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

Most, but not all, megaloblastic anemia is produced by "ineffective erythropoiesis" in the bone marrow due to either folic acid or vitamin B12 deficiency. In folic acid deficiency the cause frequently is inadequate dietary intake, whereas vitamin B12 deficiency is almost always conditioned by some specific type of malabsorption. Anemia with oval macrocytes, few reticulocytes, moderate leukopenia, and thrombocytopenia is typical of both. Aplastic anemia, refractory anemias with cellular marrow, preleukemia, aleukemia, and erythroleukemia may have somewhat similar blood findings but are usually recognizable from bone marrow biopsy. Decreased levels of folate or vitamin B12 are the most reliable criteria of megaloblastic anemia. With these available in advance, therapy with the appropriate vitamin can be begun at once. If serum levels are unavailable or available only in retrospect, initial treatment, especially of severe anemia, should be with both vitamins. Differentiation between folate and vitamin B12 deficiency is important but impossible by blood and bone marrow morphology alone. Thus, if serum levels are unavailable, the distinction must be made, sometimes retrospectively, on the basis of other laboratory examinations, such as gastric analysis, small-bowel x-ray films, and the Schilling test.
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PMID:Megaloblastic anemia. 70 1

We have investigated proliferation in bone marrow trephine biopsies from 32 patients with normal or abnormal haemopoiesis, using the monoclonal antibody PC10, which detects proliferating cell nuclear antigen (PCNA), together with immunohistochemical markers of haemopoietic cell lineage. PCNA immunostaining revealed the pattern of proliferation within individual haemopoietic lineages in normal marrow. Two unexpected observations were made: of erythroid cells, only pro-erythroblasts and occasional early normoblasts reacted, and positivity of megakaryocytes was unrelated to nuclear lobulation or CD61 expression. The pathological cases represented conditions in which haemopoiesis is increased (reactive hyperplasia, chronic granulocytic leukaemia, myeloproliferative and myelodysplastic syndromes, megaloblastic anaemia). Increases in the number, and disturbances of the spatial organization, of PCNA-expressing cells were present to a variable extent in all cases. Sheets of PCNA-positive megaloblastoid erythrocytes were frequently found in myelodysplastic and myeloproliferative tissue, associated with marked disturbances in the spatial organization of all haemopoietic lineages. Cases of megaloblastic anaemia due to vitamin B12/folate deficiency also demonstrated greatly increased erythroid PCNA expression, with positivity in some giant metamyelocytes. In addition to reflecting increased proliferation, elevated PCNA expression in some bone marrow pathologies may be due to altered kinetics of the protein induced by disturbances in growth factor production.
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PMID:A study of cell proliferation in formalin-fixed, wax-embedded bone marrow trephine biopsies using the monoclonal antibody PC10, reactive with proliferating cell nuclear antigen (PCNA). 134 81

Although an elevated erythrocyte mean corpuscular volume has been noted in many conditions, the relative frequency of various causes of macrocytosis in the pediatric population has not been defined. Therefore, the different medical conditions associated with red cell macrocytosis were retrospectively reviewed. One hundred forty-six children between 6 months and 12 years of age with a mean corpuscular volume greater than or equal to 90 fL were identified during a 13-month period. The most common association with macrocytosis was drug ingestion (anticonvulsants, zidovudine, immunosuppressive agents), observed in 51 (35%) of the cases. Other conditions associated with macrocytosis were congenital heart disease (20), Down syndrome (12), reticulocytosis (11), and marrow failure/myelodysplasia (6). Miscellaneous diseases were identified in 21 children. Twenty-four cases had no apparent cause of their macrocytosis; 21 of them had just a slight elevation of the mean corpuscular volume (91 or 92 fL), suggesting that these values probably represent the upper limit of normal. No cases of vitamin B12 or folate deficiency were observed. The use of relatively new drugs such as valproate, zidovudine, and immunosuppressants (for the treatment of diverse medical conditions) accounted for more than half of the cases of drug administration and 24% of the children with macrocytosis. Three children with bone marrow failure had macrocytosis and pancytopenia, suggesting that this finding might be the first manifestation of serious but treatable disorders such as aplastic anemia.
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PMID:Etiology of red blood cell macrocytosis during childhood: impact of new diseases and therapies. 153 2

The most common causes of macrocytic anemias in the adults are (1) alcoholism, (2) liver diseases, (3) hemolysis or bleeding, (4) hypothyroidism, (5) folate or vitamin B12 deficiency, (6) exposure to chemotherapy and other drugs, and (7) myelodysplasia. A carefully obtained history and examination with evaluation of a peripheral blood smear and reticulocyte count should be performed in most patients with macrocytosis. Serum vitamin B12 and folate levels, serum thyroid studies, liver function studies, and bone marrow aspirate and biopsy with cytogenetic analysis are frequently required to confirm a diagnosis suspected on the basis of the initial evaluation.
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PMID:A practical approach to the differential diagnosis and evaluation of the adult patient with macrocytic anemia. 157 58

The myelodysplastic syndromes are composed of a group of clonal hematologic neoplasms, the course of which is complicated by ineffective hematopoiesis or leukemic transformation (or both). Therapeutic results may have been misleading in the past. Most patients have been managed with supportive measures, such as transfusions of erythrocytes, administration of antibiotics, and transfusions of platelets during active bleeding episodes. These supportive measures have prolonged and improved the quality of life of patients with myelodysplastic syndromes. Vitamin supplementation (folate, vitamin B12, and pyridoxine) has seldom been rewarding. Differentiation agents such as cis-retinoic acid and 1,25-dihydroxyvitamin D3 have been of benefit in only a limited number of patients. Androgens have not been useful, although danazol, which is an attenuated androgen, has been effective in a subset of patients with the presence of cell-bound platelet antibodies. Low-dose cytarabine, which has been studied extensively because of its differentiating activity in vitro, is associated with a generally low rate of complete remission and substantial toxicity. Antileukemic therapy is generally useful in young patients with rapidly progressive disease. Several hematopoietic growth factors are currently being evaluated in clinical trials; their use in combination or in conjunction with chemotherapy may be opening new horizons for these patients. With improvements in the prevention and treatment of graft-versus-host disease, allogeneic transplantation is a viable option for patients younger than 55 years of age who have severe cytopenias.
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PMID:Management of patients with myelodysplastic syndromes. 203 Jun 15

Four patients with severe cerebral palsy, mental retardation, and seizures who were treated with valproic acid showed a broad spectrum of hematologic toxicity, which included thrombocytopenia, macrocytic red cells with or without anemia, and the Pelger-Huet anomaly in the segmented neutrophils, along with elevated vitamin B12 levels, normal serum folic acid levels, and elevated fetal hemoglobin values (two cases). Bone marrow findings in all four patients were abnormal, suggestive of a myelodysplastic syndrome. These hematologic findings have not been previously reported and are important for monitoring a patient on valproic acid therapy. The Pelger-Huet anomaly may be mistaken for an elevated band count, the macrocytic anemia appears not to be secondary to a vitamin B12 or folate deficiency, and the thrombocytopenia may be sensitive to drug dosage. The bone marrow changes appear to be a drug-related myelodysplastic phenomenon.
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PMID:Severe hematologic toxicity of valproic acid. A report of four patients. 210 2

This paper presents changes in the bone marrow of patients with malaria; it is based primarily on observations of bone marrows of 89 Gambian children with P. falciparum malaria and includes a review of the literature. Erythroid hyperplasia with dyserythropoiesis was found to be more common in patients with severe anemia and low grade parasitemia than in those with acute malaria. The dyserythropoietic changes are illustrated both with light photomicropraphs and with electron micrographs. The significance of the dyserythropoiesis and possible causes are discussed. Other changes in these patients with acute malaria include lymphocytosis in the bone marrow and reactive lymphocytes, monocytosis and mild neutrophilia in the peripheral blood. Giant metamyelocytes were also commonly seen in bone marrow of patients but were thought to be part of dysmyelopoiesis and not due to B12 or folate deficiency. Phagocytosis of erythrocytes, parasitized cells and nucleated cells was more commonly seen in macrophages in acute malaria, while phagocytosis of small particles such as merozoites was observed in neutrophils. Megakaryocytes were found to be increased in number in patients with acute malaria; a proportion of these cells had rounded nuclei, probably indicating accelerated platelet turnover.
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PMID:Hematopoiesis in human malaria. 225 20

The nosography of the dyserythropoietic syndromes remains poorly defined in the field of clinical hematology. The prominent pathophysiologic feature lies in the "ineffective erythropoiesis" as expressed by bone marrow erythroid hyperplasia with dysplasia accompanied by a normal or only slightly increased reticulocyte count. Both erythrokinetics and ferrokinetics are impaired, as shown by either slight reduction of the red cell survival or marked increased rate of serum iron transport together with reduced cellular iron utilization. The dyserythropoietic syndromes can be classified as acquired, secondary or congenital. The acquired ones, especially the sideroblastic forms, belonging to the myelodysplastic syndromes, are typical of the elderly whereas the congenital are of childhood. Their treatment is still a matter of controversy. However, the employment of folic acid, Vit. B12, pyridoxine and androgens can be useful in selected cases. In case of severe anemia, blood transfusion are required in association with iron chelating agents. However, some biological molecules, such as erythropoietin, interleukins 3 and 4, hemopoietic growth factors (especially GM-CSF), could represent future prospects of treatment.
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PMID:[Dyserythropoietic syndromes: incidence, diagnosis, therapy]. 229 Oct 9

59 year old female was admitted to Nagoya Memorial Hospital for anemia unknown etiology after the work up of the gastrointestinal tract. Peripheral blood count at admission was as follows: WBC 2,400/microliters, RBC 321 X 10(4)/microliters, Hb 9.8 g/dl, Ht 30.1%, Plt 8.2 X 10(4)/microliters, which showed pancytopenia with normocytic, normochromic anemia. She had no hepatosplenomegaly, vitamin B12 nor folate deficiency. Bone marrow was hyperplastic and showed trilineage megalodysplastic changes. The diagnosis of myelodysplastic syndrome (Refractory anemia) was made. Progenitor assay showed no colony formation of BFU-E but showed normal growth of CFU-GM colony and cluster. She had chromosomal abnormality of 47, XX, + 11. Administrated anabolic steroid, prednine and activated vitamin D3 were not effective and she died of brain hemorrhage in April 1987. Colony assay at this stage showed numerous leukemic clusters and no normal colonies. Re-performed chromosome assay showed 47, XX, + 11. There are only a few reports of trisomy-11 in a patient with MDS. Especially we could follow this case till her leukemic transformation by colony assay.
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PMID:[Abnormal cluster formation in a patient with myelodysplastic syndrome with trisomy-11--periodical approach by colony assay]. 236 44

Myelodysplastic syndromes (MDS) are disorders characterized by a profound impairment of proliferation and maturation of hematopoietic cells. The prognosis is poor owing to the occurrence of severe cytopenia or to the common leukemic transformation of these conditions. At present there is no available effective treatment for patients with MDS. A patient is reported with simple refractory anemia which responded to therapy with high doses of maturative factors (folic acid and vitamin B12). This therapy resulted in the disappearance of transfusion requirements and in the increase of peripheral blood cell counts. It is concluded that, in view of the lack of toxicity of the treatment with madurative factors, this therapy should be attempted in a sequential fashion in all patients with MSD.
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PMID:[Simple refractory anemia. Response to treatment using maturative factors]. 262 53


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