chemotherapies. After 3 years, she was readmitted because of leukocytosis in which 64% immature abnormal cells were detected. By conventional cytological and cytochemical evaluations, the immature abnormal cells were identified as secondary AML cells with M 2 type (FAB), peroxidase (+), My 7 (+) and chromosomal abnormality; 48, X, -X, +4, -9, +21, del (1) (p 34), i (17 q), + M 1, + M 2. Analysis of Ig and TcR genes showed TcR-beta rearrangement. It has been reported that secondary leukemia frequently causes chromosomal abnormalities and therapy resistance. Ig gene and TcR gene analysis of secondary leukemia combined with chromosome examination, which has reported little, may be useful in predicting prognosis and therapy resistance.
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PMID:[Secondary leukemia (AML) with TcR beta rearrangement]. 255 65


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