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)

Sixteen patients (age range, 3 to 17 years) with transfusion-dependent beta-thalassemia major were studied prospectively, beginning at the onset of chelation therapy with deferoxamine (desferrioxamine). A liver biopsy specimen was obtained from each patient at the start of the study, and periodically thereafter. Liver histologic features, iron content, and iron excretion were assessed during the course of the study. Hepatic iron levels from liver biopsy specimens appeared to correlate well with serum ferritin levels in the younger less heavily iron-loaded patients; however, in patients with higher serum ferritin levels, hepatic iron appeared to reach a saturation level. Fourteen of the 16 patients showed a pattern of marbled fibrosis of the liver in their initial biopsy specimens. Follow-up biopsy specimens from nearly all of the patients showed a substantial reduction in iron concentration, but only two of seven patients showed improvement in the degree of hepatic fibrosis three to five years later. Patients less than 8 years old exhibited a normal pattern of linear growth until approximately the age of 10 years, followed by a progressive decrease to the 30th to 40th percentile. Two patients, aged 18 and 22 years, died of cardiac disease during the study. These findings suggest that chelation therapy in patients with transfusion-dependent thalassemia needs to be initiated at an early age, possibly before 3 years, if significant liver fibrosis and growth impairment are to be effectively prevented.
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PMID:A prospective evaluation of iron chelation therapy in children with severe beta-thalassemia. A six-year study. 334 15

To determine the therapeutic effect of long-term, intensive iron chelation therapy, we studied liver iron content and histology in four children with thalassaemia major during 52-83 months of intensive therapy with desferrioxamine. The initial biopsies obtained prior to or within 21 months after beginning chelation therapy had Grade IV iron staining, with heavy iron deposition present in parenchymal and reticuloendothelial cells. Subsequent biopsies, obtained when serum ferritin levels had fallen to 71-246 micrograms/l, contained Grade 0 or Grade I stainable iron. Little or no iron was present in parenchymal or reticuloendothelial cells. The liver iron concentration, measured by magnetic susceptibility, returned to normal or nearly normal levels. Hepatic fibrosis did not progress during treatment with desferrioxamine. These findings demonstrate that intensive and sustained chelation therapy with desferrioxamine will remove excessive liver iron and preserve hepatocellular structure.
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PMID:Depletion of excessive liver iron stores with desferrioxamine. 647 38

Early trials of allogeneic bone marrow transplantation (BMT) for homozygous beta-thalassemia and the analyses of results of transplantation in patients less than 16 years old have allowed us to identify three classes of risk based on the following criteria: (a) hepatomegaly, (b) presence of liver fibrosis at histological examination, and (c) quality of chelation treatment given before transplant. Patients with none of these adverse criteria were assigned to Class 1; patients with either one or two adverse criteria comprised Class 2; and patients for whom all three criteria were adverse constituted Class 3. Most patients older than 16 years have disease characteristics that place them in Class 3, with very few falling into Class 2. All patients with a histocompatibility leukocyte antigen (HLA)-identical donor are actually assigned to one of two conditioning regimens on the basis of the class they belong to at the time of BMT and independently of age. For Class 1, Class 2, and Class 3 patients, the probabilities of survival and event-free survival are 95 and 90%, 86 and 82%, and 87 and 63%, respectively. For those patients older than 16 years at the time of transplant, the probabilities of survival and of event-free survival are 78 and 74%, respectively. Allogeneic BMT is currently the only rational therapeutic modality for the eradication of beta-thalassemia.
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PMID:Bone marrow transplantation in thalassemia. 759 68

We analyzed risk factors in 724 patients evaluable for acute graft-versus-host disease (GVHD) and in 614 patients evaluable for chronic GVHD who had received bone marrow transplantation (BMT) from HLA-identical siblings and/or parents for thalassemia and/or microdrepanocytosis, in a single institution. The overall incidence of grade II-IV and III-IV acute GVHD (aGVHD) was 26.9% and 13.5%, respectively. The cumulative incidence of grade II-IV aGVHD in patients treated with cyclosporine (CsA)/methylprednisolone (MP) or CsA/methotrexate (MTX)/MP was 32% and 17%, respectively (P=0.001). In logistic regression analysis, the risk factors associated with the onset of grade II-IV aGVHD in the entire group of patients were: patient age < or = 4 years (P=0.009), male patient sex (P=0.023), GVHD prophylaxis with CsA/MP or MTX/MP (P=0.000), more than twofold elevated alanine aminotransferase (P=0.001), and patient seropositivity for two to three herpes viruses (P=0.007). In patients treated with CsA/MP, splenomegaly > 2 cm (P=0.042) and donor age > or = 17 years (P=0.034) predicted aGVHD. Risk factors for grade III-IV aGVHD were similar to the risk factors identified for grade II-IV aGVHD. Moreover, moderate and severe liver fibrosis or cirrhosis predicted grade III-IV aGVHD (P=0.018). The incidence of chronic GVHD (cGVHD) was 27.3%. The probability of cGVHD at 2 years after BMT in patients with grade 0, I, II, and III-IV aGVHD was 15%, 32%, 53%, and 54%, respectively. Among patients with absent or grade I-IV aGVHD, prior aGVHD (P=0.000), female donor sex (P=0.000), use of alloimmune female donors for male patients (0.009), and GVHD prophylaxis with CsA/MP or MTX/MP (P=0.003) predicted cGVHD. This data should be considered in clinical management and in future investigations for improvement of immunosuppressive prophylaxis in BMT patients with thalassemia.
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PMID:Graft-versus-host disease after bone marrow transplantation for thalassemia: an analysis of incidence and risk factors. 908 26

The role of the orally active iron (Fe) chelator deferiprone in the treatment of beta-thalassemia remains a controversial subject. Despite initial studies showing high Fe chelation efficacy in vitro and also in animals and human subjects, several latter studies have not been so successful. In fact, it has been reported in several clinical trials that deferiprone after long-term treatment had either little effect or actually increased hepatic Fe loading. In addition, an increase in liver fibrosis was noted in one study. However, more recently, results by other investigators have suggested that the drug may be used under some circumstances without marked toxicity. In particular, it has been demonstrated that the combination of deferoxamine (DFO) and deferiprone results in more Fe excretion than when either chelator is used alone. Moreover, a combination of both drugs led to a decrease in deferiprone-mediated toxicity. Other studies performed in patients for up to 10 years showed no progressive fibrosis after deferiprone therapy, while a possible trend toward increasing fibrosis was noted in another investigation. Additional studies using larger numbers of deferiprone-treated patients are essential to determine the efficacy and safety of this drug, particularly in relation to the development of fibrosis. The present review discusses the possible role of deferiprone in the treatment of Fe overload.
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PMID:The controversial role of deferiprone in the treatment of thalassemia. 1132 29

Deferiprone, an oral iron chelator, has been licensed in Europe for the treatment of iron overload in patients with beta thalassaemia who cannot be treated with deferoxamine because of adverse effects or the difficult administration schedule. (2) The clinical dossier is thin and methodologically mediocre. Even the preclinical assessment dossier is insufficient (there are no studies of carcinogenicity or hepatotoxicity). (3) The only available comparative trial, involving a small number of patients, suggests that deferiprone is less effective than deferoxamine in reducing ferritin levels and hepatic iron stores. (4) A non comparative trial suggests that long-term deferiprone therapy would not only fail, but would also increase the risk of liver fibrosis in some patients. This doubt is not dispelled by the other available non-comparative trials. (5) Deferiprone carries a risk of agranulocytosis in an estimated 1.2% of patients. (6) Deferiprone is teratogenic in two animal species.
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PMID:Deferiprone: new preparation. Poorly assessed. 1160 11

The therapeutic aspects and future prospects of the new iron chelating drug deferiprone are reviewed, with an emphasis on its clinical use in thalassemia and other conditions of iron overload, imbalance and toxicity, as well as its possible use in other metal toxicity conditions. Orally administered deferiprone appears to be as effective as subcutaneous deferoxamine in the removal of iron in transfused iron loaded patients, with an equivalent therapeutic index profile in both animals and humans. Only about 10% of patients requiring iron chelation therapy worldwide receive deferoxamine mainly because of its high cost, toxicity and low compliance with subcutaneous administration. Deferiprone has been used by over 6000 patients in 40 countries worldwide, in some cases daily for more than 10 years, with very promising results. Doses of 50-120 mg/kg/day are effective in bringing patients to negative iron balance. Deferiprone increases urinary iron excretion, decreases serum ferritin levels and reduces liver iron in the majority of chronically transfused iron loaded patients. All of the toxic side effects of deferiprone are considered reversible and manageable, and include agranulocytosis, musculoskeletal and joint pains, gastrointestinal complaints and zinc deficiency. In general, the incidence of toxic side effects could be reduced by using lower doses or combination therapy with deferoxamine. The suggestion that deferiprone therapy may cause liver fibrosis has not been confirmed. New therapeutic protocols for maximizing the efficacy and minimizing the toxicity of deferiprone are being considered based on new findings in relation to its metal chelation, pharmacological, toxicological and metabolic properties. (c) 2001 Prous Science. All rights reserved.
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PMID:Clinical use, therapeutic aspects and future potential of deferiprone in thalassemia and other conditions of iron and other metal toxicity. 1278 95

Splenomegaly is a common finding in beta-thalassemia; however, its hemodynamic features and its potential correlations with high output state and hepatic disorders, both also frequent in thalassemia, have not yet been assessed in these patients. Eight beta-thalassemia patients with the indication for splenectomy and no symptoms or signs of heart disease, aged 25.6+/-5.5 years, were studied. Preoperative assessment included hematological profile, liver biology, hepatitis virus serology, and echocardiography. During splenectomy, splenic artery blood flow and splenic vein pressure were directly measured and liver biopsies were taken. Preoperative echocardiographic data were compared with those of 34 healthy controls. The preoperative cardiac index was significantly elevated in patients (4.8+/-1.3 vs 3.4+/-1.1 l/min per m2 in controls, p<0.001). Splenic blood flow, although increased, was not particularly high, being 285+/-56 ml/min or 0.13+/-0.04 ml/min per g of splenic mass, representing 4.1+/-0.9% of total cardiac output (CO). Splenic vein pressure was considerably elevated (29.7+/-5.5 cmH2O). Hepatic fibrosis, iron deposition, and extramedullary foci were found in all eight biopsies. Serology was positive in five of eight cases. beta-thalassemia patients with extensive splenomegaly requiring splenectomy are characterized by high output state, increased splenic blood flow, which probably makes a limited contribution to CO elevation, and portal hypertension, manifest by increased splenic vein pressure and hepatic histopathological abnormalities.
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PMID:Hemodynamic assessment of splenomegaly in beta-thalassemia patients undergoing splenectomy. 1533 97

Although it is life saving, transfusion therapy has resulted in the majority of sickle cell anemia and thalassemia patients being at risk for hemosiderosis-induced organ damage. It is unknown whether the complications of iron overload are affected by the underlying disease. In order to address this problem, we compared the prevalence of organ dysfunction in both groups of patients receiving chronic transfusion therapy (beta thalassemia, N = 30; sickle cell anemia, N = 43). Both groups had similar quantitative liver iron. Thalassemia patients had greater cardiac disease (20% vs. 0%), growth failure (27% vs. 9%), and endocrine failure (37% vs. 0%). The strongest predictors of combined endocrine and cardiac disease in multivariate analysis were duration of chronic transfusion (P = 0.03) and diagnosis (P = 0.03). Quantitative liver iron concentration on a single liver biopsy was not predictive of cardiac or endocrine injury. Viral hepatitis is the strongest predictor of hepatocellular damage (P = 0.009), while the development of liver fibrosis is more closely related to liver iron concentration (P = 0.04). In conclusion, sickle cell anemia and thalassemia differ in the prevalence of organ injury. This difference is related to the duration of iron exposure and the specific hemoglobinopathy. A prospective study with a larger number of subjects is needed to confirm the relationships between specific diagnosis, liver iron concentration over time, and organ dysfunction.
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PMID:Comparison of organ dysfunction in transfused patients with SCD or beta thalassemia. 1613 45

To assess the effects of liver iron overload and fibrosis after treatment with a chelating agent in hepatitis C virus (HCV)-infected thalassemia, from April 1999 to July 2004, 45 patients with thalassemia major (age range 9-33 years, mean 19.3) received daily deferiprone (L1) for 23-60 months (75 mg/kg). The patients were divided into two groups on the basis of their hepatitis status (27 with, 18 without). Their serum was analyzed for alanine aminotransferase (GPT), aspartate aminotransferase (GOT), bilirubin (total/direct), r-glutamyl transpeptidase (r-GT), alkaline phosphatase (Alk-P), and ferritin. Liver iron overload and fibrosis were defined by a senior pathologist. No significant differences were demonstrated in serum levels of GPT, GOT, bilirubin, r-GT, Alk-P or ferritin; comparison was made for each group before and after L1 treatment. Iron scores were 2.3 +/- 0.9 and 2.8 +/- 0.9 for the hepatitis C negative and positive groups, respectively (p = 0.07), with liver fibrosis scores of 1.0 +/- 0.5 and 0.4 +/- 0.52 (p = 0.56). The two scores were not higher for the positive group. There was no evidence of: 1) greater iron overload and fibrosis in the HCV-infected thalassemic patients; 2) L1 inducing progressive hepatic fibrosis or worsening iron overload in HCV-infected thalassemic patients after long-term therapy; 3) further damage to liver cells associated with L1 treatment.
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PMID:Effect of deferiprone on liver iron overload and fibrosis in hepatitis-C-virus-infected thalassemia. 1679 45


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