UMLS:C0026986 - FACTA Search

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Query: UMLS:C0026986 (myelodysplastic syndrome)
14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Evaluating the proliferative activity of the immature erythro- and myelopoiesis as well as the mature myelopoiesis in 21 MDS patients and 14 healthy controls by simultaneously staining bone marrow cells for surface phenotype and DNA content, we found the percentages of proliferating S-phase cells in the early stage of MDS were higher. With disease progression evaluated by the FAB classification this parameter decreased significantly for both the immature myelo- and erythropoiesis. Evaluation of the proliferative activity of the mature myelopoiesis defined by the CD66 antigen revealed no difference between the normal controls and the MDS patients. Using another assay simultaneously labelling bone marrow cells for three leucocyte differentiation antigens during treatment with GM-CSF and low-dose AraC the cells clearly differentiated in one case. In another patient the disease seemed to progress as evaluated by cells only expressing immature antigens. The above mentioned immunophenotypic changes persisted at least one month after termination of treatment. In conclusion, the evaluation of proliferation and differentiation of leucocyte subsets using multiparameter flowcytometric assays in myelodysplastic patients from different FAB groups before as well as during treatment with haemopoietic growth factors may prove valuable in the future.
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PMID:Myelopoiesis in myelodysplasia evaluated by multiparameter flow cytometry. 875 Jun 19

The survival, proliferation, differentiation and function of normal hematopoietic cells are negatively and positively controlled by various cytokines. Survival and proliferation of leukemic cells appears to be influenced, at least in vitro, by several cytokines. Among the different hematopoietic cell lineages, megakaryocytopoiesis represents a complex and unique hematopoietic system that is thought to be supported by some well-known cytokines; however, the hypothetical lineage-specific main regulator of platelet production, termed thrombopoietin (TPO) had remained elusive. Recently, characterization of the proto-oncogene c-mpl revealed structural homology with the hematopoietic cytokine receptor superfamily, specific expression on cells of the megakaryocytic lineage and functional involvement in megakaryocytopoiesis. Several groups purified and cloned the MPL ligand. Extensive in vitro and in vivo studies have shown that the MPL ligand has activity in stimulating both megakaryocytopoiesis and platelet production proving that this ligand is the long-sought growth factor TPO itself. The MPL receptor was found at the mRNA and/or protein level in 40-80% of primary acute myeloid leukemia (AML) cases in various series. MPL expression was not limited to certain morphological FAB types, although the highest percentages were seen in the M6 (erythroid) and M7 (megakaryocytic) subclasses. Among the myelodysplastic syndromes (MDS), MPL expression was detected in one third of the cases, in particular in refractory anemia with excess of blasts and chronic myelomonocytic leukemia. Lymphoid malignancies such as acute lymphoblastic leukemia (ALL), non-Hodgkin's lymphoma (NHL) and myeloma were MPL-negative. Among the large panel of human leukemia-lymphoma cell lines studied, MPL expression occurred predominantly in lines with erythro-megakaryocytic phenotypes. Nearly all primary and continuously cultured non-hematopoietic solid tumor samples were negative for MPL expression. A significant portion of AML cases and of erythroid, megakaryocytic and myeloid leukemia cell lines co-expressed TPO and MPL mRNA transcripts, although no biologically active TPO appeared to be secreted by these cells. In several studies TPO induced in vitro proliferation of 14-37% of primary AML cases, predominantly of the M2 and M7 subtypes. TPO significantly enhanced the cytokine-induced growth of AML cells in a substantial fraction of cases responsive to GM-CSF, IL-3, IL-6 or SCF. While none of 30 growth factor-independent erythro-megakaryocytic leukemia cell lines responded to TPO with increased proliferation, TPO strongly augmented the growth of several constitutively cytokine-dependent cell lines (eg HU-3, M-07e, TF-1) which can be made TPO-dependent and used as bioassays. Neither in primary cells nor in cell lines did TPO appear to induce any signs of morphological, functional or immunological differentiation. Expression of the MPL receptor is not correlated with a proliferative response to TPO. In summary, extensive studies on normal human and animal cells demonstrated the specificity and function of the MPL receptor and proved that its ligand TPO is the major physiological regulator of megakaryocytopoiesis. The data reviewed here document the wide expression of the MPL receptor on AML cells and also suggest some proliferative effects on certain leukemia cells, apparently on non-megakaryocytic AML cells as well. Thus, experimental evidence supports the notion that TPO may contribute, at least in part, to leukemogenesis, especially in combination with other hematopoietic cytokines which is of clinical significance. TPO-responsive cell lines represent powerful tools for such analyses.
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PMID:Thrombopoietin: expression of its receptor MPL and proliferative effects on leukemic cells. 875 57

G-CSF and GM-CSF have been shown in each clinical setting to reduce the duration of neutropenia, with the exception of the scant data available in the unrelated bone marrow transplant setting. These growth factors also have been shown to have no leukemogenic effect during the observation periods of the trials discussed. In MDS, one major randomized trial has demonstrated a reduction in incidence of infection. This has not yet been demonstrated in AML and allogeneic BMT. Data from ongoing and future trials will be helpful in elucidating their effect on treatment-related morbidity and overall survival.
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PMID:Clinical use of granulocyte-macrophage colony-stimulating factor and granulocyte colony-stimulating factor in neutropenia associated with malignancy. 881 4

Myeloid cells arise from a common stem cell whose development is regulated by stimulatory and inhibitory growth factors. Pluripotential hematopoietic stem cells are most influenced by IL-3, GM-CSF, and stem cell factor while committed progenitor cells are regulated by variable concentrations of GM-CSF, G-CSF, M-CSF, IL-5, Epo, and Tpo. As a result of their common origin, a key point to remember about myeloproliferative disorders is the involvement of multiple cell lines in dysplastic and neoplastic conditions. Dysplastic changes may signal early neoplastic changes with cases progressing to acute leukemia. Myelodysplastic syndrome (MDS) is associated with anemia or multiple cytopenias, normal to hypercellular bone marrow, ineffective hematopoiesis, and less than 30% blast cells of all nucleated cells in the bone marrow. Chronic myeloid leukemias also have less than 30% blast cells of all nucleated cells in the bone marrow and are distinguished from MDS by elevated cell counts of one or more cell lines with mature forms predominating. Acute myeloid leukemias, often the end result of all myeloproliferative disorders, are recognized by equal or greater 30% blast cells of all nucleated cells in the bone marrow. Additional diagnostic information from cytochemical stains, immunohistochemical staining, and cytogenetic analysis can influence the final diagnosis when morphology alone is equivocal. In conclusion, prognosis and response to treatment are best determined by application of a uniform set of standards in evaluating hematolymphatic neoplasia. Critical to diagnosis are complete blood and bone marrow evaluations including observation for dysplastic changes and blast cell quantitation. In addition, evidence for tissue infiltration identified through cytologic or histologic evaluations of lymph node, spleen, or liver is recommended.
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PMID:Myelopoiesis and myeloproliferative disorders. 886 89

Growth factors are commonly included in protocols for the treatment of acute myeloblastic leukemia (AML). Because the response of blast stem cells in culture to growth factors might influence the contribution of factor to clinical outcome, we studied 42 patients with AML or severe myelodysplasia. Peripheral blood blast cells were cultured in a clonogenic assay at three cell concentrations and with the following combinations of growth factors: no added growth factor (NF), G-CSF, GM-CSF, Kit ligand (KL), G-CSF + KL, GM-CSF + KL, and G-CSF + GM-CSF + KL. The slope of the line relating cell number plated to colony formation was calculated by least squares. The slopes were used to form three equally sized groups of patients. Marked heterogeneity was found in response of the blast populations to factor. A few general conclusions emerged: (1) autonomous blast populations are very rare; (2) although usually a population responds better to one of the growth factors than to others, seldom is the response exclusively to one factor; (3) when more than one factor is included in the cultures, synergism is usually seen. Significant associations were seen between successful remission induction for low slope values in cultures with NF or KL alone. For remission, but not survival, associations were found with intermediate values of slope in cultures with G-CSF + KL and GM-CSF + KL. We conclude that measurements of growth factor response are feasible and yield clinically useful data.
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PMID:Response of the blast stem cells of acute myeloblastic leukemia to G-CSF, GM-CSF, or the ligand for C-KIT, alone or in combination. 887 30

In the early stages of the development of granulocytic colony-stimulating factors (G-CSF and GM-CSF) in oncology and hematology, myeloid malignancies were considered to be a contraindication to their use. In fact, myeloid leukemic cells bear specific receptors for G-CSF and GM-CSF and these CSFs induce an in vitro proliferation in primary blast cells of most patients with acute myeloid leukemia (AML). In addition, autocrine or paracrine loops of stimulation have been demonstrated in some cases. Despite these theoretical risks of blast proliferation, G-CSF and GM-CSF have been extensively tested in patients with AML or myelodysplastic syndromes. Major objectives were the correction of acquired or chemotherapy-induced neutropenia, but also the reinforcement of the antileukemic efficacy of cytotoxic agents. Recently, G-CSF has also been used to mobilize hematopoietic progenitors in the peripheral blood. Major results of several double-blind clinical trials are the demonstration of the safety of CSF administration in these patients, since no risk of in vivo blast cell regrowth has been observed, and their efficacy to shorten the duration of chemotherapy-induced neutropenia. However, no significant reduction in the treatment-related mortality and no survival improvement were afforded by the use of these CSFs. From another point of view, the search for AML-specific CSF-receptor or CSF-receptor associated molecule abnormalities represents a new promising area to try to understand the mechanisms of leukemogenesis.
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PMID:Granulocytic colony-stimulating factors in the management of patients with acute myeloid leukemia. 897 86

We report a therapy-related MDS (RAEB) patient with eosinophilia, unbalanced translocation der(7)t(1;7) (q12;q22) and lung cancer. We observed no increase in cytokine levels in serum or in the conditioned medium (CM) of peripheral T cells cultured with or without IL-2. When bone marrow (BM) cells were cultured with GM-CSF, IL-3 and SCF in a semisolid system, the colonies were exclusively eosinophilic. Cytogenetic analysis of the colony cells identified the same chromosome abnormality in all metaphases to that of BM cells. Suspension and clonogenic colony assay of BM cells cultured with various cytokines showed predominant eosinophilic growth and differentiation with GM-CSF, but not with the other cytokines examined. These findings, together with mild morphological abnormalities of eosinophils, indicate clonal involvement of eosinophils in the myelodysplastic syndrome (MDS) clone, and that the eosinophilia was derived from the neoplastic clone with the translocation and was not associated with the patient's lung cancer.
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PMID:Clonal involvement of eosinophils in therapy-related myelodysplastic syndrome with eosinophilia, translocation t(1;7) and lung cancer. 898 50

In a double-blind, randomized study performed between 1988 and 1990, 40 patients undergoing allogeneic BMT from HLA-identical siblings for hematologic malignancies received 8 mg/kg/d rHuGM-CSF (molgramostim, n = 20) for 14 days. The median neutrophil count on day 14 was significantly higher in the GM-CSF group (1.90 vs 0.46 yen 10(9)/L, P < .0001). The incidence of acute GVHD and transplant-related mortality were comparable. Only two deaths occurred after 6 months; one due to pulmonary fibrosis in the GM-CSF group on day 1591, and one due to relapse on day 1590 in the placebo group. The Karnofsky score of the 10 survivors, 3 in the placebo group and 7 in the GM-CSF group, is 90-100% (median 100%), and none has chronic GVHD requiring therapy. There was no evidence of increased relapse in the GM-CSF group with only two relapses occurring; both in the placebo group. With a follow-up of 4.5-6.8 years (median 5.5 years), these patients are amongst the longest surviving patients to have received a recombinant growth factor post-allograft. We conclude that the administration of GM-CSF after allogeneic BMT does not appear to be associated with an increased incidence of chronic GVHD or relapse, or of other adverse effects such as the development of myelodysplasia.
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PMID:Long-term safety of GM-CSF (molgramostim) administration after allogeneic bone marrow transplantation for hematologic malignancies: five-year follow-up of a double-blind randomized placebo-controlled study. 915 59

Chronic myelomonocytic leukemia represents a distinct myelodysplastic syndrome in which an excess of monocytes is observed both in the blood and bone marrow of the patients. Whereas diagnosis is relatively easy, therapeutic design and efficacy is difficult and no treatment has to date provided complete or significant partial response. In vitro data suggest that the growth and differentiation of myelomonocytic progenitors may be altered inasmuch as monocytic or granulo-macrophagic colonies show spontaneous growth. Different entities may be observed: the childhood form, Juvenile Chronic Myelomonocytic Leukemia (JCML) shows in vitro a typical pattern with constitutive growth of only macrophagic colonies and hypersensitivity to GM-CSF; in the adult form at least two patterns may be observed one close to the JCML form and one more heterogeneous with absence of GM-CSF sensitivity and spontaneous growth of both CFU-GM and CFU-M colonies. Chemotherapy reduces all myeloid colonies in vitro whereas retinoic acid has a selective effect on monocytic colonies with a concomitant increase of CFU-G colonies forwarding an explanation for the correction of pancytopenia observed in some patients. Recent analysis of altered molecular pathways in this disease suggest a common disruption of intracellular signalling pathways namely the Ras pathway and targetting for drugs with may selectively control or inhibit a constitutive activation may forward novel therapeutic perspectives.
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PMID:Chronic myelomonocytic leukemia: from biology to therapy. 916 99

We examined the bone marrow of 45 patients with MDS at the time of diagnosis and in the course of the disease by means of Southern blot analysis and cytogenetic studies to detect and evaluate clonal markers and their implication on the prognosis of the disease and the response to treatment. All patients were enrolled in an EORTC study and received low-dose Ara-C with or without growth factors according to the study protocol. Thirty patients (67%) were characterized by different clonal markers, such as various gene rearrangements (eg Ig-JH, tcR-beta, bcr, GM-CSF, G-CSF or IL-3) and/or chromosomal markers at the time of diagnosis or early in the course of the disease. In 23 of 30 cases that could be studied in the course of the disease, a statement about the clonal situation was possible: in three cases (8%) the clonal situation did not change, in nine cases (39%) at least a transient reduction of clonal cells could be demonstrated, suggesting partial or complete response to therapy. In eight cases (35%) a change for the worse could be seen. In four cases (17%) involvement of multiple clones could be demonstrated with the clones exhibiting different susceptibilities to treatment. Clinical evaluation showed that patients without clonal markers at diagnosis had a better prognosis as compared to patients who presented with clonal markers. We suggest that clonality analysis at diagnosis and in the course of the disease will be a useful tool to study the biology and response to treatment in MDS.
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PMID:Clonality analysis as a tool to study the biology and response to therapy in myelodysplastic syndromes. 918 Feb 89

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