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

Acute megakaryoblastic leukemia is a rare leukemia that can present diagnostic problems. We describe two children who have this disease and had clumps of blast cells in their bone marrow, a finding usually attributed to metastatic tumor. The megakaryocytic origin of the cells was supported by their cytochemical staining pattern (positive alpha-naphthyl acetate esterase resistant to sodium fluoride inhibition and negative alpha-naphthyl butyrate esterase) and by the presence of factor VIII-related antigen. Ultrastructural studies of blast cells from one patient demonstrated platelet peroxidase. The mechanism of blast cell clump formation in these cases is unknown; nevertheless, awareness that this feature can occur in acute megakaryoblastic leukemia may avoid a misdiagnosis of metastatic solid tumor.
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PMID:Acute megakaryoblastic leukemia. Blast cell aggregates simulating metastatic tumor. 393 5

Megakaryocytopoiesis was investigated with a polyclonal (26 cases) and a monoclonal (20 cases) antibody to factor-VIII-related antigen (factor VIII RAg) with the indirect peroxidase-antiperoxidase (PAP) method on air-dried bone marrow aspirates (BM). Numerous megakaryocyte precursors were identified in 5 patients with essential thrombocythemia (ET) and the 2 patients with acute myelogeneous leukaemia (AML) after recovery from therapeutic aplasia. Small megakaryocyte precursors were rare in controls (C), patients with reactive thrombocytosis (RT) and immune thrombocytopenia (IT). In 2 patients with severe alcoholism the number of mature megakaryocytes increased after 5 and 7 days of abstinence, respectively.
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PMID:Megakaryocytopoiesis in different forms of thrombocytosis and thrombocytopenia: identification of megakaryocyte precursors by immunostaining of intracytoplasmic factor-VIII-related antigen. 393 62

77 Scottish haemophiliacs and 22 Danish haemophiliacs were serologically tested for antibodies to human T-cell leukaemia virus III (HTLV-III). Since 1979 the Scottish patients had been treated largely with factor VIII concentrate produced in Scotland, whereas all but 2 of the Danish patients had received both locally prepared concentrate and commercial concentrate made from US donor material. 15.6% of Scottish and 59.1% of Danish haemophiliacs were antibody positive (p less than 0.001). None of 11 haemophiliacs not treated in the period 1979-84 was seropositive. 2 (6.7%) of 30 subjects who had been treated with locally produced concentrate only were antibody positive, compared with 23 (39.7%) of 58 subjects who had been treated with commercial concentrate. Among 52 users of both commercially and locally produced factor VIII concentrate, seropositivity was directly correlated with the consumption of commercial concentrate (p less than 0.001) but not locally produced material. These data indicate that European haemophiliacs were exposed to HTLV-III via some factor VIII concentrates obtained from the USA.
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PMID:HTLV-III seropositivity in European haemophiliacs exposed to Factor VIII concentrate imported from the USA. 615 Oct 53

Acute leukemia with megakaryocytic differentiation has been an uncommonly recognized disorder. We used specific monoclonal and polyclonal antibody reagents (HP1-1D antibody and anti-factor VIII antibody, respectively) and an immunocytochemical staining technique to identify the megakaryocytic nature of the leukemic cells of 12 patients who presented with acute leukemia. The leukemic cells of our patients demonstrated the presence of one or both of these platelet- and megakaryocyte-related antigens, but were negative for all of the commonly employed cytochemical and immunocytochemical staining reactions, except for diffuse acid phosphatase activity and granular PAS positivity. Morphologically, the leukemic cells varied in size from 10 to 40 microns in diameter, frequently had cytoplasmic budding, and contained occasional vacuoles and/or peroxidase-negative azurophilic granules. Five patients presented with syndromes of acute myelofibrosis, and seven patients had otherwise unclassifiable acute leukemias, including three patients who had secondary leukemias. Diffuse reticulin myelofibrosis was present in all cases in which it was sought. Chromosomal abnormalities of leukemic cells were found in five cases. Two patients had deficiencies of plasma coagulation factor V. Study of one patient revealed significant platelet dysfunction. When cytoreductive chemotherapy of leukemia was attempted, the observed response was generally poor, with the exceptions of one patient who has remained in complete remission following treatment with etoposide (VP-16) and a second patient who attained remission following bone marrow transplantation. These cases of acute megakaryoblastic leukemia represented from 3.6% to 9.3% of all acute leukemia cases diagnosed concomitantly in our institution. Acute leukemia with megakaryocytic differentiation may occur more frequently than previously recognized, may present with differing syndromic features, and can be identified by the use of specific antibody reagents and relatively simple immunocytochemical techniques.
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PMID:Acute leukemia with megakaryocytic differentiation: a study of 12 cases identified immunocytochemically. 637 77

The glycoprotein fibronectin is, as well as by various other cells, also produced in leucocytes and is said to play an important role in malignant transformation of cells. Therefore, the behaviour of plasma fibronectin and of factor VIII R:AG was investigated in acute leukaemia in order to prove their significance as prognostic and therapeutic markers (method: electroimmunoassay). In patients with acute myeloid leukaemia (n = 29) and acute lymphoblastic leukaemia (n = 11) no significant changes in fibronectin concentration could be evaluated. Fibronectin levels declined significantly only during therapy with asparaginase in patients with acute lymphoblastic leukaemia, probably as a result of disturbed synthesis in the liver. Using crossed immunoelectrophoresis against fibronectin antiserum, one normal and one slower migrating antigen (FN:C) could be observed in nearly all plasma samples in patients with acute leukaemia. By means of in vitro tests with highly purified substances and intermediate gel electrophoresis it could be shown that FN:C represents fibronectin which has bound fibrinogen, probably crosslinked by activated factor XIII. Factor VIII R:AG was found to be greatly raised in patients with acute leukaemia--up to 1400% of the normal level. Increased levels correlated well with a worsening of the disease. The protein seems to be suitable for estimating the activity and prognosis of acute leukaemia.
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PMID:Fibronectin and factor VIII-related antigen in acute leukaemia. 640 58

Twenty cases of leukemia involving platelet precursors have been identified by a panel of monoclonal and polyclonal antiplatelet antibodies and by the ultrastructural demonstration of platelet peroxidase (PPO). The two techniques were in close agreement both for identification and for the quantitation of the blast cells except in three cases where PPO was present in the absence of the immunological markers. The immunological appearance of the leukemic megakaryocytic precursors was identical to that of their normal counterparts; the cells were positive with J 15 (anti GP IIb-IIIa complex), C 17 (anti GP IIIa), J 2 (anti GP 26,000) AN 51 (anti GP Ib). A diffuse cytoplasmic labelling was observed with anti factor VIII vwF and anti platelet factor 4 (PF 4). In addition, the leukemic maturation was quite similar to normal megakaryocyte differentiation since in micromegakaryocytes the expression of Gp Ib was strong and an intense granular pattern of labelling with anti factor VIII vwF and anti PF 4 was observed. In no case was the leukemic megakaryocytic series labelled by anti-erythroid antibodies, anti myeloid antibodies or J 5, B 1, OKT 11 antibodies. Using ultrastructural immunoferritin with J 15 it was possible to demonstrate that labelling with this antibody only occurred on PPO-positive cells. Immunogold or peroxidase labelling with AN 51 at the EM level in cases of mixed leukemia showed that Gp Ib was absent from proerythroblasts and myeloblasts. Therefore, in no case were specific platelet markers expressed in the leukemias of other cell lineages.
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PMID:Immunological characterization of the leukemic megakaryocytic line at light and electron microscopic levels. 649 54

Thromboembolic and haemorrhagic complications are not rarely seen in the course of malignant diseases. The underlying coagulation disorders were investigated by means of coagulation analysis in 61 patients with solid tumors and 60 control persons as well as 51 patients with leukemia and 50 control persons. As a cause for the thrombotic diathesis in patients with solid tumors and leukemias can be demonstrated a hypercoagulability (shortened PTT and raised factor VIII activity). In addition we found a raised level of fibrinogen, a hypofibrinolysis (prolonged euglobulin lysis time) and in increased platelet aggregation in patients with solid tumors. Predominantly bleeding complications in leukemias are caused by thrombopenia. Another reason, however, may be an activated fibrinolysis or a clot instability because of the reduction of factor XIII. Pathogenetic mechanisms, underlying the tumor induced coagulation disorders, as for example the release of tumor cell thromboplastins from malignant cells are discussed.
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PMID:[Coagulation disorders in tumors and hemoblastoses]. 675 31

Factor VIII procoagulant activity (VIII:C), factor VIII related antigen (VIIIR:AG) and von Willebrand factor activity (ristocetin cofactor, VIII:WF) were estimated in plasma from 37 patients with acute leukaemia. Of 25 patients in the active state of the disease, before or during cytostatic treatment, 19 (76%) showed abnormally high VIIIR:AG levels, between 240 and 780 U/100 ml. Fifteen of them also had elevated VIII:C and VIII:WF (184--480 U/100 ml and 182--360 U/100 ml respectively). The ratio of VIIIR:AG to VIII:C in this group of patients ranged from 0.53 to 4.39 with a mean of 1.35 +/- 0.8. Of 12 patients in partial or complete remission, only 3 (25%) had elevated VIIIR:AG. Four other patients showed high levels of VIII:C and normal values for VIIIR:AG and VIII:WF. The ratio of VIIIR:AG to VIII:C in the patients during remission ranged from 0.46 to 2.86 with a mean of 0.98 +/- 0.7. No relationship was apparent between the factor VIII-related activities and cytochemical type of leukaemia or leucocyte count in peripheral blood. Crossed antigen-antibody electrophoresis of factor VIII protein which was performed in 5 patients with high levels of VIIIR:AG turned up to be completely normal. In the vast majority of patients, plasma fibrinogen and serum fibrinogen degradation products were within the normal range.
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PMID:[Factor VIII complex activities in acute leukemia]. 679 20

Although the exact mechanism for the progression of myelofibrosis in acute megakaryoblastic leukaemia is unclear, certain humoral factors released from the proliferating megakaryoblasts that are unable to store these factors in their defective alpha-granules, including platelet derived growth factor (PDGF), fibroblast growth factors (FGF), platelet factor-4 (PF-4), transforming growth factor-beta (TGF-beta) and beta-thromboglobulin, could result in increased collagen synthesis by bone marrow fibroblasts. Recently, the human megakaryoblastic leukaemia cell line MEG-01 has been shown to produce both TGF-beta and PF-4 which have enhanced the growth of bone marrow fibroblasts. Therefore, we have examined the presence of a fibroblast growth stimulating activity and the humoral factors that might be responsible for it in the supernatant of the human megakaryoblastic leukaemia cell line ELF-153 recently established in our laboratory from a patient with acute myelofibrosis. A new fibroblast growth stimulating activity has been identified in the supernatant of the ELF-153 human megakaryoblastic leukaemia cell line that is independent of the percentage of fetal calf serum in NRK-49F fibroblast agar clonogenic assays and is not due to any of the known fibroblast growth stimulating humoral factors including PDGF, epithelial growth factor, TGF-alpha or beta, tumour necrosis factor-alpha, interleukin-1, 2, 4 or 6, FGF, fibronectin, PF-4 and factor VIII AG. Also, in vivo, subcutaneous injection of ELF-153 megakaryoblastic leukaemia cells into nude mice formed, in three out of the five mice after 6 weeks, subcutaneous tumours with a very rigid texture whose histological examination revealed dense infiltration by blast cells and pronounced reticular fibrosis. Immunohistochemistry demonstrated exclusive deposition of collagen III in the extracellular matrix whereas laminin and collagen IV were absent.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A new fibroblast growth stimulating activity from the human megakaryoblastic leukaemia cell line ELF-153: in vitro and in vivo findings. 748 50

An immunohistochemical study by avidin-biotin-peroxidase was performed on paraffin-embedded and decalcified bone marrow biopsies in 31 acute leukemias (19 myeloid and 12 lymphoblastic). The Ulex Europaeus lectin and 14 antibodies (anti-CD45, -CD34, -myeloperoxidase, -lysozyme, -CD15, -CD68, -carcinoembryonic antigen, -factor VIII-related antigen, BNH9, anti-CD45RO, -CD3, -CD20, DBB42 and DBA44) were tested. All acute myeloid leukemias from M0 to M5 type were stained by either the anti-myeloperoxidase or anti-lysozyme antibodies. CD68, CD15 and the carcinoembryonic antigen were respectively expressed in 80%, 40% and 20% of myeloid leukemias from M1 to M5 type. The Ulex Europaeus lectin and the anti-factor VIII-related antigen antibody stained only the M7 leukemia and the anti-CD3 antibody stained only the T acute lymphoblastic leukemia. DBB42 was expressed by 63% of B-lineage lymphoblastic leukemias and CD20 by 36%. No leukemia was stained by DBA44. Immunohistochemistry on bone marrow biopsy can assess the lineage of most acute leukemias with the use of a panel of antibodies such as the anti-myeloperoxidase, -lysozyme, -CD68, -CD20, DBB42, -CD3, BNH9, anti-factor VIII-related antigen antibodies and the Ulex Europaeus lectin.
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PMID:[Immunohistochemical characterization of acute leukemia. Study of 31 bone marrow biopsies]. 753 64


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