Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The butyrate derivative isobutyramide (IBT) increases fetal hemoglobin (HbF) in patients with beta-hemoglobinopathies, but little is known about its usefulness for prolonged therapeutic use. We treated 8 patients with transfusion-dependent beta-thalassemia with 350 mg/kg of body weight per day of oral IBT for 126 to 384 days. During the trial period, the hemoglobin level was maintained between 85 g/L (range 82-87 g/L) (pretransfusion) and 115 g/L (range 110-119 g/L) (post-transfusion) (median, interquartile range), corresponding to 4-week transfusion intervals in all patients during the pretreatment phase. Adverse effects (bitter taste, epigastric discomfort) did not cause discontinuation of IBT. HbF increased in all patients from 3.1% (range 1.9%-4.8%) to 6.0% (range 3.3%-8.7) (P =.0017), while free Hb dropped from 0.48 g/L (range 0.39-0.81 g/L) to 0.19 g/L (range 0.16-0.24 g/L) (P <.0001). Transfusion intervals were consistently extended to 8 or 9 weeks in 1 patient, resulting in a decrease of daily iron load from 455 microgram/kg per day (range 451-459 microgram/kg per day) before therapy to 211 microgram/kg per day (range 203-286 microgram/kg per day) during the 12-month treatment period. Prolongation of transfusion intervals achieved by IBT was less consistent in another patient, whose parenteral iron load nevertheless decreased from 683 microgram/kg per day (range 618-748 microgram/kg per day) to 542 microgram/kg per day (340-596 microgram/kg per day). In the other 6 patients, no prolongation of transfusion intervals was achieved. Response to treatment was associated with high pretreatment HbF (> 4.5%), high parental HbF, and increased erythropoietin levels (> 150 IU/L). We conclude that IBT prolongs transfusion intervals and reduces parenteral iron burden in some patients with transfusion-dependent beta-thalassemia.
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PMID:Oral isobutyramide reduces transfusion requirements in some patients with homozygous beta-thalassemia. 1107 27

We have studied the effects of hydroxyurea on growth and differentiation of early erythroid progenitor cells (BFU-e) from peripheral blood of sickle cell disease patients (five SS and two Hb S/beta-thalassemia) in the presence or absence of exogenous stimulating factors. When the mononuclear cells from the sickle cell disease patients were cultured at diagnosis (before hydroxyurea treatment), there was an increased number of BFU-e in relation to controls (p < 0.05, Wilcoxon test) when cells were grown in the presence or absence of 5637 conditioned medium and erythropoietin. Colonies that developed in the absence of added growth factors were considered "spontaneous". A significant difference was observed after hydroxyurea treatment in the number of BFU-e obtained in the presence and absence of stimulus, with a higher reduction in the spontaneous BFU-e number. As expected, there was an increased Hb F level in these patients when compared with their pretreatment levels. There was no correlation between spontaneous BFU-e and hemoglobin levels in all patients studied.
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PMID:Hydroxyurea promotes the reduction of spontaneous BFU-e to normal levels in SS and S/beta thalassemic patients. 1130 Mar 42

Beta-thalassaemia is highly prevalent and world wide in its distribution. The gene to modify the clinical course of patients with transfusion-dependent thalassaemia (thalassaemia major), the gamma-globin gene, is already present in these patients but silenced in the course of development. During erythropoiesis, progenitors are believed to go through a phase where the milieu favours gamma-globin production. One pharmacological strategy to increase gamma-globin production is directed at recruiting such early progenitors through the use of cytotoxic agents (+/- erythropoietin) that presumably deplete more mature progenitors. Another promising strategy is to use chromatin-modifying agents that prevent the silencing of the gamma-globin gene that occurs during development. These agents, the methyl-transferase inhibitors and histone deacetylase inhibitors, either alone or in combination, may be able to produce the robust increase in gamma-globin and hence fetal haemoglobin and total haemoglobin, needed to successfully treat thalassaemia major. Studies of these agents, which are already available for clinical trials, should be encouraged.
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PMID:Advances in experimental treatment of beta-thalassaemia. 1132 66

We report on a 28-year-old patient with transfusion-dependent beta-thalassemia major, who was treated effectively with recombinant human erythropoietin (rHuEpo). rHuEpo promotes the differentiation and proliferation of erythroid cells, induces the production of fetal hemoglobin (HbF), and could be useful in the treatment of some selected transfusion-dependent thalassemia patients. Prior to rHuEpo treatment, the patient was on a regular blood transfusion regimen. Splenectomy did not decrease the transfusion requirements. Additionally, red cell alloimmunization had developed; therefore, we decided to start rHuEpo treatment (Eprex, Jansen Cilag, Greece) in an attempt to improve his anemia and the quality of life. Our patient responded well to rHuEpo treatment and was able to extend the intervals between transfusions from 10-14 to 55-65 days and to sustain a pretransfusion hemoglobin level above 7 g/dl. HbF levels were slightly increased from 55% to 60-65%. Indicators of vascular endothelial activation [serum endothelin-3, intracellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin] were decreased during treatment. rHuEpo was well tolerated without complications. rHuEpo treatment seemed to have had a beneficial effect and to have improved the quality of life in beta-thalassemia major, although it did have a slight effect on HbF levels, suggesting other possible mechanisms of rHuEpo action.
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PMID:Recombinant human erythropoietin therapy in a transfusion-dependent beta-thalassemia major patient. 1156 99

Serum erythropoietin (Epo) and soluble transferrin receptor (sTR) were measured in a locally defined reference population (n=100): healthy volunteers (n=50); iron- deficiency anaemia (n=41) and haemolytic anaemia (n=9) (beta-thalassaemia, n = 4; autoimmune, n=5). Our data demonstrated an inverse relationship between erythroid activity and Epo levels. The regression line between Ln Epo and haemoglobin (Hb) was highly significant: P < 0.0001, r2=0.8275, Ln Epo=8.5346-0.04275 Hb, confidence limit 95%. The mean observed/predicted (O/P) ratio of Ln (Epo) was 1.01 +/- 0.11. We demonstrated that the serum Epo concentration in this particular population correlated consistently with clinical measures of erythropoietic activity. sTR, a new index of erythropoiesis, varied from 16.1 to 148 nmol/l, mean 62.0 nmol/l in the anaemic patients' group. The relationship between Ln Epo and Ln sTR was highly significant: P < 0.0001. We conclude that locally defined regression analyses are crucial for correct data interpretation and can indicate whether or not Epo production is appropriate or inappropriate. Serial determinations of sTR could help in the assessment of response to therapeutic doses of Epo.
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PMID:Serum erythropoietin and its relation with soluble transferrin receptor in patients with different types of anaemia in a locally defined reference population. 1170 10

Eighty multi-transfused beta-thalassemics--40 of them on regular transfusion (RT) (every 3-4 weeks) and 40 irregularly transfused (IT)-and 20 age- and-sex-matched controls were evaluated for serum erythropoietin (sEpo) and soluble serum transferrin receptors (sTfr) as indicators of erythropoietic activity. All subjects were studied for pre-transfusion hemoglobin (Hb), reticulocytic index (RI), serum ferritin, sEpo and sTfr. Results showed that the mean RI, sEpo and sTfr values were significantly higher in the IT group (2.8; 80 mU/ml; and 19 microg/ml, respectively) compared to the RT group (1.2; 35.2 mU/ml; and 13.9 microg/ml, respectively) and controls (1.1; 22.6 mU/ml; and 7 microg/ml, respectively) (p < 0.05); while only the mean sTfr value was significantly higher in the RT group compared to controls. The mean pre-transfusion Hb was significantly lower in the IT group (8 g/dl) compared to both the RT group (9.3 g/dl) and controls (12.5 g/dl) (p < 0.05); while the RT group level was significantly lower than controls. There was an inverse correlation between Hb level on one hand and sEpo (r = 0.324,p < 0.05), sTfr (r = -0.651, p < 0.05) and RI (r = -0.451, p < 0.05) on the other. In summary, sEpo, sTfr and RI could be used as accurate and reliable indicators of successful erythroid marrow suppression and for the determination of optimal pre-transfusion Hb level in thalassemia on an individual basis, with sTfr being the most sensitive indicator.
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PMID:Evaluation of serum soluble transferrin receptors and erythropoietin levels as indicators for erythropoietic activity among multi-transfused beta-thalassemic patients. 1186 34

BACKGROUND: The thalassemic syndromes originate from mutations of the globin genes that cause, besides the characteristic clinical picture, also an increased Hb F amount. It is not yet clear if there are more factors, besides the beta globin genotype, determining the Hb F production. We have tried to find out if there are relations between total Hb and Hb F, between erythropoietin (Epo) and Hb F, between Hb F and point mutations of the gamma gene promoters. MATERIALS AND METHODS: Hematologic parameters, iron status, alpha/non-alpha globin ratio, Epo level, and thalassemic defects of the alpha-, beta-, and gamma-globin genes were explored using standard methods in patients affected by thalassemic diseases. Ninety-five non thalassemic individuals have been examined as controls. RESULTS: Two clinical variants of beta-thalassemia intermedia referred to as beta-thal int sub-silent and evident are associated with distinct sets of mutations of the beta-globin gene. Silent beta thal mutations are invariably associated with sub-silent beta thal int; beta degrees or severe beta+ thal mutations are associated with evident beta thal int (88%) and almost invariably (98%) with thalassemia major. A positive correlation was observed between the severity of the disease and the Hb F level, but no correlation was found between the Hb F and erythropoietin (Epo) level. The mutation Ggamma -158 C&RightArrow;T was detected in 26.9% of patients affected by beta-thal int sub-silent and evident, respectively, but only in 2% of patients with thalassemia major. CONCLUSIONS: The severity of beta-thal int and the increased Hb F level are strictly dependent from the type of beta-globin gene mutations. No relation is found between Hb F synthesis and Epo secretion. The mutation Ggamma -158 C&RightArrow;T, common among patients affected by beta-thal int and very rare in thal major patients, does not seem, in this study, to influence the Hb F content in beta thal int patients.
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PMID:Factors regulating Hb F synthesis in thalassemic diseases. 1194 67

A drug that specifically inhibits erythropoiesis would be clinically useful. The erythropoietin (Epo) mutant Epo (R103A) could potentially be used for this purpose. Epo (R103A) has a single amino acid substitution of alanine for arginine at position 103. Because of this mutation, Epo (R103A) is only able to bind to one of the 2 subunits of the erythropoietin receptor (EpoR) homodimer and is thus a competitive inhibitor of Epo activity. To produce large quantities of Epo (R103A) to test in animal models of thalassemia and sickle cell disease, we expressed and purified recombinant Epo (R103A) from the yeast Pichia pastoris. Using this method milligram quantities of highly purified Epo (R103A) are obtained. The yeast-expressed Epo (R103A) is properly processed and glycosylated and specifically inhibits Epo-dependent cell growth and (125)I-Epo binding. Epo (R103A) does not, however, directly induce apoptosis in 32D cells expressing EpoR. Epo (R103A) inhibits erythropoiesis of human CD34(+) hematopoietic cells and completely blocks erythroid burst-forming unit formation in normal human bone marrow colony assays. Yeast-expressed Epo (R103A) is a specific inhibitor of primary erythropoiesis suitable for testing in animal models.
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PMID:Purification and characterization of the yeast-expressed erythropoietin mutant Epo (R103A), a specific inhibitor of human primary hematopoietic cell erythropoiesis. 1203 68

Presently, the assays for serum erythropoietin (EPO) seem valuable tools for clinical research, but their roles in routine clinical practice remain undefined. Some studies mentioned that serum EPO measurements, which are now easily and reliably performed, should be used in monitoring the therapy of beta-thalassemia major. Here, we report our experience in the determination of serum EPO in children with beta-thalassemia/Hb E and also compared the results with those in hemoglobin E trait, beta-thalassemia/Hb E as well as healthy non-anemic controls of similar age. Fifty five transfusion-dependent beta-thalassemia/Hb E, fifteen hemoglobin E trait, five beta-thalassemia trait cases and twenty five controls were studied for their serum EPO levels. The mean (S.D.) EPO concentrations were 19.94 (17.40) U/L for the controls, 16.13 (8.47) U/L for the hemoglobin E trait, 24.40 (8.20) U/L for the beta-thalassemia trait and 372.19 (432.04) U/L for the beta-thalassemia/Hb E cases. The mean EPO concentration for the normal controls was near to that of the hemoglobin E trait (P = 0.06) and beta-thalassemia trait (P = 0.25) but eighteen times less than that for the beta-thalassemia major cases (P<0.0005).
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PMID:Serum erythropoietin levels in pediatric patients with beta-thalassemia/hemoglobin E. 1246 48

This report describes the sustained response of an Iranian girl with homozygous beta(0) thalassemia (IVS-II-1G-->A) to hydroxyurea (HU) and recombinant erythropoietin (rEPO). Since the start of this regimen 7 years ago, she has been transfusion-independent and her hemoglobin is maintained between 9.5-11.0 gm/dL. She is maintaining consistent growth around the 10th percentile for age and enjoys a good quality of life. She has not had any therapy-related adverse effects. This experience suggests that therapy with HU and rEPO may be useful long-term in some patients with beta thalassemia.
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PMID:Use of hydroxyurea and recombinant erythropoietin in management of homozygous beta0 thalassemia. 1246 25


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