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

Anemia can result from deficient erythropoiesis [aplastic anemia, myelodysplastic syndromes (MDS), iron deficiency anemia, anemia of chronic disease (ACD), thalassemia, megaloblastic anemia, chronic renal failure, hematological malignancies, etc.], excessive RBC destruction [hereditary spherocytosis, inherited enzyme deficiency, hemoglobinopathies, autoimmune hemolytic anemia (AIHA), paroxysmal nocturnal hemoglobinuria (PNH), etc.], and blood loss. Based on the measured red cell size(MCV), anemia is classified as microcytic, normocytic, or macrocytic. Iron parameters (serum iron, serum ferritin, etc.), reticulocyte count, bone marrow examination, Coombs test, serum vitamin B12 level, and Ham test are also useful in the differential diagnosis of anemia. Novel treatment of anemia includes lenalidomide for 5q(-)MDS, azacitidine for high-risk MDS, and eculizumab for PNH. Oral iron chelator(deferasirox) developed for the treatment of transfusional iron overload is also very useful for the management of patients with bone marrow failure syndromes.
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PMID:[Pathophysiology, diagnosis and treatment of anemia]. 1832 12

The pharmacokinetics (PK) and pharmacodynamics (PD) of the once-daily, oral ironchelating agent, deferasirox (Exjade, ICL670), have been evaluated further in a Phase I, openlabel, multicenter, dose-escalation study in Japanese patients with myelodysplastic syndromes, aplastic anemia, and other anemias. Deferasirox was initially administered as a single dose of 5 (n = 6), 10 (n = 7), 20 (n = 6) or 30 (n = 7) mg/(kg day) and then after 7 days seven daily doses were administered. Linear PK (C (max) and AUC) were observed at all doses after a single dose and at steady state, and dose-dependent iron excretion was observed. Pharmacokinetic/pharmacodynamic parameters were similar to those reported in a Caucasian beta-thalassemia cohort. Following the single- and multiple-dose phases, 21 of 26 patients progressed to a 3-year extension phase of the study, where dose reductions and increases [5-30 mg/(kg day)] were allowed following safety and efficacy assessments. In the interim, 1-year data show that deferasirox was well tolerated, with generally infrequent and mild adverse events. Reductions in serum ferritin levels were observed and a negative iron balance achieved at doses of 20-30 mg/(kg day). These data suggest that deferasirox has a stable and predictable PK/PD profile, irrespective of underlying disease or race, and a predictable and manageable safety profile suitable for chronic administration.
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PMID:A safety, pharmacokinetic and pharmacodynamic investigation of deferasirox (Exjade, ICL670) in patients with transfusion-dependent anemias and iron-overload: a Phase I study in Japan. 1859 54

Erythroblastic islands, the specialized niches in which erythroid precursors proliferate, differentiate, and enucleate, were first described 50 years ago by analysis of transmission electron micrographs of bone marrow. These hematopoietic subcompartments are composed of erythroblasts surrounding a central macrophage. A hiatus of several decades followed, during which the importance of erythroblastic islands remained unrecognized as erythroid progenitors were shown to possess an autonomous differentiation program with a capacity to complete terminal differentiation in vitro in the presence of erythropoietin but without macrophages. However, as the extent of proliferation, differentiation, and enucleation efficiency documented in vivo could not be recapitulated in vitro, a resurgence of interest in erythroid niches has emerged. We now have an increased molecular understanding of processes operating within erythroid niches, including cell-cell and cell-extracellular matrix adhesion, positive and negative regulatory feedback, and central macrophage function. These features of erythroblast islands represent important contributors to normal erythroid development, as well as altered erythropoiesis found in such diverse diseases as anemia of inflammation and chronic disease, myelodysplasia, thalassemia, and malarial anemia. Coupling of historical, current, and future insights will be essential to understand the tightly regulated production of red cells both in steady state and stress erythropoiesis.
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PMID:Erythroblastic islands: niches for erythropoiesis. 1865 Apr 62

Alpha thalassaemia myelodysplastic syndrome (ATMDS) is an unusual complication of chronic myeloid malignancy that is associated with a striking red cell phenotype. It represents an acquired form of alpha-thalassaemia that most commonly arises in the context of myelodysplasia. It has recently been shown that this condition occurs in association with somatic mutations of a known X-encoded trans-acting regulator of alpha globin gene (HBA) expression, ATRX. There is an unexplained, strong male preponderance of individuals with the ATMDS phenotype with a >5:1 male-female ratio and furthermore, all the somatic ATRX mutations described to date have been in males. Here we report the identification, in a single centre, of two females with ATMDS and mutations in the ATRX gene, proving that ATMDS associated with such mutations may occur, albeit rarely, in females. It seemed possible that females might be less likely to develop ATMDS if the inactivated copy of the ATRX gene (ATRX) became progressively re-activated throughout life. This study ruled out this hypothesis by investigating the pattern of ATRX inactivation in a cross-sectional analysis of normal females at ages ranging from newborn to 90 years.
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PMID:The role of X-inactivation in the gender bias of patients with acquired alpha-thalassaemia and myelodysplastic syndrome (ATMDS). 1905 64

Iron overload occurs in patients who require regular blood transfusions to correct genetic and acquired anaemias, such as beta-thalassaemia major, sickle cell disease, and myelodysplastic syndromes. Although iron overload causes damage in many organs, accumulation of cardiac iron is a leading cause of death in transfused patients with beta-thalassaemia major. The symptoms of cardiac iron overload will occur long after the first cardiac iron accumulation, at a point when treatment is more complex than primary prevention would have been. Direct measurement of cardiac iron using T2* magnetic resonance imaging, rather than indirect methods such as measuring serum ferritin levels or liver iron concentration have contributed to earlier recognition of myocardial iron loading and prevention of cardiac toxicity. Cardiac siderosis occurs in all transfusional anaemias, but the relative risk depends upon the underlying disease state, transfusional load, and chelation history. All three available iron chelators can be used to remove cardiac iron, but each has unique physical properties that influence their cardiac efficacy. More prospective trials are needed to assess the effects of single-agent or combination iron chelation therapy on the levels of cardiac iron and cardiac function. Ultimately, iron chelation therapies should be tailored to meet individual patient needs and lifestyle demands.
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PMID:Cardiac iron across different transfusion-dependent diseases. 1905 52

Haemopoietic stem cell transplantation (HSCT) is an important intervention for malignant and non-malignant blood diseases. However, HSCT is also associated with considerable morbidity and mortality, some of which may be related to iron overload. Levels of serum iron are elevated in patients undergoing HSCT as a result of disturbed iron metabolism, pre-transplantation blood transfusions, or cytotoxic therapy for conditioning before HSCT. The complications of iron overload in HSCT patients include infections, mucositis, chronic liver disease (fibrosis progression), sinusoidal obstruction syndrome, and idiopathic pneumonia syndrome. Iron overload has an adverse impact on survival in patients undergoing HSCT for beta-thalassaemia major or haematological malignancies including myelodysplastic syndromes. It has been suggested that all candidates for and all survivors of HSCT should be screened for iron overload at various time points before and after transplantation. Few studies of iron chelation therapy after HSCT have been reported, but one small study has indicated that deferoxamine is at least as effective as phlebotomy in reducing post-transplantation iron overload in patients with beta-thalassaemia major. The new oral chelator deferasirox may be better tolerated than phlebotomy or deferoxamine infusion, and two prospective phase II studies in patients with iron overload after HSCT are now recruiting candidates.
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PMID:The role of iron in patients after bone marrow transplantation. 1905 53

Deferasirox is an oral iron chelator, with a long half-life, that can be given once daily, because it provides a 24-hour chelation. Several phase II trials and a pivotal phase III trial have established that, in transfusion-dependent patients with beta-thalassaemia major, deferasirox has a similar efficacy to previously available deferoxamine. A deferasirox dose of 20 mg/kg/day stabilizes serum ferritin levels and liver iron concentration, while a dose of 30 mg/kg/day reduces serum ferritin and liver iron concentration and achieves negative iron balance. Efficacy has also been shown across various transfusion-dependent anaemias including myelodysplastic syndromes, sickle cell disease, and other rare transfusion-dependent anaemias. Deferasirox is generally well tolerated, with the most common adverse events being gastrointestinal disturbances and rash. Longer-term studies with a median follow-up of 3.5 years have confirmed the efficacy and safety of deferasirox. It is recommended that patients treated with deferasirox are monitored regularly for iron status and adverse events, to ensure that an effective and tolerable iron chelation regimen is established for each individual patient.
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PMID:Long-term efficacy and safety of deferasirox. 1905 55

From March 1991 through 31st December 2007, 2042 patients underwent stem cell transplantation at the Hematology-Oncology and Stem Cell Transplantation Research Center, affiliated to Tehran University of Medical Sciences. These transplantations included 1405 allogeneic stem cell transplantation, 624 autologous stem cell transplantation, and 13 syngeneic stem cell transplantation. Stem cell transplantation was performed for various diseases including acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphoblastic leukemia, thalassemia major, sickle cell thalassemia, sickle cell disease, multiple myeloma, myelodysplasia, mucopolysaccharidosis, paroxysmal nocturnal hemoglobinuria, non-Hodgkin's lymphoma, Hodgkin's disease, severe aplastic anemia, plasma cell leukemia, Niemann-Pick disease, Fanconi anemia, severe combine immunodeficiency, congenital neutropenia, leukocyte adhesion deficiencies, Chediak-Higashi syndrome, osteopetrosis, histiocytosis X, Hurler syndrome, amyloidosis, systemic sclerosis, breast cancer, Ewing's sarcoma, testicular cancer, germ cell tumors, neuroblastoma, medulloblastoma, renal cell carcinoma, nasopharyngeal carcinoma, ovarian cancer, Wilms' tumor, rhabdomyosarcoma, pancreatoblastoma, and multiple sclerosis. We had 105 cellular therapies for postmyocardial infarction, multiple sclerosis, cirrhosis, head of femur necrosis, and renal cell carcinoma. About 30 patients were retransplanted in this center. About 74.9% of the patients (1530 of 2042) remained alive between one to 168 months after stem cell transplantation. Nearly 25.1% (512 of 2042) of our patients died after stem cell transplantation. The causes of deaths were relapse, infections, hemorrhagic cystitis, graft versus host disease, and others.
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PMID:Stem cell transplantation; Iranian experience. 1911 Oct 33

Iron overload, characterized by excessive iron deposition, occurs commonly in patients with hereditary or refractory anemias such as beta-thalassemia major, sickle cell anemia, and myelodysplastic syndromes, whose anemia is managed with frequent blood transfusions. Without adequate iron chelation therapy, almost all patients with beta-thalassemia will accumulate potentially fatal iron levels. Myocardial siderosis and resulting cardiac complications are among the leading causes of death in such patients. Unfortunately, even with the administration of effective subcutaneous iron chelation therapy with desferrioxamine (DFO), over 50% of patients die before the age of 35 years, largely because of poor compliance with subcutaneous chelation regimens. Recently introduced oral chelation agents, deferiprone and deferasirox, are associated with higher compliance rates, and greater reductions in cardiac iron levels, than those achieved with DFO. This article reviews the pharmacologic properties and clinical efficacy of currently available iron chelation therapies in the management of transfusional chronic iron overload.
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PMID:Treatment of iron overload in thalassemia. 1933 80

Deferasirox is a once-daily, orally administered, tridentate iron chelator that is indicated in the treatment of iron overload resulting from regular packed red blood cell transfusions in patients with transfusion-dependent anemias, such as beta-thalassemia, sickle cell disease, myelodysplastic syndrome and other rare anemias. Randomized, controlled trials have established its efficacy to reduce liver iron concentration and serum ferritin levels to be comparable to the historic standard iron chelator, deferoxamine, which is administered as a parenteral infusion. However, deferasirox may be more effective than deferoxamine in actual clinical practice owing to the improvement in quality of life and, hence, increased compliance associated with the oral route of administration. The higher acquisition cost of deferasirox may be counterbalanced by savings in the administration cost, as well as the treatment of complications of iron overload that result from noncompliance with therapy attributable to the parenteral mode of administration. Deferasirox may also have potential as an important supplement and even an alternative to phlebotomies in nontransfusional, genetic iron overload disorders, such as hereditary hemochromatosis.
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PMID:Pharmacoeconomic benefits of deferasirox in the management of iron overload syndromes. 1967 Sep 88


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