losartan-potassium and beta-Thalassemia

Erythropoiesis regulation is essential in normal physiology and pathology, particularly in myelodysplastic syndromes (MDS) and β-thalassemia. Several signaling transduction processes, including those regulated by inositides, are implicated in erythropoiesis, and the latest MDS or β-thalassemia preclinical and clinical studies are now based on their regulation. Among others, the main pathways involved are those regulated by transforming growth factor (TGF)-β, which negatively regulates erythrocyte differentiation and maturation, and erythropoietin (EPO), which acts on the early-stage erythropoiesis. Also small mother against decapentaplegic (SMAD) signaling molecules play a role in pathology, and activin receptor ligand traps are being investigated for future clinical applications. Even inositide-dependent signaling, which is important in the regulation of cell proliferation and differentiation, is specifically associated with erythropoiesis, with phospholipase C (PLC) and phosphatidylinositol 3-kinase (PI3K) as key players that are becoming increasingly important as new promising therapeutic targets. Additionally, Roxadustat, a new erythropoiesis stimulating agent targeting hypoxia inducible factor (HIF), is under clinical development. Here, we review the role and function of the above-mentioned signaling pathways, and we describe the state of the art and new perspectives of erythropoiesis regulation in MDS and β-thalassemia.

Topics: Animals; beta-Thalassemia; Cell Differentiation; Cell Proliferation; Clinical Trials as Topic; Erythropoiesis; Erythropoietin; Glycine; Hematinics; Humans; Hypoxia-Inducible Factor 1; Isoquinolines; Ligands; Mice; Myelodysplastic Syndromes; Phosphatidylinositol 3-Kinases; Signal Transduction; Smad Proteins; Transforming Growth Factor beta; Type C Phospholipases

This review presents the indications and contraindications (pros and cons) for the potential use of erythropoietin (Epo) as a treatment in β-thalassemia and sickle cell anemia (SCA). Its high cost and route of administration (by injection) are obvious obstacles, especially in underdeveloped countries, where thalassemia is prevalent. We believe that from the data summarized in this review, the time has come to define, by studying in vitro and in vivo models, as well as by controlled clinical trials, the rationale for treating patients with various forms of thalassemia and SCA with Epo alone or in combination with other medications.

Topics: Anemia, Sickle Cell; beta-Thalassemia; Drug Therapy, Combination; Erythropoietin; Hemoglobinopathies; Humans; Treatment Outcome

Haemoglobin E-beta thalassaemia (Hb E/β-thalassaemia) is the genotype responsible for approximately one-half of all severe beta-thalassaemia worldwide. The disorder is characterized by marked clinical variability, ranging from a mild and asymptomatic anaemia to a life-threatening disorder requiring transfusions from infancy. The phenotypic variability of Hb E/β-thalassaemia and the paucity of long-term clinical data, present challenges in providing definitive recommendations for the optimal management of patients. Genetic factors influencing the severity of this disorder include the type of beta-thalassaemia mutation, the co-inheritance of alpha-thalassaemia, and polymorphisms associated with increased production of foetal haemoglobin. Other factors, including a variable increase in serum erythropoietin in response to anaemia, previous or ongoing infection with malaria, previous splenectomy and other environmental influences, may be involved. The remarkable variation, and the instability, of the clinical phenotype of Hb E beta-thalassaemia suggests that careful tailoring of treatment is required for each patient, and that therapeutic approaches should be re-assessed over-time.

Topics: alpha-Thalassemia; beta-Thalassemia; Blood Transfusion; Erythropoietin; Fetal Hemoglobin; Genotype; Hemoglobin E; Humans; Malaria; Phenotype; Polymorphism, Genetic; Splenectomy

β-Thalassemia is a genetic disorder caused by mutations in the β-globin gene and characterized by chronic anemia caused by ineffective erythropoiesis, and accompanied by a variety of serious secondary complications such as extramedullary hematopoiesis, splenomegaly, and iron overload. In the past few years, numerous studies have shown that such secondary disease conditions have a genetic basis caused by the abnormal expression of genes with a role in controlling erythropoiesis and iron metabolism. In this article, the most recent discoveries related to the mechanism(s) responsible for anemia/ineffective erythropoiesis and iron overload are discussed in detail. Particular attention is paid to the pathway(s) controlling the expression of hepcidin, which is the main regulator of iron metabolism, and the Epo/EpoR/Jak2/Stat5 signaling pathway, which regulates erythropoiesis. Better understanding of how these pathways function and are altered in β-thalassemia has revealed several possibilities for development of new therapeutic approaches to treat of the complications of this disease.

Topics: Anemia; Animals; Antimicrobial Cationic Peptides; beta-Thalassemia; Erythropoiesis; Erythropoietin; Hepcidins; Humans; Iron; Iron Overload; Receptors, Erythropoietin

For the majority of children with beta- hemoglobinopathies and -thalassemias who do not have a transplant donor, survival is shortened and morbidity is high. Hydroxyurea, EPO preparations, sodium phenylbutyrate, arginine butyrate, and 5-azacytidine/decitabine have shown efficacy in approximately 40% to 70% of sickle cell and beta-thalassemia patients. Many responses, although significant, were not completely ameliorating of symptoms or pathology, and trials of new agents with dual actions, or drug combinations, are needed. Ideally, limiting chemotherapeutic exposure is desirable for long-term treatment of children, and an oral therapeutic at tolerable doses is necessary for practical use. A new oral therapeutic candidate that induces fetal hemoglobin production and also stimulates erythropoiesis is entering clinical evaluation. Use of agents that should have additive or synergistic effects in combination, such as EPO and hydroxyurea or a short-chain fatty acid derivative (SCFAD), offer better therapeutic potential than hydroxyurea alone. Childhood is an optimal time to introduce such therapies, particularly the non-mutagenic SCFADs, while the erythroid marrow reserve is preserved and before organ damage has become widespread. A challenge for successful application of these therapies is to define patient subsets that are most likely to respond to a particular agent, or which require combination therapies, and to develop optimal dose regimens in thalassemias with rapid erythroid apoptosis. Development of this therapeutic avenue will require close collaboration among treating and academic physicians, families and patients, funding agencies, and researchers.

Topics: Anemia, Sickle Cell; Antisickling Agents; beta-Thalassemia; Erythropoiesis; Erythropoietin; Fatty Acids; Hemoglobinopathies; Humans; Hydroxyurea; Trans-Activators

A long-term observational study of Hb E-beta-thalassemia in Sri Lanka is beginning to define some of the genetic and environmental factors that are responsible for its remarkable phenotypic variability. In this population there is a very small difference between the steady-state hemoglobin levels between the mild and severe phenotypes, and it has been possible to stop transfusion in many of those who have been on long-term treatment of this kind. These preliminary observations, made over the last 7 years, provide directions for future research into this increasingly important disease.

Topics: Adolescent; Adult; beta-Thalassemia; Blood Transfusion; Case Management; Child; Child, Preschool; Combined Modality Therapy; Erythropoietin; Female; Genetic Heterogeneity; Hemoglobin E; Hemoglobins; Humans; Infant; International Cooperation; Iron Overload; Longitudinal Studies; Male; Middle Aged; Phenotype; Pregnancy; Pregnancy Complications, Hematologic; Severity of Illness Index; Splenectomy; Sri Lanka; Transfusion Reaction

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.

Topics: Azacitidine; beta-Thalassemia; Drug Therapy, Combination; Erythropoietin; Histone Deacetylase Inhibitors; Humans; Hydroxyurea; Iron Chelating Agents

Erythropoietin (Epo) is a glycoprotein hormone produced by genetic engineering. Many pathologic conditions could benefit from its administration, such as chronic renal failure or hemoglobinopathies. Epo secretion from genetically modified tissued could be proposed to patients only if the protocol is low cost and low risk. For that purpose, retroviral vectors and adeno-associated vectors expressing the Epo cDNA were developed. Gene transfer was performed into skeletal muscles. To avoid polycythemia, a tetracycline-regulated system was used to control the levels of protein secretion in vivo. beta-thalassemias are among diseases that could benefit from an Epo gene transfer. beta-thalassemias are attributable to deficient synthesis of beta-globin and accumulation of unpaired alpha-chains. Stimulation of fetal globin synthesis is one strategy to correct the globin chain imbalance. There is evidence that Epo could play this role. In a mouse model of beta-thalassemia, an adeno-associated vector expressing the Epo cDNA was injected intramuscularly. Epo was secreted continuously during at least 1 yr. Erythropoiesis was improved in those mice by increasing the synthesis of fetal hemoglobin.

Topics: Animals; beta-Thalassemia; Cell Transplantation; Erythropoietin; Gene Transfer Techniques; Genetic Engineering; Genetic Therapy; Humans

Homozygous beta thalassemia affects thousands of people around the world. Current management of this condition includes regular transfusion of red cells, which leads to transfusional iron overload requiring chelation therapy: increasing hemoglobin levels while decreasing or eliminating iron overload is therefore a major therapeutic goal in the treatment of thalassemia. Bone marrow transplantation may achieve this goal, but it is not an option for most patients. This study reports on efforts to increase gamma-globin transcription and HbF production using sodium phenylbutyrate (SPB) and hydroxyurea (HU). It was found that 36% (4/11) of all patients or 50% (4/8) of non-transfused patients responded to SPB (increase in Hb levels of 1 g/dL). A positive correlation between baseline serum erythropoietin level and likelihood of response to SPB was observed. Since HU may also increase HbF production, evaluation of combination therapy with these drugs is underway and preliminary results are reported.

Topics: Antisickling Agents; beta-Thalassemia; Blood Transfusion; Erythropoietin; Fetal Hemoglobin; Globins; Humans; Hydroxyurea; Phenylbutyrates; Transcription, Genetic

The rationale for treatment with recombinant human erythropoietin (rHuEPO) in thalassemia came from studies in baboons, thalassemic mice and in erythroid cultures. The results demonstrated an increase in gamma globin synthesis and consequently in fetal Hb (Hb F) resulting in improvement in erythropoietic parameters. In addition, endogenous serum Epo levels in various forms of thalassemia were inconsistent and not related to the severity of the anemia. Therefore, several preliminary studies with rHuEPO were performed, mainly on patients with beta thalassemia intermedia. The results indicate: a) a significant, dose-related (500 u/kg to 1000 u/kg x 3/week) increase in thalassemia erythropoiesis without changes in % of Hb F, MCV and MCH, mainly in splenectomized patients; b) the minimum effective dose is 500 u/kg x 3/week; c) there were no major side effects during the continuous treatment period of 9 months. In order to improve both quantitative and qualitative thalassemia erythropoiesis, several trials were undertaken combining rHuEPO with hydroxyurea (HU), which is known to increase % Hb F, MCV and MCH without a major effect on Hb levels. The designed trial included 3 to 6 months of HU alone (20 mg/kg x 4/week), or with rHuEPO alone (500 u/kg x 3/week or 375 u/kg x 2/week) or a combination of the two drugs. The results show an additive effect of the two drugs, in some of the patients. It is not known whether the addition of oral iron to rHuEPO is warranted for maximal erythropoietic response. The major limiting factor in designing large scale clinical trials is the relatively high cost of the drug. Nevertheless rHuEPO alone or in combination with other Hb F modulating drugs may have a positive effect in thalassemia with resulting improvement in the quality of life.

Topics: Animals; beta-Thalassemia; Erythropoiesis; Erythropoietin; Fetal Hemoglobin; Globins; Humans; Kidney Failure, Chronic; Mice; Recombinant Proteins

Topics: Azacitidine; beta-Thalassemia; Butyrates; Butyric Acid; Erythropoietin; Fetal Hemoglobin; Homozygote; Humans; Hydroxyurea; Treatment Outcome

Topics: Anemia, Sickle Cell; Antineoplastic Agents; Antisickling Agents; Azacitidine; beta-Thalassemia; Erythropoietin; Fetal Hemoglobin; Humans; Hydroxyurea; Phenylbutyrates

The spectrum of anemias treated with recombinant human erythropoietin is rapidly broadening. Lifelong treatment with very high doses is now under evaluation for beta-thalassemia and sickle cell anemia. These indications make it worthwhile to search for methods that will allow a permanent systemic delivery of the hormone. Here, we review experimental gene-transfer-based procedures for erythropoietin delivery in vivo. In mice, both ex vivo and direct in vivo approaches for gene transfer have resulted in the long-term production of therapeutic levels of the hormone. Gene transfer of erythropoietin could become a viable alternative to the injection of the purified recombinant protein once reliable procedures for controlling transgene expression are available.

Topics: Anemia; Animals; beta-Thalassemia; Cell Transplantation; Erythropoiesis; Erythropoietin; Gene Transfer Techniques; Genetic Therapy; Humans; Recombinant Proteins

To assess the efficacy and safety of combined hydroxyurea (HU) and recombinant human erythropoietin (rHuEPO) in β-thalassemia intermedia (TI) patients compared with single HU therapy.. An interventional prospective randomized study registered in the ClinicalTrials.gov (NCT01624038) was performed on 80 TI patients (≤ 18 yr) divided into group A (40 patients received combined HU and rHuEPO) and group B (40 patients received single HU therapy). Baseline serum EPO levels were measured, and both groups were followed up for a mean period of 1 yr with regular assessment of transfusion requirements, blood pressure, ferritin, liver and renal functions, hemoglobin, and HbF. Quality of life (QoL) was assessed at the start and end of the study.. Transfusion frequency and index were significantly decreased, while QoL was increased in group A compared with group B where 85% of patients showed improvement on combined therapy compared with 50% of patients on HU. Hemoglobin and HbF were significantly increased in both TI groups; however, this was more evident in group A than in group B. Also, 37.5% of patients in group A became transfusion-independent compared with 15% in group B. EPO levels were negatively related to increments of hemoglobin and HbF. Splenectomized patients and those with initial HbF% >40% had the best response to combined therapy. No serious adverse events necessitating discontinuation of therapy in both groups.. HU was effective in management of TI; however, combination with rHuEPO gave a superior therapeutic effect resulting in the best clinical and hematological responses without adverse events.

Topics: Adolescent; Age Factors; beta-Thalassemia; Blood Transfusion; Child; Drug Therapy, Combination; Erythropoietin; Female; Follow-Up Studies; Hemoglobins; Humans; Hydroxyurea; Male; Recombinant Proteins; Risk Factors; Treatment Outcome

Topics: Adolescent; Adult; Anemia; beta-Thalassemia; Darbepoetin alfa; Erythropoietin; Female; Hematinics; Humans; Male; Young Adult

Hepcidin, a regulator for iron homeostasis, is induced by inflammation and iron burden and suppressed by anemia and hypoxia. This study was conducted to determine the hepcidin levels in patients with congenital chronic anemias.. Forty-nine subjects with anemia, varying degrees of erythropoiesis and iron burden were recruited. Eight children with immune thrombocytopenia were included as approximate age-matched controls. Routine hematologic labs and urinary hepcidin (uhepcidin) levels were assessed. For thalassemia major (TM) patients, uhepcidin was obtained pre- and post-transfusion.. In TM, uhepcidin levels increased significantly after transfusion, demonstrated wide variance, and the median did not significantly differ from controls or thalassemia intermedia (TI). In both thalassemia syndromes, the hepcidin to ferritin ratio, a marker of the appropriateness of hepcidin expression relative to the degree of iron burden, was low compared to controls. In TI and sickle cell anemia (SCA), median uhepcidin was low compared to controls, P = 0.013 and <0.001, respectively. In thalassemia subjects, uhepcidin levels were positively associated with ferritin. In subjects with SCA, uhepcidin demonstrated a negative correlation with reticulocyte count.. This study examines hepcidin levels in congenital anemias. In SCA, hepcidin was suppressed and inversely associated with erythropoietic drive. In thalassemic syndromes, hepcidin was suppressed relative to the degree of iron burden. Transfusion led to increased uhepcidin. In thalassemia, the relative influence of known hepcidin modifiers was more difficult to assess. In thalassemic syndromes where iron overload and anemia have opposing effects, the increased erythropoietic drive may positively influence hepcidin production.

Topics: Adolescent; Adult; Aged; Anemia, Sickle Cell; Antimicrobial Cationic Peptides; beta-Thalassemia; Biomarkers; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Female; Gene Expression Regulation; Hepcidins; Humans; Iron; Male; Middle Aged; Purpura, Thrombocytopenic, Idiopathic; Reticulocyte Count; Syndrome

Patients with E/beta(0) thalassaemia, the most common haemoglobinopathy in many Asian countries, might benefit from drugs that increase fetal and total haemoglobin and thereby decrease the need for transfusions. The long-term clinical efficacy and safety of such therapy is unknown, limiting its use in countries where resources for safe and regular transfusion are scarce. In this study, 45 patients were treated with hydroxyurea (18-20 mg/kg) for 24+/-9 months, hydroxyurea with sodium phenyl butyrate (n=8) and hydroxyurea with erythropoietin (n=9), each for approximately 6 months, and followed for 3 years from study exit. Hydroxyurea had minimal toxicity, resulted in a mean 1.3 g/dl steady-state increase in haemoglobin in 40% of patients, and a milder response (

Topics: Adolescent; beta-Thalassemia; Blood Transfusion; Child; Drug Therapy, Combination; Erythrocyte Aging; Erythropoiesis; Erythropoietin; Female; Fetal Hemoglobin; Hemoglobins; Humans; Hydroxyurea; Iron Overload; Male; Phenylbutyrates; Prospective Studies; Recombinant Proteins; Treatment Outcome

Patients with hemoglobin E (Hb E)-beta 0-thalassemia, one of the most common hemoglobinopathies worldwide, could benefit from drugs that increase fetal and total hemoglobin levels and thereby decrease the need for transfusions. The long-term clinical outcome of such therapy, its hematologic effects, and which patients are likely to benefit from treatment are unknown. Consequently, the use of such drugs for Hb E-beta 0-thalassemia is limited, and countries where resources for safe and regular transfusion are scarce cannot benefit from them. In a multicenter trial of 42 patients treated with hydroxyurea for two years, almost half the patients demonstrated a significant increase in steady-state hemoglobin level. Drug toxicity was minimal. Combined treatment of hydroxyurea with erythropoietin benefited selected patients, but the addition of sodium phenyl butyrate was ineffective. After 5 years of follow-up, a subset of patients remained off transfusions. Hydroxyurea should be considered for a subset of Hb E-beta 0-thalassemia patients.

Topics: beta-Thalassemia; Blood Transfusion; Combined Modality Therapy; Drug Therapy, Combination; Erythropoiesis; Erythropoietin; Facial Bones; Fetal Hemoglobin; Gene Expression; Genotype; Globins; Hematopoiesis, Extramedullary; Hemoglobin E; Humans; Hydroxyurea; Phenylbutyrates; Radiography; Recombinant Proteins; Splenectomy; Splenomegaly; Treatment Outcome

Accelerated apoptosis of erythroid progenitors in beta-thalassemia is a significant barrier to definitive therapy because the beneficial effects of fetal globin-inducing agents on globin chain balance may not be inducible in cells in which programmed cell death is established early. Accordingly, our objectives have been to identify methods to decrease cellular apoptosis and to identify orally tolerable fetal globin gene inducers. A pilot clinical trial was conducted to determine whether combined use of a fetal globin gene inducer (butyrate) and rhu-erythropoietin (EPO), the hematopoietic growth factor that prolongs erythroid cell survival and stimulates erythroid proliferation, would produce additive hematologic responses in any thalassemia subjects. Butyrate and EPO were administered in 10 patients. Novel fetal globin gene inducers that also stimulate erythroid proliferation were evaluated for pharmacokinetic profiles. Patients with beta+-thalassemia had relatively low levels of endogenous EPO (<145 mU/mL) and had additive responses to administered EPO and butyrate. Patients with at least one beta 0-globin mutation had higher baseline HbF levels (>60%) and EPO levels (>160 mU/mL), and three-fourths of these subjects responded to the fetal globin gene inducer alone. A few select fetal globin-inducing short-chain fatty acid derivatives that stimulated cell proliferation also had favorable pharmacokinetics. These studies identify a significant subset of thalassemia patients who appear to require exogenous EPO to respond optimally to any HbF inducer, as well as new therapeutic candidates that act on both cellular and molecular pathologies of beta-thalassemia. Both approaches now offer excellent potential for tolerable, definitive treatment of beta-thalassemia.

Topics: Animals; Apoptosis; beta-Thalassemia; Blood Transfusion; Butyrates; Cells, Cultured; Combined Modality Therapy; Drug Evaluation, Preclinical; Drug Therapy, Combination; Erythroid Cells; Erythropoietin; Fatty Acids, Volatile; Fetal Hemoglobin; Gene Expression; Humans; Papio; Pilot Projects; Recombinant Proteins; Treatment Outcome

The most common single genetic disorder and a major public health issue in Greece and other Mediterranean countries is beta-thalassemia. Current therapeutic approaches for homozygous beta-thalassemia entail blood transfusions and iron chelation therapy with deferoxamine or deferiprone for preventing tissue hemosiderosis. Recently, much effort has focused on various inducers of fetal hemoglobin (HbF) such as recombinant human erythropoietin (rHuEPO), especially in beta-thalassemia intermedia. Ten adult patients, 5 with beta-thalassemia major and 5 with beta-thalassemia intermedia, received 150 IU/kg rHuEPO (epoetin-alpha) subcutaneously three times a week. Seven patients were transfused every 14-30 days and 3 with beta-thalassemia intermedia were only occasionally transfused. The minimum duration of treatment was 12 weeks in order to define if there was any response. Transfusion intervals were modified according to the rHuEPO response to maintain stable Hb values. Lower transfusion requirements were observed in 5 patients after rHuEPO treatment (p = 0.028). In the 3 non-transfused patients, Hb values increased, and the patients are still being treated and followed up for a period ranging from 14 weeks to 2 years. Two patients with thalassemia major discontinued treatment after 12 weeks, as they did not achieve any response regarding transfusion requirements or Hb values. Pretreatment serum transferrin receptor levels were higher than in controls (p < 0.001) and significantly increased following rHuEPO treatment (p = 0.027). Patients had higher serum endothelin-3, sICAM-1 and sE-selectin values before rHuEPO treatment compared to controls (p < 0.001, p < 0.001 and p = 0.016, respectively), but these values were not altered during treatment. HbF values presented a slight, non-significant increase. rHuEPO treatment has a beneficial effect in transfusion-dependent beta-thalassemia patients. Although a slight increase in HbF levels was observed, other possible mechanisms are probably involved. None of our patients experienced thrombotic complications and a rise in blood pressure.

Topics: Adolescent; Adult; beta-Thalassemia; Blood Transfusion; Cell Adhesion Molecules; E-Selectin; Endothelin-3; Erythropoietin; Female; Fetal Hemoglobin; Hemoglobins; Humans; Intercellular Adhesion Molecule-1; Male; Middle Aged; Receptors, Transferrin; Recombinant Proteins; Solubility; Treatment Outcome

It is unknown whether chronic erythropoietin (EPO) treatment is able to normalize hemoglobin (Hb) levels and ameliorate cardiac remodeling avoiding blood transfusions in uremic blood transfusion-dependent patients with beta-thalassemia minor (beta-thal).. In 12 hemodialysis (HD) patients with beta-thal, requiring blood transfusions despite EPO therapy, we planned to increase Hb levels up to the target levels (11-12 g/dl) within a one-year period by administering progressively higher doses of EPO (correction phase). We also planned to maintain the Hb target for an additional year (maintenance phase).. In the year before the study, patients required 3.3 +/- 0.9 units of packed red blood cells. At baseline, the Hb level obtained with an EPO dose of 212 +/- 73 U/kg/week i.v. was 8.2 +/- 0.8 g/dl. The EPO dose was gradually increased within the first year up to 458 +/- 78 U/kg/week at month 12 (correction phase) and then significantly tapered down during the maintenance phase (390 +/- 54 U/kg/week at month 24). During the correction phase, the Hb levels markedly increased (11.1 +/- 0.3 g/dl at month 12) and did not change in the maintenance phase. No blood transfusion was required throughout the 2 years of follow-up. Left ventricular (LV) mass index progressively decreased from the basal value of 144 +/- 12 to 124 +/- 11 g/m2 in the first year and normalized in all patients at month 24 (109 +/- 12 g/m2, p < 0.001); this occurred in the absence of any change of LV cavity volume index (<90 ml/m2).. In HD transfusion-dependent patients with beta-thal, the administration of high EPO dose for 2 years permits the attainment and the maintenance of Hb targets without blood transfusions. This therapeutic approach permits a complete remission of concentric LV hypertrophy without any adverse effects on the vascular system.

Topics: beta-Thalassemia; Blood Transfusion; Erythropoietin; Female; Hematologic Tests; Hemodynamics; Hemoglobins; Humans; Male; Middle Aged; Prospective Studies; Renal Dialysis; Treatment Outcome; Ventricular Remodeling

Nine patients with either beta-thalassaemia/haemoglobin E (7) or homozygous beta-thalassaemia (2) not requiring regular transfusions were treated with the oral iron chelator, deferiprone 25-50 mg/kg/d for between 17 and 86 weeks (mean 49 weeks). There were significant decreases in serum ferritin (initial mean +/- standard deviation 2168 +/- 1142, final 418 +/- 247 micro g/l; t-test for paired samples, P = 0.005), hepatic iron (initial 20.3 +/- 6.26, final 11.7 +/- 4.83 mg/g/dry weight; P = < 0.02), red cell membrane iron (initial 76.2 +/- 3.64, final 7.2 +/- 0.56 mmol/mg protein; P = < 0.0005) and serum non-transferrin bound iron (initial 9.0 +/- 0.56, final 5.9 +/- 0.89 micro mol/l; P = < 0.0005). There was also a significant rise in serum erythropoietin (initial 240 +/- 195.1, final 433.2 +/- 269.2 U/l; P = 0.034). The haemoglobin level rose in three patients and transfusion requirements were reduced substantially in four patients. Serum thiobarbituric acid reactive substance (TBARS) also fell in six of eight patients. Patients generally improved clinically, with weight gain observed. Side-effects were mild and included gastrointestinal symptoms (6) and arthralgia (1), not requiring withdrawal of the drug. One patient died at 17 weeks of therapy as a result of an intercurrent infection. His neutrophil count was normal. We conclude that deferiprone is an effective, well-tolerated iron chelator for patients with thalassaemia intermedia. Further studies are needed to determine the optimum dose and length of treatment needed to reduce iron burden to a safe level in these patients.

Topics: Administration, Oral; Adult; beta-Thalassemia; Deferiprone; Erythrocyte Membrane; Erythropoietin; Female; Ferritins; Hemoglobin E; Humans; Iron; Iron Chelating Agents; Liver; Male; Middle Aged; Pyridones; Receptors, Transferrin; Thailand; Thiobarbituric Acid Reactive Substances

The use of hydroxyurea for the prevention of sickle cell crises in patients with homozygous HbS disease is now well established. The beneficial effects of this compound stem from (a) selective enrichment of red cells containing an increased amount of fetal hemoglobin, which inhibits HbS polymerization, and (b) a decrease of leukocytes, platelets, and reticulocytes, which significantly limits their adherence to the vascular wall. We report the results of a clinical trial of hydroxyurea on 55 Greek-origin patients with sickle cell/beta-thalassemia and 14 patients with homozygous HbS disease who have been treated with hydroxyurea for several years. Such patients have a higher probability to benefit from hydroxyurea therapy, since in addition to its antisickling effect, the increase of gamma-chain synthesis is expected to diminish the deleterious effects of the unbound alpha-globin chains. Selection of patients and monitoring throughout the whole trial were done by the same clinicians. Quantitative expression of the clinical condition was done using a system scoring several outcome parameters. For a period of 52 months prior to starting treatment, the total score of severity for 59 evaluable patients was 1182 points (3068 patient-weeks), while for the 12,018 patient-weeks of the trial this parameter fell to only 82 points. Other observations of interest include the significant improvement of a group of patients with hepatic cholestasis, the development of leg ulcers possibly related to the treatment, and the dramatic increase of hemoglobin F, often in association with an increase of the total hemoglobin levels as a result of decreased hemolysis.

Topics: Acute Disease; Adolescent; Adult; Anemia, Sickle Cell; Antisickling Agents; beta-Thalassemia; Erythrocyte Count; Erythrocyte Indices; Erythrocytes; Erythropoietin; Female; Fetal Hemoglobin; Greece; Hemoglobins; Humans; Hydroxyurea; Leg Ulcer; Male; Middle Aged; Pancreatitis; Patient Compliance; Patient Selection; Receptors, Transferrin; Severity of Illness Index

The aims of this study were to ascertain tolerability, safety and efficacy of oral isobutyramide (150 mg/kg bw/day) in stimulating fetal hemoglobin production in twelve thalassemia intermedia patients. Patients were treated for 28 days and followed for a further 28 days. Efficacy was monitored by non-alpha/alpha globin chain ratio and percentage of HbF. Five patients experienced increases of non-alpha/alpha ratio ranging between 5.3 and 100% at the end of treatment. Five patients show an increase of HbF ranging between 4.4 and 26%. Their HbF% continues to increase during follow-up period. The analysis of variance for HbF showed a time effect close to significance both in treatment period (p = 0.06) and in follow-up period (p = 0.08). Moreover, to evaluate a possible erythropoietic modification, serum Erythropoietin (sEpo) and serum Transferrin Receptor (sTfR) were evaluated. Serum Epo and sTfR levels were significantly increased during treatment (p < 0.05 vs baseline).

Topics: Adult; Amides; beta-Thalassemia; Blood Transfusion; Erythropoietin; Female; Fetal Hemoglobin; Globins; Humans; Male; Receptors, Transferrin

The clinical effectiveness of Hydroxyurea in thalassemia is still controversial. The present paper puts together the authors' experience in two groups of patients with thalassemia intermedia and sickle cell/beta-thalassemia treated with varying dosages of hydroxyurea over several months. A third group received hydroxyurea along with recombinant human erythropoietin. Our observations are summarized in that treatment with hydroxyrea results in a significant increase of fetal hemoglobin with no change of the total hemoglobin levels. The drug causes also a considerable increase of the erythrocyte volume and hemoglobin content while the MCHC values remain unchanged. As a rule, and without objective criteria so far, patients state feeling better and having more energy. The authors postulate that this feeling may reflect the significant decrease of ineffective erythropoiesis resulting by the replacement of the poorly hemoglobinized, prematurely dying erythroid progenitor and red cell population by another population of cells with higher hemoglobin content and longer survival, the regeneration of which requires less energy and consumption. As expected, patients with sickle cell/beta-thalassemia have also fewer crises and painful episodes. The above findings are in keeping with the few available reports in the literature.

Topics: Anemia, Sickle Cell; Antisickling Agents; beta-Thalassemia; Drug Therapy, Combination; Erythropoiesis; Erythropoietin; Fetal Hemoglobin; Hemoglobins; Humans; Hydroxyurea; Recombinant Proteins

Four patients (1 male, 3 female, age range 16-56 yr) with beta-thalassemia intermedia were given high doses of recombinant human erythropoietin (rHuEpo), iron sulfate and folic acid in an attempt to improve their anemia. The dose schedule was: rHuEpo, 500 U/kg 3 times weekly, iron sulfate, 300 mg/d and folic acid, 5 mg/d. All patients were red blood cell transfusion-dependent. Hematological data and fetal hemoglobin (HbF) were assayed every 2 wk. XmnI polymorphism and beta-thalassemia mutations were identified by PCR. All patients showed a moderate to high increase in hemoglobin values (mean value: 2.5 g/dl) and in 1 patient HbF levels also increased; 3 patients became red blood cell transfusion-independent and 1 patient was able to extend the intervals between transfusions significantly. No side effects were observed during rHuEpo therapy.

Topics: Adolescent; Adult; beta-Thalassemia; Drug Administration Schedule; Erythropoietin; Female; Humans; Male; Middle Aged; Recombinant Proteins; Treatment Outcome

Augmentation of gamma-gene synthesis by using recombinant human erythropoietin (r-Hu-EPO) represents a new approach to the therapy of beta-thalassemia. A prospective study was conducted in 26 transfusion-dependent beta-thalassemia major patients. r-Hu-EPO (Eprex/Cilag, Switzerland) was given to the patients at an initial dose of 500 IU/kg s.c. 3 times a week for at least 2 months during which no transfusion was applied. A sustained hemoglobin (Hb) level greater than 8 g/dl was considered as a response to EPO treatment. In the patients whose Hb levels remained under 8 g/dl or did not increase in comparison to pretreatment levels within 4 weeks, the dose of r-Hu-EPO was increased to 1,000 IU/kg 3 times a week and applied for another 4 weeks. Only 16 cases also received oral iron supplementation. The whole blood and reticulocyte counts, the biochemical tests including BUN, creatinine, AST, ALT, alkaline phosphatase and ferritin were done and the percentages of HbF and F cells were analyzed regularly. At the end of the 2nd month, 6 cases qualified to continue with the trial. At the end of the 6th month, r-Hu-EPO therapy was ceased in 3 cases of the 6 since their Hb levels had decreased below 7 g/dl. Only 3 cases (11.5%) continued with the r-Hu-EPO therapy without transfusion for up to 12 months. In conclusion, r-Hu-EPO may be useful in some selected transfusion-dependent patients with beta-thalassemia major. Selection criteria should include a mild beta-genotype of coinheritance of alpha-thalassemia, splenectomy and pretreatment reticulocyte response of the patients as well as the patients' compliance.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Child, Preschool; Erythropoietin; Female; Hemoglobins; Humans; Male; Prospective Studies; Recombinant Proteins

Topics: Adolescent; Adult; Anemia, Sickle Cell; beta-Thalassemia; Erythropoietin; Female; Fetal Hemoglobin; Hemoglobin A; Humans; Postpartum Period; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Trimester, Third; Recombinant Proteins

It has been shown that high doses of human recombinant erythropoietin (r epo) increase haemoglobin levels by augmentation of F-cells, and Hb-F production in animal models and in human trials. In this study, r epo was used in patients with beta thalassemia intermedia. Our purpose was to improve haemoglobin levels by at least 2 g and maintain an average level between 10 and 12 g/dl. Ten patients aged 6-29 years (mean 14 +/- 7.6 years) with thalassemia intermedia were treated with r epo. It was given subcutaneously in rising doses from 500 to 1000 U/kg three times weekly for 3 months. During r epo therapy eight cases (80 per cent) showed an increase in haemoglobin, haematocrit, and reticulocyte levels, and an increase of at least 2 g of haemoglobin was obtained. Blood transfusion was not needed during the study except in one case. Five cases (50 per cent) improved life quality with therapy. Hb levels of all patients returned to baseline values over 1 or 2 months after r epo was discontinued. There was no significant change in absolute Hb-F, F-cells, and ferritin levels during treatment. Generally, the drug was well tolerated. No patient had hypertension. Recombinant erythropoietin seems to be an effective treatment for anaemia of beta-thalassemia intermedia, but longer term randomized trials are needed especially in patients with beta thalassemia major.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Erythropoietin; Female; Hematocrit; Hemoglobins; Humans; Male; Prospective Studies; Radioimmunoassay; Recombinant Proteins

Seven sickle cell disease (SCD) patients [sickle cell anaemia = 4 (males 2, females 2, age range 18-40 years), and sickle cell beta (0)-thalassaemia = 3 (all females, age range 20-47 years)], suffering from a severe form of the disease were enrolled in a treatment protocol using hydroxyurea (HU) for up to 12 months followed by a combination therapy with HU and human recombinant erythropoietin (rHuEpo; using 400 U/kg/week i.v.) for 3-4 weeks. Following the withdrawal of rHuEpo the patients were maintained on HU alone. The patients were characterised on the basis of the 'severity index' prior to the initiation of the therapy. Haematological and relevant biochemical parameters, Hb A2 fetal haemoglobin (HbF), HbF cells, reticulocytes and platelet counts were estimated at least at three occasions to determine the mean and range of the parameters. During the treatment period the patients were followed every 2-4 weeks where the haematological and biochemical parameters were assessed. The results were separately analysed and mean +/- SD were obtained for each parameter at the end of each protocol. The statistical significance of the difference in the results obtained on treatment and the baseline results was examined using the paired t test. No toxic side effects of HU and rHuEpo (as judged from reduction in platelet and white blood cell count) were documented during and after the whole period of treatment. The patients showed a significant clinical improvement. Total haemoglobin, haematocrit, red cell count, HbF and HbF cells increased, while white blood cells, reticulocyte counts and bilirubin level decreased. Platelet count decreased but remained within the normal range. The results revealed that 5 of the patients on HU treatment showed a significant increase in the HbF level and HbF cells, while 2 patients (1 sickle cell anaemia and 1 Hb S/beta(0)-thalassaemia patient) did not and were considered as 'non-responders'. The rHuEpo and HU combination therapy elevated the HbF level, with a varying degree, in all patients except 2, who had already reached a high HbF level and showed a decrease in HbF during the rHuEpo protocol. Variable individual response to both HU and rHuEpo therapy was a common feature. We recommend the use of HU for the treatment of SCD and a combination therapy using HU and rHuEpo for the non-responders.

Topics: Adolescent; Adult; Anemia, Sickle Cell; Antisickling Agents; beta-Thalassemia; Drug Therapy, Combination; Erythropoietin; Female; Humans; Hydroxyurea; Male; Middle Aged; Recombinant Proteins

Butyrate analogues have been shown to increase fetal hemoglobin (HbF) production in vitro and in vivo. Sodium phenylbutyrate (SPB), an oral agent used to treat individuals with urea-cycle disorders, has been shown to increase HbF in nonanemic individuals and in individuals with sickle cell disease. We have treated eleven patients with homozygous beta thalassemia (three transfusion dependent) and one sickle-beta-thalassemia patient with 20 g/d (forty 500-mg tablets) of SPB for 41 to 460 days. All patients showed an increase in the percent of F reticulocytes associated with treatment, but only four patients responded by increasing their Hb levels by greater than 1 g/dL (mean increase, 2.1 g/dL; range, 1.2 to 2.8 g/dL). None of the transfusion-dependent thalassemia subjects responded. Increase in Hb was associated with an increase in red blood cell number (mean increase, 0.62 x 10(12)/L), and mean corpuscular volume (mean increase, 6 fL). Changes in percent HbF, absolute HbF levels, or alpha- to non-alpha-globin ratios as measured by levels of mRNA and globin protein in peripheral blood did not correlate with response to treatment. Response to treatment was not associated with the type of beta-globin mutation, but baseline erythropoietin levels of greater than 120 mU/mL was seen in all responders and only two of eight nonresponders to SPB. Compliance with treatment was greater than 90% as measured by pill counts. Side effects of the drug included weight gain and/or edema caused by increase salt load in 2/12, transient epigastric discomfort in 7/12, and abnormal body odor in 3/12 subjects. Two splenectomized patients who were not on prophylactic antibiotics developed sepsis while on treatment. We conclude that SPB increases Hb in some patients with thalassemia, but the precise mechanism of action is unknown.

Topics: Adult; Anemia, Sickle Cell; beta-Thalassemia; Blood Transfusion; Erythropoietin; Female; Fetal Hemoglobin; Globins; Hemoglobins; Hemolysis; Homozygote; Humans; Male; Mutation; Patient Compliance; Phenylbutyrates; Reticulocytes

Recombinant human erythropoietin (rHuEPO) was given subcutaneously three times per week in an escalating dose from 500 u/kg to 950 u/kg together with ferrous fumarate 305 mg and folic acid 5 mg/d, to 10 patients from four unrelated Arab families with homozygous beta-thalassaemia. Six splenectomized patients showed a mean (+/- standard error) increase in haemoglobin from 7.1 +/- 0.1 to 9.3 +/- 0.1 g/dl (P = 0.0001), in RBC from 4.0 to 5.0 x 10(12)/l (P = 0.0001) and in nucleated RBC from 32 +/- 7 x 10(10)/l to 82 +/- 6 x 10(10)/l while receiving 750 u/kg three times per week which persisted for 4-11 months. In two patients there was no need for further blood transfusions. In three out of four unsplenectomized patients there were no changes in Hb and RBC despite dose escalation. There were no significant changes in MVC, MCH and reticulocyte count, serum bilirubin, LDH, malonyldialdehyde (MDA) and vitamin E levels. After 13 weeks of rHuEPO there was a mean increase in the percentage of F cells from 31 +/- 10% to 86 +/- 6% (P < 0.003) in three splenectomized patients and in one unsplenectomized patient from 56.4% to 80% without changes in the levels of Hb F. Globin chain synthesis ratios did not change in four responding patients. Mean serum iron and transferrin saturation index did not change, whereas mean serum ferritin increased from 299 +/- 45 micrograms/l to 480 +/- 20 micrograms/l (P < 0.001). In seven responding patients an accelerated linear growth was indicated by positive changes in height standard deviation score for chronological age. Side-effects were minimal throughout the treatment period.

Topics: Administration, Cutaneous; Adolescent; beta-Thalassemia; Child; Dose-Response Relationship, Drug; Erythrocyte Count; Erythropoietin; Female; Ferritins; Ferrous Compounds; Folic Acid; Hemoglobins; Humans; Iron; Long-Term Care; Male; Recombinant Proteins; Splenectomy

Topics: Adult; beta-Thalassemia; Dose-Response Relationship, Drug; Erythropoietin; Female; Heterozygote; Homozygote; Humans; Injections, Subcutaneous; Male; Recombinant Proteins

Transferrin receptor 1 (TfR1) performs a critical role in cellular iron uptake. Hepatocyte TfR1 is also proposed to influence systemic iron homeostasis by interacting with the hemochromatosis protein HFE to regulate hepcidin production. Here, we generated hepatocyte Tfrc knockout mice (Tfrcfl/fl;Alb-Cre+), either alone or together with Hfe knockout or β-thalassemia, to investigate the extent to which hepatocyte TfR1 function depends on HFE, whether hepatocyte TfR1 impacts hepcidin regulation by serum iron and erythropoietic signals, and its contribution to hepcidin suppression and iron overload in β-thalassemia. Compared with Tfrcfl/fl;Alb-Cre- controls, Tfrcfl/fl;Alb-Cre+ mice displayed reduced serum and liver iron; mildly reduced hematocrit, mean cell hemoglobin, and mean cell volume; increased erythropoietin and erythroferrone; and unchanged hepcidin levels that were inappropriately high relative to serum iron, liver iron, and erythroferrone levels. However, ablation of hepatocyte Tfrc had no impact on iron phenotype in Hfe knockout mice. Tfrcfl/fl;Alb-Cre+ mice also displayed a greater induction of hepcidin by serum iron compared with Tfrcfl/fl;Alb-Cre- controls. Finally, although acute erythropoietin injection similarly reduced hepcidin in Tfrcfl/fl;Alb-Cre+ and Tfrcfl/fl;Alb-Cre- mice, ablation of hepatocyte Tfrc in a mouse model of β-thalassemia intermedia ameliorated hepcidin deficiency and liver iron loading. Together, our data suggest that the major nonredundant function of hepatocyte TfR1 in iron homeostasis is to interact with HFE to regulate hepcidin. This regulatory pathway is modulated by serum iron and contributes to hepcidin suppression and iron overload in murine β-thalassemia.

Topics: Animals; beta-Thalassemia; Erythropoietin; Hemochromatosis Protein; Hepatocytes; Hepcidins; Homeostasis; Iron; Iron Overload; Mice; Mice, Knockout; Receptors, Transferrin

To track post-transfusion changes on the erythropoietin (EPO)-erythroferrone (ERFE)-hepcidin axis, we collected blood samples from 82 regularly transfused patients with β-thalassaemia major (β-TM) immediately before and 4-6 days after transfusion. The post-transfusion haemoglobin, hepcidin, and ferritin levels were increased, while the EPO, ERFE, and soluble transferrin receptor were suppressed. In addition, hepcidin change was inversely associated with erythropoietic change, which was confirmed by an increase in the hepcidin-to-ERFE ratio after transfusion. Age was the main predictor of serum ERFE, followed by EPO, transfusion frequencies, and ferritin. We found ERFE to be a highly sensitive indicator of erythroid activity in β-TM and that the hepcidin-to-ERFE ratio after transfusion may be used as an appropriateness index of serum hepcidin regulation relative to the degree of erythropoiesis.

Topics: beta-Thalassemia; Cohort Studies; Epoetin Alfa; Erythropoiesis; Erythropoietin; Ferritins; Hepcidins; Humans; Iron; Thalassemia

Although patients with either β-thalassemia or chronic kidney disease (CKD) clinically correlate with severe osteoporosis, the mechanism by which CKD exposed to high phosphate affects bone turnover has not been characterized in β-thalassemia. We aimed to determine the effects of renal insufficiency on high phosphate intake induced changes in bone metabolism after 5/6th nephrectomy in hemizygous β-globin knockout (BKO) mice. Male BKO mice manifested severe anemia and osteopenia. Nephrectomy induced renal fibrosis and reduced renal function as assessed by increased serum urea nitrogen levels. Moreover, nephrectomy increased bone turnover leading to bone loss in wild type (WT) but not BKO mice. In nephrectomized BKO, PBS in drinking water induced hyperphosphatemia, and hypercalcemia along with osteopenia in both cancellous and cortical bone. Histomorphometric analysis confirmed reduced cancellous bone volume due to decreased bone formation rate, osteoblast number and osteoclast number. The mRNA levels for Alpl, Sp7, Kl, Tnfsf11, and Tnfsf11/Tnfrsf11b were decreased in nephrectomized BKO mice drinking PBS. Interestingly, Fgf23, a bone-derived hormone produced by osteocytes and osteoblasts in response to hyperphosphatemia, were remarkably increased in nephrectomized BKO mice following PBS intake. Serum FGF23 and erythropoietin levels were markedly elevated in BKO mice. Nephrectomy decreased serum erythropoietin but not FGF23 levels. Hyperphosphatemia in BKO mice increased serum erythropoietin, FGF23, and PTH levels, nominating these factors as candidate mediators of bone loss in thalassemic mice with CKD during phosphate retention.

Topics: Animals; beta-Thalassemia; Bone Diseases, Metabolic; Erythropoietin; Fibroblast Growth Factors; Humans; Hyperphosphatemia; Male; Mice; Phosphates; Renal Insufficiency, Chronic

β-Thalassemia intermedia is a disorder characterized by ineffective erythropoiesis (IE), anemia, splenomegaly, and systemic iron overload. Novel approaches are being explored based on the modulation of pathways that reduce iron absorption (ie, using hepcidin activators like Tmprss6-antisense oligonucleotides [ASOs]) or increase erythropoiesis (by erythropoietin [EPO] administration or modulating the ability of transferrin receptor 2 [Tfr2] to control red blood cell [RBC] synthesis). Targeting Tmprss6 messenger RNA by Tmprss6-ASO was proven to be effective in improving IE and splenomegaly by inducing iron restriction. However, we postulated that combinatorial strategies might be superior to single therapies. Here, we combined Tmprss6-ASO with EPO administration or removal of a single Tfr2 allele in the bone marrow of animals affected by β-thalassemia intermedia (Hbbth3/+). EPO administration alone or removal of a single Tfr2 allele increased hemoglobin levels and RBCs. However, EPO or Tfr2 single-allele deletion alone, respectively, exacerbated or did not improve splenomegaly in β-thalassemic mice. To overcome this issue, we postulated that some level of iron restriction (by targeting Tmprss6) would improve splenomegaly while preserving the beneficial effects on RBC production mediated by EPO or Tfr2 deletion. While administration of Tmprss6-ASO alone improved the anemia, the combination of Tmprss6-ASO + EPO or Tmprss6-ASO + Tfr2 single-allele deletion produced significantly higher hemoglobin levels and reduced splenomegaly. In conclusion, our results clearly indicate that these combinatorial approaches are superior to single treatments in ameliorating IE and anemia in β-thalassemia and could provide guidance to translate some of these approaches into viable therapies.

Topics: Animals; beta-Thalassemia; Cells, Cultured; Erythropoiesis; Erythropoietin; Gene Expression Regulation; Genetic Therapy; Iron; Iron Overload; Male; Membrane Proteins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Oligonucleotides, Antisense; Receptors, Transferrin; Serine Endopeptidases

Erythropoietin (EPO) has been reported as a novel determinant of fibroblast growth factor 23 (FGF23) production; however, it is unknown whether FGF23 is stimulated by chronic exposure to EPO or by EPO administration in nonpolycystic chronic kidney disease (CKD) models.. We analyzed the effects of chronic EPO on FGF23 in murine models with chronically high EPO levels and normal kidney function. We studied the effects of exogenous EPO on FGF23 in wild-type mice, with and without CKD, injected with EPO. Also, in four independent human CKD cohorts, we evaluated associations between FGF23 and serum EPO levels or exogenous EPO dose.. Mice with high endogenous EPO have elevated circulating total FGF23, increased disproportionately to intact FGF23, suggesting coupling of increased FGF23 production with increased proteolytic cleavage. Similarly, in wild-type mice with and without CKD, a single exogenous EPO dose acutely increases circulating total FGF23 out of proportion to intact FGF23. In these murine models, the bone marrow is shown to be a novel source of EPO-stimulated FGF23 production. In humans, serum EPO levels and recombinant human EPO dose are positively and independently associated with total FGF23 levels across the spectrum of CKD and after kidney transplantation. In our largest cohort of 680 renal transplant recipients, serum EPO levels are associated with total FGF23, but not intact FGF23, consistent with the effects of EPO on FGF23 production and metabolism observed in our murine models.. EPO affects FGF23 production and metabolism, which may have important implications for CKD patients.

Topics: Animals; beta-Thalassemia; Cohort Studies; Erythropoietin; Female; Fibroblast Growth Factor-23; Fibroblast Growth Factors; Gene Expression Regulation; Humans; Kidney Transplantation; Male; Mice; Mice, Transgenic; Middle Aged; Prognosis; Renal Insufficiency, Chronic

Thalassemia intermedia (TI) describes a disease ranging in severity between β thalassemia major (TM) and β thalassemia trait. Osteoporosis is observed in TI and TM. The exact reason of osteoporosis in TI could be hypogonadism and/or an increase in erythropoietin (EPO) levels. The carboxy-terminal collagen cross links (CTX), a marker of bone resorption, and the N-terminal propeptide of type 1 collagen (P1NP), a marker of bone formation are serum markers of osteoporosis. The receptor activator of NF-kappaB ligand (RANKL)/receptor activator of NF-kappaB (RANK)/osteoprotegerin (OPG) axis plays an important role in metabolic bone diseases. Herein, we tested the relationship between the RANKL/RANK/OPG axis and the bone-turnover markers CTX and P1NP in TI.. We recruited 44 TI patients and 33 non-thalassemic controls and measured the serum levels of hemoglobin, sex steroid hormones, CTX, P1NP, RANKL and OPG. We then used a general linear model to test the association of the above variables with CTX and P1NP as outcome variables. We showed that EPO levels were the strongest predictor of CTX change (P < 0.000), followed by RANKL (P = 0.017). On the other hand, RANKL was the strongest predictor of P1NP change (P < 0.000), followed by OPG (P = 0.009) and EPO (P = 0.024).

Topics: beta-Thalassemia; Biomarkers; Bone Density; Case-Control Studies; Child; Erythropoietin; Female; Humans; Jordan; Male; NF-kappa B; Osteoporosis; Osteoprotegerin; RANK Ligand

β-thalassemias are genetic disorders characterized by anemia, ineffective erythropoiesis, and iron overload. Current treatment of severe cases is based on blood transfusion and iron chelation or allogeneic bone marrow (BM) transplantation. Novel approaches are explored for nontransfusion-dependent patients (thalassemia intermedia) who develop anemia and iron overload. Here, we investigated the erythropoietin (EPO) receptor partner, transferrin receptor 2 (TFR2), as a novel potential therapeutic target. We generated a murine model of thalassemia intermedia specifically lacking BM

Topics: Anemia; Animals; beta-Thalassemia; Cells, Cultured; Disease Models, Animal; Erythroid Cells; Erythropoiesis; Erythropoietin; Female; Gene Deletion; Genetic Therapy; Iron Overload; Male; Mice, Inbred C57BL; Receptors, Transferrin

Erythropoietin (EPO) plays an essential role in the regulation of erythropoiesis. Its production is under the control of the Hypoxia Inducible Factor (HIF) protein whose stability varies according to the oxygen level. During chronic renal failure, EPO deficiency is the main cause of anemia, but other factors such as iron deficiency and inflammatory syndrome are also involved. More recently, it is hypothesized that other factors such an excess of GDF-11 production may be also involved. Thus, beside Epo treatment HIF and GDF-11 are potentially new therapeutic targets in anemia of chronic kidney disease.

Topics: Anemia; Animals; beta-Thalassemia; Bone Morphogenetic Proteins; Disease Management; Disease Models, Animal; Erythropoiesis; Erythropoietin; Forecasting; Growth Differentiation Factors; Humans; Hypoxia; Hypoxia-Inducible Factor 1; Immunoglobulin A; Intestinal Absorption; Iron Deficiencies; Iron, Dietary; Kidney Failure, Chronic; Mice; Models, Biological; Receptors, Transferrin

Topics: Adolescent; Adult; Animals; beta-Thalassemia; Blood Donors; Child; Erythropoietin; Hepcidins; Humans; Male; Mice; Middle Aged; Peptide Hormones

Cellular biobanking is a key resource for collaborative networks planning to use same cells in studies aimed at solving a variety of biological and biomedical issues. This approach is of great importance in studies on β-thalassemia, since the recruitment of patients and collection of specimens can represent a crucial and often limiting factor in the experimental planning.. Erythroid precursor cells were obtained from 72 patients, mostly β-thalassemic, expanded and cryopreserved. Expression of globin genes was analyzed by real time RT-qPCR. Hemoglobin production was studied by HPLC.. In this paper we describe the production and validation of a Thal-Biobank constituted by expanded erythroid precursor cells from β-thalassemia patients. The biobanked samples were validated for maintenance of their phenotype after (a) cell isolation from same patients during independent phlebotomies, (b) freezing step in different biobanked cryovials, (c) thawing step and analysis at different time points. Reproducibility was confirmed by shipping the frozen biobanked cells to different laboratories, where the cells were thawed, cultured and analyzed using the same standardized procedures. The biobanked cells were stratified on the basis of their baseline level of fetal hemoglobin production and exposed to fetal hemoglobin inducers.. The use of biobanked cells allows stratification of the patients with respect to fetal hemoglobin production and can be used for determining the response to the fetal hemoglobin inducer hydroxyurea and to gene therapy protocols with reproducible results.

Topics: Antigens, CD34; beta-Thalassemia; Biological Specimen Banks; Biomarkers; Cell Differentiation; Cells, Cultured; Chromatography, High Pressure Liquid; Cryopreservation; Erythroid Precursor Cells; Erythropoietin; Fetal Hemoglobin; Hemoglobins; Humans; Kinetics; Reproducibility of Results; RNA, Messenger

Serum EPO concentration is related primarily to the rate of erythrocyte production and, under the stimulation of hypoxia, increases exponentially as hemoglobin (Hb) decreased. The level of EPO was determined in 141 subjects including 43 normal, 44 thalassemic patients and 54 thalassemic trait subjects. The EPO level was significantly higher in the thalassemic patients (54.8mU/ml in HbH disease [α thal1/α thal2;], 78.1mU/ml in HbH with Hb CS [α thal 1/CS]; 95.6mU/ml in β-thal/HbE splenectomized [BE(S)]; and 114.8mU/ml in β-thal/HbE non-splenectomized [BE(NS)]as compared with 12.0mU/ml in normal subjects. No significant differences were detected in thalassemic trait subjects. In addition, the levels of EPO in thalassemic patients is correlated significantly with the number of reticulocytes and the reticulocyte fractions especially the fraction of immature reticulocytes. Interestingly, the highest level of EPO/% retic ratio as indicated for EPO non-responder was detected in BE(NS) patients. However, the impaired reticulocytes maturation was found to be related significantly with the levels of TNF-α,IFN-γ,IL-10, and VEGF. Since, TNF-α, IFN-γ, IL-10 and VEGF are reported as the cytokines with erythropoietic inhibitory mediators, the variation of these cytokines in thalassemic environments may be associated to the anemic crisis in these patients.

Topics: beta-Globins; beta-Thalassemia; Case-Control Studies; Cell Differentiation; Erythropoiesis; Erythropoietin; Gene Expression; Hemoglobin E; Humans; Interferon-gamma; Interleukin-10; Reticulocytes; Tumor Necrosis Factor-alpha; Vascular Endothelial Growth Factor A

Thalassemia is one of the genetic diseases that cause anemia and ineffective erythropoiesis. Increased levels of several inflammatory cytokines have been reported in β-thalassemia and might contribute to ineffective erythropoiesis. However, the mechanism by which tumor necrosis factor-alpha (TNF-α) is involved in ineffective erythropoiesis in thalassemic patients remains unclear. The objective of this study is to investigate the effect of TNF-α on the erythropoietin (EPO) and erythropoietin receptor (EPOR) expression involved in proliferation of β-thalassemia/hemoglobin (Hb) E erythroid progenitor cells compared with cells from healthy subjects.. CD34-positive cells were isolated from heparinized blood by using the EasySep® CD34 selection kit. Cells were then cultured with suitable culture medium in various concentrations of EPO for 14 days. The effect of TNF-α on percent cell viability was analyzed by trypan blue staining. In addition, the percentage of apoptosis and levels of EPOR protein were measured by flow cytometry.. Upon EPO treatment, a higher cell number was observed for erythroid progenitor cells from both healthy participants and β-thalassemia/Hb E patients. However, a reduction of apoptosis was found in EPO-treated cells especially for β-thalassemia/Hb E patients. Interestingly, TNF-α caused higher levels of cell apoptosis and lower levels of EPOR protein in thalassemic erythroid progenitor cells.. TNF-α caused a reduction in the level of EPOR protein and EPO-induced erythroid progenitor cell proliferation. It is possible that TNF-α could be involved in the mechanism of ineffective erythropoiesis in β-thalassemia/Hb E patients.. Amaç: Talasemi anemi ve inefektif eritropoeze neden olan genetik hastalıklardan birisidir. Enflamatuvar sitokinlerin bir çoğunun seviyelerinde artma b-talasemide gösterilmiş olup, bu durum inefektif eritropoeze katkıda bulunabilir. Ancak, tümör nekrozlaştırıcı faktör-alfa’nın (TNF-α) talasemik hastalarda inefektif eritropoeze nasıl bir mekanizma ile neden olduğu bilinmemektedir. Bu çalışmanın amacı b-talasemi/hemoglobin (Hb) E eritroid öncül hücrelerinde sağlıklı kontrollerin hücreleri ile karşılaştırıldığında TNF-α’nın eritropoetin (EPO) ve eritropoetin reseptör (EPOR) sunumu üzerine etkisinin araştırılmasıdır. Gereç ve Yöntemler: CD34-pozitif hücreler EasySep® CD34 seçim kiti yardımı ile heparinli kandan izole edildi. Hücreler 14 gün boyunca uygun kültür ortamında değişik EPO konsantrasyonlarında kültürde bekletildi. TNF-α’nın hücre canlılık yüzdesine etkisi tripan mavisi boyası ile incelendi. Bunun yanında, apopitoz yüzdesi ve EPOR protein seviyeleri akış sitometrisi ile ölçüldü. Bulgular: EPO tedavisi ile eritroid öncül hücrelerinin sayısında hem sağlıklı katılımcılarda hem de b-talasemi/Hb E hastalarında artış olduğu görüldü. Ancak özellikle b-talasemi/Hb E hastalarında EPO ile muamele edilmiş hücrelerde apopitozda azalma görüldü. İlginç olarak, TNF-α talasemik eritroid öncül hücrelerde hücre apopitoz oranında artmaya ve EPOR protein seviyelerinde azalmaya neden oldu. Sonuç: TNF-α EPOR protein düzeyi ve EPO ile uyarılmış eritroid öncül hücre çoğalmasında azalmaya neden oldu. b-talasemia/Hb E hastalarında TNF-α inefektif eritropoez mekanizmasında yer alıyor olabilir.

Topics: Adult; Apoptosis; beta-Thalassemia; Cell Division; Cells, Cultured; Down-Regulation; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Gene Expression Regulation; Hemoglobin E; Hemoglobinuria; Heterozygote; Humans; Primary Cell Culture; Receptors, Erythropoietin; Tumor Necrosis Factor-alpha; Young Adult

Recovery from blood loss requires a greatly enhanced supply of iron to support expanded erythropoiesis. After hemorrhage, suppression of the iron-regulatory hormone hepcidin allows increased iron absorption and mobilization from stores. We identified a new hormone, erythroferrone (ERFE), that mediates hepcidin suppression during stress erythropoiesis. ERFE is produced by erythroblasts in response to erythropoietin. ERFE-deficient mice fail to suppress hepcidin rapidly after hemorrhage and exhibit a delay in recovery from blood loss. ERFE expression is greatly increased in Hbb(th3/+) mice with thalassemia intermedia, where it contributes to the suppression of hepcidin and the systemic iron overload characteristic of this disease.

Topics: Anemia; Animals; beta-Thalassemia; Blotting, Western; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Epoetin Alfa; Erythropoiesis; Erythropoietin; Gene Expression Profiling; Hemoglobins; Hemorrhage; Hepcidins; Hormones; Iron; Iron Overload; Liver; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Molecular Sequence Data; Real-Time Polymerase Chain Reaction; Recombinant Proteins; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger

CNTO 530 is an erythropoietin receptor agonist MIMETIBODYTM construct. CNTO 530 has been shown to be active in a number of rodent models of acquired anemia (e.g. renal insufficiency and chemotherapy induced anemia). We investigated the efficacy of CNTO 530 in murine models of β-thalassemia and sickle cell anemia (Berkeley mice). β- thalassemic mice are deficient in expression of α-globin chain and heterozygous mice are characterized by a clinical syndrome similar to the human β-thalassemia intermedia. Berkeley mice are knocked out for murine alpha and beta globin and are transgenic for human alpha, beta (sickle) and gamma globin genes. Berkeley mice thus express human sickle hemoglobin A (HbS) and can also express human fetal hemoglobin. These mice express a severe compensated hypochromic microcytic anemia and display the sickle cell phenotype. To test the effectiveness of CNTO 530, mice from both genotypes received a single subcutaneous (s.c.) dose of CNTO 530 or darbepoetin-α (as a comparator) at 10,000 U/kg, a dose shown to cause a similar increase in reticulocytes and hemoglobin in normal mice. Hematologic parameters were evaluated over time. CNTO 530, but not darbepoetin-α, increased reticulocytes, red blood cells and total hemoglobin in β- thalassemic mice. In Berkeley mice CNTO 530 showed an increase in reticulocytes, red blood cells, F-cells, total hemoglobin and fetal hemoglobin. In conclusion, CNTO 530 is effective in murine models of β-thalassemia and sickle cell anemia. These data suggest that CNTO 530 may have beneficial effects in patients with genetically mediated hemoglobinopathies.

Topics: Anemia, Sickle Cell; Animals; beta-Thalassemia; Darbepoetin alfa; Disease Models, Animal; Erythrocyte Count; Erythropoietin; Female; Hematinics; Hemoglobins; Mice; Mice, Inbred C57BL; Mice, Transgenic; Receptors, Erythropoietin; Recombinant Fusion Proteins

To evaluate the association between fetal hemoglobin (HbF) levels and morbidity in β-thalassemia intermedia (TI), we analyzed data from 63 untransfused patients who had also never received HbF induction therapy. Patient records were reviewed for any history of 10 predefined morbidities. Laboratory measurements for markers of ineffective erythropoiesis were also obtained. The mean age of patients was 32.1 years, 47.6% were males, and the median HbF level was 37.2%. HbF levels correlated positively with total hemoglobin, yet negatively with growth differentiation factor-15 and non-transferrin-bound iron levels. Median HbF levels were significantly lower in patients with the majority of evaluated morbidities than in those without. There was a strong negative adjusted linear correlation between the HbF level and the total number of morbidities (R(2) = 0.825, P < .001). The HbF threshold of 63.7% had 95.5% sensitivity and 100% specificity for ensuring absence of morbidity. There exists a strong association between HbF levels and morbidity in the subset of untransfused patients with TI.

Topics: Adolescent; Adult; Aged; beta-Thalassemia; Child; Cross-Sectional Studies; Erythropoiesis; Erythropoietin; Female; Fetal Hemoglobin; Humans; Male; Middle Aged; Morbidity; Receptors, Transferrin; Young Adult

Enhanced erythropoietic drive and iron deficiency both influence iron homeostasis through the suppression of the iron regulatory hormone hepcidin. Hypoxia also suppresses hepcidin through a mechanism that is unknown. We measured iron indices and plasma hepcidin levels in healthy volunteers during a 7-day sojourn to high altitude (4340 m above sea level), with and without prior intravenous iron loading. Without prior iron loading, a rapid reduction in plasma hepcidin was observed that was almost complete by the second day at altitude. This occurred before any index of iron availability had changed. Prior iron loading delayed the decrease in hepcidin until after the transferrin saturation, but not the ferritin concentration, had normalized. We conclude that hepcidin suppression by the hypoxia of high altitude is not driven by a reduction in iron stores.

Topics: Adult; Altitude; Antimicrobial Cationic Peptides; beta-Thalassemia; Case-Control Studies; Erythropoiesis; Erythropoietin; Ferritins; Gene Expression Regulation; Growth Differentiation Factor 15; Hepcidins; Homeostasis; Humans; Hypoxia; Iron; Iron Metabolism Disorders; Iron, Dietary; Transferrin

Bone marrow mesenchymal stem cells (BM-MSCs) are the main cellular components of the bone marrow, providing a supportive cellular microenvironment to maintain healthy hematopoiesis. β-thalassemia major (β-TM) is characterized by anemia that is caused by a genetic defect in hemoglobin synthesis and results in ineffective erythropoiesis (IE). The alterations in the microenvironment in thalassemic bone marrow during IE can cause changes in BM-MSCs. This study aimed to investigate global structural and compositional changes in BM-MSCs in β-TM that may provide a basis in understanding interactions of hematopoietic stem cells (HSCs)-MSCs in such a pathological bone marrow microenvironment. Following characterization of morphological, immunophenotypical, and differentiation properties, the changes in healthy and thalassemic BM-MSCs before and after bone marrow transplantation (BMT) were examined by attenuated total reflection-Fourier transform infrared (ATR-FTIR). The significant increase in lipid, protein, glycogen, and nucleic acid contents in thalassemic BM-MSCs with respect to healthy BM-MSCs was attributed to enhanced cell proliferation and BM activity during IE. The significant decreases in the content of mentioned macromolecules in post-transplant group BM-MSCs versus pre-transplant BM-MSCs was interpreted as restoring effect of BMT therapy on IE and defective BM microenvironment. These alterations were also supported by ELISA results of erythropoietin (EPO) and growth differentiation factor (GDF15) in bone marrow plasma samples as a reflection of IE and by MTT proliferation assay on BM-MSCs. Based on these changes, sampling groups were discriminated by cluster analysis. These results provide information for the studies that concentrate on interactions between HSCs-MSCs in bone marrow.

Topics: Adipogenesis; beta-Thalassemia; Bone Marrow; Bone Marrow Transplantation; Case-Control Studies; Cell Proliferation; Cell Shape; Cells, Cultured; Cellular Microenvironment; Enzyme-Linked Immunosorbent Assay; Erythropoiesis; Erythropoietin; Glycogen; Growth Differentiation Factor 15; Hematopoietic Stem Cells; Humans; Lipid Metabolism; Mesenchymal Stem Cells; Osteogenesis; Spectroscopy, Fourier Transform Infrared; Structure-Activity Relationship; Thy-1 Antigens

The study explored the level of serum erythropoietin in patients with intermediate beta-thalassemia to determine possible correlations with hemoglobin level and fetal hemoglobin level and other parameters. The sampling consisted of 58 examined patients with intermediate beta-thalassemia. The contrl group consisted of 30 healthy persons. All patients underwent the identification of erythrocytes count, hemoglobin level, hematocrit indicator, erythrocyte indices (MCV, MCH, MCHC), fetal hemoglobin level, hemoglobin A2 level. Also, to all patients the identification of serum erythropoietin and ferritin levels was applied The presence/absence of relationship between these indicators was established using the correlation coefficient calculation. The study results demonstrated that under intermediate beta-thalassemia are observed statistically valid decrease of level of hemoglobin and erythrocytes, increase of percentage of fetal hemoglobin, hemoglobin A2 ferritin and serum erythropoietin as compared with standard values. The analysis of correlation relationships between indicators under study revealed that under the intermediate beta-thalassemia in many cases the failure of interdependencies of indicators marked as normal are established. The presence of clear-cut inverse interrelationship between serum erythropoietin level and hemoglobin level has to be taken into account in the process of treatment of this disease with medications of recombinant erythropoietin.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Erythrocyte Count; Erythropoietin; Female; Ferritins; Fetal Hemoglobin; Hematocrit; Hemoglobin A2; Humans; Male; Middle Aged

The purpose of this study was to focus on pathophysiological mechanisms linking β-thalassemia intermedia (β-TI) and minor (β-TMI) with cardiovascular risk. Iron status, prooxidant-antioxidant balance and lipid profiles in serum, and lipid content in peripheral blood mononuclear cells (PBMCs) were evaluated in 20 β-TMI subjects, 22 β-TI patients and in 30 nonthalassemic blood donors. The mRNA levels of some genes involved in the regulation of iron and cholesterol metabolism were also determined. In β-TI and in β-TMI, serum iron, prooxidant-antioxidant ratio, transferrin saturation and erythropoietin levels were higher, while transferrin and hepcidin were lower compared to controls. Hepcidin and interleukin-1α mRNA levels were found to be reduced in β-TI- and β-TMI-PBMCs, while those of tumor necrosis factor alpha were increased. A reduction in high-density lipoprotein cholesterol in serum and an accumulation of neutral lipids coupled with increased mRNA levels of acetyl-coenzyme A:cholesterol acyltransferase and decreased neutral cholesterol ester hydrolase in PBMCs were also observed in β-TI and β-TMI compared to controls. Taken together, these findings provide experimental support for the idea that not only β-TI patients but also β-TMI have a proatherogenic biochemical phenotype which may contribute to increase their cardiovascular disease risk.

Topics: Acetyl-CoA C-Acetyltransferase; Adult; Antimicrobial Cationic Peptides; Atherosclerosis; beta-Thalassemia; Cholesterol, HDL; Erythropoietin; Female; Hepcidins; Humans; Interleukin-1alpha; Iron; Italy; Leukocytes, Mononuclear; Male; Middle Aged; Oxidative Stress; Phenotype; Risk Factors; RNA, Messenger; Severity of Illness Index; Sterol Esterase; Transferrin; Tumor Necrosis Factor-alpha

The percentage of hypochromic red cells (%Hypo) is a diagnostic tool that has been used with biochemical markers to diagnose iron disturbances and is incorporated to National Kidney Foundation KDOQI guidelines for monitoring recombinant human erythropoietin therapy. %Hypo measurement has been restricted to analysers manufactured by Siemens. Low haemoglobin density (LHD%), a new parameter provided by Beckman-Coulter, is derived from the traditional mean cell haemoglobin concentration (MCHC), using the mathematical sigmoid transformation [see equation in text]. This study aimed to establish LHD% values in the normal population and in different types of anaemia, to investigate its clinical usefulness in the study of iron status and its correlation with %Hypo. Samples from 449 patients [120 healthy individuals, 86 iron deficiency anaemia (IDA), 102 chronic kidney disease, 58 anaemia of chronic disease and 83 beta-thalassaemia carriers] were run sequentially on the LH 750 (Beckman-Coulter) and Advia 2120 (Siemens) analysers. The reliability of LHD% as a marker of iron deficiency was evaluated on a group of 152 consecutive patients with IDA. Good correlation was observed between %Hypo and LHD%, r(2) = 0.869. Receiver operating characteristic curve analysis for LHD% and the diagnosis of iron deficiency was: cut-off point 4.0%; area under the curve 0.976; sensitivity 95.2%; specificity 93.3%. There was a good level of agreement between LHD% and %Hypo. Both are suitable parameters for determining iron status and its availability for erythropoiesis, with the same clinical significance.

Topics: Anemia, Iron-Deficiency; Automation, Laboratory; beta-Thalassemia; Erythrocyte Indices; Erythropoietin; Hemoglobins; Humans; Kidney Failure, Chronic; Reference Values

Ex vivo generated erythroblasts are being evaluated for transfusion. Expression of balanced levels of globin mRNA is essential for normal red blood cell function and survival but it is unknown whether the expression of the globin genes in ex vivo expanded cells is balanced.. Immature erythroblasts (IEs) were expanded in human erythroid massive amplification cultures from blood mononuclear cells of 19 normal donors and four beta(0)-thalassemia patients (for comparison) and induced to mature for 4 days in the presence of erythropoietin. mRNA was prepared from IEs and mature erythroblasts to evaluate the expression of alpha-, beta-, and gamma-globin genes and of adult hemoglobin-stabilizing protein (AHSP) and BCL11A, two proteins directly controlling globin function and/or production. Results were analyzed using Pearson's correlation coefficient, the Wilcoxon signed rank, and the Mann-Whitney rank sum tests.. The absolute levels of globin, AHSP, and BCL11A mRNA expressed by erythroblasts generated ex vivo from normal donors were distributed along a 2-log range. With maturation, the levels of gamma-globin and BCL11A mRNA did not decrease while those of alpha-globin, gamma + beta-globins, and AHSP mRNA greatly increased. In normal cells, the modest imbalance (two- to fourfold) observed between alpha- and gamma + beta-globin mRNA was fully compensated by AHSP expression. Thus, the levels of alpha-globin mRNA were correlated with those of gamma + beta-globin (R(2) = 0.93, p < 0.0001) and AHSP (R(2) = 0.86, p < 0.0001).. Ex vivo expanded erythroblasts from normal donors express modestly imbalanced levels of alpha-globin and gamma + beta-globin fully compensated by AHSP expression, likely ensuring normal function and survival.

Topics: Adult; beta-Thalassemia; Blood Proteins; Carrier Proteins; Cell Survival; Cells, Cultured; Erythroblasts; Erythropoietin; Female; Gene Expression Regulation; Globins; Humans; Male; Molecular Chaperones; Nuclear Proteins; Repressor Proteins; RNA, Messenger

Individuals with beta-thalassemia develop progressive systemic iron overload, resulting in high morbidity and mortality. These complications are caused by labile plasma iron, which is taken up by parenchymal cells in a dysregulated manner; in contrast, erythropoiesis depends on transferrin-bound iron uptake via the transferrin receptor. We hypothesized that the ineffective erythropoiesis and anemia observed in beta-thalassemia might be ameliorated by increasing the amount of circulating transferrin. We tested the ability of transferrin injections to modulate iron metabolism and erythropoiesis in Hbb(th1/th1) mice, an experimental model of beta-thalassemia. Injected transferrin reversed or markedly improved the thalassemia phenotype in these mice. Specifically, transferrin injections normalized labile plasma iron concentrations, increased hepcidin expression, normalized red blood cell survival and increased hemoglobin production; this treatment concomitantly decreased reticulocytosis, erythropoietin abundance and splenomegaly. These results indicate that transferrin is a limiting factor contributing to anemia in these mice and suggest that transferrin therapy might be beneficial in human beta-thalassemia.

Topics: Animals; Apoptosis; beta-Thalassemia; Cell Survival; Disease Models, Animal; Erythropoietin; Hematopoiesis, Extramedullary; Mice; Splenomegaly; Transferrin

Two patients with thalassemia minor and end-stage renal failure on hemodialysis were treated with epoetin zeta (Silapo, Retacrit; STADA, Germany), a medicinal product that was developed and registered as biosimilar to epoetin alfa. Dosing was titrated individually for two patients to achieve a stable hemoglobin (Hb) concentration of 10.5-12.0 g/dL. One patient was treated intravenously with epoetin zeta; the other patient was treated subcutaneously. After 12 weeks of therapy both patients achieved Hb levels within the target range, confirming the effi cacy of epoetin zeta in patients with thalassemia minor.

Topics: Adult; Anemia; beta-Thalassemia; Erythropoietin; Humans; Kidney Failure, Chronic; Male; Middle Aged; Recombinant Proteins; Renal Dialysis

CD177 (PRV1) expression is strongly related to polycythaemia vera (PV). Whilst studying CD177 expression in PV patients and controls, individuals with beta-thalassaemia minor were found to display an elevated expression of CD177. The study was expanded to include patients with thalassaemia intermedia, sickle cell/beta-thalassaemia and thalassaemia major. CD177 expression was increased in these thalassaemic groups and correlated with their erythropoietic activity, as assessed by the measurement of serum erythropoietin and soluble transferrin receptor levels. Within this context, elevated CD177 expression is not only a specific feature of PV but may be an indicator of increased erythropoietic activity in thalassaemia syndromes.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; beta-Thalassemia; Erythropoiesis; Erythropoietin; Gene Expression; Genotype; GPI-Linked Proteins; Humans; Isoantigens; Janus Kinase 2; Membrane Glycoproteins; Middle Aged; Mutation; Polycythemia Vera; Receptors, Cell Surface; Receptors, Transferrin; RNA, Messenger

Normal stem cells usually express a low level of telomerase activity that serves to stabilize the chromosomes during cell division and helps prevent cell senescence. Human telomerase reverse transcriptase (hTERT) is a rate-limiting enzyme that dictates the activity of human telomerase and thus decides the life span of cells. The expression of hTERT and its roles in beta-thalassemia major are unclear, however.. hTERT mRNA expression in bone marrow (BM) CD34+ cells from 25 children with beta-thalassemia major and 15 control subjects was investigated using real-time reverse transcription polymerase chain reaction (RT-PCR) analysis. The serum erythropoietin (sEPO) and hemoglobin (Hb) levels in peripheral blood were also determined. The relationship between hTERT and sEPO as well as Hb was then examined.. It was found that hTERT mRNA expression was significantly up regulated in BM CD34+ cells from patients with beta-thalassemia major. Furthermore, a significantly positive correlation was found between hTERT mRNA and sEPO (r = 0.771, p < 0.001). A significantly inverse correlation, however, was found between hTERT mRNA and Hb concentration (r = -0.929, p < 0.001).. Our findings suggest that severe anemia with low Hb concentration might up regulate hTERT expression of BM CD34+ cells and sEPO levels in patients with beta-thalassemia major.

Topics: Adolescent; Antigens, CD34; beta-Thalassemia; Bone Marrow Cells; Child; Child, Preschool; Erythropoietin; Female; Gene Expression Regulation, Enzymologic; Hematopoietic Stem Cells; Hemoglobins; Humans; Infant; Male; RNA, Messenger; Severity of Illness Index; Telomerase

Severe forms of anemia in children in the developing countries may be characterized by different clinical manifestations at particular stages of development. Whether this reflects developmental changes in adaptation to anemia or other mechanisms is not clear. The pattern of adaptation to anemia has been assessed in 110 individuals with hemoglobin (Hb) E beta-thalassemia, one of the commonest forms of inherited anemia in Asia. It has been found that age and Hb levels are independent variables with respect to erythropoietin response and that there is a decline in the latter at a similar degree of anemia during development. To determine whether this finding is applicable to anemia due to other causes, a similar study has been carried out on 279 children with severe anemia due to Plasmodium falciparum malaria; the results were similar to those in the patients with thalassemia. These observations may have important implications both for the better understanding of the pathophysiology of profound anemia in early life and for its more logical and cost-effective management.

Topics: Adaptation, Physiological; Adolescent; Adult; Age Distribution; Aging; Anemia; Animals; beta-Thalassemia; Child; Child, Preschool; Developing Countries; Erythropoietin; Humans; Infant; Malaria, Falciparum; Middle Aged

A patient with thalassemia minor and idiopathic scoliosis was scheduled for posterior vertebral arthrodesis. The diagnosis of thalassemia minor was made during the preoperative assessment. Preoperative blood cell count displayed the following data: red blood count 5.4 x 106/microL, haemoglobin 11.6 g/dL and hematocrit 36.9%. As corrective surgery for scoliosis is associated with major blood loss, the patient was scheduled for preoperative treatment with human recombinant erythropoietin (rHuEPO), autologous blood donation, intraoperative blood cell salvage and administration of tranexamic acid. The use of rHuEPO was intended to increase hemoglobin (12.1 g/dL) levels at the moment of surgery following the donation of 2 autologous blood units. 1000 mL of salvaged blood were processed. The output line of the blood cell salvage machine did not show any sign of increased red cell haemolysis. The postoperative course was uneventful and the patient was discharged from the postoperative intensive care unit on day 7 after surgery with no allogenic blood transfusion. No references detailing the use of rHuEPO and autologous blood donation preoperatively in patients with thalassemia minor and only one case report discussed the utility of intraoperative blood cell salvage in a patient with thalassemia intermedia. Although further experience is needed, this case report suggests that even for patients with thalassemia minor, methods focused on allogenic blood salvage can be used safely.

Topics: Adolescent; beta-Thalassemia; Blood Preservation; Blood Transfusion, Autologous; Erythrocyte Count; Erythropoietin; Female; Hematocrit; Hemoglobins; Humans; Intraoperative Care; Recombinant Proteins; Scoliosis

The present study found that the cyclic adenosine monophosphate (cAMP)-dependent pathway efficiently induced gamma-globin expression in adult erythroblasts, and this pathway plays a role in gamma-globin gene (HBG) expression in beta-thalassaemia. Expression of HBG mRNA increased to about 46% of non-HBA mRNA in adult erythroblasts treated with forskolin, while a cyclic guanosine monophosphate (cGMP) analogue induced HBG mRNA to levels <20% of non-HBA mRNA. In patients with beta-thalassaemia intermedia, cAMP levels were elevated in both red blood cells and nucleated erythroblasts but no consistent elevation was found with cGMP levels. The transcription factor cAMP response element binding protein (CREB) was phosphorylated in nucleated erythroblasts and its phosphorylation levels correlated with HBG mRNA levels of the patients. Other signalling molecules, such as mitogen-activated protein kinases and signal transducers and activators of transcription proteins, were phosphorylated at variable levels and showed no correlations with the HBG mRNA levels. Plasma levels of cytokines, such as erythropoietin, stem cell factor and transforming growth factor-beta were increased in patients, and these cytokines induced both HBG mRNA expression and CREB phosphorylation. These results demonstrate that the cAMP-dependent pathway, the activity of which is augmented by multiple cytokines, plays a role in regulating HBG expression in beta-thalassaemia.

Topics: Adolescent; Adult; beta-Thalassemia; Blotting, Western; Case-Control Studies; Chromatography, High Pressure Liquid; Cyclic AMP; Cyclic AMP Response Element-Binding Protein; Erythroblasts; Erythropoietin; Gene Expression; Gene Expression Regulation; Globins; Humans; Phosphorylation; RNA, Messenger; Signal Transduction; Stem Cell Factor; Transforming Growth Factor beta

Anemia in pregnancy is seen often because of iron deficiency and the "physiologic dilution" that occurs in the third trimester. Other causes include genetic conditions, such as sickle cell anemia and thalassemias. In cases not responding to iron therapy, patients occasionally require a blood transfusion to restore adequate circulating red blood cell mass. In patients belonging to the Jehovah's Witness sect, transfusion of blood products is not allowed, and treatment of anemia in pregnancy may require use of erythropoietin.. A 26-year-old, African American woman belonging to the Jehovah's Witness sect presented with anemia associated with beta-thalassemia. Iron therapy and prenatal vitamins did not correct the anemia, and the patient became symptomatic, with fatigue and shortness of breath when walking. Therapy with synthetic erythropoietin corrected the anemia, and the patient had an otherwise-uncomplicated pregnancy and delivery.. Synthetic erythropoietin has been used successfully in patients with renal failure and anemia. In pregnancy associated with renal failure and anemia, synthetic erythropoietin has been shown to be safe except for rare cases of hypertension. We treated anemia caused by beta-thalassemia in pregnancy with synthetic erythropoietin to avoid a transfusion in a Jehovah's Witness.

Topics: Adult; Anemia, Iron-Deficiency; beta-Thalassemia; Erythropoietin; Female; Follow-Up Studies; Gestational Age; Humans; Jehovah's Witnesses; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Outcome; Risk Assessment; Treatment Outcome

The beta thalassemias are one of a few medical conditions in which reactivation of a gene product that is expressed during fetal life can functionally replace a deficiency of essential proteins expressed at a later developmental stage. The fetal globin genes are present and normally integrated in hematopoietic stem cells, and at least one fetal gene appears accessible for reactivation, particularly in beta degrees thalassemia. However, rapid cellular apoptosis from alpha globin chain precipitation, and relatively low levels of endogenous erythropoietin (EPO) in some beta(+) thalassemia patients contribute to the anemia in beta thalassemia syndromes. In clinical trials, three classes of therapeutics have demonstrated proof-of-principle of this approach by raising total hemoglobin levels by 1-4 g/dL above baseline in thalassemia patients: EPO preparations, short chain fatty acid derivatives (SCFADs), and chemotherapeutic agents. Although thalassemic erythrocytes survive only for a few days, the magnitude of these responses is similar to those induced by rhu-EPO in anemic conditions of normal erythrocyte survival. New oral therapeutic candidates, which stimulate both fetal globin gene expression and erythropoiesis, and combinations of therapeutics with complementary molecular actions now make this gene-reactivation approach feasible to produce transfusion independence in many patients. Development of the candidate therapeutics is hindered largely by costs of drug development for an orphan patient population.

Topics: alpha-Globins; Anemia; beta-Thalassemia; Cell Division; Cell Survival; Erythrocytes; Erythropoietin; Fatty Acids; Fetal Hemoglobin; gamma-Globins; Gene Expression Regulation; Genetic Therapy; Humans

Hemoglobin E (Hb E)-beta-thalassemia patients display a range of clinical severities, from nearly asymptomatic to transfusion-dependent thalassemia major. Given this clinical heterogeneity, additional genetic factors modifying disease severity remain to be discovered. Association studies are being conducted to elucidate the role of genetic polymorphisms as disease severity modifiers in Hb E-beta-thalassemia patients. Using strict scoring criteria, 1060 Hb E-beta-thalassemia patients were categorized into mild, moderate, and severe groups. Taking a candidate gene approach, we found no statistically significant differences between the mild and severe patients groups in allelic or genotypic frequencies for single nucleotide polymorphisms within five genes known to influence globin gene expression and erythropoiesis.

Topics: Adolescent; Adult; Alleles; beta-Thalassemia; Blood Proteins; Child; Child, Preschool; China; Epistasis, Genetic; Erythropoietin; Female; GATA1 Transcription Factor; Globins; Hemoglobin E; Homeodomain Proteins; Humans; Kruppel-Like Transcription Factors; Male; Middle Aged; Molecular Chaperones; NF-E2 Transcription Factor, p45 Subunit; Polymorphism, Single Nucleotide; Receptors, Erythropoietin; Severity of Illness Index; Thailand; Transcription Factors

Iron deficiency anaemia and the thalassemia syndromes, a group of disorders resulting from inherited abnormality of globin chain production, are common causes of anaemia in Thailand, and in the Far East in general. Monitoring erythropoiesis in these patient is very important in evaluating the disease and the response to treatment. Recently, our group has just reported the feasibility in using serum erythropoietin (EPO) for monitoring purposes in thalassemia and demonstrated that the determination of serum EPO can be an alternative choice in the follow up of these conditions. This study reports a cost effectiveness analysis comparing the recently reported radioimmunoassay (RIA) for serum EPO determination and the previously used tool, the reticulocyte count. The study reports a higher detection rate for ineffective erythropoiesis when using serum EPO determination, however, the increased sensitivity is at balanced by a higher unit cost. In this analysis, the cost effectiveness for serum EPO and reticulocyte are 208.33 and 50 baht/detection, respectively. () Therefore, the reticulocyte count is more cost effective and is recommended for routine usage in our current medico-economic setting.

Topics: Anemia, Iron-Deficiency; beta-Thalassemia; Cost-Benefit Analysis; Erythropoiesis; Erythropoietin; Hemoglobin E; Humans; Monitoring, Physiologic; Radioimmunoassay; Reticulocyte Count; Thailand

In vivo gene transfer is being considered in the systemic delivery of therapeutic proteins. This report evaluates the use of AAV vectors administered into muscle to deliver erythropoietin (Epo) for the treatment of anemia in a mouse model of beta-thalassemia. Injection of vector expressing Epo from a constitutive promoter resulted in Epo overproduction and improved erythropoiesis. However, severe and lethal polycythemia developed. In order to titrate the expression of Epo to therapeutic and non-toxic levels, vectors were constructed to allow pharmacologic control of Epo transcription. Specifically, expression of Epo was dependent on the presence of a chimeric transcription factor that is activated by the orally available small molecule drug rapamycin. beta-thalassemic mice injected with vectors containing the regulated Epo gene failed to show any effect until they were administered a regimen of rapamycin, which led to the production of Epo and an increase in hematocrit values. Epo expression and its hematologic consequences were directly dependent on the dose of rapamycin and were completely reversed when rapamycin was withdrawn. The increase in hematocrit was associated with partial improvements in the abnormalities of red blood cell morphology. This study confirms the value of pharmacologic regulation of transgene expression in the development of safe and effective gene therapies in which biologically active secreted proteins are produced.

Topics: Animals; beta-Thalassemia; Dependovirus; Erythropoietin; Gene Expression Regulation; Genetic Vectors; Mice; Mice, Inbred C57BL; Mice, Knockout; Sirolimus

In dialysis patients beta-thalassemia is a cause of resistance to erythropoietin (EPO). The aim of the present study is to evaluate the relationship between the amount of circulating anomalous hemoglobin chain and EPO resistance in hemodialysis. Ten hemodialyzed patients with beta-thalassemia minor were studied. The mean hemoglobin level was 9.22 +/- 0.91 g/dl, the HbA2 ranging between 5.6 and 6.8%; the weekly EPO dose was 13,500 +/- 7,185 IU/week and significantly correlated with HbA2 (r = 0.965; p = 0.0001). When stratifying patients in two groups according to HbA2 level (LOW <6%, n = 4; HIGH >6%, n = 6; HbA2 levels, respectively, 5.7 +/- 0.1 and 6.4 +/- 0.3 g/dl, p = 0.002), it was evidenced that the need of EPO was 13,200 +/- 3,033 IU/week in LOW and 36,167 +/- 13,060 IU/week in HIGH (p < 0.001). The EPO Resistance Index in the two groups was 13.4 +/- 4.1 IU/kg BW/week/g Hb in LOW and 21.9 +/- 10.0 in HIGH (p < 0.05). No differences were evidenced between the two groups regarding age, dialysis, body weight, serum levels of urea nitrogen, creatinine, albumin, C-reactive protein, aluminum, ferritin, transferrin and parathyroid hormone. In conclusion, in patients with beta-thalassemia minor on chronic hemodialysis, the amount of anomalous hemoglobin chain directly correlate with EPO dose, strongly indicating the magnitude of resistance to erythropoietin.

Topics: Adult; Aged; beta-Thalassemia; Drug Administration Schedule; Drug Resistance; Erythropoietin; Female; Globins; Hematologic Tests; Hemoglobin A2; Hemoglobins; Humans; Male; Middle Aged; Prospective Studies; Renal Dialysis; Statistics, Nonparametric; Time Factors

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).

Topics: beta-Thalassemia; Blood Transfusion; Case-Control Studies; Child; Child, Preschool; Erythropoietin; Hemoglobin E; Humans; Thailand

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.

Topics: Antisickling Agents; beta-Thalassemia; Child; Erythropoietin; Female; Hepatomegaly; Humans; Hydroxyurea; Recombinant Proteins; Splenomegaly; Stem Cell Transplantation

Erythropoiesis has been considered as a potential treatment for beta-thalassemia. Although Epo secretion from genetically engineered muscles allowed long-term correction of the disease in the mouse, repeated injections of rHuEpo were disappointing in human patients. Whether different mechanisms operate in humans and mice or whether Epo exhibits different biological activity depending on the administration route is currently unknown. We provide evidence that mechanisms recruited over a 36-week follow-up in beta-thalassemic mice were similar to those acting during stress-induced erythropoiesis in humans. beta-Thalassemic mice were rendered steadily normocythemic by the intramuscular injection of a tetracycline-inducible AAV vector encoding mouse Epo. Doxycycline dosage was adapted to hematocrit. Circulating red blood cells essentially synthesized beta-minor globin, the mouse equivalent to human gamma-globin. Quantification of erythroid progenitors indicated a steady-state expansion of erythroid burst-forming units programmed for beta-minor globin synthesis and a hastening of their maturation to hemoglobin-synthesizing cells. We discuss hypotheses that could account for the failure to recruit this mechanism over the long term in beta-thalassemic patients and raise the possibility of Epo gene therapy trials to treat beta-thalassemia.

Topics: Animals; beta-Thalassemia; Bone Marrow Cells; Cell Division; Dependovirus; Doxycycline; Erythroid Precursor Cells; Erythropoietin; Genetic Therapy; Genetic Vectors; Globins; Mice; Mice, Inbred C57BL; Muscles; RNA, Messenger; Spleen; Time Factors

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.

Topics: Adolescent; Adult; Analysis of Variance; beta-Thalassemia; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Female; Hemoglobins; Humans; Male; Receptors, Transferrin; Solubility

A new intramuscular DNA electrotransfer method for erythropoietin (EPO) expression was evaluated in the natural mouse model of human beta-thalassemia (Hbb-thal1) in terms of its ability to reverse the anemia and improve the thalassemic features of erythrocytes.. Intramuscular injection of small amounts of a plasmid encoding mouse EPO, immediately followed by controlled electric pulses, was used.. This procedure induced very high hematocrit levels in beta-thalassemic mice compared to nonelectrotransferred mice. The hematocrit increase was dose dependent, still increased 4 months after injection of plasmid DNA, and associated with a high transgenic EPO blood level in all mice (up to 2500 mU/mL of plasma). EPO gene electrotransfer not only led to a long-lasting and dose-dependent increase in the hematocrit but also to a 100% increase in the lifespan of erythrocytes of thalassemic mice. This was related to a nearly complete reestablishment of alpha/beta globin chain balance, as demonstrated by a marked decrease in unpaired alpha globin chain. Eight months after the first electrotransfer of pCMV-mEPO plasmid, reinjection of the same construct raised the hematocrit to a level close to that observed following the first electrotransfer.. This is the first description of the use of plasmid DNA to achieve long-term improvement in a mouse model of a human genetic disorder.

Topics: Animals; beta-Thalassemia; Cytomegalovirus; Disease Models, Animal; DNA, Recombinant; Electroporation; Erythropoietin; Female; Gene Deletion; Genetic Therapy; Genetic Vectors; Globins; Hematocrit; Injections, Intramuscular; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Promoter Regions, Genetic; Recombinant Fusion Proteins; Transgenes

Mechanisms governing the induction of effective erythropoiesis in response to erythropoietin (Epo) oversecretion have been investigated in beta thalassemic C57Bl/6(Hbbth) mice. Naked DNA encoding an expression vector for mouse Epo was introduced into skeletal muscles by electrotransfer. A transient increase of serum Epo concentrations with a proportional augmentation of hematocrit values was observed. Various parameters relevant to beta thalassemia were surveyed in blood samples taken before treatment, at the peak of Epo secretion, and when the phenotype reverted to anemia. We measured globin messenger RNA (mRNA) levels in reticulocytes by real-time quantitative polymerase chain reaction, globin chain synthesis levels, and several indicators of erythrocyte membrane quality, including bound alpha chains, bound immunoglobulins, main protein components, and iron compartmentalization. Data indicated that high serum Epo levels primarily affect betaminor-globin mRNA accumulation in reticulocytes. Other changes subsequent to intense Epo stimulation, like increased betaminor/alpha-globin chain synthesis ratio, reduced levels of alpha chains and immunoglobulins bound to membranes, improved spectrin/band 3 ratio, increased red blood cell survival, and improved erythropoiesis appeared as consequences of increased betaminor-globin mRNA levels. This conclusion is consistent with models postulating that intense Epo stimulation induces the expansion and differentiation of erythroid progenitors committed to fetal erythropoiesis. Although phenotypic correction was partial in mice, and comparable achievements will probably be more difficult to obtain in humans, naked DNA electrotransfer may provide a safe and low-cost method for reassessing the potentials of Epo as an inducer of fetal erythropoiesis reactivation in patients with beta thalassemia.

Topics: Animals; Anion Exchange Protein 1, Erythrocyte; beta-Thalassemia; Cell Compartmentation; Cell Differentiation; Disease Models, Animal; DNA, Complementary; Electroporation; Erythrocytes; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Genetic Complementation Test; Globins; Injections, Intramuscular; Iron; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle, Skeletal; Phenotype; Polymerase Chain Reaction; Recombinant Fusion Proteins; Reticulocytes; RNA, Messenger; Spectrin; Transfection

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.

Topics: Anemia, Sickle Cell; Antisickling Agents; beta-Thalassemia; Blood Cell Count; Cell Differentiation; Cell Division; Cells, Cultured; Culture Media, Conditioned; Erythroid Precursor Cells; Erythropoietin; Heterozygote; Humans; Hydroxyurea; Sickle Cell Trait

High doses of recombinant human erythropoietin (rhEpo) are required for the treatment of chronic anemia. Thus, it is clear that therapy for chronic anemia would greatly benefit from an erythropoietin derivative with increased erythropoietic activity rather than the native endogenous hormone. In this report, the activity of a human Epo-Epo dimer protein, obtained by recombinant technology, is described and compared with its Epo monomer counterpart produced under identical conditions. Although monomer Epo and dimer Epo-Epo had similar pharmacokinetics in normal mice, the increase in hematocrit value was greater with the dimer than with the monomer. Moreover, in clonogenic assays using CD34(+) human hematopoietic cells, the human dimer induced a 3- to 4-fold-greater proliferation of erythroid cells than the monomer. Controlled secretion of dimeric erythropoietin was achieved in beta-thalassemic mice by in vivo intramuscular electrotransfer of a mouse Epo-Epo plasmid containing the tetO element and of a plasmid encoding the tetracycline controlled transactivator tTA. Administration of tetracycline completely inhibited the expression of the mEpo dimer. On tetracycline withdrawal, expression of the Epo-Epo dimer resumed, thereby resulting in a large and sustained hematocrit increase in beta-thalassemic mice. No immunologic response against the dimer was apparent in mice because the duration of the hematocrit increase was similar to that observed with the monomeric form of mouse erythropoietin. (Blood. 2001;97:3776-3782)

Topics: Animals; beta-Thalassemia; Cells, Cultured; Dimerization; Erythropoiesis; Erythropoietin; Genetic Vectors; Hematocrit; Humans; Injections; Mice; Mice, Inbred C3H; Mice, Mutant Strains; Muscle, Skeletal; Recombinant Fusion Proteins; Transfection

We have developed a murine model of in utero transplantation in nonanemic, beta-thalassemic mice to study chimerism, tolerance, and changes in hematological parameters in response to cytokines and postnatal boosts with donor cells. We have documented improved survival of homozygous fetuses by 40% as compared with controls. Low-level, mixed chimerism was improved by postnatal cytokine therapy and boosts and was associated with improvement in hemoglobin levels, reticulocyte counts, and iron stores. Cytotoxicity assays demonstrated higher responses to donor cells in control mice as compared with in utero transplanted animals (at 50:1 effector to target ratios, transplanted mice showed 8.66% target lysis and control mice showed 51.85% target lysis, P=0.0003), indicating tolerance. The combination of prenatal tolerance to allogeneic cells with postnatal boosts in primed hosts may become an effective, nontoxic strategy for the improvement of hemolytic anemia in beta-thalassemic patients.

Topics: Animals; Animals, Newborn; beta-Thalassemia; Blood Physiological Phenomena; Cell Transplantation; Chimera; Cytokines; Erythropoietin; Fetus; Granulocyte Colony-Stimulating Factor; Immune Tolerance; Liver; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Stem Cell Factor

Topics: Aldosterone; Anemia, Sickle Cell; beta-Thalassemia; Erythropoietin; Humans; Kidney Diseases; Kidney Function Tests; Kidney Glomerulus; Kidney Tubules, Proximal; Proteinuria

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.

Topics: Adult; beta-Thalassemia; Blood Transfusion; Erythropoietin; Humans; Isoantibodies; Male; Recombinant Proteins

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.

Topics: Adolescent; Adult; Aged; Anemia; Anemia, Hemolytic; Anemia, Iron-Deficiency; beta-Thalassemia; Erythropoietin; Female; Hemoglobins; Humans; Linear Models; Male; Middle Aged; Predictive Value of Tests; Receptors, Transferrin; Solubility

beta-Thalassemias are highly prevalent genetic disorders that can cause severe hemolytic anemia. The main pathophysiologic feature of beta-thalassemia is the accumulation of unpaired alpha-globin chains in erythrocyte precursors and red blood cells (RBCs). This accumulation alters cell membrane function and results in early cell destruction and ineffective erythropoiesis. Correction of globin chain imbalance through the induction of fetal hemoglobin (HbF) synthesis is a tentative therapeutic approach for this class of diseases. In short-term in vitro or in vivo assays, recombinant human erythropoietin increases the frequency of erythroid precursors programmed to HbF in humans and to beta-minor globin in mice. In contrast, long-term treatment of beta-thalassemic patients did not induce HbF significantly. We took advantage of highly efficient adeno-associated virus-mediated (AAV-mediated) gene transfer into mouse muscle to induce a robust and sustained secretion of mouse erythropoietin in beta-thalassemic mice, which represent a suitable model for human beta-thalassemia intermedia. A 1-year follow-up of 12 treated animals showed a stable correction of anemia associated with improved RBC morphology, increased beta-minor globin synthesis, and decreased amounts of alpha-globin chains bound to erythrocyte membranes. More effective erythropoiesis probably accounted for a reduction of erythroid cell proliferation, as shown by decreased proportions of circulating reticulocytes and by reduced iron 59 ((59)Fe) incorporation into erythroid tissues. This study indicates that the continuous delivery of high amounts of autologous erythropoietin induced a sustained stimulation of beta-minor globin synthesis and a stable improvement of erythropoiesis in the beta-thalassemic mouse model. (Blood. 2000;95:2793-2798)

Topics: Animals; beta-Thalassemia; Cell Division; Dependovirus; Erythrocyte Count; Erythropoiesis; Erythropoietin; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Globins; Hematocrit; Humans; Iron; Mice; Mice, Mutant Strains; Muscle, Skeletal; Reticulocyte Count

Juvenile hemochromatosis is a rare genetic disorder that causes iron overload. Clinical complications, which include liver cirrhosis, heart failure, hypogonadotropic hypogonadism and diabetes, appear earlier and are more severe than in HFE-related hemochromatosis. This disorder, therefore, requires an aggressive therapeutic approach to achieve iron depletion. We report here the case of a young Italian female with juvenile hemochromatosis who was unable to tolerate frequent phlebotomy because of coexistent ss-thalassemia trait. The patient was successfully iron-depleted by combining phlebotomy with recombinant human erythropoietin.

Topics: Adrenal Cortex Hormones; Adrenal Insufficiency; Adult; Arrhythmias, Cardiac; beta-Thalassemia; Chelation Therapy; Chromosomes, Human, Pair 1; Deferoxamine; Erythropoietin; Estrogen Replacement Therapy; Female; Hemochromatosis; Hemosiderosis; Hormone Replacement Therapy; Humans; Hypogonadism; Liver Cirrhosis; Phlebotomy; Progesterone; Recombinant Proteins

In non-thalassaemic women serum erythropoietin (Epo) level increases during pregnancy, whereas that of soluble transferrin receptor (STFR) drops slightly in the first two trimesters to attain the original values in the third trimester. In this study the time-course of these two parameters was explored in b-thalassemic and non-b-thalassemic women, both pregnant and not.. Two hundred and fifty-seven women were studied: 64 non-b-thalassemic, non-pregnant women made up the reference group, 89 were non-b-thalassemic pregnant women, and 104 were b-thalassemic pregnant or non-pregnant women. The full blood count, hemoglobin levels and iron status (serum iron and serum ferritin levels) were explored by traditional methods. Serum Epo and STFR levels were measured with standard commercial kits.. In non-b-thalassemic women the mean non-pregnant Epo level (10.95 +/-4. 7 mU/mL) increased in the first trimester (17.12 +/-5.18 mU/mL), was stationary in the second, and increased again in the third (31. 43+/-14.13 mU/mL). STFR mean value dropped in early pregnancy from 2. 40+/-0.72 mg/L to 1.78 +/- 0.64 mg/L, and then returned to the original value (2.38 +/- 0.94 mg/L). In b-thalassemic women the mean non-pregnant Epo level (15.00 +/-6.56 mU/mL) was higher than in non-thal non-pregnant women. During pregnancy it progressively increased to 35.60+/-25.46 mU/mL. STFR (non-pregnant level 3.37+/-1. 07 mg/L) gradually increased throughout the whole gestation period and by the third trimester its level was markedly higher than that of non-b-thal women at the corresponding stage of gestation (9. 41+/-5.39 mg/L vs 2.40+/-0.72 mg/L).. The STFR level changed to different extents in non-b-thal and b-thal women during their pregnancies. In the former STFR markedly decreased in early pregnancy; in the latter it showed no decrease in the first trimester, increased in the second and reached very high values in the third. This time course is likely to be the consequence of erythroid bone marrow hyperplasia and hyperactivity, which are usually present in all b-thalassemic patients and in heterozygous carriers as well.

Topics: Adolescent; Adult; beta-Thalassemia; Erythropoietin; Female; Hematocrit; Hemoglobins; Heterozygote; Humans; Middle Aged; Pregnancy; Pregnancy Complications, Hematologic; Pregnancy Trimesters; Receptors, Transferrin; Solubility

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.

Topics: Administration, Oral; Adolescent; Adult; Amides; Antineoplastic Agents; beta-Thalassemia; Blood; Blood Transfusion; Child; Child, Preschool; Drug Evaluation; Erythrocyte Indices; Erythropoietin; Female; Fetal Hemoglobin; Genotype; Hemoglobins; Hemolysis; Homozygote; Humans; Iron; Longitudinal Studies; Male; Patient Compliance; Time Factors

Administration of hydroxyurea in sickle cell disease is associated with a dramatic increase of HbF along with a significant clinical improvement and, occasionally, increased total hemoglobin levels. The underlying mechanisms are not yet fully elucidated.. We report the response of three patients with homozygous sickle cell disease and 10 patients with compound HbS/beta-thalassemia (four with beta(o)thal/HbS and six with beta(+)thal/HbS respectively) to hydroxyurea treatment with regards to their serum erythropoietin levels (sEpo).. Baseline sEpo levels varied from 33.0 to 284.0 IU/L and showed a significant negative correlation with the respective Hb values (P<0.007). Two to three weeks after initiation of treatment, the sEpo values started to increase and reached levels three to 31 times higher than the baseline two to three weeks later. Thereafter, in most cases the Epo values decreased and remained at intermediate levels throughout the rest of hydroxyurea administration, while in a few cases, they returned to baseline. An inappropriate increase of sEpo following treatment with various cytostatic drugs, independently of anemia induced by cytostatic agents, has already been reported in the literature. The cytostatics included cyclophosphamide, anthracyclines, cytosine arabinoside etc., but not hydroxyurea. The results described here with hydroxyurea are virtually similar, ie, they show a significant sEpo increase five to ten days post therapy with no apparent cause. Pulses of high dose Epo have been reported to promote proliferation of erythroid precursors with HbF synthesizing capacity.. Our hypothesis is that a similar phenomenon may occur here also, in the sense that peaks of endogenous Epo may promote proliferation of erythroid precursors which maintain the capacity to synthesize HbF.

Topics: Adolescent; Adult; Anemia, Sickle Cell; beta-Thalassemia; Erythroid Precursor Cells; Erythropoietin; Female; Fetal Hemoglobin; Gene Expression Regulation; Humans; Hydroxyurea; Kidney; Liver; Male; Middle Aged; Sickle Cell Trait; Time Factors

In the management of patients requiring chronic transfusion, various parameters may be used to evaluate the degree of erythroid marrow suppression. The aim of our study was to assess which of these parameters provide the most useful assessment of erythropoiesis. We studied 27 chronically transfused patients, 19 with sickle cell disease (SS patients) and 8 with thalassemia. Thirty-one nonchronically transfused SS patients and 74 healthy children served as controls. We measured serum transferrin receptor levels, reticulocyte counts, hemoglobin (Hb) concentrations and erythropoietin levels. The serum transferrin receptor levels were very elevated in control SS patients and remained significantly elevated in those on transfusion therapy, but were normal in thalassemia patients, indicating a more complete suppression of erythropoiesis. The reticulocyte counts were elevated in all SS patients, even when on chronic transfusion, but were in the normal range in patients with thalassemia. Erythropoietin levels were elevated in patients with thalassemia and in all the SS patients. Hb levels negatively correlated with serum transferrin receptor and erythropoietin in all SS patients. In the transfused SS patients, a higher HbS level correlated with higher reticulocyte counts, transferrin receptor, and erythropoietin levels. In thalassemia patients, erythropoiesis was more completely suppressed, as reflected both by normal reticulocyte counts and near-normal transferrin receptor levels. Though the reticulocyte counts were not significantly different in the transfused SS patients, the serum transferrin receptor levels were less elevated than in SS patients not on transfusion. The serum transferrin receptor level appears to be the most useful marker of marrow erythropoietic activity in chronically transfused SS patients. We recommend that reticulocyte counts be integrated with periodic measurements of serum transferrin receptor levels.

Topics: Adolescent; Adult; Anemia, Sickle Cell; beta-Thalassemia; Child; Child, Preschool; Erythropoiesis; Erythropoietin; Female; Hemoglobins; Humans; Infant; Male; Receptors, Transferrin; Reticulocyte Count; Transfusion Reaction

The ability of circulating progenitor cells to develop erythroid colonies was studied in vitro in the presence or absence of growth factors (5637-CM and erythropoietin) in 63 patients with sickle cell disease (SCD) (36 homozygotes for hemoglobin [Hb] S, 13 double heterozygotes for Hb S and beta thalassemia, and 14 SC patients) in Southeast Brazil. In the presence of growth factors, SCD patients (all genotypes) presented significantly higher numbers of circulating burst-forming unit-erythroid (BFU-E/5 x 10(5) MNC), when compared with control subjects. However, when the progenitor cells were cultured in the absence of added stimulus, high numbers of BFU-E were observed only in the genotypes SS and S/beta thalassemia. SC patients presented a similar response to the control subjects. Moreover, there was an inverse correlation between spontaneous (without stimulus) BFU-E and Hb levels in SCD patients. These results suggest that the formation of spontaneous BFU-E observed in SCD may be due to an expanded erythropoiesis secondary to hemolysis.

Topics: Adult; Anemia, Sickle Cell; beta-Thalassemia; Brazil; Cell Differentiation; Cell Division; Colony-Forming Units Assay; Erythroid Precursor Cells; Erythropoietin; Genotype; Hemoglobin SC Disease; Humans; Recombinant Proteins; Sickle Cell Trait

The goal of the present study was to analyze if sustained delivery of elevated doses of recombinant erythropoietin (Epo), by genetically modified and immunoprotected allogenic cells, was able to correct the chronic anemia, characteristic of a spontaneous mouse model of beta-thalassemia (Hbb thal 1). Mouse C2C12 myoblast cells were transfected with a plasmid containing the mouse Epo cDNA and a mutated dihydrofolate reductase (DHFR) gene for gene amplification upon administration of increasing doses of methotrexate. In order to immunoprotect the transplanted cells, the stably modified cells were loaded into polyethersulfone microporus hollow fibers which were implanted subcutaneously into Hbb thal 1 mice. An increase in hematocrit starting 2 weeks after implantation was associated with elevated blood levels of Epo and an improved red blood cell phenotype. The latter indicated an improvement of cell morphology and membrane defects, in particular a reduced amount of free alpha hemoglobin chain, the hallmark of globin chain imbalance in beta-thalassemia. A reduction of reticulocyte count contrasting with the increase in hematocrit was also observed suggesting an improved erythrocyte survival. We conclude that the phenotype can be durably improved in some beta-thalassemic mice upon in vivo delivery of recombinant Epo by polymer encapsulated cells. Sustained elevated delivery of recombinant Epo holds promise for the treatment of beta-thalassemia-associated chronic anemia.

Topics: Animals; beta-Thalassemia; Capsules; Cell Line; Erythrocytes; Erythropoietin; Female; Gene Deletion; Genetic Therapy; Genetic Vectors; Hematocrit; Mice; Mice, Inbred C3H; Mice, Inbred DBA; Mice, Transgenic; Muscle, Skeletal; Recombinant Proteins; Reticulocyte Count; Reticulocytes; Transfection

We report here the functional and structural characterization of Hb Acharnes [beta53(D4) Ala --> Thr], an unstable and electrophoretically silent variant, that was found associated in trans with a beta(0)-thalassemic mutation (IVSI-1 G --> A), in a patient with thalassemia intermedia syndrome. This case is discussed in comparison with other sporadic cases that we have previously investigated, resulting from the co-inheritance of a beta(0)-thalassemic mutation (CD39 C --> T) with two other types of unstable hemoglobins, Hb Köln [beta98(FG5) Val --> Met], and Hb Arta [beta45(CD4) Phe --> Cys]. It may be concluded that, in these associated forms, both the degree of instability of the variant and the altered oxygen binding properties (affecting the degree of tissue hypoxia) are major determinants of their clinical expression.

Topics: beta-Thalassemia; Child; DNA; Erythropoietin; Female; Hemoglobins, Abnormal; Humans; Mutation; Oxygen Consumption; Receptors, Transferrin

SV40-based vectors are very efficient in gene delivery into human hematopoietic cells. In the present work, we investigated the expression of constructs carrying the human beta-globin gene that were delivered as beta-globin pseudovirions. Expression studies were performed by RNA analysis of primary human erythroid progenitors cultivated from peripheral blood of beta(0)-thalassemia patients who are unable to produce normal beta-globin RNA. This erythroid culture system recapitulates in vitro the process of growth, differentiation, and maturation of authentic erythroid precursors. The progenitors were induced to differentiate by the addition of erythropoietin (EPO). Five days later, the cells were infected with pseudovirions containing the normal beta-globin gene, and RNA was harvested on day 8. The results showed significant levels of normal beta-globin gene mRNA. A small DNA fragment derived from the 5'-region of the HSII element of the human beta-globin locus control region (LCR) enhanced expression of the linked beta-globin gene 20-30-fold. Normal beta-globin mRNA expression was in direct correlation to the multiplicity of infection. These studies suggest the potential feasibility of using the beta-globin delivery system for gene therapy of beta-thalassemia.

Topics: beta-Thalassemia; Cell Differentiation; Cells, Cultured; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Feasibility Studies; Gene Expression Regulation, Developmental; Genetic Therapy; Genetic Vectors; Globins; Humans; RNA, Messenger; Simian virus 40

Serum erythropoietin (EPO) levels were determined by enzyme linked immunosorbent assay (ELISA) in 61 thalassemic patients, consisting of 23 thalassemia major (TM) patients with multiple transfusion, 38 patients with thalassemia intermedia (TI). Thirty-two normal controls were also studied. The mean serum EPO levels were significantly higher in both groups with TM (165.96 +/- 17.31 mlU/ml) and TI (126.43 +/- 50.56 mlU/ml) compared with the control group (8.33 +/- 3.91 mlU/ml). The mean value of hematocrit (Hct) in the patients with TM (18.70 +/- 3.51%) was lower than those with TI (25.24 +/- 4.19 %) whereas the mean serum EPO level were significantly higher in TM than TI patients. An inverse correlation between the serum values of EPO and Hct was observed in both TI and TM patients, however this correlation was significant only in TI (r = -0.61, p<0.001). These data showed that serum EPO levels increased in all thalassemia patients despite repeated transfusion. Multiple transfusion may modulate the response of serum EPO to the degree of anemia, resulting in increased EPO levels and independent anemia in the TM patients.

Topics: Adolescent; Adult; beta-Thalassemia; Biomarkers; Case-Control Studies; Child; Child, Preschool; Erythropoietin; Female; Hematocrit; Hemoglobin E; Hemoglobinopathies; Humans; Linear Models; Male; Thailand

Serum erythropoietin (sEpo) concentration is primarily related to the rate of renal production and, under the stimulus of hypoxia, increases exponentially as hemoglobin (Hb) decreases. Additional factors, however, appear to influence sEpo, and in this work, we performed studies to evaluate the role of the red blood cell precursor mass. We first compared the relationship of sEpo with Hb in patients with low versus high erythroid activity. The first group included 27 patients with erythroid aplasia or hypoplasia having serum transferrin receptor (sTfR) levels < 3 mg/L (erythroid activity < 0.6 times normal), while the second one included 28 patients with beta-thalassemia intermedia having sTfR levels > 10 mg/L (erythroid activity > 2 times normal). There was no difference between the two groups with respect to Hb (8.3 +/- 1.6 v 8.0 +/- 1.3 g/dL, P > .05), but sEpo levels were notably higher in patients with low erythroid activity (1,601 +/- 1,542 v 235 +/- 143 mU/mL, P < . 001). In fact, multivariate analysis of variance (ANOVA) showed that, at any given Hb level, sEpo was higher in patients with low erythroid activity (P < .0001). Twenty patients undergoing allogeneic or autologous bone marrow transplantation (BMT) were then investigated. A marked increase in sEpo was seen in all cases at the time of marrow aplasia, disproportionately high when compared with the small decrease in Hb level. Sequential studies were also performed in five patients with iron deficiency anemia undergoing intravenous (IV) iron therapy. Within 24 to 72 hours after starting iron treatment, marked decreases in sEpo (up to one log magnitude) were found before any change in Hb level. Similar observations were made in patients with megaloblastic anemia and in a case of pure red blood cell aplasia. These findings point to an inverse relationship between red blood cell precursor mass and sEpo: at any given Hb level, the higher the number of red blood cell precursors, the lower the sEpo concentration. The most likely explanation for this is that sEpo levels are regulated not only by the rate of renal production, but also by the rate of utilization by erythroid cells.

Topics: Anemia; Anemia, Aplastic; Anemia, Hypochromic; Anemia, Megaloblastic; Antineoplastic Combined Chemotherapy Protocols; beta-Thalassemia; Bone Marrow Transplantation; Erythrocyte Indices; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Feedback; Folic Acid; Hodgkin Disease; Humans; Iron; Kidney; Receptors, Transferrin; Transplantation Conditioning; Vitamin B 12

Topics: Animals; beta-Thalassemia; Erythropoietin; Humans; Mice; Mice, Inbred C57BL; Mice, Mutant Strains; Recombinant Proteins; Reference Values

Erythropoietin levels were determined in 50 Greek females: 20 beta-thalassaemia (beta-thal) heterozygotes, 15 with a diagnosis of iron-deficiency anaemia and 15 normal controls. In beta-thal trait carriers, the erythropoietin levels were slightly higher than in normal controls (16.65 +/- 4.43 vs. 12.84 +/- 2.47 mU/ml); these levels were significantly lower than those in iron-deficient subjects with the same degree of anaemia (55.24 +/- 31.35 mU/ml). In both groups, the erythropoietin levels are statistically correlated with the severity of anaemia (r = -0.537 p < 0.05 for iron deficiency; r = -0.610 p < 0.01 for beta-thal heterozygotes). In beta-thal heterozygotes, a close inverse correlation with red cell number and erythropoietin levels was also noted. It is suggested that microcytosis accompanying beta-thal trait constitutes an additional factor intervening in the regulation of erythropoiesis.

Topics: Adult; Anemia, Iron-Deficiency; beta-Thalassemia; Erythropoietin; Female; Heterozygote; Humans

Thalassemia is one of the most common genetic disorders in Thailand. The thalassemic patients have many pathophysiologic changes secondary to chronic anemia. During these last few years there have been many trials to cure or improve the anemic condition in thalassemia by using various agents, including erythropoietin (EPO). Thus it is very important to understand the EPO response to different degree of anemia in the thalassemic patients. In this study we evaluated the EPO status in 53 beta-thalassemia/HbE patients, from 4-61 years old, by enzyme-linked immunosorbent assay. The results showed that the levels of EPO in beta-thalassemia/HbE patients were much higher than in normal control subjects: mean +/- SE = 527 +/- 183.20 and 3.45 +/- 0.47 mIU/ml respectively. The reverse correlation between the levels of EPO and hematocrit (r = -0.704) was also observed. There was also a tendency to have higher levels of EPO in beta-thal/HbE children than in adults, although this was statistically insignificant. The observed versus predicted levels of EPO (log O/P ratio) showed that most patients had good EPO response to the degree of anemia. However, inappropriate decrease of EPO response was observed in 8/40 adult patients. The EPO levels in these patients were not correlated with any physical or laboratory studies, including kidney function. We thus propose that if EPO is to be considered as one of the alternative treatment to the thalassemic patients, in the future, it may benefit only the patients with low EPO levels.

Topics: Adolescent; Adult; Age Factors; beta-Thalassemia; Child; Child, Preschool; Erythropoietin; Female; Ferritins; Hematocrit; Hemoglobin E; Humans; Male; Middle Aged; Thailand

To demonstrate that intravenous (IV) iron therapy rapidly can secure the physiologic correction of severe nonhemorrhagic anemia more safely than blood component therapy and recombinant erythropoietin treatment.. An 18-year-old woman with beta-thalassemia in her 33rd week of gestation had a hemoglobin level of 4.8 g/dL and an erythropoietin value of 191 mU/mL. After IV iron administration, erythropoietin rapidly decreased and hemoglobin increased to 8.1 g/dL in correlation with estriol elevation. A healthy infant with normal hemoglobin and ferritin levels was delivered at 42 weeks by cesarean.. Intravenous iron administration rapidly corrected severe nonhemorrhagic anemia in a pregnant patient and may produce an improvement in fetal indices. High erythropoietin levels predict a good response to iron and may obviate the need for blood transfusions and recombinant erythropoietin administration, at least until this therapy is tried.

Topics: Adult; Anemia, Iron-Deficiency; beta-Thalassemia; Erythropoietin; Female; Humans; Infusions, Intravenous; Iron; Pregnancy; Pregnancy Complications, Hematologic

beta thalassemia (beta thal) in DBA/2J mice is a consequence of the spontaneous and complete deletion of the beta major globin gene. Homozygous beta thal mice have clinical and biological features similar to those observed in human beta thal intermedia. Erythrocytes in human beta thal are characterized by a relative cell dehydration and reduced K+ content. The role of this erythrocyte dehydration in the reduced erythrocyte survival, which typifies the disease, has not previously been evaluated. We examined for 1 month the effects on the anemia and the erythrocyte characteristics of beta thal mice of daily treatment with either clotrimazole (CLT), an inhibitor of red blood cell (RBC) dehydration via the Gardos channel, or human recombinant erythropoietin (r-HuEPO), or hydroxyurea (HU). The use of either r-HuEPO or HU induced a significant increase in hemoglobin (Hb), hematocrit (Hct), erythrocyte K+ and a decrease in percent reticulocytes, suggesting improved erythrocyte survival. CLT alone decreased only mean corpuscular hemoglobin concentration (MCHC) and cell density and increased cell K+. Thus, though the Gardos channel plays a major role in cell dehydration of murine beta thal erythrocyte survival. Combination therapy with r-HuEPO plus HU produced no incremental benefit beyond those of single drug therapy. However, addition of CLT to r-HuEPO, to HU, or to combined r-HuEPO plus HU led to statistically significant increase in Hb, Hct, and erythrocyte K+ compared with any of the regimens without CLT. These results suggest that CLT not only inhibits erythrocyte dehydration, but also potentiates the erythropoietic and cellular survival responses to r-HuEPO and HU.

Topics: Animals; beta-Thalassemia; Body Water; Calcimycin; Calcium; Calcium Channel Blockers; Chlorides; Clotrimazole; Disease Models, Animal; Drug Synergism; Drug Therapy, Combination; Erythrocyte Aging; Erythrocyte Count; Erythrocyte Deformability; Erythrocytes, Abnormal; Erythropoietin; Female; Gene Deletion; Globins; Hematocrit; Humans; Hydroxyurea; Intracellular Fluid; Male; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mice, Mutant Strains; Potassium; Potassium Channels; Recombinant Proteins; Reticulocytes; Rubidium

Congenital dyserythropoietic anemia (CDA) type I is a rare macrocytic anemia of unknown etiology. In the present study, we redefined the clinical and laboratory picture of CDA type I, some of its pathogenic aspects, and the association with thalassemia-like features in 20 patients, all of whom belong to one Bedouin tribal group and are probably descended from a common ancestor. In each case ultrastructural studies of bone marrow (BM) erythroblasts showed the classic morphological findings of CDA type I. Serological tests for CDA type II were negative. The clinical picture was variable, but mostly benign. Some patients displayed elevated hemoglobin A2 levels or high ratio of alpha- to non-alpha- globin. However, neither family studies nor complete sequence analysis of the beta-globin was compatible with beta-thalassemia. Increased erythropoiesis was manifested by a high number of BM erythroid burst-forming units. Serum erythropoietin was also elevated. BM flow cytometry studies demonstrated arrest of erythroid precursors in the S phase of the cell cycle. The ultrastructural morphological features of the erythroid precursors, showing peripheral chromatin condensation, suggest apoptosis. Additional studies are indicated to define the molecular basis of this disease.

Topics: Adolescent; Adult; Anemia, Dyserythropoietic, Congenital; Apoptosis; Arabs; beta-Thalassemia; Bone Marrow; Child; Child, Preschool; Consanguinity; Erythroblasts; Erythropoiesis; Erythropoietin; Female; Globins; Hemoglobin A2; Humans; Infant; Israel; Male; Microscopy, Electron; Pedigree; S Phase

Topics: Adult; Anemia; beta-Thalassemia; Erythropoietin; Female; Hematocrit; Hemoglobins; Humans; Infant, Newborn; Pregnancy; Pregnancy Complications, Hematologic; Recombinant Proteins

This report describes the peri- and postoperative management of a patient with a critical blood loss (hemoglobin of 22 g/l) as a consequence of a surgical intervention, i.e. a radical resection of an advanced malignant gynecological tumor. The patient refused autologous and homologous blood transfusions for religious reasons (Jehovah's Witness). During surgery, hemodilution and cell salvage were used. Postoperatively she developed coagulopathy and hemorrhage with the lowest hemoglobin value of 22 g/l. The patient recovered under a therapy regimen of recombinant human erythropoietin and parenteral iron. The hemoglobin values returned to the lower normal range within 4 weeks. Consequences of hypoxia could not be seen.

Topics: Adult; beta-Thalassemia; Blood Loss, Surgical; Carcinoma, Squamous Cell; Christianity; Combined Modality Therapy; Erythropoietin; Female; Hemodilution; Hemoglobinometry; Hemorrhage; Humans; Iron; Postoperative Complications; Religion and Medicine; Uterine Cervical Neoplasms

In the management of beta-thalassaemia major, different transfusion schemes are employed with baseline haemoglobin levels ranging from 8 to over 12 g/dl. We studied the relationship between transfusion regimen and suppression of erythropoiesis in 52 patients with beta-thalassaemia major whose mean pretransfusion haemoglobin levels ranged from 8.6 to 10.9 g/dl. Multiple, regression analysis showed that serum transferrin receptor was the parameter more closely related to mean pretransfusion haemoglobin (r = -0.77, P < 0.001). As measured through serum transferrin receptor, erythroid activity was 1-2 times normal for pretransfusion haemoglobin levels between 10 and 11 g/dl. 1-4 times normal for levels from 9 to 10 g/dl, and 2-6 times normal for levels from 8.6 to 9 g/dl. Mean pretransfusion haemoglobin was also inversely related to serum erythropoietin (r = -0.72, P < 0.001), whereas it showed no or a weak relationship with Hb F, reticulocyte count, or circulating nucleated red cell count. This study suggests that serum transferrin receptor is a reliable indicator of suppression of erythropoiesis in beta-thalassaemia major. On the basis of our findings, pretransfusion haemoglobin values of < or = 9 g/dl should be adopted with caution, because these levels can be associated with an insufficient inhibition of erythroid marrow expansion. However, a transfusion programme, with a baseline haemoglobin of 9-10 g/dl, may provide enough suppression of erythropoiesis and allow a reduction in blood consumption as compared with the classic hyper- or supertransfusion schemes. Since fixed haemoglobin levels may not be the best target for transfusion treatment in all thalassaemic patients, assay of serum transferrin receptor may be helpful for individualizing the transfusion regimens.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Child, Preschool; Erythrocyte Transfusion; Erythropoiesis; Erythropoietin; Hemoglobins; Humans; Receptors, Transferrin; Regression Analysis

Understanding the mechanism of developmental regulation of hemoglobin switching has scientific as well as clinical relevance because of the influence of fetal hemoglobin (HbF) production in adulthood on the clinical manifestation of thalassemia and sickle cell anemia. We have previously found that the normal developmental patterns of globin gene expression are recapitulated in an experimental system of primary cultures that support differentiation of erythroid progenitors. We further found that high activities of the transcriptional activators, GATA-1 and SP1, are associated with normal adult erythroid differentiation.. In the present work, we have studied, the activities of GATA-1 and SP1 during differentiation of cultured erythroid progenitors derived from cord blood and from fetal livers, as well as from beta zero-thalassemia patients.. The results showed high GATA-1 binding activity and very low SP1 activity in the fetal liver cultures. This pattern was in contrast to cultures derived from normal adult peripheral blood, in which both GATA-1 and SP1 activities were high. Cord blood cultures showed an additive combination of "adult" and "fetal" patterns. The progenitors derived from a beta zero-thalassemia patient with high HbF production showed "fetal" pattern. On the other hand, in cultures of 2 beta zero-thalassemia patients without high HbF, "adult" pattern was observed.. In the present work, we show that human fetal and adult erythroid progenitors are distinct in their transcription factors, and that the commitment to fetal or adult program occurs at a very early differentiation stage. Our studies also demonstrate that under anemic stress, recruitment of fetal progenitors may occur in adulthood.

Topics: Adult; Base Sequence; beta-Thalassemia; Cell Differentiation; Cells, Cultured; DNA-Binding Proteins; Erythrocytes; Erythroid Precursor Cells; Erythroid-Specific DNA-Binding Factors; Erythropoietin; Fetal Blood; Fetal Hemoglobin; GATA1 Transcription Factor; Genes, Switch; Globins; Humans; Liver; Molecular Sequence Data; RNA, Messenger; Sp1 Transcription Factor; Transcription Factors; Zinc Fingers

Topics: Adult; Anemia; beta-Thalassemia; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Male; Renal Dialysis

Clinical data suggest that in beta-thalassemia-intermedia patients, higher levels of circulating fetal hemoglobin (HbF) are associated with greater disease severity at comparable degrees of anemia. We assessed the influence of the amount of circulating HbF on serum erythropoietin (s-Epo) levels and on serum transferrin receptor, a measure of erythropoiesis, in 30 beta-thalassemia-intermedia patients. Twenty-four showed more than 40% HbF (21 of whom with beta (0)-thalassemia) and 6 presented lower HbF levels (beta(+)-thalassemia). The two groups of patients did not differ in age (15.3 v 19 years, respectively) or degree of anemia (Hb = 8.8 g/dL in both groups). Log (s-Epo) was correlated inversely with Hb (r = -0.47; P < .01), and directly with HbF (r = .55; P < .001). Multivariate regression analysis showed that Hb and HbF were independently correlated with s-Epo levels. High-HbF patients had greater s-Epo values at the same Hb level than low-HbF patients. Considering that iron-deficiency anemia control patients represented the predicted physiologic response of s-Epo to anemia, the observed/predicted s-Epo ratio in low-HbF thalassemic patients was no different from controls, but was increased in the high-HbF group. High-HbF patients also showed an expansion of erythropoiesis as much as four to nine times the normal value at the same Hb level as low-HbF patients. We conclude that HbF exerts an independent regulatory effect on erythropoietin production and erythropoiesis that is detectable only when HbF levels exceed 40%.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Child, Preschool; Erythropoiesis; Erythropoietin; Female; Fetal Hemoglobin; Humans; Infant; Male; Receptors, Transferrin

Six sickle cell/beta-thalassemia patients (3 males and 3 females) were treated with 500 U/kg body weight human recombinant erythropoietin (h-rEPO) along with 300 mg/day iron sulfate in two phases, for a period of 90 days. Fetal hemoglobin (HbF) was assayed every 2 weeks and the gamma-chain ratio at three successive intervals during the treatment. All patients showed a moderate to high increase in their HbF values (1.25- to 12-fold). The gamma-chain ratio, as determined by high performance liquid chromatography was found to be unaffected by the HbF increase. Two patients with the newborn gamma-chain ratio, responded faster to the h-rEPO treatment and achieved higher HbF values than the rest of the group. The h-rEPO treatment was very well tolerated and had a positive effect on the general clinical condition of all the patients.

Topics: Adolescent; Adult; Anemia, Sickle Cell; beta-Thalassemia; Child; Drug Evaluation; Drug Therapy, Combination; Erythrocyte Indices; Erythropoietin; Female; Ferrous Compounds; Fetal Hemoglobin; Globins; Humans; Male; Middle Aged; Recombinant Proteins; Stimulation, Chemical; Time Factors

Topics: beta-Thalassemia; Erythropoietin; Female; Hemoglobins; Humans; Kidney Failure, Chronic

Repeated injections of large doses of erythropoietin (Epo) have been shown to be of benefit in the treatment of murine and human beta-thalassemia. To determine whether Epo gene therapy could replace this treatment for long-term periods, lethally irradiated beta-thalassemic (Hbbd3th haplotype) and normal DBA/2J (Hbbd haplotype) mice were grafted with syngeneic bone marrow cells infected with a retroviral vector carrying the Epo cDNA. In normal mice, dysregulated Epo production induced elevated serum Epo levels (176 +/- 68 mU/mL), high hematocrit levels (73% +/- 8%), and elevated beta-minor globin chain synthesis. In contrast, in thalassemic mice, moderate increases in the hematocrit levels (from 33% +/- 1% to 43% +/- 9%), associated with limited increases in the initially elevated Epo levels (from 83 +/- 22 to 190 +/- 230 mU/mL), were recorded 2 months after transplantation. In mice in which the hematocrit increased most, from 33% +/- 1% before transplantation to 49% +/- 10%, the retroviral Epo gene expression induced a striking improvement of the beta-thalassemic syndrome. These mice exhibited normal or near-normal beta/alpha-globin chain synthesis ratios, induced by the activation of the beta-minor chain. This led to the elimination of the high amounts of unpaired alpha chains in erythrocytes and finally reduced the reticulocyte count despite the permanent Epo stimulation. These results show that efficient Epo gene expression corrects the erythrocyte phenotype of the mouse beta-thalassemic syndrome. However, the incidence of lethal polycythemia or of transient improvements indicates that the present strategy is only the first step toward such indirect gene therapy.

Topics: Animals; beta-Thalassemia; Bone Marrow; DNA, Viral; Erythropoietin; Female; Gene Transfer Techniques; Genetic Therapy; Genetic Vectors; Hematocrit; Hematopoiesis; Hematopoietic Stem Cells; Mice; Mice, Inbred DBA; Phenotype; Proviruses; Retroviridae; Spleen

Hydroxyurea increases the production of fetal hemoglobin in patients with sickle cell anemia, inhibiting the polymerization of hemoglobin S and potentially improving vaso-occlusive manifestations and hemolysis. Recombinant erythropoietin increases the number of reticulocytes containing fetal hemoglobin in laboratory animals and in humans. We studied whether hydroxyurea and erythropoietin might have a potentiating effect on the production of fetal hemoglobin in patients with sickle cell disease.. We treated four patients who were receiving hydroxyurea for sickle cell disease (three who were homozygous for sickle cell anemia and one with sickle beta zero-thalassemia) with escalating doses of intravenous erythropoietin for seven weeks, along with oral iron sulfate. Doses of hydroxyurea on four consecutive days were alternated with doses of erythropoietin on three consecutive days.. There was a 28 percent increase in the number of reticulocytes containing fetal hemoglobin and a 48 percent increase in the percentage of fetal hemoglobin, as compared with the maximal values obtained with hydroxyurea alone. The percentage of erythrocytes containing fetal hemoglobin (F cells) increased from 64 to 78 percent. As compared with hydroxyurea alone, treatment with hydroxyurea and erythropoietin decreased the mean (+/- SD) serum indirect bilirubin level from 0.8 +/- 0.2 to 0.5 +/- 0.1 mg per deciliter (13.3 +/- 2.9 to 8.9 +/- 2.2 mumol per liter) (P = 0.02), suggesting a further decrease in hemolysis. Red-cell filterability improved.. Intravenous recombinant erythropoietin with iron supplementation alternating with hydroxyurea elevates fetal-hemoglobin and F-cell levels more than hydroxyurea alone. Such increases decrease intracellular polymerization of hemoglobin S and improve the overall rheologic characteristics of erythrocytes. A reduced dosage of hydroxyurea alternating with erythropoietin may prove less myelotoxic than hydroxyurea given daily or in pulsed-dose regimens. It may also increase levels of fetal hemoglobin in patients with sickle cell disease who have not been helped by hydroxyurea alone.

Topics: Adult; Anemia, Sickle Cell; beta-Thalassemia; Drug Synergism; Drug Therapy, Combination; Erythrocyte Count; Erythrocyte Indices; Erythropoietin; Ferrous Compounds; Fetal Hemoglobin; Humans; Hydroxyurea; Male; Recombinant Proteins; Reticulocytes

Topics: Adolescent; Adult; beta-Thalassemia; Blood Transfusion; Bone Marrow; Child; Child, Preschool; Erythropoiesis; Erythropoietin; Female; Humans; Infant; Male; Receptors, Transferrin; Solubility

Fifteen thalassemia intermedia patients were considered, whose clinical and radiological findings were examined and compared. Eight patients underwent regular transfusion therapy. All patients underwent total body CT: the volume of ectopic erythropoiesis foci was calculated by a digital calculation algorithm (ROI volume). This work was aimed at correlating the quantitative measures of ectopic erythropoiesis assessed by CT with serum level of erythropoietin (EPO) and of trasferrin-free receptors (TfR) in both transfused and non-transfused patients, also considering the volume changes of ectopic erythropoiesis and bone changes over 36 months' follow-up. A direct correlation was demonstrated between serum transferrin and ectopic erythropoietic masses in transfusion-dependent patients: in fact, increased values of serum transferrin correspond to the enlargement of these masses and to bone lesion worsening.

Topics: Adolescent; Adult; beta-Thalassemia; Child; Erythropoietin; Female; Hematopoiesis, Extramedullary; Humans; Male; Receptors, Transferrin; Tomography, X-Ray Computed

An immunoenzymatic assay (Epo-Eia) has been used in order to evaluate the seric Epo level in beta-thalassemic heterozygous subjects. The present results lead one to conclude that serum Epo levels in thalassemic subjects are higher than in normal subjects and that the differences between thalassemic and normal females are highly significant statistically (p < 0.01). The Epo levels in thalassemic females are also higher than those in thalassemic males (0.01 < p < 0.05). Differences in Epo levels may be observed between thalassemic and normal males although they are not highly significant statistically. No correlations seem to exist between Epo and Hb values.

Topics: Adult; beta-Thalassemia; Erythropoietin; Female; Heterozygote; Humans; Immunoenzyme Techniques; Male; Middle Aged; Sex Characteristics

Thalassemia is a common genetic disorder among the South Chinese. To see if thalassemia would adversely affect the erythrocyte response to recombinant human erythropoietin (rHuEPO, Epogen) in dialysis patients, the response to rHuEPO in 4 dialysis patients with thalassemic traits (thal-t) was compared with that of 4 control patients who were matched for age, sex, mode of dialysis and baseline hemoglobin levels over a 6-month period. Patients with thal-t showed a reduced erythrocyte response to rHuEPO compared to control dialysis patients as reflected by a reduced reticulocyte index, a slower rise in hemoglobin or hematocrit levels, requirement of a higher cumulated dose of rHuEPO to achieve a target hemoglobin of 10 g/dl and a higher maintenance dose of rHuEPO. A dialysis patient with hemoglobin H disease (HbHD) was also studied. He failed to respond to rHuEPO despite that the dose was increased to 250 U/kg/week. In contrast, his matched control dialysis patient, despite a lower baseline hemoglobin level (6.1 versus 8.8 g/dl), was able to reach a target hemoglobin level of 10 g/dl by 6 weeks and could be maintained at this level with 50 U/kg/week. The patient with HbHD had splenomegaly and a higher baseline serum erythropoietin level, reticulocyte count, serum bilirubin, serum ferritin and serum iron saturation than control patients and patients with thal-t. It was concluded that thal-t reduces the erythrocyte response to rHuEPO in dialysis patients and that in the presence of active hemolysis and enhanced endogenous erythropoietin secretion, dialysis patients with HbHD are resistant to treatment with rHuEPO.

Topics: Adult; alpha-Thalassemia; Anemia; beta-Thalassemia; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Male; Recombinant Proteins; Renal Dialysis

Topics: beta-Thalassemia; Child; Cystinosis; Drug Resistance; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Recombinant Proteins

The cell cycle status of human erythroid precursors generated in a two-step liquid culture was studied by a double-labeling flow cytometric technique. Following a first phase, where peripheral blood mononuclear cells were cultured in the presence of a combination of growth factors, not including erythropoietin (Epo), the cells were washed and recultured in a second phase in the presence of Epo. This procedure resulted in a stimulation of the proliferation and maturation of erythroid precursors. In the presence of optimal concentrations of Epo (2 U/mL), a high percentage (> 40%) of cells were found in the S phase of the cell cycle until day 10. Then, as a result of maturation, the proportion of cells in S gradually decreased, reaching less than 2.0% by day 21. At this time, the culture consisted of > 95% hemoglobin-containing, nonproliferating, orthochromatic normoblasts. Cell cycle analysis of this normoblast population demonstrated a bimodal distribution; while the majority of the cells had a diploid (2C) DNA content, i.e., cells in G1 (or G0) phase, a sizable fraction was tetraploid (4C) corresponding to cells in G2. In contrast, in cultures stimulated with physiological concentrations of Epo (around 50 mU/mL), all the terminally differentiated cells were arrested at the G1 phase. These results suggest that Epo is an essential growth-promoting factor for erythroid precursors, but supraphysiological concentrations, such as present in vivo in severe anemia (e.g., aplastic anemia) or after Epo administration, may be associated with development of normoblasts with abnormal DNA content.

Topics: beta-Thalassemia; Cell Differentiation; Cells, Cultured; DNA; Erythroblasts; Erythroid Precursor Cells; Erythropoietin; Fluorescent Antibody Technique; G2 Phase; Humans; Ploidies

Topics: Adult; Anemia; beta-Thalassemia; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Male

Colony assays in methylcellulose (semisolid medium) of erythroid precursors and granulocyte-macrophage precursors from the peripheral blood of 34 patients with beta-thalassemia major and 31 age-matched normal controls were studied. In patients homozygous for beta-thalassemia, a significant increase of circulating erythroid progenitor cells to 3-5 times of normal controls was observed. Furthermore, the number of circulating colony forming units-granulocyte-macrophage (CFU-GM) and colony forming units-mixed (CFU-Mixed) also increased significantly. In these subjects, there was a linear relationship between the number of burst forming units-erythroid (BFU-E) and CFU-GM. The serum level of erythropoietin (EPO) was also significantly higher than that of normal controls (p < 0.05). The increased hematopoiesis, indicated by an increased number of circulating hematopoietic progenitor cells and an elevated serum level of EPO, suggests that the physiologic regulation of erythropoiesis still operated in patients with beta-thalassemia major.

Topics: Adolescent; Adult; beta-Thalassemia; Blood Cell Count; Child; Child, Preschool; Erythroid Precursor Cells; Erythropoietin; Female; Hematopoietic Stem Cells; Humans; Male

Topics: beta-Thalassemia; Blood; Epoetin Alfa; Erythropoietin; Mice; Thalassemia; Urine

Topics: Anemia; beta-Thalassemia; Epoetin Alfa; Erythroblasts; Erythropoietin; Humans; Protein Deficiency