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 French-American-British classification scheme of myelodysplastic syndromes includes a category of refractory cytopenia that includes refractory thrombocytopenia (RTC). Because dysmegakaryopoiesis manifesting as an isolated cytopenia can be difficult to identify morphologically and because it may be accompanied by megakaryocytic hyperplasia, RTC may be confused with idiopathic thrombocytopenic purpura. A review of 1,220 cases of myelodysplastic syndromes at Mayo Clinic Jacksonville and Mayo Clinic Rochester from 1979 to 1990 yielded 9 cases (0.7%) of isolated thrombocytopenia (RTC) associated with clonal chromosome abnormalities. Review of 319 marrow chromosome analyses performed at the cytogenetics laboratory at Mayo Clinic Rochester from 1979 to 1990 for patients with low platelet count yielded two additional cases of RTC (0.6%). Of the 11 RTC cases, 3 previously had been misdiagnosed as idiopathic thrombocytopenic purpura. All patients had oval macrocytes in peripheral blood smears and abnormal megakaryocyte morphology in bone marrow aspirates, lacked antiplatelet antibodies, and did not have splenomegaly on clinical examination. The most common clonal chromosome abnormalities involved chromosomes 3, 5, 8, or 20. Steroid therapy was ineffective. Clinical and laboratory findings can establish the diagnosis of RTC and allow the physician to avoid recommending inappropriate therapy (steroids or splenectomy) for these patients.
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PMID:Refractory thrombocytopenia. A myelodysplastic syndrome that may mimic immune thrombocytopenic purpura. 148

Regulation of megakaryocyte and platelet production remains poorly understood. In culture system two separate activities are needed for maximum production of megakaryocyte progenitors: promotor of clonal expansion and promoter of maturation, other growth factors and cells also contribute to regulation of megakaryocytopoiesis. Increased proliferation of megakaryocytes is observed in myeloproliferative disorders and idiopathic thrombocytopenic purpura, and decreased proliferation is found in aplastic anaemia and hypomegakaryocytic thrombocytopenia. Dysmegakaryocytopoiesis is present in myelodysplastic syndromes and acute leukaemia, and a proliferation of immature megakaryocytes in acute megakaryoblastic leukaemia. Increased understanding of human megakaryocytopoiesis is beginning to help in rational clinical management.
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PMID:Human megakaryocytopoiesis--normal and abnormal. 169 25

Peripheral cytopenias are common in patients with myelodysplastic syndromes. We previously successfully treated three such patients with improvement of some cytopenias with the impeded androgen danazol. To confirm this finding and elucidate the mechanism of response, we treated an additional 22 patients with myelodysplasia with oral danazol (600-800 mg daily) for 3-12 months. Eleven of 22 evaluable patients taking danazol met our criteria for improvement of peripheral counts, mainly thrombocytopenia. Chromosome analysis, marrow culture studies and serial bone marrow biopsies revealed no alteration of the abnormal clone or normal haematopoiesis in patients on danazol therapy. This suggested that improvement in blood counts was not related to modulation of ineffective haematopoiesis. Investigation of the thrombocytopenia in these patients revealed that most patients presented with markedly elevated platelet associated IgG (PAIgG), elevated plasma platelet-bindable IgG (PBIgG), and an elevated number of monocyte Fc gamma receptors. Treatment with danazol was associated with a decline in monocyte Fc gamma receptor number without significantly altering the elevated PAIgG or PBIgG levels. These results are similar to our observations in patients treated with danazol for chronic idiopathic thrombocytopenia purpura (ITP). Our data suggest that a component of the thrombocytopenia occurring in patients with myelodysplasia may be due to enhanced peripheral blood cell destruction by abnormal macrophages. Danazol may modulate cytopenia by decreasing the number of monocyte Fc gamma receptors. Danazol treatment was associated with minimal toxicity, but clinically meaningful responses were rare.
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PMID:Danazol treatment of myelodysplastic syndromes. 825 1

Sialyl Lewisx-i (SLX) was found in more than 40% of patients with acute leukemia or chronic myelogenous leukemia, and in about 20% of those with myelodysplastic syndrome or malignant lymphoma. This tumor marker was absent in all patients with polycythemia vera, essential thrombocythemia, primary myelofibrosis, chronic lymphatic leukemia, multiple myeloma, and those with acute leukemia or malignant lymphoma in remission. The marker was found in 8% and of the patients with idiopathic thrombocytopenic purpura and 33% of those with autoimmune hemolytic anemia but in no patient with aplastic anemia or megaloblastic anemia. Immunostaining with SLX antibody showed that tumor cells of the patients with high levels of serum SLX were producing the SLX antigen. The detection of this marker in the serum is thought to be useful not only in the diagnosis but also in the observation of the recurrence of the diseases.
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PMID:Evaluation of serum sialyl Lewisx-i in hematologic disorders. 207 71

Danazol, an attenuated androgen developed for the treatment of endometriosis, has recently been found useful in the treatment of several hematologic disorders, including idiopathic thrombocytopenic purpura (ITP), autoimmune hemolytic anemia (AIHA), paroxysmal nocturnal hemoglobinuria, myelodysplastic syndrome, and others. Our studies of the past 6 years have demonstrated that danazol is advantageous in the treatment of AIHA, and in specifically defined populations of ITP patients. Of 96 ITP patients treated with danazol 61% overall had excellent/good responses, but this rate varied markedly with prognostic factors, e.g. 82% in older women versus only 18% in younger women. Of 28 AIHA patients, 77% with idiopathic type and 60% with secondary type were excellent/good responders. When the drug was discontinued after 1 year or more of therapy, lasting unmaintained remissions of up to 5 years were often observed in both ITP and AIHA, a notably important benefit. The side-effects of danazol are generally much less serious than with glucocorticoids. Glucocorticoids can be tapered off and in most cases discontinued completely with danazol therapy in AIHA and chronic ITP. Approximately one third of ITP patients who failed on glucocorticoids are successfully maintained on danazol. Its mechanism of action in these disorders is currently under study in our laboratory, stimulated by new findings. Tentatively, danazol appears to modify cell membranes in a manner leading to specific immune modulations, as discussed. Further study is warranted to explore its application to other autoimmune and membrane-related disorders, and to clarify its mechanism of therapy.
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PMID:Efficacy of danazol in hematologic disorders. 212 61

Neutrophil-associated IgG (NAIgG) and neutrophil-binding IgG in sara (NBIgG) of 77 patients with neutropenia suspected to be caused by autoimmune mechanisms (group A) and 31 patients with aplastic anemia or myelodysplastic syndrome (group B) were assayed by flow cytometry. Auto-NBIgG was elevated in 32% of the patients in group A, particularly in about 70% of those with collagen diseases or ITP, but the level was normal in group B. Elevated NAIgG with normal auto-NBIgG levels was found in 27% of the patients in group A and in 64% of the patients in group B. The assay of auto-NBIgG was useful for detection of anti-neutrophil autoantibodies and for the diagnosis of autoimmune neutropenia. In addition, the level of NAIgG may be non-specifically elevated in non-immune neutropenia.
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PMID:[Neutrophil-associated IgG and neutrophil-binding IgG in autoimmune neutropenia]. 258 44

Although immune mechanisms are known to be partially responsible for the thrombocytopenia of patients infected with HIV-1, an understanding of the mechanism underlying this disorder is incomplete. A casual observation that bone marrow biopsies of HIV-infected individuals seem to exhibit an unusually large number of denuded megakaryocyte nuclei (DN-MK) prompted a study comparing MK of 20 HIV-seropositive individuals with those of 10 patients with HIV-negative idiopathic thrombocytopenic purpura and 10 hematologically normal subjects. In normal marrows the number of DN-MK average 2.1 +/- 0.5 SE per 10 low power field. In patients with ITP the average number was 6.5 +/- 1.4 SEM, whereas HIV-ITP marrows had an average of 42.5 +/- 3.7 SEM. Electron microscopy of AIDS megakaryocytes exhibited ballooning of the peripheral zone to an extent not seen by us in any other myelodysplastic syndromes. These observations support the concept that the pathophysiology affecting MK/platelets in HIV-infection should not be equated with the destructive process underlying other immune thrombocytopenias.
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PMID:Structural changes in the megakaryocytes of patients infected with the human immune deficiency virus (HIV-1). 275 19

We describe a prospective study comparing four different assays for PAIgG. Platelets from patients with a variety of thrombocytopenic disorders were collected into ACD, washed, and the PAIgG then measured using three assays for surface PAIgG. These included: (a) a direct binding assay using 125I-monoclonal anti-IgG (MoAb); (b) a direct binding assay using 125I-staphylococcal protein A (SPA); and (c) a two-stage assay. PAIgG also was measured using an assay for 'total' PAIgG following platelet lysis. The mean +/- SD number of molecules of IgG per platelet on washed platelets from 29 healthy, non-thrombocytopenic controls was: 86 +/- 80 (125I-MoAb); 94 +/- 96 (125I-SPA); 3520 +/- 1890 (two-stage surface assay); and 10,850 +/- 3720 (total PAIgG). A total of 62 different patients with idiopathic thrombocytopenic purpura or thrombocytopenia complicating systematic lupus erythematosus, and 73 different patients with 'non-immune' thrombocytopenia, were tested using each of the four assays. These 'non-immune' thrombocytopenic patients included patients with carcinoma, septicaemia, pre-eclampsia, chronic leukaemia, thrombotic thrombocytopenic purpura, haemolytic uraemic syndrome, acute leukaemia and myelodysplasia. All four assays gave similar results for both the immune and non-immune thrombocytopenic patients. The sensitivity of the assays for the most severely thrombocytopenic patients with immune thrombocytopenia was: MoAb 60%; SPA 88%; two-stage 82%; and 'total' PAIgG 88%. The specificity of the four assays in the non-immune thrombocytopenic patients was 57% 'total' PAIgG; 63% two-stage surface; 25% SPA; 38% MoAb.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A prospective comparison of four techniques for measuring platelet-associated IgG. 291 34

The relationship between mean platelet volume (MPV) and platelet count was evaluated in 259 patients with rheumatoid arthritis and 311 patients with various haematological disorders. Platelet volume-number relationships determined in a previous study on normal subjects were used as a reference range. There was a significant inverse relationship between MPV and platelet count in patients with rheumatoid arthritis (r = -0.49; P less than 0.0001), which by interval analysis was shown to be non-linear. In the patients with haematological disorders, the platelets were found to be disproportionately small for number in patients with aplastic anaemia, chemotherapy-induced marrow suppression and some cases of acute idiopathic thrombocytopenic purpura (ITP). In subjects with chronic ITP followed longitudinally, the inverse platelet volume-number relationship was retained. MPV was appropriate for platelet number in myelodysplastic syndromes, variable in iron deficiency anaemia and disproportionately large in myeloproliferative syndromes, most notably in agnogenic myeloid metaplasia. The observation that the MPV was disproportionately large in comparison with the platelet count was used in establishing the diagnosis of an hereditary giant platelet syndrome in a family of British origin.
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PMID:Platelet parameters. Part II. Platelet volume-number relationships in various normal and disease states. 334 Sep

Bone marrow biopsies and smears were examined from 70 patients with acquired immunodeficiency syndrome (AIDS) or AIDS related conditions: 32 patients with AIDS; 9, at risk, group patients with B-cell lymphoma; 22 patients with AIDS related complex (ARC) and 7, at risk, group patients with idiopathic thrombocytopenic purpura (ITP). The first three groups showed similarity with respect to frequency of nonspecific findings: hypo and hypercellularity, marrow damage, lymphoid aggregates, histiocytosis, plasmacytosis and features of myelodysplasia. AFB and fungal organisms were present in the biopsies of 17 per cent of AIDS and 18 per cent of ARC patients. The organisms were associated with bone marrow granulomas or histiocytosis, peripheral lymphopenia and anemia. Only one out of 9 biopsies in patients with previous diagnoses of lymphoma showed involvement of the marrow. One case each of Hodgkin's disease and non-Hodgkin's lymphoma were discovered incidentally among the 22 biopsies from ARC patients without a previous diagnosis of lymphoma. Except for those presenting with ITP alone, bone marrow changes are similar in patients with AIDS and AIDS related conditions.
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PMID:A comparison of bone marrow findings in patients with acquired immunodeficiency syndrome (AIDS) and AIDS related conditions. 349 63


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