Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026986 (myelodysplastic syndrome)
 14,926 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The diagnosis of myelodysplastic syndromes (MDS) is based on peripheral cytopenias, bone marrow (BM) morphology and karyotyping. This may be difficult in cases with few dysplastic elements in BM and a normal karyotype. We examined the utility of flow cytometric analysis for the differential diagnosis between MDS and non-clonal disorders (NCD) presenting peripheral cytopenias. Quantitative assessment of CD45, CD16, CD13, CD11b, CD10 and CD64 in granulocytes and monocytes, and CD71 and glycophorin A in erythroblasts besides CD34+ cell count was performed in BM of 31 consecutive newly diagnosed patients with MDS, 11 patients with NCD and 11 healthy controls (BM donors). In MDS, the median number of phenotypic abnormalities found was 3 (1-8). The WPSS score showed a correlation with the total number of changes per case (r=0.48; p=0.002). Decreased SSC in promyelocytes correlated with the peripheral neutrophil count (r=-0.46; p=0.007). In NCD, the normal variation of antigen expression along granulocytic and erythroblast maturation was always maintained. In the discriminant analysis, SSC of CD34+ cells, together with that of promyelocytes and metamyelocytes were able to correctly classify 87% of the cases as clonal or non-clonal. Our quantitative approach permitted to detect at least one abnormality in antigen expression in every case of MDS. However, the most important parameters for differential diagnosis with NCD were the analysis of the granularity in immature cells, especially of the granulocytic series.
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PMID:Detection of hematopoietic maturation abnormalities by flow cytometry in myelodysplastic syndromes and its utility for the differential diagnosis with non-clonal disorders. 1675 Aug 52

GATA-1 is a transcription factor governing the production of erythroid and megakaryocytic cells. Unobstructed GATA-1 expression in early progenitor cells commits them to the myeloid lineage, channeling its differentiation towards erythrocytes and megakaryocytes. Myelodysplastic Syndromes (MDS) are clonal disorders of the hematopoietic stem cell frequently presenting dysplasia in erythroid and/or megakaryocytic lineage. We reasoned that measurement of GATA-1 expression levels in hematopoietic progenitor CD34(+) and the committed erythroid CD71(+) cells, from various MDS subcategories, could demonstrate GATA-1 involvement in the pathogenesis of the syndrome. In this study, MDS patients displayed significantly elevated GATA-1 mRNA expression, in bone marrow mononuclear cells (BMMCs), progenitor CD34(+) and erythroid CD71(+) cells in contrast to the control population (P < 0.001). Additionally, GATA-1 mRNA expression in MDS CD71(+) cells was positively correlated with their apoptotic levels (rho = 0.58, P = 0.03). Furthermore, GATA-1 expression levels were found to correlate with the disease progression. MDS patients in high/INT-2 IPSS risk group expressed significantly higher GATA-1 mRNA levels, in both CD34(+) and CD71(+) cells, as opposed to low/INT-1 patients (P < 0.001). Moreover, the former displayed increased apoptosis in the CD71(+) cells and significantly reduced neutrophil and platelet numbers and hemoglobin levels compared with the latter. We conclude that MDS patients display an increase of GATA-1 mRNA expression in BM cells, with high/INT-2 patients showing significantly higher levels. The higher level of GATA-1 mRNA in erythroid cells was positively correlated with their degree of apoptosis. These findings suggest that the up-regulation of GATA-1 may be responsible for the peripheral cytopenias in MDS.
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PMID:GATA-1 transcription factor is up-regulated in bone marrow hematopoietic progenitor CD34(+) and erythroid CD71(+) cells in myelodysplastic syndromes. 1757 May 14

TNF-alpha is a pleitropic cytokine that expresses both pro- and anti-inflammatory activity and transgenic mice expressing human tumor necrosis factor-alpha (TNF-alpha) exhibit a progressive polyarthritis that models rheumatoid arthritis (RA). One of the common comorbidities of RA is anemia of chronic disease (ACD). The purpose of these experiments was to study the changes in the bone marrow and peripheral blood that accompany polyarthritis in TNF-alpha transgenic mice in an effort to better understand the pathogenesis of myelodysplasia and ACD. Polychromatic cytometry, hematology and serum cytokine analysis were used to study the pathogenesis of ACD in human TNF-alpha transgenic mice. Our hematological evaluation revealed a mild, compensated, microcytic hypochromic anemia, and monocytosis. In the bone marrow, we observed alterations in cell kinetics, decreased relative expression of transferrin receptor and increased apoptosis and cell death in several late precursor cell populations. Although significant levels of human TNF-alpha were found in the serum, neither change in serum murine erythropoietin nor any significant difference observed in serum levels of murine IL-beta, IL-5, IL-6, IL-10, IL-12(p70), IL-17, TNF-alpha, IFNgamma, GM-CSF, MIP-1alphaJE, MCP-5 was observed. Tg197 mice develop a compensated, microcytic, hypochromic anemia, and a functional iron deficiency by 9 weeks of age. Changes in peripheral blood are reflected in alterations in cell kinetics, transferrin receptor expression and markedly increased apoptosis and cell death in the bone marrow indicating that TNF-alpha may contribute to myelodysplasia in ACD. Moreover, since human TNF-alpha can interact only with murine TNFR1, our data suggest that TNFR1 may play an important role in the development of ACD.
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PMID:Myelodysplasia and anemia of chronic disease in human tumor necrosis factor-alpha transgenic mice. 1820 95

Transferrin receptors (TfRs) are the conventional pathway by which cells acquire iron for physiological requirements. Under iron-deficient conditions there is an increased concentration of surface TfR, especially on bone marrow erythroid precursors, as a mechanism to sequester needed iron. TfRs are also present in the circulation, and the circulating serum TfR (sTfR) level reflects total body TfR concentration. Under normal conditions erythroid precursors are the main source of sTfR. Disorders of the bone marrow with reduced erythroid precursors are associated with low sTfR levels. The sTfR concentration begins to rise early in iron deficiency with the onset of iron-deficient erythropoiesis, and continues to rise as iron-deficient erythropoiesis progressively worsens, prior to the development of anemia. The sTfR level does not increase in anemia of chronic inflammation, but is increased when anemia of chronic inflammation is combined with iron deficiency. The sTfR level is also increased in patients with expanded erythropoiesis, including hemolytic anemias, myelodysplastic syndromes, and use of erythropoietic stimulating agents. The ratio of sTfR/ferritin can be used to quantify the entire spectrum of iron status from positive iron stores through negative iron balance, and is particularly useful in evaluating iron status in population studies. The sTfR/log ferritin ratio is valuable for distinguishing anemia of chronic inflammation from iron deficiency anemia, whether the latter occurs alone or in combination with anemia of chronic inflammation.
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PMID:Serum transferrin receptor. 1882 9

This study highlights the iron profile of myelodysplastic patients in the era of hepcidin and its pro-hormone, pro-hepcidin. Previous studies have focused on the anemia of chronic renal failure, thalassemia, and hemochromatosis. We determined if pro-hepcidin played a role in iron overload in patients with myelodysplasia (MDS). Thirty adult patients with MDS and 20 healthy adults (controls) were selected. Our results revealed a statistically significant difference in pro-hepcidin levels between the two tested groups (Z = 2.9, p = 0.003). There was a weak positive correlation between pro-hepcidin and hematocrit (HCT; r = 0.49, p = 0.02) in the healthy group only. Neither age, subtypes of MDS, gender, soluble transferrin receptor (sTFR) or ferritin affected the pro-hepcidin level in patients with MDS. The role of ineffective erythropoiesis in the regulation of pro-hepcidin is superior to the role of chronic blood transfusion therapy.
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PMID:Serum prohepcidin level in myelodysplasia. 2050 58

Accurate analysis of the erythroid lineage is essential in evaluating bone marrow biopsy specimens and can be particularly challenging in the setting of dyserythropoiesis. Transferrin receptor (CD71) mediates the uptake of transferrin-iron complexes and is highly expressed on the surface of cells of the erythroid lineage. Although CD71 has been used for flow cytometric analysis, its usefulness in paraffin-embedded bone marrow biopsy specimens has not been examined. This study defined the immunohistochemical profile of CD71, as compared with glycophorin A (CD235a) and hemoglobin, in 65 bone marrow biopsy specimens, including normal marrow specimens and cases of myelodysplastic syndrome, acute myeloid leukemia, acute lymphoblastic leukemia, plasma cell neoplasm, and metastatic carcinoma. Immunoreactivity for CD71 was restricted to erythroid precursors in normal and dyspoietic marrow samples and exhibited a membranous and cytoplasmic staining pattern. The vast majority of mature erythrocytes lack expression of CD71, greatly facilitating interpretation. CD71 is a highly effective marker for the detection of cells of erythroid lineage in bone marrow biopsy specimens.
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PMID:CD71 (transferrin receptor): an effective marker for erythroid precursors in bone marrow biopsy specimens. 2071 99

Serum erythropoietin level less than 100U/L and a transfusion requirement of less than 2 units per month are the best predictive factors for response to treatment by erythropoiesis-stimulating agents in low/int-1 myelodysplastic syndromes. To investigate the factors influencing the response to erythropoiesis-stimulating agents, we enrolled 127 low/int-1 myelodysplastic syndrome patients at diagnosis in a biological study of erythropoiesis. The 54 non-responders had a significantly lower number of burst-forming unit-erythroid and colony-forming unit-erythroid than responders. Erythropoietin-dependent proliferation and survival, and phospho (p)-ERK1/2 expression in steady state and after erythropoietin stimulation were defective in cultured erythroblasts. By flow cytometry, p-ERK1/2 was significantly lower in bone marrow CD45(-)/CD71(+)/GPA(-)cells from non-responders compared to responders or controls. Receiver Operator Characteristic curve analysis showed that this flow cytometry test was a sensitive biomarker for predicting the response to erythropoiesis-stimulating agents.
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PMID:p-ERK1/2 is a predictive factor of response to erythropoiesis-stimulating agents in low/int-1 myelodysplastic syndromes. 2082 31

Acute erythroid leukemia in children is very rare. Here is a case of erythroleukemia in a child of age 1.5 years, which was diagnosed on peripheral smear, bone marrow examination, cytochemistry but was confirmed on immunophenotyping. CD45 versus side scatter demonstrated blast population (29%) expressing CD45 of variable intensity (dim to negative). The myeloid nature of blast population showed bright expression of cytoplasmic myeloperoxidase (MPO), heterogenous positivity of CD117 and dim expression of CD13, CD33. These blasts also showed bright positivity for CD71 which showed erythroid nature of blasts. Flow cytometry can be comprehensive enough to completely subtype cases of leukemias/myelodysplastic syndromes, polycythemia rubra vera, non-neoplastic conditions like reactive erythroid hyperplasia following immunosuppressive therapy or viral infections or nutritional deficiencies, unlyzed RBCs or thrombocytosis which may mimic acute erythroid leukemia on flow cytometry.
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PMID:Childhood acute erythroleukemia diagnosis by flow cytometry. 2139 10

The hypomethylating agent 5-aza-2'-deoxycytidine (5-aza-CdR) and its derivatives have been successfully used for the treatment of myelodysplastic syndromes, and they frequently improve the anemia that usually accompanies these disorders. However, the molecular mechanisms underlying this action remain poorly understood. In this study, we used two erythroid models, murine erythroid leukemia cells and erythroid burst-forming unit-derived erythroblasts, to show that 5-aza-CdR induced erythroid differentiation and increased the expression of transferrin receptor 1 (TfR1) and ferrochelatase (Fech), thereby increasing iron uptake and heme biosynthesis. We have identified new regulatory E-boxes that lie outside of CpG islands in the TfR1 and Fech promoters, and the methylation status of these sites can be altered by 5-aza-CdR treatment. This in turn altered the binding of the transcription factor c-Myc to these promoter elements. Furthermore, 5-aza-CdR promoted the nuclear translocation of c-Myc and its binding to Max to form functional complexes. The coordinated actions of 5-aza-CdR on the methylation status of the target genes and in stimulating the nuclear translocation of c-Myc provide new molecular insights into the regulation of E-boxes and explain, at least in part, the increased erythroid response to 5-aza-CdR treatment.
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PMID:5-aza-2'-deoxycytidine activates iron uptake and heme biosynthesis by increasing c-Myc nuclear localization and binding to the E-boxes of transferrin receptor 1 (TfR1) and ferrochelatase (Fech) genes. 2190 80

We used flow cytometry to analyze the cell cycle, DNA damage, and apoptosis in hematopoietic subsets in MDS marrow. Subsets were assigned using CD45, side scatter, CD34, and CD71. Cell cycle fractions were analyzed using DRAQ 5 (DNA content) and MPM-2 (mitoses). DNA damage was assessed using p-H2A.X, and apoptosis using Annexin V. Compared to controls, MDS patients demonstrated no increased mitoses in erythroid, myeloid, or CD34+ cells. Myeloid progenitors demonstrated increased G2 cells, which with no increased mitoses suggested delayed passage through G2. Myeloid progenitors demonstrated increased p-H2A.X, consistent with DNA damage causing this delay. Annexin V reactivity was equivalent in MDS and controls. Results for each parameter varied among hematopoietic compartments, demonstrating the need to analyze compartments separately. Our results suggest that peripheral cytopenias in MDS are due to delayed cell cycle passage of marrow progenitors and that this delayed passage and leukemic progression derive from excessive DNA damage.
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PMID:Innovative analyses support a role for DNA damage and an aberrant cell cycle in myelodysplastic syndrome pathogenesis. 2204 73


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