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

In this study we describe the morphologic and immunohistochemical evaluation of bone marrow biopsies from 14 patients with therapy-related myelodysplastic syndromes (t-MDS). We employed CD34, anti-HLA-Dr, anti-elastase, CD68, anti-glycophorin, CD61 monoclonal antibodies immunostaining, and enzyme histochemistry for chloroacetate esterase. Moreover, we used PC10, a MAb raised against the proliferating cell nuclear antigen, to study the proliferative capacity of these marrows. Our data suggest that diagnosis of refractory anemia with excess of blasts (versus chronic myelomonocytic leukemia), the abnormal localization of immature precursors, marrow fibrosis, and augmented CD34 expression in the bone marrow biopsy are ominous prognostic factors at a statistically significant level (p < 0.0005). A combined morpho-immunohistochemical analysis of bone marrow biopsy correctly classifies t-MDS cases according to the biologic and clinical aggressiveness.
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PMID:Therapy-related myelodysplastic syndromes: FAB classification, bone marrow histology, and immunohistology in the prognostic assessment. 768 97

We have reviewed the clinical, morphologic, immunophenotypic, and cytogenetic features of 52 patients with erythroleukemia (FAB Cooperative Group; AML-M6) studied by the Cancer and Leukemia Group B (CALGB). The purpose of this study was to correlate morphology with the clinical features, immunophenotypes, and karyotypes of neoplastic cells, and with the response to therapy of patients with AML-M6. Thirty-three patients (63%) were male, median age 59 (range 16-81) years, 47 patients (90%) were white, and 42 patients (81%) had a performance status of < 2. Myelodysplastic changes were observed in at least 1 cell lineage in all cases, and in 2 cell lineages in 45 of 52 (86%) cases. Fifty percent or more of cases studied were positive for CD11b, CD13, CD15, CD33, glycophorin-A, and HLA-DR markers. Fourteen of 27 cases (52%) in whom karyotypic analyses were conducted had cytogenetic abnormalities. Five (19%) were simple (< 3 karyotypic abnormalities), while 9 (33%) were complex (> or = 3 abnormalities). We observed either a complete or partial loss of chromosomes 5, 7, or 12p, or the presence of trisomy 8, in 11 of 27 (41%) patients. Cases of AML-M6 were divided into group 1 (14 patients with bone marrow proerythroblasts and basophilic erythroblasts > 25% of all erythroblasts) and group 2 (38 patients with proerythroblasts and basophilic erythroblasts < or = 25% of all erythroblasts). We observed no significant differences between groups 1 and 2 in regard to sex, age, race, performance status, percentage of blood erythroblasts or myeloblasts, percentage of bone marrow erythroblasts, and periodic acid-Schiff (PAS) or myelodysplasia scores. Six of 6 (100%) patients of group 1, and 7 of 21 (33%) patients of group 2, had normal karyotypes (P = .006). Nine of 13 (69%) patients of group 1 and 15 of 33 (45%) patients of group 2 had a complete remission (CR) (P = .2). Eight of 11 (73%) cytogenetically normal patients achieved CR: 5 of 6 (83%) in group 1, and 3 of 5 (60%) in group 2. Five of 12 (42%) cytogenetically abnormal patients achieved CR. No difference in duration of survival (group 1, median = 4.6 months vs. group 2, median = 10.2 months; P = .93) was observed between the 2 groups. We conclude that AML-M6 is typified by multilineage involvement of hematopoietic cells. The morphology of erythroblasts in patients with AML-M6 may correlate with cytogenetic abnormalities and rate of CR.
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PMID:Morphologic characteristics of erythroleukemia (acute myeloid leukemia; FAB-M6): a CALGB study. 774 Nov 35

The proliferative activity of the haematopoietic and plasma cells in bone marrow was evaluated under normal and neoplastic conditions, by means of a sequential double immunostaining technique, using monoclonal antibody MIB-1 recognizing the cell proliferation-associated nuclear antigen Ki-67, and antibodies against glycophorin-C, myeloperoxidase, factor VIII-related antigen, and immunoglobulin light chains. Fifty-eight B5 fixed, paraffin-embedded bone marrow biopsies were analysed, including 11 normal controls. 10 cases of myelodysplasia, 14 cases of chronic myeloproliferative disorder, eight cases of acute non-lymphoid leukaemia, and 15 cases of myeloma. In normal marrows, the highest proliferative activity was noticed in the erythroid cells (75% to 95%; mean 90%), in comparison with myeloid precursors (15% to 80%; mean 38%), and megakaryocytes (10% to 20%; mean 14%): no Ki-67 positive plasma cells were found. In all investigated haematological disorders, the expression of MIB-1 by erythroid cells was similar to that observed in controls. Similarly, the percentage of MIB-1 + myeloid precursors in chronic myeloproliferative disorders and myelodysplasia largely overlapped the values observed in normals, and comparable values were also found in the blast cells from acute non-lymphoid leukaemia type M1 and M2. These findings suggest that the evaluation of either erythroid or myeloid proliferative activity is of little value in the differential diagnosis between these myeloproliferative disorders. By contrast, the obvious increase of Ki-67 expression of megakaryocytes in chronic myeloproliferative disorders, with labelling also of micro-megakaryocytes, might sustain the diagnosis in controversial cases. Since cases of mature myeloma showed less than 2% of Ki-67 positive cells, evaluation of proliferative activity is of no value in the differential diagnosis with reactive plasmacytosis. The sequential double immunophenotyping for Ki-67 antigen and for haematopoietic cell lineage-associated markers can be applied in a consistent manner to routine bone marrow biopsies to evaluate proliferating cells in normal and neoplastic conditions.
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PMID:Assessment of cell proliferation in normal and pathological bone marrow biopsies: a study using double sequential immunophenotyping on paraffin sections. 857 29

Using flow cytometry and immunoprecipitation (IP), we have investigated the deleted in colon cancer (DCC) protein expression on the bone marrow (BM) and peripheral blood (PB) cells of 16 normal subjects, 17 myelodysplastic syndrome (MDS) patients, and 10 acute myelogenous leukemia (AML) patients. With regard to the BM mononuclear cells (BM-MNCs) of normal subjects, the DCC protein expression ranged from 6.6 to 57.0%. Two-color flow cytometry revealed that among the IBM-MNCs the DCC protein was clearly expressed on the CD14+, CD13+, and factor 8+ cells, whereas it was low on the CD19+ and CD7+ cells and did not express on the CD34+, CD8+, and the glycophorin A+ cells. Further, the DCC protein expression was not seen on the PB CD11b+ and CD13+ cells. The IP results revealed that the 180-kD DCC protein was detected on the MNCs of both the BM and PB cells by the antibodies AF5, specific for the DCC extracellular domain, and G97-449, specific for the cytoplasmic domain. In contrast, flow cytometry did not detect the DCC protein on any BM-MNC MDS lineages (0.1-1.5%) or on AML leukemic cells (0.1-0.9%). The IP results indicated that the AF5 antibody did not detect the DCC protein on BM-MNCs of three of five MDS patients and four of five AML patients; however, the G97-449 antibody detected the 180-kD DCC protein in two MDS patients in whom AF5 had detected greatly reduced DCC band. These findings suggest that the DCC protein presence appears to be associated with normal hematopoiesis, and that its absence on the surfaces of the BM-MNCs and AML cells may contribute to the MDS and AML pathogenesis.
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PMID:DCC protein expression in hematopoietic cell populations and its relation to leukemogenesis. 860 44

Ineffective erythropoiesis in myelodysplasia is characterized by a defect in erythroid progenitor growth and by abnormal erythroid differentiation. Increased apoptosis of erythroid, granulocytic and megakaryocytic lineages is thought to account for cytopenias. Erythropoietin (Epo)-induced BFU-E and CFU-E growth was studied in 25 myelodysplastic syndrome (MDS) marrow specimens and found to be drastically diminished. To investigate the functionality of Epo-R in MDS marrow, we focused on Epo-induced STAT5 activation. Epo was able to stimulate STAT5 DNA binding activity in all normal and 12/24 MDS marrows tested, with no correlation between the level of STAT5 activation and the development of erythroid colonies in response to Epo. In contrast, impaired proliferation of erythroid progenitors was related to an increased expression of the transmembrane mediator of apoptotic cell death Fas/CD95 on the glycophorin A+ subpopulation. Therefore we conclude that the stimulation of pro-apoptotic signals rather than the defect of anti-apoptotic pathways resulting from Epo-stimulated Jak2-STAT5 pathway, predominantly accounts for ineffective erythropoiesis in myelodysplasia.
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PMID:Ineffective erythropoiesis in myelodysplastic syndromes: correlation with Fas expression but not with lack of erythropoietin receptor signal transduction. 1046 Jun 7

Patients with secondary myelodysplasias and acute myeloid leukemias (MDS/AML) frequently exhibit interstitial deletions of the chromosome-5q resulting in hemizygous loss of the transcription transactivator Smad5. Smad5 is a member of the signal transducer family conveying the pleiotropic TGF-gb/BMP cytokine signals with roles in development, cell growth control, and tumor progression. Here we present a study of the Smad5 expression and its functional role in leukemia cell lines as well as in primary CD34+ progenitors of MDS/AML patients and healthy individuals. Consistent Smad5 gene expression in these cell types and the gradual increase in its mRNA and protein levels in a model of induced erythroid differentiation of murine erythroleukemia (MEL) cells suggest a role of the gene in hematopoiesis. We show that bone morphogenetic protein 4 (BMP4) directs Smad5 activation in human hematopoietic cells, as monitored at the levels of protein phosphorylation, nuclear translocation, and specific transcription response. In vitro induction of normal human CD34+ cells by BMP4 results in significantly increased proliferation of erythroid progenitors (BFU-E) and formation of glycophorin-A+ cells, whereas perturbation of Smad5 expression by antisense oligonucleotides causes significantly decreased rates of BMP4-induced erythroid differentiation. We have not detected any effects of Smad5 inhibition on BMP4-stimulated progenitors of the granulocyteNmacrophage lineage. We propose that the BMP4/Smad5 signal transduction pathway activates hematopoietic differentiation programs that may be impaired in anemia manifestations in MDS and AML patients with Smad5 haploinsufficiency.
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PMID:Inhibition of Smad5 in human hematopoietic progenitors blocks erythroid differentiation induced by BMP4. 1206 18

Lentivectors, derived from human immunodeficiency virus-1 (HIV-1), represent a novel investigational and therapeutic tool for targeting hematopoietic progenitor cells. We describe a new protocol whereby we achieved a highly efficient lentiviral transduction of erythroid precursor cells originating from the bone marrow of healthy adults and patients with myelodysplastic syndromes (MDS). CD34(+) stem cells from healthy subjects were cultured with erythropoietin, IL-3 and stem cell factor, and thereby expanded approximately 300-fold. When these cultures were transduced with a lentiviral vector expressing GFP as a reporter gene, 70% glycophorin(+) cells were GFP(+). Although proliferation and levels of transduction were reduced in cultures of CD34(+) stem cells from patients with myelodysplastic syndromes, 50% of glycophorin(+) cells became GFP(+), amongst which 30% were sideroblastic erythroid precursors. This study demonstrates that lentiviral vectors are capable of efficiently transducing MDS precursors and offers new perspectives to investigate the influence of specific genes on normal erythroid differentiation. This may eventually help to correct defects in patients suffering from myelodysplastic syndromes.
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PMID:Optimized lentiviral transduction of erythroid precursors from healthy adults and patients with myelodysplastic syndromes. 1209 56

Myelodysplastic syndromes (MDS) are characterized by impaired erythropoiesis, possibly caused by proapoptotic cytokines. We focused our study on the cytokine TRAIL (TNF-related apoptosis-inducing ligand), which has been shown to exhibit an anti-differentiation activity on erythroid maturation. Immunocytochemical analysis of bone marrow mononuclear cells (BMMC) showed an increased expression of TRAIL in MDS patients with respect to acute myeloid leukemia (AML) patients and normal BM donors. TRAIL expression was increased predominantly in myeloid precursors of granulocytic lineage and in a subset of monocytes and pro-erythroblasts. Significant levels of soluble TRAIL were released in 21 of 68 BMMC culture supernatants from MDS patients. On the other hand, TRAIL was detected less frequently in the culture supernatants of AML (4 of 33) and normal BMMC (0 of 22). Analysis of peripheral blood parameters revealed significantly lower levels of peripheral red blood cells and hemoglobin in the subset of patients whose BMMC released TRAIL in culture supernatants compared to the subgroup of patients who did not release TRAIL. Moreover, TRAIL-positive BMMC culture supernatants inhibited the differentiation of normal glycophorin A+ erythroblasts generated in serum-free liquid phase. Thus, increased expression and release of TRAIL at the bone marrow level is likely to impair erythropoiesis and to contribute to the degree of anemia, the major clinical feature of MDS.
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PMID:Evidence for a role of TNF-related apoptosis-inducing ligand (TRAIL) in the anemia of myelodysplastic syndromes. 1568 38

The main clinical problems of low-risk patients with myelodysplastic syndromes (MDS), as defined by the International Prognostic Scoring System, are infections and the need for frequent transfusions due to ineffective myelopoiesis and peripheral blood cytopenia. Promising results in treating MDS-related anemia have been obtained using high-dose recombinant human erythropoietin (rhEPO). To evaluate the molecular basis of the response to rhEPO, we used commercially available macro-arrays to investigate gene expression profiles in the glycophorin-expressing (Gly+) bone marrow (BM) erythroid cells of five responders (ERs) and five non-responders (ENRs) to rhEPO treatment. The cells were separated by means of positive selection using an immunomagnetic procedure, after which flow cytometry showed that their purity was more than 97% in all cases. The array data were validated by means of real time RT-PCR. The results showed that the genes responsible for proliferation/differentiation and DNA repair/stability were repressed in the BM Gly+ erythroid cells of the ENRs, but almost normally expressed in the ERs. Furthermore, the expression of genes involved in signal transduction suggested that the activity of the MAPK signaling pathway is inhibited in ERs. The different gene expression profiles of ERs and ENRs may provide a basis for early gene testing as a means of predicting the response to rhEPO of MDS patients with low endogenous EPO levels.
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PMID:Bone marrow glycophorin-positive erythroid cells of myelodysplastic patients responding to high-dose rHuEPO therapy have a different gene expression pattern from those of nonresponders. 1838 21

Paroxysmal nocturnal hemoglobinuria (PNH) and myelodysplastic syndromes (MDS) are clonal disorder of haematopoietic stem cells that may eventually lead to chronic anemia. The ultrastructural defects in erythrocyte membranes may have a role in early red cell destruction within circulation. The lifespan of the erythrocyte primarily correlates to externalization of phosphatidylserine (PS) and loss of glycophorins from the erythrocyte surface. The span of survival of mature erythrocytes in the circulation in case of MDS and PNH is yet unclear and has been studied by measuring simultaneous exposure of PS and loss of glycoconjugates, primarily glycophorins from membrane surface. The extent of the loss of PS asymmetry and cell surface glycophorins in density separated erythrocytes of six MDS and three PNH patients has been probed by fluorochrome conjugated annexin V and wheat germ agglutinin using flow cytometry. The cells with lighter density showed a higher amount of PS on the outer surface compared to those of heavier cells in all PNH and MDS cases, showing the opposite trend to that observed in normal erythrocytes. In addition, the lighter cells had more cell surface glycophorins compared to heavier cells in all the cases. Such lowering of glycophorin levels from the lighter to heavier cells was maximum in refractory anaemia (RA) and minimum in the normal cells studied. Greater loss of PS asymmetry and cell surface glycophorin in the lighter or younger erythrocytes together could be responsible for their faster destruction and removal (eryptosis) in PNH and MDS.
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PMID:Erythrocyte membrane defects and asymmetry in paroxysmal nocturnal hemoglobinuria and myelodysplastic syndrome. 2067 Apr 83


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