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)

Recombinant human erythropoietin (rhEPO) has now been in clinical trials for over three years. It has been shown to be nearly uniformly effective in correcting the anaemia of patients on haemodialysis or patients with progressive chronic renal failure not yet on dialysis. Preliminary results indicate that rhEPO is effective in increasing the ability of individuals to donate blood for self-use and early trials have shown the drug to increase the haematocrit in patients with rheumatoid arthritis. Trials in patients with anaemia associated with cancer or myelodysplastic syndromes are warranted. rhEPO will have a major impact as a therapeutic, particularly in patients with renal disease.
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PMID:The use of recombinant human erythropoietin in humans. 218 Jun 46

In a dose escalation study we tested the feasibility and tolerance of high-dose recombinant human erythropoietin (r-HuEPO) therapy in four patients with ineffective erythropoiesis due to myelodysplastic syndromes (MDS) or paroxysmal nocturnal hemoglobinuria (PNH). Recombinant human EPO was administered i.v. with an initial dose of 50 U/kg body weight (BW) three times per week. The dose was increased by steps of 25 or 50 U/kg bW with intervals of 1-4 weeks up to a maximum dose of 500 U/kg BW three times per week. All patients were treated as outpatients. Pre-study treatment with cyclosporin A and/or Danazol was continued in three patients. In one patient r-HuEPO was discontinued after 20 weeks because of relapse of severe aplastic anemia. No major side effects were observed even at the maximum dose. One patient with PNH showed an increase of hemoglobin from 89 to 139 g/liter that permitted monthly phlebotomies to reduce his iron overload. In one patient with MDS the reticulocyte count increased from 2.5 to 50 x 10(9)/liter, and the transfusion requirement decreased to 2 U every 3-4 weeks instead of every 2 weeks. Two patients did not complete the whole treatment period and showed no rise in reticulocyte count. We conclude that high dose r-HuEPO therapy is feasible in patients with anemia due to MDS or PNH. High-dose r-HuEPO appears to have some effect on anemia due to ineffective erythropoiesis in a subgroup of patients. Further studies are needed to identify potential responders and to define the optimal administration of r-HuEPO.
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PMID:High-dose recombinant human erythropoietin for treatment of anemia in myelodysplastic syndromes and paroxysmal nocturnal hemoglobinuria: a pilot study. 222 80

Erythropoietin-dependent regulation of erythropoiesis in myelodysplastic syndromes (MDS) was evaluated by measuring the in vitro response of primitive (BFU-E) and relatively mature (CFU-E) erythroid progenitors from 12 patients and from eight healthy donors to recombinant human erythropoietin (rhEPO), and by quantifying relationships between circulating EPO levels and progenitor cell frequencies in MDS marrow. Half-maximal growth of MDS CFU-E and BFU-E was detected at a 4-fold higher rhEPO concentration than required by control erythroid progenitors. Nine of the patients evaluated exhibited maximal growth of erythroid colonies at 5- to 20-fold higher than control saturating rhEPO concentrations. Circulating EPO levels in MDS patients were elevated, with a mean value approximately 35-fold higher than that of controls. The frequency of MDS marrow CFU-E and BFU-E was 57 +/- 42% and 18 +/- 9% of the mean control values, respectively. Correlation analysis of the relationships between MDS EPO levels and erythroid progenitors indicated that the anemia in MDS is not attributable to an abnormality in the capacity of EPO to induce the generation of CFU-E, but may be influenced by the BFU-E population, whose severe deficiency results in insufficient influx of EPO-responsive cells. Our findings therefore suggest that treatment of MDS patients with rhEPO may be of limited benefit, since the generation of BFU-E from more primitive ancestors and the initial growth requirements of these cells are not under the regulatory influence of this hormone.
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PMID:In vitro studies of erythropoietin-dependent regulation of erythropoiesis in myelodysplastic syndromes. 223 91

Eight patients with myelodysplastic syndromes (MDS) and four patients with aplastic anemia (AA) were treated with recombinant erythropoietin (rEpo) to investigate its effect on the anemia of these patients. rEpo was administered by i.v. injection three times a week for at least four weeks. The doses were 3,000, 6,000, or 12,000 U/day. Despite an elevated "endogenous" Epo level, a greater than 1.5 g/dl increase in hemoglobin (Hb) concentration was observed in one patient with refractory anemia (RA), one patient with refractory anemia with excess of blasts (RAEB), and one patient with AA. A greater than 50% decrease in red cell transfusion requirement was observed in one patient with RA and one patient with AA. One RA patient and one AA patient have received rEpo as maintenance therapy for more than 64 and 100 weeks, respectively. They no longer need red cell transfusions and have had a normal Hb concentration and normal ferrokinetics. No side effect was seen. These results indicate that rEpo may benefit some patients with MDS and AA who are dependent on red cell transfusions while further studies will be necessary to elucidate the mechanism by which rEpo stimulates erythropoiesis and improves anemia in patients with these diseases.
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PMID:Improvement of anemia by recombinant erythropoietin in patients with myelodysplastic syndromes and aplastic anemia. 227 98

Recombinant human erythropoietin (rHuEpo) has now been in clinical trials for over four years. rHuEpo has been shown to be nearly uniformly effective in correcting the anaemia of patients on haemodialysis or patients with progressive chronic renal failure not yet on dialysis. rHuEpo has been shown to be effective in increasing the ability of individuals to donate blood for self-use and to increase the haematocrit in patients with rheumatoid arthritis. Preliminary results indicate that rHuEpo will decrease transfusion requirements of patients with the acquired immune deficiency syndrome who are anaemic. Trials in patients with anaemia associated with cancer or myelodysplastic syndromes are in early stages. rHuEpo will have a major impact as a therapeutic agent, particularly in patients with renal disease.
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PMID:The use of recombinant human erythropoietin (rHuEpo) in humans. 227 12

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

Ineffective erythropoiesis is an early feature of the myelodysplastic syndromes (MDS), usually accompanying an hypercellular marrow. In a previous study, concentrations of serum erythropoietin (EPO) in MDS have been shown to correlate inversely both with haemoglobin concentration and with % bone marrow erythroblasts. We have measured erythroid production using a radioisotopic technique in 20 patients with MDS. Although haemoglobin concentration shows a weak inverse relationship with serum EPO concentration there is considerable variation in EPO concentration at a given haemoglobin level. There is no correlation between serum EPO and total erythroid production, though there is a weak correlation with effective erythropoiesis. The data suggests that control mechanisms of erythropoiesis in patients with MDS are complex.
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PMID:Serum erythropoietin and erythropoiesis in patients with myelodysplastic syndromes. 230 17

Responsiveness of bone marrow erythropoietic stem cells (CFU-E and BFU-E) to recombinant human erythropoietin (rh-Ep) was examined in vitro in 23 patients with aplastic anemia and 14 with myelodysplastic syndrome (MDS) to investigate the clinical use of rh-Ep for these diseases. Bone marrow mononuclear cells were cultured by methylcellulose methods for CFU-E and BFU-E assays. In normals, the CFU-E numbers reached a plateau of increase at Ep doses of almost 2-5 units, and no further increase was observed with the addition of larger Ep doses. In aplastic anemia, the responses of CFU-E to Ep were relatively good in nonsevere type and generally poor in severe type. However, the CFU-E numbers increased with increasing doses of Ep in some of the patients with aplastic anemia. Among the patients with MDS, the responses of CFU-E to Ep were relatively good in primary acquired refractory anemia (PARA) and primary acquired sideroblastic anemia. On the other hand, the responses of CFU-E to Ep were poor in refractory anemia with an excess of blasts (RAEB) and RAEB in transformation among the MDS patients. BFU-E responses to Ep were poor in severe aplastic anemia, RAEB, and RAEB-T. However, there are Ep responsive patients in some of aplastic anemia and PARA. High titers of rh-Ep were suggested to be effective clinically in some patients with aplastic anemia and those with PARA.
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PMID:Responsiveness of bone marrow erythropoietic stem cells (CFU-E and BFU-E) to recombinant human erythropoietin (rh-Ep) in vitro in aplastic anemia and myelodysplastic syndrome. 238 70

Clinical trials of recombinant biologic agents have resulted in new treatment options for hematologic, oncologic, and cardiologic disorders. These agents include the interferons, recombinant human erythropoietin (r-HuEPO), colony-stimulating factors (CSFs), interleukins (ILs), and tissue plasminogen activator (t-PA). Interferon alfa has proven efficacious in treating certain hematologic malignancies and solid tumors and has recently been indicated for acquired immunodeficiency syndrome (AIDS)-related Kaposi's sarcoma. Treatment with r-HuEPO has relieved the chronic anemia of hemodialysis patients. Recombinant human granulocyte CSF (G-CSF) or human granulocyte macrophage CSF (GM-CSF) has been used to treat patients after autologous bone marrow transplantation for lymphoid or solid malignancies, resulting in increased production of granulocytes and platelets. G-CSF and GM-CSF have been used to treat aplastic anemia, myelodysplastic syndromes, chemotherapy-induced neutropenia, and neutropenia associated with AIDS. In patients with evolving myocardial infarction, the recombinant agent t-PA has proved more efficacious than streptokinase in terms of average coronary artery patency rates and survival rates in patients with evolving myocardial infarction. While these agents all offer promising therapeutic advances, the expenses associated with developing and testing biotherapeutic substances have resulted in high treatment costs. Since in many instances investigational therapy is the best treatment option available, physicians, patients, the pharmaceutical industry, the government, and insurance carriers must work together to ensure that these therapies are financially available to those in need.
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PMID:New directions in hematologic biotherapy. 247 3

Recombinant DNA technology has allowed for the production of large quantities of several hematopoietic growth factors as cloned gene products. Three of these factors--recombinant human erythropoietin (r-HuEPO), granulocyte macrophage colony-stimulating factor (GM-CSF), and granulocyte colony-stimulating factor (G-CSF)--are currently undergoing clinical trials and appear to offer considerable promise for the treatment of a variety of hematopoietic abnormalities. Therapy with r-HuEPO can raise the hematocrit levels of patients with end-stage renal disease. Therapy with GM-CSF in patients undergoing marrow transplantation results in acceleration of granulocyte and platelet recovery by 1 to 2 weeks, leading to fewer infections and earlier discharge from the hospital. Other demonstrated uses of GM-CSF include treatment for aplastic anemia, myelodysplastic syndromes, chemotherapy-induced neutropenia, and neutropenia associated with the acquired immunodeficiency syndrome (AIDS). Similar beneficial effects have been reported with G-CSF. Other hematopoietic growth factors, including the interleukins (IL)-1, -3, and -6, will soon be entering clinical trials. For the first time, the availability of a large number of hematopoietic growth factors may allow physicians to regulate closely the entire hematopoietic system of their patients.
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PMID:The clinical use of hematopoietic growth factors. 247 5


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