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

The clinical significance of a low percentage of myeloperoxidase-positive blast cells in childhood acute nonlymphoblastic leukemia was determined. Of 155 consecutive cases studied by cytochemical staining methods, 14 were characterized by 4% to 15% (median 6%) myeloperoxidase-positive blasts. All 14 cases showed reactivity to Sudan black B stain, and 7 had Auer rods. The morphological subtypes of leukemia were M1 (8 cases), M2 (3), M4 (1), and M5 (2). Immunological marker studies disclosed the lymphoid-associated T11 antigen on cells from 8 of the 11 cases tested. Other lymphoid-related findings in these 8 cases included the T3 antigen and E rosette formation in 1 case each. Among cases that were prospectively studied for the expression of lymphoid-associated markers, 6 of 8 with low levels of myeloperoxidase positivity compared with only 1 of 44 with higher levels (greater than 15%) possessed such features (P less than 0.001). We conclude that low levels of myeloperoxidase reactivity distinguish cases of acute leukemia in which the blast cells coexpress lymphoid (T11 antigen) and myeloid markers.
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PMID:Clinical significance of low levels of myeloperoxidase positivity in childhood acute nonlymphoblastic leukemia. 303 78

A novel surface molecule, Tp90, is described which appears to be involved in an antigen-independent pathway of human T lymphocyte activation. The Tp90 molecule was identified by a monoclonal antibody (mAb), MX20, obtained from a fusion using spleen cells of a mouse immunized with cells from two T cell leukemia lines, Jurkat and HPB-ALL. Biochemical data show that Tp90 is distinct and physically independent from the structures already known to be involved in T cell activation, namely T11, T44 or T3/TCR. These results were confirmed by antibody-induced antigen modulation experiments. Modulation of Tp90 had no effect on the expression of T3 and of the T cell receptor. Conversely, the expression of Tp90 was not affected by modulation of the T3/TCR molecular complex by either anti-T3 or anti-TCR antibody. Functional studies showed that anti-Tp90 mAb MX20 induced high levels of interleukin 2 production in Jurkat cells. Modulation of the T3/TCR complex significantly decreased the response of Jurkat cells to stimulation by antibody MX20, suggesting that the T3/TCR complex regulates the ability of the Tp90 molecule to induce IL 2 synthesis. In addition to its effect on Jurkat cells, anti-Tp90 mAb was found to be mitogenic for peripheral blood T cells. As the magnitude of the proliferative response elicited by anti-Tp90 mAb was lower than that induced by anti-T3 mAb, the possibility was considered that only a subpopulation of T cells is reactive with anti-Tp90. Indeed as determined by FACS analyses, only 3-14% of E-rosette-positive cells were stained with mAb MX20. In addition, multicolor flow cytometry analysis showed that the Tp90+ cells belong preferentially to the CD8 subset.
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PMID:A novel 90-kDa polypeptide (Tp90) possibly involved in an antigen-independent pathway of T cell activation. 303 40

It has been suggested that the malignant transformation, in some of the acute leukemias, may involve totipotent stem cells resulting in a biphenotypic leukemia expressing both myeloid, and lymphoid characteristics. We describe here a hybrid cell acute leukemia, in a 16-day-old infant, in whom leukemic cells coexpressed myeloid and lymphoid B cell antigens. Blast cells in the bone marrow showed L2 morphology according to the French American British (FAB) classification, with positive periodic-acid Schiff, and nonspecific esterase staining. Sudan black, and specific esterase were negative. Terminal deoxynucleotidyl transferase, was strongly positive in 5% of blasts, and faintly reactive with the rest. Karyotypic analysis demonstrated a translocation of t(11:17);(q23;p13). Immunoglobulin gene analysis revealed rearrangement of the heavy chain genes. The blasts' phenotype was HLA/DR+ B4+ My7+ My9+ common acute lymphoblastic leukemia antigen (CALLA) B1- T11-. Dual immunofluorescence staining using anti My7, and My9 fluorescein isothiocyanate, and anti B4 pycoerythrin conjugated monoclonal antibodies, and flow cytofluorometry, revealed a labeling pattern of 25% B4+; 10% to 15% My7+; 17% My9+; and 50% of cells coexpressing B4 My7, and My9 antigens. These results provide evidence for a hybrid leukemia with lymphomyeloblasts being part of a single clone, which may indicate the origin of this leukemic clone from a pluripotent (lymphoid/myeloid) stem cell.
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PMID:Undifferentiated leukemia of infancy with t(11:17) chromosomal rearrangement. Coexpressing myeloid and B cell restricted antigens. 310 33

Plasmacytoid T cells (PTC) are known to home to thymic (T) zones in human lymph nodes and are characterized by their abundant, concentrically layered, rough endoplasmic reticulum. These cells have been found in reactive and neoplastic conditions. Three cases of PTC lymphomas have so far been reported. All of them were complicated by a myelomonocytic leukemia leading to the assumption of a functional relationship between PTC and the myeloid system. The immunologic phenotype of PTC, as revealed on frozen tumor tissue sections, comprised the expression of CD5 (T1), CD4 (T4), and HLA-DR, but not CD8 (T8) and CD2 (T11) and suggested an affiliation to the T cell system. Extending our previous report on one of these cases we here present the first study on the immunological marker profile of suspended PTC. The employment of unfractionated or PTC-enriched tumor cell suspensions rendered possible the application of a panel of monoclonal antibodies (moAbs) on both fixed and unfixed cells and enabled us to allocate various markers either to the intracytoplasmic or surface domain of this cell type. Our results suggest that PTC from our case rest in the G0/G1 phase of the cell cycle. They express the transferrin receptor, but not the Il-2 receptor (CD25) or the nuclear antigen Ki-67. No T cell antigen was demonstrated on the surface of unfixed suspended PTC. Under these conditions only HLA-DR and a predominantly monocytic antigen (CD36/moAb 5F1) were identified. Fixed cells, however, showed a weak cytoplasmic reactivity for CD5 and two myelomonocytic antigens (CD15/moAb 1G10 and CD14/moAb My4). Our findings do not sustain positive evidence for a T cell nature of PTC. Whether their phenotypical pattern indicates terminal differentiation with concomitant loss of T cell antigens or points to a cytogenetic relationship of PTC to the myeloid system, remains speculative. Until the cytogenesis of PTC is clarified we propose the noncommitted term "plasmacytoid T-zone cells" for this elusive cell type.
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PMID:Single cell studies on the immunological marker profile of plasmacytoid T-zone cells. 310 84

The normal tissue counterpart of hairy cell leukemia is unknown. Because of the morphologic similarities of hairy cells to reactive and lymphomatous monocytoid cells, we compared the phenotypic characteristics of seven spleens involved by hairy cell leukemia with four reactive lymph nodes containing benign monocytoid B cells and three lymph nodes diagnosed as monocytoid B cell lymphoma. The hairy cells had a phenotype of surface Ig+, B1/Leu-14+, Leu-M5+, PCA-1+, Tac+, B2-, BA-1-, BA-2-, J5-, T10-, T11-, Leu-1-, Leu-2a-, Leu-3a-. The immunophenotype of both the reactive and neoplastic monocytoid B lymphocytes was virtually identical to the hairy cells. The major difference was that monocytoid B cells failed to react with anti-Tac and that PCA-1 expression was inconsistent. Despite these variances, the immunophenotypic similarities are remarkable, particularly the common expression of B1/Leu-14 and Leu-M5 (S-HCL3), and suggest a possible lineage relationship between hairy and monocytoid B cells.
Leukemia 1987 Apr
PMID:Hairy cells and monocytoid B lymphocytes: are they related? 311 7

Development of monoclonal antibodies to lymphoid cells has allowed for simple methods for the classification of leukemias. Using the monoclonal antibodies, B1, B4, T1, T11, Ia, CALLA, My7, My9, and a polyclonal TdT reagent, we report a number of unusual phenotypes analyzed by flow cytometry. Two cases of mixed linkage leukemia are reported, one marked with anti-CALLA and My9, the other marked with T11 and Ia. Three rare cases of pediatric CLL are reported. Both were of B cell origin with chromosome transformation. These studies demonstrate the clinical importance of monoclonal antibodies in leukemia classification. The results also show that the so-called rare leukemias may not be as rare as previously thought.
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PMID:The utilization of monoclonal antibodies in the diagnosis of unusual leukemias. 318 Jan 37

Fifty cases of acute leukemia were analyzed by means of flow cytometry. The results obtained were correlated with morphology and routine cytochemistries. The panel selected was useful in classifying an acute leukemia as acute lymphocytic (ALL) or acute nonlymphocytic (ANLL), which is of primary importance for therapeutic considerations. Common ALL (CALLA) (J5) was a good marker for classifying the leukemia as ALL. Monoclonal antibodies (MoAbs) T1 and/or T11 further delineated the lymphoid leukemia as T-cell ALL while MoAbs B4 or B1 delineated the lymphoid leukemia as non-T-cell ALL. Eighteen cases of ALL were diagnosed and consisted of five cases of T-cell ALL and 13 cases of non-T-cell ALL. Both the T-cell ALL cases and non-T-cell ALL cases were found to be heterogeneous and could be further subgrouped by phenotypic expression with additional MoAbs in the panel. A monoclonal antibody panel consisting of My4, My7, My9, Mo1, and Mo2 was useful in characterizing an acute leukemia as ANLL. This panel was less useful in distinguishing myeloid from monocytic subtypes although My4, Mo1, or Mo2 when present, appeared to favor a monocytic component. Of interest, a case of biclonal leukemia with two distinct blast populations on the flow cytogram was discovered. Morphology alone was successful in diagnosing ALL from ANLL in 35 cases (70%). It was not useful in distinguishing non-T-ALL cases from T-ALL cases. The ambiguous cases could be resolved by cytometric means. Flow cytometry has much to offer as a diagnostic aid in the evaluation of acute leukemia.
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PMID:Flow cytometry in the diagnosis of acute leukemia. 325 16

Philadelphia chromosome-positive (Ph1) acute leukemia is a heterogeneous subset of acute leukemia with a poor prognosis. We studied five patients to determine the potential for phenotypic and molecular heterogeneity. Cellular characterization studies included light myeloperoxidase (L-MPO), terminal deoxynucleotidyl transferase (TdT), ultrastructural MPO (U-MPO), and immunophenotyping by flow cytometry using T11, T3, T4, T8, Leu 1, B1, Leu 12, HLA-DR (la), CALLA (J5), OKM1, My4, My7, My8, My9, and My10. DNA was analyzed for rearrangements of the breakpoint cluster region (bcr), immunoglobulin heavy chain, joining region (JH), immunoglobulin kappa light chain constant region (C kappa), and T cell receptor (TcR beta). RNA dot blots were hybridized by using molecular probes for MPO and TdT. We found that four of five cases were acute mixed-lineage leukemia (AMLL). One patient had acute unclassifiable leukemia. Of the four patients classified as having AMLL, three showed myeloid and lymphoid features, with one patient showing myeloid, T cell, and B cell features. The last case showed T cell and B cell features only. In one patient MPO/RNA was positive in spite of insufficient L-MPO or U-MPO to diagnose acute myelogenous leukemia (AML), thereby suggesting significant MPO gene expression before the production of sufficient MPO protein to meet the French-American-British criteria for AML. Three of the five patients showed rearrangement of bcr (cases 1, 2, and 5). Studies of these five patients support the concepts of molecular and phenotypic heterogeneity in Ph1 acute leukemia, demonstrate a high incidence of AMLL in this subset of acute leukemia, and support the use of lineage-associated molecular probes to define lineage at an earlier stage than previously possible.
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PMID:Phenotypic and molecular heterogeneity in Philadelphia chromosome-positive acute leukemia. 333 95

Immunological and biochemical markers of leukemia/lymphoma cells have provided valuable insight into hematopoietic malignancy and normal differentiation. The general assumption is that as early lymphoid cells become committed towards terminal differentiation they lose their capacity for bimodal differentiation and cells become restricted to B or T cell development and function. We have observed that phenotypically "late" leukemic B cells close to secretory stage can spontaneously express mature T cell antigens (T11, T4 and T8) after culture in vitro. In further studies of these cells, it was found that the biochemical marker lactate Dehydrogenase (LD) follows the intermediate pattern expressed by thymocytes rather than that of typical B cells. The expression of T cell antigens can be blocked by incubating these cells with the phorbol ester TPA (12-0-tetradecanoyl phorbol 13 acetate) which promotes unidirectional B cell maturation to plasmacytoid cells in a way that mimics normal B cell differentiation. These observations indicate that presecretory malignant B cells are still programmed to express T cell biochemical and antigenic markers and this expression can be influenced by environmental conditions in vitro.
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PMID:Secretory leukemic B cells express T cell markers in vitro. A phenomenon suppressed by TPA. 348 92

Rearrangement of germ-line genes coding for T and B cell antigen receptor molecules is an early event in lymphoid development which eventually leads to the generation of clonal diversity in receptor-positive lymphocytes. Three T cell-associated rearranging genes have been described. Two, T alpha and T beta, code for the two polypeptide chains that form the T cell receptor heterodimer. The function of the third gene, the gamma-gene (T gamma), is not known. To learn more about the behavior of T gamma during lymphoid ontogeny, we compared rearrangement of T gamma and T beta genes in leukemic cells arrested at varied stages of lymphoid and myeloid development. We analyzed 38 fresh cell lines and 15 established cell lines from a total of 53 leukemic patients. Cells were immunophenotyped with a panel of monoclonal antibodies recognizing T-, B-, or myeloid-associated surface markers. Sixteen T-lineage cases were studied; 15 displayed both T beta and T gamma rearrangements. The exception (germ-line for T beta and T gamma) was an immature CD2(T11)+, CD3(T3)-, CD7(3A1)+, CD1(T6)+, CD5(T101)+ phenotype. Fourteen non-T non-B leukemias were analyzed; eight were germ-line for both T beta and T gamma, four had rearrangements involving both T beta and T gamma, and two were germ-line for T beta and rearranged to T gamma. Four cases with acute biphenotypic leukemia were studied; two had rearrangements of T beta and T gamma, and two were germ-line for both genes. Cells from nonlymphocytic leukemias were studied in 19 cases. All were found to be germ-line for both T beta and T gamma. Fifty-one of 53 genomic DNA samples were concordant for T gamma and T beta rearrangement. These results indicate that rearrangement of T gamma can occur in leukemic cells of B cell as well as T cell precursor origin, as has been reported previously for T beta.
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PMID:Human T cell gamma-chain gene rearrangements in acute lymphoid and nonlymphoid leukemia: comparison with the T cell receptor beta-chain gene. 348 46


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