losartan-potassium and Thalassemia

Hemoglobins (Hbs) are heme-containing proteins binding oxygen, carbon monoxide, and nitric oxide. While erythrocytes are the most well-known location of Hbs, Hbs also exist in neurons, glia and oligodendroglia and they are primarily localized in the inner mitochondrial membrane of neurons with likely roles in cellular respiration and buffering protons. Recently, studies have suggested links between hypoxia and neurodegenerative disorders such as Alzheimer Disease (AD) and furthermore suggested involvement of Hbs in the pathogenesis of AD. While cellular immunohistochemical studies on AD brains have observed reduced levels of Hb in the cytoplasm of pre-tangle and tangle-bearing neurons, other studies on homogenates of AD brain samples observed increased Hb levels. This potential discrepancy may result from differential presence and function of intracellular versus extracellular Hbs. Intracellular Hbs may protect neurons against hypoxia and hyperoxia. On the other hand, extracellular free Hb and its degradation products may trigger inflammatory immune and oxidative reactions against neural macromolecules and/or damage the blood-brain barrier. Therefore, biological processes leading to reduction of Hb transcription (including clinically silent Hb mutations) may influence intra-erythrocytic and neural Hbs, and reduce the transport of oxygen, carbon monoxide and nitric oxide which may be involved in the (patho)physiology of neurodegenerative disorders such as AD. Agents such as erythropoietin, which stimulate both erythropoiesis, reduce eryptosis and induce intracellular neural Hbs may exert multiple beneficial effects on the onset and course of AD. Thus, evidence accumulates for a role of Hbs in the central nervous system while Hbs deserve more attention as possible candidate molecules involved in AD.

Topics: Alzheimer Disease; Animals; Blood-Brain Barrier; Brain; Cell Hypoxia; Disease Models, Animal; Erythropoietin; Hemoglobins; Humans; Mutation; Neurons; Thalassemia

Erythropoiesis is finely regulated by two major cytokines, stem cell factor (SCF) and erythropoietin (Epo). Decrease levels of Epo result in caspase activation and erythroid progenitors apoptosis. However, normal erythroid cell maturation requests caspase activation and cleavage of various caspase substrates, except the erythroid transcription factor GATA-1, that is protected by interaction with the chaperone HSP70 in the nucleus. Therefore, molecular abnormalities associated with decrease of HSP70 expression in the nucleus may result in ineffective erythropoiesis characterized by apoptosis and impaired maturation of erythroid precursors. These findings open new potential targeted therapies for erythroid disorders.

Topics: Animals; Apoptosis; Caspases; Cell Differentiation; Cell Nucleus; Enzyme Activation; Erythroblasts; Erythrocyte Aging; Erythropoiesis; Erythropoietin; GATA1 Transcription Factor; HSP70 Heat-Shock Proteins; Humans; Myelodysplastic Syndromes; Neoplasm Proteins; Neoplasms; Protein Processing, Post-Translational; Proteolysis; Stem Cell Factor; Thalassemia

New drugs, recently available for treatment of different forms of anaemia, have somehow changed the therapeutic scenario in paediatric haematology. The aim of this review is to focus on the newest molecules discussing indications, clinical usefulness and related problems. Erythropoietin, the specific growth factor of red cell precursors, is now an established option for anaemia of chronic renal failure, prematurity, bone marrow transplantation and chemotherapy. Anti-CD20 monoclonal antibody, a novel cytotoxic molecule for mature B lymphocytes, has proven to be effective in the treatment of refractory autoimmune cytopenias. Haemoglobin analogues are currently under investigation, in order to obtain a synthetic oxygen-carrier that can substitute blood transfusions. Finally drugs that are able to increase the production of haemoglobin F have been used in thalassemias and haemoglobinopathies. For patients with sickle cell disease, hydroxyurea is no longer an experimental tool; it has given rise to several trials, where it has proven to be effective in terms of both clinical and haematological improvement.

Topics: Adult; Age Factors; Anemia; Anemia, Hemolytic, Autoimmune; Anemia, Sickle Cell; Antibodies, Monoclonal; Antibodies, Monoclonal, Murine-Derived; Antineoplastic Agents; Antisickling Agents; Blood Substitutes; Bone Marrow Transplantation; Butyrates; Child; Clinical Trials as Topic; Erythropoietin; Fetal Hemoglobin; Forecasting; Hemoglobinopathies; Hemoglobins; Humans; Hydroxyurea; Infant, Newborn; Infant, Premature, Diseases; Kidney Failure, Chronic; Organ Transplantation; Rituximab; Thalassemia; Tissue Donors

Iron deficiency is the most frequently encountered cause of suboptimal response to recombinant human erythropoietin (rHuEPO). Carefully assessing iron status is of paramount importance in chronic renal failure patients prior to or during rHuEPO therapy. Because there is great need for iron in the EPO-stimulated erythroid progenitors, it is essential that serum ferritin and transferrin saturation levels should be maintained over 300 microg/liter and 30%, respectively. Investigators have shown that oral iron is unlikely to keep pace with the iron demand for an optimal rHuEPO response in uremics. Therefore, patients with iron deficiency will always require intravenous iron therapy. The early and prompt iron supplementation can lead to reductions in rHuEPO dose and hence cost. After the iron deficiency has been corrected or excluded, we must remember all of the possible causes of hyporesponsiveness in every rHuEPO-treated patient. As dose requirements vary, it is not clear which dose of rHuEPO causes this hyporesponsiveness. However, if the patient with iron repletion does not respond well after the induction period, the major causes blunting the response to rHuEPO should be investigated. Most factors are reversible and remediable, except resistant anemia associated with hemoglobinopathy or bone marrow fibrosis, which requires a further increase in the rHuEPO dose. By means of early detection and correction of the possible causes, the goal of increasing therapeutic efficacy can be achieved. Iron overload may lead to an enhanced risk for infection, cardiovascular complication, and cancer. Over-treatment with iron should be avoided in dialysis patients, despite the fact that the safe upper limit of serum ferritin to avoid iron overload is not clearly defined. On the other hand, functional iron deficiency may develop even when serum ferritin levels are increased. Controversy remains as to whether intravenous iron therapy can overcome this form of hyporesponsiveness in iron-overloaded patients. Moreover, a treatment option of iron supplementation is not warranted in these patients, as the potential hazards of iron overload will be worsened. We demonstrated that the mean hematocrit significantly increased from 25.1+/-0.9% to 31+/-1.2% after eight weeks of intravenous ascorbate therapy (300 mg three times a week) in 12 hemodialysis patients with serum ferritin levels of more than 500 microg/liter. The enhanced erythropoiesis paralleled with a rise in transferrin sa

Topics: Aluminum; Anemia; Erythropoietin; Hemoglobinopathies; Hemolysis; Humans; Infections; Inflammation; Iron; Iron Deficiencies; Iron Overload; Kidney Failure, Chronic; Recombinant Proteins; Thalassemia

Re-activation of the fetal globin genes is the most realistic approach to correct the deranged pathophysiology of the haemoglobinopathies because the presence of gamma-chains can neutralize the toxic effects of the unbound alpha-globin chains in the beta-thalassaemias and inhibit the polymerization of Hb S in the sickle cell syndromes. Re-induction of fetal haemoglobin synthesis can be brought about either by direct activation of the respective promoter genes and possibly other positively acting elements, or by recruitment into proliferation and differentiation of a population of erythroid precursors which retain the gamma-chain synthesis programme but remain dormant in the bone marrow of the adult unless called up in cases of acute erythroid expansion. Examples of the first group include the butyric acid and derivatives and 5' azacytidine. The second group comprises erythropoietin and a series of cytostatics, with hydroxyurea as the main representative. The activity of most of the above agents has already been studied in cell cultures and animals and confirmed in several patients, both at the haematological and biochemical level as well as through their frank clinical improvement. However, application of these drugs at large is not yet justified because a series of questions concerning their long-term efficacy, the correct dosage and timing, their tolerance and toxicity, and the potential long-term dangers, including mutagenicity are still unresolved.

Topics: Anemia, Sickle Cell; Antisickling Agents; Butyrates; Butyric Acid; Drug Therapy, Combination; Erythropoietin; Hemoglobinopathies; Humans; Hydroxyurea; Thalassemia

The past decade has witnessed profound increases in knowledge of the structure, function, and developmental regulation of the human globin genes. This information has deepened our understanding of the molecular and cellular mechanisms underlying inherited disorders affecting hemoglobin, and it has provided a new perspective for attaining meaningful increases in fetal hemoglobin synthesis in the management of sickle cell anemia and beta thalassemia. Efforts to provide therapy for these disorders are based on three factors: an understanding of their pathophysiology; the potential for fetal hemoglobin to alter its manifestation; and the concept that developmental changes in globin gene expression might be reversed by manipulating cellular and molecular regulatory mechanisms. In this review we discuss these topics and examine critically recent efforts to apply various pharmacological agents to in vitro, animal, and human models with the goal of increasing HbF synthesis. Several agents have demonstrated activity in patients with hemoglobin disorders. One such agent, hydroxyurea, has been shown to be potentially efficacious in phase II clinical trials in patients with sickle cell anemia and awaits testing in a placebo-controlled phase III study.

Topics: Anemia, Sickle Cell; Animals; Azacitidine; Erythropoietin; Fetal Hemoglobin; Gene Expression Regulation; Hemoglobinopathies; Humans; Hydroxyurea; Thalassemia

Topics: Anemia, Sickle Cell; Erythropoietin; Fetal Hemoglobin; Humans; Hydroxyurea; Thalassemia

There have been numerous new contributions to the knowledge of foetal haemoglobin over the last few years. It is, therefore, timely to review them together. They throw light on the arrangement on the chromosome of non-alpha chain genes, and on the condition generally known as Hereditary Persistence of Foetal Haemoglobin (HPFH) and have contributed to other aspects of human ontogeny and physiology.

Topics: Adult; Amino Acid Sequence; Anemia, Aplastic; Anemia, Sickle Cell; Child; Erythrocytes; Erythropoietin; Female; Fetal Blood; Fetal Hemoglobin; Genes; Genetic Linkage; Genetic Variation; Genetics, Population; Hemoglobinopathies; Humans; Infant; Infant, Newborn; Leukemia; Oxygen; Pregnancy; Protein Denaturation; Suppression, Genetic; Thalassemia

Topics: Anemia, Hemolytic; Anemia, Neonatal; Bilirubin; Birth Weight; Blood Group Antigens; Diet; Erythrocytes; Erythrocytes, Abnormal; Erythropoiesis; Erythropoietin; Folic Acid Deficiency; Gestational Age; Hemoglobinometry; Hemorrhage; Humans; Immunization; Infant; Infant, Newborn; Isoantigens; Kinetics; Rh-Hr Blood-Group System; Thalassemia; Vitamin E Deficiency

We studied the therapeutic benefit of recombinant human erythropoietin (rHuEPO) in dialysis patients with thalassemia minor. Four of the 40 randomly selected patients (22 on hemodialysis [HD], 18 on continuous ambulatory peritoneal dialysis [CAPD]) were identified to be thalassemic prior to a trial of rHuEPO (alpha-thalassemia trait in three and beta-thalassemia minor in one). All patients were initially treated with rHuEPO at a dose of 100 +/- 25 U/kg/wk subcutaneously depending on the hemoglobin level. EPO injections were continued for 16 weeks with further adjustments of the doses according to the hemoglobin level increases attained. All nonthalassemic patients reached a target hemoglobin of 10 g/dL at week 16, with an average maintenance dose of 120 +/- 7.8 U/kg/wk, but the hemoglobin was increased by only 1 g/dL in the thalassemic patients receiving 175 U/kg/wk. Following cessation of rHuEPO therapy for 6 weeks, all four thalassemic patients and 18 randomly selected nonthalassemic patients received a fixed dose of rHuEPO 4,000 U/wk (equivalent to 80 U/kg/wk) for 16 weeks. The hemoglobin remained unchanged in the thalassemic patients, but a progressive and significant increase of hemoglobin was observed in the nonthalassemic patients. At the last phase of the study, the thalassemic patients received rHuEPO at a dose of 100 or 125 U/kg/wk with 4-weekly increments of 25 U/kg/wk until their hemoglobin reached 10 g/dL. One patient developed uncontrolled hypertension with a dose of 150 U/kg/wk, and one reached the target hemoglobin at a dose of 200 U/kg/wk.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Drug Evaluation; Erythropoietin; Female; Humans; Kidney Failure, Chronic; Male; Peritoneal Dialysis, Continuous Ambulatory; Recombinant Proteins; Renal Dialysis; Thalassemia

Topics: Anemia, Sickle Cell; Erythropoietin; Fetal Hemoglobin; Humans; Hydroxyurea; Thalassemia

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

Extramedullary hematopoiesis (EMH) is common in non-transfusion-dependent thalassemia (NTDT) patients. Clinical presentations of EMH vary as MRI screening is not feasible. Hence, serum biomarkers are used to predict the risk of EMH.. 52 NTDT patients, including 26 EMH (+) and 26 EMH (-), together with 26 healthy controls, were enrolled in this case-control study from 2013 to 2016. EMH was confirmed by computed tomography or MRI. Demographic, transfusion, genetic, laboratory, and liver iron concentration (LIC) data, as well as clinical complications, were analyzed.. EMH (+) patients had significantly higher serum ferritin (SF), growth differentiation factor 15 (GDF15), and erythropoietin (EPO) levels compared with EMH (-) patients and controls. The levels of erythroferrone (ERFE), hepcidin, and sTfR did not differ significantly between EMH (+) and EMH (-) patients (p>0.05). In NTDT patients, serum ERFE was not related to SF, LIC, hepcidin, sTfR, EPO, GDF15, and Hb levels. GDF15, EPO concentrations, and GDF15 to sTfR and GDF15 to EPO ratios are able to determine the presence of EMH with considerable sensitivity and specificity.. GDF15, EPO, and GDF15 to EPO and GDF15 to sTfR ratios are potential biomarkers for the early prediction of NTDT in patients who are at risk for EMH.

Topics: Adult; Antigens, CD; Biomarkers; Case-Control Studies; Erythropoiesis; Erythropoietin; Female; Ferritins; Growth Differentiation Factor 15; Hematopoiesis, Extramedullary; Hepcidins; Homeostasis; Humans; Iron; Magnetic Resonance Imaging; Male; Middle Aged; Peptide Hormones; Receptors, Transferrin; Risk Factors; Thalassemia; Tomography, X-Ray Computed

Topics: Aged; Aged, 80 and over; alpha-Globins; Asymptomatic Diseases; beta-Globins; Blood Transfusion; Bone Marrow; Delayed Diagnosis; Diagnosis, Differential; Erythropoiesis; Erythropoietin; Female; Follow-Up Studies; Hemoglobins; Heterozygote; Humans; Incidental Findings; Male; Myelodysplastic Syndromes; Phenotype; Thalassemia

To study the status of iron metabolism and erythropoietic proliferation in children with various genotypes of thalassemia.. Serum concentrations of ferritin (SF), transferrin receptor (sTfR) and erythropoietin (EPO) were measured in 158 children with thalassemia. The differences in the concentrations of the three indices among children with different genotypes of thalassemia were compared. The correlations of the hemoglobin level with sereum SF, sTfR and EPO levels were assessed.. Among the 158 children with thalassemia, 52(32.9%) were diagnosed with alpha-thalassemia minor, 27(17.1%) with HbH disease, 59(37.4%) with beta-thalassemia minor, 13(8.2%) with beta-thalassemia major, and 7(4.4%) with combining alpha beta thalassemia. The SF levels in children with HbH disease or beta-thalassemia major were significantly higher than those in the other thalassemia groups (P<0.01). The sTfR levels in children with beta-thalassemia major were the highest when compared with those in the other thalassemia groups (P<0.05). The EPO levels in children with beta-thalassemia major were also the highest when compared with those in the other thalassemia groups (P<0.01). There was a negative correlation between hemoglobin and EPO levels in children with HbH disease (r=-0.656, P<0.01) and beta-thalassemia major (r=-0.641; P<0.05).. The status of iron metabolism and erythropoietic proliferation is different in children with different genotypes of thalassemia. A combined measurement of SF, sTfR and EPO may reflect the status of erythropoietic proliferation.

Topics: Adolescent; Child; Child, Preschool; Erythropoiesis; Erythropoietin; Female; Ferritins; Genotype; Humans; Infant; Iron; Male; Receptors, Transferrin; Thalassemia

Topics: Carnitine; Drug Therapy, Combination; Erythrocytes; Erythropoietin; Humans; Renal Dialysis; Thalassemia; Treatment Outcome; Uremia; Vitamin B Complex

Current regular blood transfusion programs and chelation treatment have considerably improved survival of patients with thalassemia, which resulted in a larger proportion of adult patients. However, disease- and treatment-related complications in these patients progress over time, causing severe morbidity and shortened life expectancy. Stem cell transplantation still remains the only cure currently available for patients with thalassemia. This study updates transplant outcomes in 107 adult patients with median age of 22 years (range, 17-35 years) who received bone marrow transplantation (BMT) from human leukocyte antigen (HLA)-identical related donors between 1988 and 1996 (group A) and describes the results of BMT in 15 adult patients with median age of 21 years (range, 17-31 years) who were treated with a new treatment protocol (Protocol 26) between 1997 and 2003 (group B). The probability of survival, event-free survival, nonrejection mortality, and rejection for group A patients were 66%, 62%, 37%, and 4%, respectively, with a median follow-up of 12 years (range, 8.3-16.2 years). Group B patients treated with the new protocol had some improvement in thalassemia-free survival (67%) and lower transplant-related mortality (27%) than that of previous protocols. However, transplant-related mortality in these high-risk patients remains elevated. Current myeloablative BMT in adult patients is characterized by higher transplant-related toxicity due to an advanced phase of disease. Although this new approach to transplant adult patients with a reduced-dose intensity-conditioning regimen has improved thalassemia-free survival, transplant-related mortality in these high-risk patients remains elevated.

Topics: Adolescent; Adult; Azathioprine; Bone Marrow Transplantation; Busulfan; Chelation Therapy; Clinical Protocols; Combined Modality Therapy; Comorbidity; Deferoxamine; Disease-Free Survival; Erythrocyte Transfusion; Erythropoietin; Female; Follow-Up Studies; Graft vs Host Disease; Granulocyte Colony-Stimulating Factor; Hematopoietic Cell Growth Factors; Hemosiderosis; Humans; Hydroxyurea; Immunosuppressive Agents; Iron Chelating Agents; Life Tables; Liver Cirrhosis; Male; Phlebotomy; Postoperative Complications; Survival Analysis; Thalassemia; Transfusion Reaction; Transplantation Conditioning; Transplantation, Homologous; Treatment Outcome; Vidarabine

We evaluated sera from 58 thalassemic patients for the presence of antierythropoietin antibodies to investigate whether these autoantibodies may relate with modest response to treatment with recombinant human erythropoietin (rhEpo). Thirty-seven patients had beta-thalassemia major, 9 patients had beta-thalassemia intermedia, and 12 patients had sickle/beta(+)-thalassemia. Of 58 patients, 24 were on rhEpo treatment in order to increase the intervals between transfusions or the hemoglobin (Hb) values. The study population was divided into three groups according to rhEpo treatment. Group A consisted of 15 patients who were on rhEpo treatment (400-600 IU/kg three times per week, subcutaneously) showing an increase of Hb values or reduction of transfusion requirements. Group B included 9 patients who did not respond to rhEpo and group C consisted of 34 patients who did not receive rhEpo. Laboratory studies included a complete blood count, measurement of serum erythropoietin, immunological evaluation, and determination of antierythropoietin antibodies using enzyme-linked immunosorbent assay (ELISA). There were no significant differences among groups A, B, and C concerning age, Hb, and endogenous erythropoietin values. Fifteen patients had positive antinuclear antibodies and three patients had positive rheumatoid factor. Antierythropoietin antibodies were detected in the sera of seven patients (five men and two women) who received rhEpo. The male patients and one female patient had no response to rhEpo while the other female patient showed response when the dose increased. Other autoantibodies seem to have no clinical significance. In the present study, we detected for the first time in thalassemia patients the presence of antierythropoietin antibodies, which may contribute to rhEpo resistance. Thalassemia patients with low response rates to rhEpo should be evaluated for the presence of antierythropoietin antibodies.

Topics: Adolescent; Adult; Autoantibodies; Blood Cell Count; Blood Transfusion; Erythropoietin; Female; Hemoglobins; Humans; Male; Middle Aged; Recombinant Proteins; Thalassemia

We report in this paper that the DNA-binding drug mithramycin is a potent inducer of gamma-globin mRNA accumulation and fetal hemoglobin (HbF) production in erythroid cells from healthy human subjects and beta-thalassemia patients. Erythroid precursors derived from peripheral blood were grown in 2-phase liquid culture. In this procedure, early erythroid progenitors proliferate and differentiate during phase 1 (in the absence of erythropoietin) into late progenitors. In phase 2, in the presence of erythropoietin, the latter cells continue their proliferation and mature into Hb-containing orthochromatic normoblasts. Compounds were added on days 4 to 5 of phase 2 (when cells started to synthesize Hb), and cells were harvested on day 12. Accumulation of mRNAs for gamma-globin, beta-globin, alpha-globin, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and beta-actin were measured by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR); induction of HbF was analyzed by high-performance liquid chromatography (HPLC) and, at cellular level, by flow cytometry. We demonstrated that mithramycin was able to up-regulate preferentially gamma-globin mRNA production and to increase HbF accumulation, the percentage of HbF-containing cells, and their HbF content. Mithramycin was more effective than hydroxyurea, being, in addition, not cytotoxic. This was shown by the lack of cytotoxicity on erythroid and myeloid in vitro primary cell cultures treated with mithramycin at concentrations effective for HbF induction. These results are of potential clinical significance because an increase of HbF alleviates the symptoms underlying beta-thalassemia and sickle cell anemia. The results of this report suggest that mithramycin and its analogs warrant further evaluation as potential therapeutic drugs.

Topics: Actins; Cell Culture Techniques; Cell Differentiation; Cell Division; Erythroid Precursor Cells; Erythropoietin; Fetal Hemoglobin; Flow Cytometry; Globins; Glyceraldehyde-3-Phosphate Dehydrogenases; Humans; Hydroxyurea; K562 Cells; Plicamycin; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Thalassemia; Up-Regulation

immunosorbent To determine serum EPO and soluble transferrin receptor (sTfR) level and to assess the degree of erythropoietic proliferation in patients with thalassemia of Li nationality, 50 cases and 50 normal individuals were studied. Enzyme-linked immunosorbent assay was used for EPO and sTfR. Results showed that serum EPO and sTfR levels in beta-thalasemia major patients were significantly higher than those in normal control group, and no significant difference in beta-thalassemia minor cases with those in control. It is concluded that increase of serum EPO and sTfR level is related to the type of thalassemia.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Child; Child, Preschool; China; Erythropoietin; Female; Humans; Infant; Male; Middle Aged; Receptors, Transferrin; Thalassemia

Topics: Aged; Anemia; Erythropoietin; Humans; Male; Nephrotic Syndrome; Recombinant Proteins; Thalassemia

We report a patient with thalassemia intermedia who developed a mediastinal syndrome due to the growth of paravertebral hematopoietic masses in the posterior mediastinum. Because the patient did not receive blood transfusions due to alloimmunization, she was first treated with human recombinant erythropoietin (escalating low-moderate doses) to recover hemoglobin levels, then in association with radiotherapy to prevent a worsening of her anemia. The mean Hb level dramatically increased and peaked at week 11, to 83 g/l, and remained unchanged before and after radiotherapy (81 versus 78 g/l). Immediately after radiotherapy extramedullary hematopoiesis volume decreased by 16.4%.

Topics: Adult; Erythropoietin; Female; Hematopoiesis, Extramedullary; Humans; Isoantibodies; Radiotherapy; Recombinant Proteins; Thalassemia

Topics: Adult; Aged; Drug Resistance; Erythropoiesis; Erythropoietin; Female; Humans; Iron Deficiencies; Kidney Failure, Chronic; Male; Middle Aged; Recombinant Proteins; Renal Dialysis; Thalassemia

Serum concentrations of erythropoietin (EPO) were determined by immunoassay in 45 patients with thalassemia intermedia (TI). The mean serum level of EPO was significantly higher in the thalassemic patients than in the controls, but transfused subjects had lower pretransfusional serum concentrations of EPO than untransfused ones. An inverse relationship between the serum values of EPO and total hemoglobin was observed only in the untransfused thalassemic patients. These data suggest that in TI, even a low transfusional regimen may cause a decrease in serum concentration of EPO, independent of the level of total Hb.

Topics: Adolescent; Adult; Blood Transfusion; Erythroblasts; Erythropoietin; Female; Ferritins; Humans; Male; Middle Aged; Thalassemia

Serum erythropoietin levels (s-Epo) were measured by radioimmunoassay in 61 consecutive anaemic patients (Hb < 12 g/dl) with myelofibrosis with myeloid metaplasia (MMM). S-Epo was inversely correlated with Hb (r = -0.48, P < 0.0001). When observed s-Epo values were compared with predicted levels based on the relationship between s-Epo and Hb in control subjects, all but eight patients (87%) had s-Epo levels appropriate for the degree of anaemia. The observed/predicted (O/P) s-Epo ratio was significantly lower in patients with signs of active disease, and a significant inverse correlation was found between the O/P ratio and erythrokinetic measurement of the extent of erythropoiesis (r = 0.31; P = 0.02). Circulating Epo levels were appropriate for the variations in Hb during the postsplenectomy period in three patients. In conclusion, this study does not support the idea that therapy with erythropoietin should be extensively used in anaemic patients with MMM, but rather that it should be considered only in selected cases.

Topics: Adult; Aged; Anemia; Anemia, Hypochromic; Blood Component Transfusion; Erythropoiesis; Erythropoietin; Female; Hemoglobins; Humans; Male; Middle Aged; Primary Myelofibrosis; Splenectomy; Thalassemia

Topics: Erythropoietin; Female; Humans; Male; Peritoneal Dialysis; Renal Dialysis; Thalassemia

Topics: Adolescent; Child; Erythropoietin; Female; Ferritins; Hemoglobins; Humans; Male; Middle Aged; Recombinant Proteins; Reticulocytes; Thalassemia; Time Factors

Blood erythroid progenitors (BFU-E) from patients with sickle and thalassemic syndromes were compared with those from normal individuals. The day of maximal colony formation in methyl cellulose was slightly later in the cultures from the patients with hemoglobinopathies than in the normal cultures. The number of colonies/100,000 mononuclear cells was similar in all cultures on day 13, but was higher in the hemoglobinopathy cultures on the day of maximal growth. The number of BFU-E/mL of blood was significantly higher than normal at all times in both sickle cell anemia and thalassemia. The proportional synthesis of gamma globin was twice normal in all sickle cultures, and 4 times normal in those from beta+-thalassemia. Hemin and interleukin-3 increased the numbers of erythroid colonies in all cultures, but did not consistently alter the globin synthesis patterns. Each progenitor population has a unique pattern in terms of time course, number of BFU-E, and level of gamma globin synthesis. These features indicate distinct types of BFU-E, or differences in accessory cells, or both, which distinguish blood-borne erythropoiesis in normals and those with hemoglobinopathies.

Topics: Adolescent; Adult; Anemia, Sickle Cell; Cell Count; Child; Child, Preschool; Colony-Forming Units Assay; Erythroid Precursor Cells; Erythropoiesis; Erythropoietin; Female; Globins; Hemin; Humans; Interleukin-3; Male; Middle Aged; Reference Values; Sensitivity and Specificity; Thalassemia

We evaluated a new commercially available two-site immunoradiometric assay (IRMA; BioMérieux 125I-EPO CoatRIA) for erythropoietin (EPO) in human serum. The precision (CV) was 4.1% intra-assay and 8% interassay for a serum pool with an EPO concentration of 17 int. units/L; the detection limit was 0.5 int. unit/L, one order of magnitude lower than by classical radioimmunoassay (RIA), although standardization of IRMA and RIA were similar. Results by both IRMA and RIA are compared for normal subjects, patients with nonrenal noninflammatory anemias, patients with beta-thalassemia major, hemodialysis patients, and patients with primary or secondary polycythemia. Values by IRMA compared well with those by RIA in the upper area of the range; IRMA and RIA values for EPO show parallel expected variations with the degree of anemia. However, because of its greater sensitivity and specificity, we consider the IRMA more appropriate than RIA for investigating patients with sub-normal EPO concentrations.

Topics: Adolescent; Adult; Aged; Anemia; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Female; Humans; Immunoradiometric Assay; Infant; Kidney Failure, Chronic; Male; Middle Aged; Polycythemia; Radioimmunoassay; Renal Dialysis; Thalassemia

Serum immunoreactive erythropoietin (EPO) was measured sequentially in 8 patients with thalassaemia major. The EPO levels were distinctly increased before transfusion; they did not significantly change just after transfusion, but subsequently decreased. Pretransfusion EPO levels were similar to those observed in patients with non renal non inflammatory anaemias of the same severity. Our results show that production of EPO is appropriately increased in thalassaemia major and confirm that stimulation of endogenous erythropoiesis is not completely suppressed by the hypertransfusion regimen commonly used in this disease. As hyperstimulated ineffective erythropoiesis may lead to invalidating complications, we suggest that serum EPO measurements, which are now easily and reliably performed, should be used in monitoring the therapy of thalassaemia major.

Topics: Adolescent; Adult; Biomarkers; Blood Transfusion; Child; Erythropoietin; Female; Follow-Up Studies; Humans; Male; Thalassemia

Serum erythropoietin levels were measured in 67 regularly transfused thalassemic patients with pre-transfusion hematocrit ranging from 25-32% and in 40 normal individuals. In patients, mean erythropoietin levels were slightly increased (mean 91.5 miu/ml) as compared to normal individuals (mean 42 miu/ml). The distribution of erythropoietin (Ep) was wide in thalassemic patients. 40% had normal or decreased and 60% increased Ep levels. A reverse relation between pretransfusion Hct and erythropoietin activity was observed only among patients with normal erythropoietin levels and splenectomized patients with high erythropoietin titers suggesting that a normal feedback between tissue hypoxia and erythropoietin activity occurs in these groups. The effect of regular blood transfusions in reversing tissue hypoxia resulting from anemia in the majority of regularly transfused thalassemic patients seems to be satisfactory, as it is assessed by serum erythropoietin levels.

Topics: Adolescent; Adult; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Female; Hematocrit; Humans; Male; Thalassemia

Topics: Adult; Erythropoietin; Female; Humans; Male; Recombinant Proteins; Thalassemia

Homozygous beta thalassemic mice received 50 U (1,660 U/kg) of recombinant human erythropoietin (rhEpo) 5 days a week for 2 weeks. Hemoglobin increased from 9.2 +/- 0.6 g/dL to 10.5 +/- 0.4 g/dL (P = .002) and hematocrit increased from 29.2% +/- 0.9% to 34.1% +/- 1.9% (P = .0014). The beta minor/alpha globin chain synthesis ratio increased slightly but significantly between day -4 (0.75 +/- 0.07) and day 4 (0.81 +/- 0.04) (P = .01) and reached a minimum ratio (0.67 +/- 0.03) on day 15 (P = .001), being parallel to reticulocyte counts and to the incorporated trichloracetic acid (TCA)-insoluble radioactivity, therefore parallel to the erythropoietic output in thalassemic mice, as in normal mice. Erythrocyte defects were improved in beta thalassemic mice treated by rhEpo: membrane-associated alpha globin was significantly decreased (P less than .01), thiol group reactivity of ankyrin was significantly improved (P less than .05), spectrin alterations were reduced, and deformability of mouse thalassemic red blood cells was normalized. These results provide experimental criteria for modulating globin chain imbalance necessary for the therapy of human beta thalassemia intermedia, and suggest that rhEpo might be of interest to improve the red blood cell mass and reduce erythrocyte alterations in this disease.

Topics: Animals; Erythrocyte Deformability; Erythrocyte Membrane; Erythropoietin; Globins; Hematocrit; Hemoglobins; Homozygote; Humans; Mice; Mice, Inbred DBA; Recombinant Proteins; Thalassemia

Topics: Adolescent; Adult; Blood Transfusion; Child; Child, Preschool; Erythropoietin; Folic Acid; Hemoglobins; Humans; Infant; Reference Values; Thalassemia; Vitamin B 12

Hemopoiesis is studied in vitro mainly in semisolid culture, where hemopoietic progenitors develop into discrete colonies. We describe a liquid culture system that supports the proliferation and maturation of human erythroid progenitors. We seeded mononuclear cells from the peripheral blood (PB) of patients with beta-thalassemia in liquid medium in the presence of conditioned medium from human bladder carcinoma cells. Seven days later, RBCs, normoblasts, granulocytes, and monocytes disappeared, and the number of lymphocytes dropped considerably. In contrast, erythroid colony-forming cells increased fourfold to tenfold. The next step entailed the removal of colony-stimulating factor (CSF) and CSF-secreting cells, the exclusion of macrophages by harvesting nonadherent cells, and the lysis of T lymphocytes by treatment with monoclonal rat antihuman lymphocyte antibodies (CAMPATH-1) and complement. Reculture of the remaining cells in liquid medium supplemented with recombinant erythropoietin (EPO) resulted in the exclusive development of erythroid cells, with myeloid cells reduced to less than 2%. Stainable hemoglobin (Hb) appeared on day 3, with over 85% of the population containing hemoglobin by day 11 and the cell number increasing from 0.2 X 10(6) to 3 X 10(6) mL. By permitting the manipulation of culture conditions and components and increasing the cell yield, the liquid system may facilitate quantitative analysis of growth kinetics as well as biochemical and immunologic characterization of the developing erythroid cell.

Topics: Cell Count; Cell Differentiation; Cell Division; Cells, Cultured; Clone Cells; Colony-Forming Units Assay; Culture Media; Erythroblasts; Erythropoietin; Hematopoietic Stem Cells; Humans; Kinetics; Suspensions; Thalassemia

Topics: Adolescent; Adult; Cells, Cultured; Child; Erythropoietin; Female; Hematopoietic Stem Cells; Humans; Male; Splenectomy; Thalassemia

Conditions for the in vitro culture of multipotential and committed progenitor cells obtained from the peripheral blood of transfusion-dependent beta-thalassemic individuals have been determined. When stimulated by either human placental-conditioned medium (HPCM), phytohemagglutinin-stimulated leukocyte-conditioned medium (PHA-LCM), or U5637-conditioned medium and erythropoietin, colonies containing neutrophils, neutrophils and macrophages, macrophages, eosinophils, erythroid cells, or mixtures of erythroid cells and neutrophils, eosinophils, or macrophages were obtained in cultures of beta-thalassemic mononuclear cells. Removal of adherent cells from beta-thalassemic peripheral blood demonstrated the presence of cells capable of the autostimulation of all of the above colony types in the presence of erythropoietin. In addition, adherent cells also appeared to inhibit erythropoiesis in cultures stimulated with HPCM. In cultures of nonadherent beta-thalassemic mononuclear cells, one population of BFU-E was stimulated by erythropoietin and a second required both erythropoietin and HPCM. Titration of erythropoietin, in the presence of optimal stimulation by HPCM, showed that beta-thalassemic peripheral blood BFU-E were more responsive to erythropoietin than was normal peripheral blood BFU-E. Stimulation of multipotential cells in cultures of nonadherent mononuclear cells was dependent upon HPCM. Using these culture conditions, the studies show that, compared with normals, the peripheral blood of transfusion-dependent beta-thalassemic patients contain elevated numbers of multipotential and committed progenitor cells, and that splenectomy did not account for the elevated numbers of these cells.

Topics: Cells, Cultured; Colony-Forming Units Assay; Culture Media; Erythropoiesis; Erythropoietin; Globins; Hematopoiesis; Hematopoietic Stem Cells; Humans; Thalassemia

In guinea pig bone marrow cultures with heterozygous alpha-thalassemic serum, 59Fe uptake values are elevated above iron values of cultures with serum of normal subjects. These results show that erythropoietin (EP) activity values in heterozygous alpha-thalassemia are comparable to those previously observed by ourselves in heterozygous beta-thalassemia despite of the different Hb concentration in these thalassemic syndromes. This points to the existence of signals which regulate Ep synthesis independently of Hb levels.

Topics: Adolescent; Adult; Child; Erythropoietin; Female; Heterozygote; Humans; Male; Middle Aged; Thalassemia

Serum erythropoietic activity was determined in 32 patients with beta thalassemia major and intermedia. Quantitation was performed by an in vitro bioassay using rabbit erythroid precursor cells (CFU-E) either by colony assay or by 3H-thymidine uptake. 20 polytransfused beta-thalassemic major patients had erythropoietic activity (mean 89.3 +/- 36 milliunits/ml) which was not significantly different (p greater than 0.2) from normal individuals (51.3 +/- 32 milliunits/ml). 12 untransfused patients with beta thalassemia intermedia were found to have comparable serum erythropoietic activity (p greater than 0.01). These levels were much lower than those found in patients with aplastic anemia who had a comparable degree of anemia. We have shown that the low EPO activity in thalassemic patients was not due to experimental conditions (excess of ferritin, low transferrin) nor to specific inhibitors appearing in this disease. No correlation was found between the erythropoietic activity and sex or other clinical parameters of the patients such as severity of the anemia, splenectomy, iron chelation or transfusion therapy. 4 young thalassemic children (1-2 yr of age) studied had high erythropoietic activity ranging from 661 to 5793 milliunits/ml--significantly different from normal children of the same age. It is suggested, therefore, that a decrease in serum erythropoietin levels develops during the course of the disease.

Topics: Anemia, Aplastic; Blood Transfusion; Colony-Forming Units Assay; Erythropoiesis; Erythropoietin; Female; Ferritins; Hot Temperature; Humans; Iron; Male; Thalassemia

A 4 year-old child being treated for neuroblastoma developed erythroblastopenia. We used specific erythroid lineage markers (hemoglobin and spectrin) and in vitro erythroid colony assays to characterize this hematologic picture and discuss its relationships with the disease and its treatment.

Topics: Bone Marrow; Cells, Cultured; Erythroblasts; Erythropoietin; Fluorescent Antibody Technique; Humans; Infant; Male; Neuroblastoma; Thalassemia

In the present work the capacity of serum of beta-thalassemic heterozygous and normal subjects to stimulate 59Fe uptake into heme in guinea pig bone marrow cultures is analyzed. The results show that labelled iron uptake is higher in cultures with thalassemic serum than in cultures with normal serum. No correlation between labelled iron uptake and Hb level or sex has been found in either group.

Topics: Adult; Aged; Bone Marrow; Erythropoietin; Female; Heterozygote; Humans; Iron; Iron Radioisotopes; Male; Middle Aged; Thalassemia

Topics: Anemia, Dyserythropoietic, Congenital; Cell Differentiation; Erythropoiesis; Erythropoietin; Fanconi Anemia; Fetal Hemoglobin; Hematopoietic Stem Cells; Humans; Models, Biological; Thalassemia

Erythroid burst colonies derived from the cord blood of nine neonates and from the blood and liver of three fetuses aborted after 20 weeks of gestation were grown in plasma clot culture. Their quantitative study revealed a higher proportion of burst-forming units (BFU-Es) in cord blood than in cord blood of normal adults. In addition, colony-forming units (CFU-Es) were present in cord blood but absent from adult blood. Study of haemoglobin synthesis in 14-day cultures of cord blood BFU-Es showed a significantly higher degree of Hb A synthesis than was found in reticulocytes from fresh cord blood; this proportion was, however, similar to that expected in vivo about three weeks after birth. These data suggest that the hemoglobin switch is already programmed in most of the early erythroid precursors present in cord blood or full-term neonates and indicate that the differentiation time is probably of the same order of magnitude in vivo and in vitro. The proportion of Hb A and F synthesis in erythroid bursts was not influenced by the concentration of erythropoietin in the range studied--ie, from 0.5 to 12 international units. Low but identical proportions of Hb A synthesis were found both in erythroid cells from liver after two hours of incubation with [3H]-leucine, and in 14-day liver bursts from fetuses aborted at 20 weeks of gestation.

Topics: Adult; Blood; Culture Techniques; Erythrocyte Aging; Erythrocytes; Erythropoietin; Fetal Blood; Fetal Hemoglobin; Fetus; Hematopoietic Stem Cells; Hemoglobin A; Humans; Infant, Newborn; Liver; Reticulocytes; Thalassemia

Topics: Adenosine Triphosphate; Anemia, Aplastic; Anemia, Sideroblastic; Aspartate Aminotransferases; Blood Transfusion; Carbon Dioxide; Diphosphoglyceric Acids; Electrophoresis, Starch Gel; Erythrocyte Count; Erythrocytes; Erythropoietin; Fructose-Bisphosphate Aldolase; Glutathione; Glyceraldehyde-3-Phosphate Dehydrogenases; Glycolysis; Hematocrit; Hemoglobins; Hexokinase; Humans; Hydrogen-Ion Concentration; Lactates; Methemoglobin; Oxygen Consumption; Phosphofructokinase-1; Phosphorus; Potassium; Reticulocytes; Sodium; Thalassemia

Topics: Anemia, Aplastic; Anemia, Sideroblastic; Animals; Biological Assay; Circadian Rhythm; Computers; Dialysis; Erythropoietin; Evaluation Studies as Topic; Female; Freeze Drying; Hemagglutination Tests; Hemoglobinuria, Paroxysmal; Humans; Iron Radioisotopes; Male; Methods; Mice; Mice, Inbred Strains; Microchemistry; Oxygen Consumption; Thalassemia; Ultrafiltration

Topics: Adolescent; Anemia; Anemia, Aplastic; Anemia, Hemolytic; Anemia, Hypochromic; Anemia, Sickle Cell; Animals; Biological Assay; Blood Cell Count; Bone Marrow Examination; Child; Child, Preschool; Erythrocytes; Erythropoiesis; Erythropoietin; Female; Hemoglobinometry; Humans; Iron; Iron Isotopes; Male; Rats; Reticulocytes; Thalassemia

Topics: Animals; Erythropoietin; Female; Humans; Leukemia; Male; Rats; Thalassemia

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

Topics: DNA; Epoetin Alfa; Erythropoiesis; Erythropoietin; Hemoglobins; Kinetics; Models, Theoretical; Proteins; RNA; RNA, Messenger; Thalassemia