Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002874 (aplastic anemia)
 5,905 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired clonal stem cell disorder characterized by intravascular haemolysis, venous thrombosis, marrow hypoplasia, frequent episodes of infection, and rarely leukaemic conversion. At the cellular level, PNH is characterized by the decrease or absence of glycosylphosphatidylinositol (GPI)-anchored molecules, such as CD55 and CD59, from the cell surface. PNH-like clones have been described in various haematological disorders. The link between PNH and aplastic anaemia (AA) has been established but the relationship of PNH with myelodysplastic syndromes (MDS) or myeloproliferative disorders (MPD) remains unclear. In this study, the presence of CD55 and/or CD59 defective (PNH-like) red cell populations was evaluated in 21 patients with AA, 133 with MDS, 197 with MPD, 7 with PNH and in 121 healthy blood donors using the Sephacryl Gel Test microtyping system. Red cell populations deficient in both molecules CD55 and CD59 were detected in 33.3% of AA patients, in 16.5% of MDS patients (50% with hypoplastic bone marrow), in 14.2% of MPD patients (more often in essential thrombocythemia, 21.2%) and in all PNH patients. CD55 deficient red cell populations were found in 14.2% of patients with AA, 12.7% of patients with MDS and 21.3% of patients with MPD. CD59 deficient populations were found in 9.5% of AA patients, 2.2% of MDS patients and 2% of MPD patients. These results indicate an association between PNH, AA and MDS or even between PNH and MPD. Further investigation is necessary to work out the mechanisms of this association, and to define classification criteria for borderline cases, where diagnosis is difficult.
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PMID:Detection of CD55 and/or CD59 deficient red cell populations in patients with aplastic anaemia, myelodysplastic syndromes and myeloproliferative disorders. 1134 8

To clarify the pathologic significance of granulocytes exhibiting the paroxysmal nocturnal haemoglobinuria (PNH) phenotype in patients with aplastic anaemia (AA), we examined peripheral blood from 100 patients with AA for the presence of granulocytes deficient in glycosylphosphatidylinositol (GPI)-anchored proteins using a sensitive flow cytometric assay. A significant increase in the frequency of CD55-CD59-CD11b+ granulocytes (>0.003%) compared to normal individuals was observed in 31 of 35 (88.6%) patients with untreated AA at diagnosis. The proportions of patients showing increased PNH granulocytes in treated AA patients with a short (<5 yr) and long (>5 yr) disease duration were 68.6% (11/16) and 20.4% (10/49), respectively. When 19 patients showing increased frequency of PNH granulocytes before therapy were studied 6-12 months after antithymocyte globulin plus cyclosporin A therapy, the frequency decreased to 0.01-90% of pretreatment values in 15 recovering patients. These findings suggest that a relative increase in the number of PNH granulocytes is a common feature of AA at diagnosis, and that it may represent the presence of immunologic pressure to normal haematopoietic stem cells as a cause of AA.
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PMID:Relative increase of granulocytes with a paroxysmal nocturnal haemoglobinuria phenotype in aplastic anaemia patients: the high prevalence at diagnosis. 1135 Apr 89

The expansion of paroxysmal nocturnal hemoglobinuria (PHN) clone was evaluated in a patient with aplastic anemia (AA) of 18 years of evolution during an hemolytic crisis. On day 0, Ham and Sucrosa tests were positive and hematological parameters were altered. Low hemoglobin (Hb) levels and erythrocyte and leukocyte counts were found and continued decreasing on days 7 and 24 (last day of study). High LDH levels, indirect bilirubin and reticulocyte counts were detected throughout. We evaluated CD55 and CD59 on erythrocytes by flow cytometry. Our results showed low CD55 expression with respect to the normal pattern. Since day 0, CD59 staining detected two red cell populations: PNH I (48%), cells with positive fluorescence similar to normal and PNH III (52%), negative cells (PNH clone). These negative cells increased, reaching 70% on day 24. Other membrane anchored leukocyte proteins were also absent (CD14) or decreased (CD16). We found a good correlation between clinical observations, evolution of the laboratory values and expansion of the PNH clone.
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PMID:[Evolution of paroxysmal nocturnal hemoglobinuria clone during an hemolytic crisis in a patient with aplastic anemia. Flow cytometry study]. 1172 26

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal disorder characterized by a decrease or absence of glycosylphosphatidylinositol (GPI)-anchored molecules such as CD55 and CD59 from the surface of affected cells, resulting in intravascular hemolysis, cytopenia, and venous thrombosis. A PNH-like phenotype has been detected in various hematological disorders, mainly in aplastic anemia and myelodysplastic syndromes, but also in lymphoproliferative syndromes (LPSs). To the best of our knowledge, CD55- or CD59-deficient red cells have not been detected in plasma cell dyscrasias (PCDs). The aim of this study was the detection of CD55- and/or CD59-deficient red cell populations in patients with PCD. Seventy-seven patients were evaluated; 62 with multiple myeloma (MM), 7 with Waldenstrom macroglobulinemia (WM), 6 with monoclonal gammopathy of undetermined significance (MGUS), and 2 with heavy chain disease (HCD). The sephacryl gel microtyping system was applied; Ham and sucrose lysis tests were also performed on all samples with CD55- or CD59-negative populations. Red cells deficient in both molecules were detected in 10 (12.9%) of 77 patients with PCD: 2 (28.6%) of 7 with WM, 1 (16.6%) of 6 with MGUS, 6 (9.6%) of 62 with MM, and 1 of 2 patients with HCD. Isolated CD55 deficiency was found in 28.5% of all PCD patients, whereas isolated CD59 deficiency was not observed in any patients. These findings illustrate the existence of the PNH phenotype in the red cells of patients with PCD; further investigation is needed into the mechanisms and significance of this phenotype.
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PMID:Detection of CD55- and/or CD59-deficient red cell populations in patients with plasma cell dyscrasias. 1184 89

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem cell disorder characterized by the deficiency of all proteins anchored to the membrane by the glycosyl-phosphatidylinositol (GPI) anchor. The receptor for urokinase-type plasminogen activator (uPAR) also is attached to the cell membrane by a GPI anchor, and that soluble uPAR (suPAR) is present in plasma. In the present study, we measured uPAR, CD55, and CD59 on granulocytes by means of flow cytometry and suPAR in plasma by means of immunoradiometric assay. The subjects were 20 patients with PNH, 59 other patients with anemia, and 21 healthy individuals. In patients with PNH, both the mean fluorescence intensity and the positive percentage of fluorescence-activated granulocytes of uPAR, CD55, and CD59 were remarkably decreased, whereas in patients with other forms of anemia, except 2 patients with aplastic anemia, the results were not altered in comparison with those for the healthy individuals. The level of uPAR was reduced to the same extent as were those of CD55 and CD59 on the PNH-affected granulocytes. Some peak shape abnormalities (double peaks, peak tailing, or both) in the histogram of fluorescence intensity were also found in patients with PNH. The suPAR concentration of PNH plasma was 4.04+/-2.47 ng/mL, which was higher than that of the healthy individuals, 1.73+/-0.96 ng/mL (P < .01). The positive percentage of fluorescence-activated granulocytes was inversely associated with the plasma suPAR level in patients with PNH (r = -0.79, P < .01). Our data suggest that measurement of uPAR on granulocytes by means of flow cytometry and of suPAR in plasma by means of immunoradiometric assay are specific techniques for the diagnosis of PNH.
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PMID:Diagnostic significance of measurement of the receptor for urokinase-type plasminogen activator on granulocytes and in plasma from patients with paroxysmal nocturnal hemoglobinuria. 1204 78

A minor population of blood cells deficient of glycosylphosphatidylinositol (GPI)-anchored membrane proteins is often detected in patients with aplastic anemia (AA), though the clinical significance of such paroxysmal nocturnal hemoglobinuria (PNH)-type cells remains unclear. To clarify this issue, we studied 164 patients with myelodysplastic syndrome (MDS) for the presence of CD55(-)CD59(-) granulocytes and red blood cells using sensitive flow cytometry. Among the different subgroups of MDS, a significant increase (ie, at least 0.003%) of PNH-type cells was detected in 21 of 119 patients with refractory anemia (RA); this frequency (17.6%) of RA patients with increased PNH-type cells (PNH(+) patients) was much lower than what we previously reported (52.0%) for AA patients. PNH(+) RA patients had distinct clinical features compared with RA patients without increased PNH-type cells (PNH(-) patients), such as less pronounced morphologic abnormality of blood cells, more severe thrombocytopenia, lower rates of karyotypic abnormality (4.8% vs 32.8%) and of progression to acute leukemia (0% vs 6.2%), higher probability of response to cyclosporine therapy (77.8% vs 0%), and higher incidence of HLA-DR15 (90.5% vs 18.5%). These data indicate that the presence of a minor population of PNH-type cells suggests a benign type of bone marrow failure, probably caused by an immunologic mechanism. To choose an appropriate therapy, peripheral blood should be tested using sensitive flow cytometry for the presence of PNH-type cells in all patients with bone marrow failure before treatment.
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PMID:Clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria-type cells in bone marrow failure syndrome. 1239 38

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal stem cell disorder resulting from a somatic mutation in the hematopoietic stem cell. It is characterized by intravascular hemolysis, cytopenias, frequent infections, bone marrow hypoplasia, and a high incidence of life-threatening venous thrombosis. An absent glycosylphosphatidylinositol (GPI)-anchored receptor prevents several proteins from binding to the erythrocyte membrane. These include the complement-regulatory proteins, CD55 and CD59, whose absence results in enhanced complement-mediated lysis. Patients present with anemia and hemoglobinuria. Laboratory diagnosis includes the sucrose hemolysis test, Ham acid hemolysis test, and fluorescent-activated cell analysis. There is considerable overlap between PNH, aplastic anemia, and myelodysplastic syndrome and some cases evolve into acute leukemia. Treatment is mainly supportive consisting of transfusion therapy, anticoagulation, and antibiotic therapy. Hematopoietic stem cell transplantation may be curative.
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PMID:Paroxysmal nocturnal hemoglobinuria. 1531 92

A 31-year-old woman was given a diagnosis of aplastic anemia (AA) in 2000 and was treated with anti-thymocyte globulin (ATG) (horse serum), cyclosporine and granulocyte-colony stimulating factor (G-CSF). In 2002, she came to our hospital. The laboratory data revealed severe cytopenia according to the criteria by Camitta. A cytogenetic study revealed a normal female karyotype. We demonstrated CD55-negative and CD59-negative clones in her erythrocytes and granulocytes. HLA-DR 1501 was negative. After corticosteroid pulse therapy, the del(13q) (7/21 cells) was noted in her marrow cells. She was re-treated with ATG (rabbit serum), cyclosporine and G-CSF without particular cytogenetic changes after the therapy. Deletion of the 13q anomaly is rarely detected in patients with AA and its clinical significance in this disease is not well known. In the literature, AA patients with the del(13q) responded well to immunosuppressive therapy, irrespective of the timing of the appearance of the del(13q) anomaly. Further investigation will be needed to clarify the significance of del(13q) in AA.
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PMID:[Deletion of 13q in aplastic anemia after treatment with anti-thymocyte globulin]. 1560 87

We investigated the clinical significance of a minor population of paroxysmal nocturnal hemoglobinuria (PNH)-type blood cells in patients with acquired aplastic anemia (AA). We quantified CD55-CD59- granulocytes and red blood cells (RBCs) in peripheral blood from 122 patients with recently diagnosed AA and correlated numbers of PNH-type cells and responses to immunosuppressive therapy (IST). Flow cytometry detected 0.005% to 23.1% of GPI-AP- cells in 68% of patients with AA. Sixty-eight of 83 (91%) patients with an increased proportion of PNH-type cells (PNH+) responded to antithymocyte globulin (ATG) + cyclosporin (CsA) therapy, whereas 18 of 39 (48%) without such an increase (PNH-) responded. Failure-free survival rates were significantly higher (64%) among patients with PNH+ than patients with PNH- (12%) at 5 years, although overall survival rates were comparable between the groups. Numbers of PNH-type and normal-type cells increased in parallel among most patients with PNH+ who responded to IST, suggesting that these cells are equally sensitive to immune attack. These results indicate that a minor population of PNH-type cells represents a reliable marker of a positive IST response and a favorable prognosis among patients with AA. Furthermore, immune attack against hematopoietic stem cells that allows PNH clonal expansion might occur only at the onset of AA.
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PMID:Minor population of CD55-CD59- blood cells predicts response to immunosuppressive therapy and prognosis in patients with aplastic anemia. 1617 71

Although increased blood cell deficiency of glycosyl phosphatidylinositol-anchored membrane proteins has often been detected in patients with aplastic anemia (AA) and myelodysplastic syndrome (MDS), the clinical significance of such paroxysmal nocturnal hemoglobinuria (PNH)-type cells remains to be elucidated. We established a sensitive flow cytometric assay capable of detecting less than 0.01% of CD59-CD55- blood cells in a sample and used the assay to examine a large number of patients with bone marrow failure. An increase in the proportion of PNH-type cells was detectable in approximately 60% of all AA patients and in 20% of all refractory anemia (RA)-MDS patients. The increase was undetectable in patients with RA with an excessive number of blasts, acute myelogenous leukemia, multiple myeloma, or systemic lupus erythematosus. Our study showed that the presence of an increased number of PNH-type cells was predictive of a good response to immunosuppressive therapy and a favorable prognosis among patients with recently diagnosed AA and RA. A sensitive flow cytometric analysis for detection of a small population of PNH-type cells in peripheral blood cells is one of the most important examinations in the management of bone marrow failure.
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PMID:Clinical significance of a small population of paroxysmal nocturnal hemoglobinuria-type cells in the management of bone marrow failure. 1692 32


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