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1.
J Cardiovasc Magn Reson ; 19(1): 36, 2017 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-28343449

RESUMO

BACKGROUND: Heart failure related to cardiac siderosis remains a major cause of death in transfusion dependent anaemias. Replacement fibrosis has been reported as causative of heart failure in siderotic cardiomyopathy in historical reports, but these findings do not accord with the reversible nature of siderotic heart failure achievable with intensive iron chelation. METHODS: Ten whole human hearts (9 beta-thalassemia major, 1 sideroblastic anaemia) were examined for iron loading and fibrosis (replacement and interstitial). Five had died from heart failure, 4 had cardiac transplantation for heart failure, and 1 had no heart failure (death from a stroke). Heart samples iron content was measured using atomic emission spectroscopy. Interstitial fibrosis was quantified by computer using picrosirius red (PSR) staining and expressed as collagen volume fraction (CVF) with normal value for left ventricle <3%. RESULTS: The 9 hearts affected by heart failure had severe iron loading with very low T2* of 5.0 ± 2.0 ms (iron concentration 8.5 ± 7.0 mg/g dw) and diffuse granular myocardial iron deposition. In none of the 10 hearts was significant macroscopic replacement fibrosis present. In only 2 hearts was interstitial fibrosis present, but with low CVF: in one patient with no cardiac siderosis (death by stroke, CVF 5.9%) and in a heart failure patient (CVF 2%). In the remaining 8 patients, no interstitial fibrosis was seen despite all having severe cardiac siderosis and heart failure (CVF 1.86% ±0.87%). CONCLUSION: Replacement cardiac fibrosis was not seen in the 9 post-mortem hearts from patients with severe cardiac siderosis and heart failure leading to death or transplantation, which contrasts markedly to historical reports. Minor interstitial fibrosis was also unusual and very limited in extent. These findings accord with the potential for reversibility of heart failure seen in iron overload cardiomyopathy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00520559.


Assuntos
Transfusão de Sangue , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/patologia , Hemossiderose/metabolismo , Hemossiderose/patologia , Ferro/análise , Miocárdio/química , Miocárdio/patologia , Talassemia beta/terapia , Adolescente , Adulto , Autopsia , Compostos Azo/química , Transfusão de Sangue/mortalidade , Cardiomiopatias/mortalidade , Cardiomiopatias/cirurgia , Causas de Morte , Criança , Colágeno/análise , Corantes/química , Feminino , Fibrose , Insuficiência Cardíaca/mortalidade , Insuficiência Cardíaca/cirurgia , Transplante de Coração , Hemossiderose/mortalidade , Hemossiderose/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Índice de Gravidade de Doença , Espectrofotometria Atômica , Coloração e Rotulagem/métodos , Adulto Jovem , Talassemia beta/sangue , Talassemia beta/diagnóstico , Talassemia beta/mortalidade
2.
Haematologica ; 101(1): 38-45, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26385212

RESUMO

Non-transferrin-bound iron and its labile (redox active) plasma iron component are thought to be potentially toxic forms of iron originally identified in the serum of patients with iron overload. We compared ten worldwide leading assays (6 for non-transferrin-bound iron and 4 for labile plasma iron) as part of an international inter-laboratory study. Serum samples from 60 patients with four different iron-overload disorders in various treatment phases were coded and sent in duplicate for analysis to five different laboratories worldwide. Some laboratories provided multiple assays. Overall, highest assay levels were observed for patients with untreated hereditary hemochromatosis and ß-thalassemia intermedia, patients with transfusion-dependent myelodysplastic syndromes and patients with transfusion-dependent and chelated ß-thalassemia major. Absolute levels differed considerably between assays and were lower for labile plasma iron than for non-transferrin-bound iron. Four assays also reported negative values. Assays were reproducible with high between-sample and low within-sample variation. Assays correlated and correlations were highest within the group of non-transferrin-bound iron assays and within that of labile plasma iron assays. Increased transferrin saturation, but not ferritin, was a good indicator of the presence of forms of circulating non-transferrin-bound iron. The possibility of using non-transferrin-bound iron and labile plasma iron measures as clinical indicators of overt iron overload and/or of treatment efficacy would largely depend on the rigorous validation and standardization of assays.


Assuntos
Transfusão de Sangue , Hemocromatose/sangue , Ferro/sangue , Síndromes Mielodisplásicas/sangue , Transferrina/metabolismo , Talassemia beta/sangue , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/terapia , Talassemia beta/terapia
3.
Am J Hematol ; 91(10): 1026-31, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27415835

RESUMO

Use of the iron chelator deferiprone for treatment of iron overload in thalassemia patients is associated with concerns over agranulocytosis, which requires weekly absolute neutrophil counts (ANC). Here, we analyze all episodes of agranulocytosis (n = 161) and neutropenia (n = 250) during deferiprone use in clinical trials (CT) and postmarketing surveillance programs (PMSP). Rates of agranulocytosis and neutropenia in CT were 1.5% and 5.5%, respectively. Of the agranulocytosis cases, 61% occurred during the first 6 months of therapy and 78% during the first year. These events appeared to be independent of dose, and occurred three times more often in females than males. Their duration was not significantly shortened by use of G-CSF. No patient with baseline neutropenia (n = 12) developed agranulocytosis during treatment, which raises questions about the validity of prior neutropenia as a contraindication to use. Only 1/7 novel neutropenia cases in CT progressed to agranulocytosis with continued treatment, indicating that neutropenia does not necessarily lead to agranulocytosis. The agranulocytosis fatality rate was 0% in CT and 15/143 (11%) in PMSP. Rechallenge with deferiprone produced agranulocytosis in 75% of patients in whom the event had already occurred, and in 10% with previous neutropenia. Weekly ANC monitoring allows early detection and interruption of therapy, but does not prevent agranulocytosis from occurring. Its relevance appears to decrease after the first year of therapy, when agranulocytosis occurs less often. Based upon analysis of data collected over the past 20 years, it appears that patient education may be the key to minimizing agranulocytosis-associated risks during deferiprone therapy. Am. J. Hematol. 91:1026-1031, 2016. © 2016 The Authors. American Journal of Hematology Published by Wiley Periodicals, Inc.


Assuntos
Agranulocitose/induzido quimicamente , Piridonas/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Ensaios Clínicos como Assunto/estatística & dados numéricos , Deferiprona , Feminino , Humanos , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Contagem de Leucócitos , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Neutrófilos/citologia , Educação de Pacientes como Assunto , Vigilância de Produtos Comercializados/estatística & dados numéricos , Piridonas/uso terapêutico , Fatores de Risco , Fatores Sexuais , Talassemia/complicações , Adulto Jovem
4.
Circulation ; 129(3): 338-45, 2014 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-24081970

RESUMO

BACKGROUND: Pulmonary arterial hypertension (PAH) remains a concern in patients with ß-thalassemia major (TM) and intermedia (TI); however, studies evaluating its prevalence and risk factors using systematic confirmation on right heart catheterization are lacking. METHODS AND RESULTS: This was a multicenter cross-sectional study of 1309 Italian ß-thalassemia patients (mean age 36.4±9.3 years; 46% men; 74.6% TM, 25.4% TI). Patients with a tricuspid-valve regurgitant jet velocity ≥3.2 m/s (3.6%) on transthoracic echocardiography further underwent right heart catheterization to confirm the diagnosis of PAH (mean pulmonary arterial pressure ≥25 mm Hg and pulmonary capillary wedge pressure ≤15mm Hg). The confirmed PAH prevalence on right heart catheterization was 2.1% (95% confidence interval [CI], 1.4-3.0) and was higher in TI (4.8%; 95% CI, 3.0-7.7) than TM (1.1%; 95% CI, 0.6-2.0). The positive predictive value for the tricuspid-valve regurgitant jet velocity ≥3.2 m/s threshold for the diagnosis of pulmonary hypertension was 93.9%. Considerable functional limitation and decrease in the 6-minute walk distance were noted in patients with confirmed PAH. On multivariate logistic regression analysis, independent risk factors for confirmed PAH were age (odds ratio, 1.102 per 1-year increase; 95% CI, 1.06-1.15) and splenectomy (odds ratio, 9.31; 95% CI, 2.57-33.7). CONCLUSIONS: The prevalence of PAH in ß-thalassemia patients as confirmed on right heart catheterization was 2.1%, with an ≈5-fold higher prevalence in TI than TM. Advanced age and splenectomy are risk factors for PAH in this patient population. CLINICAL TRIAL REGISTRATION URL: http://www.ClinicalTrials.gov. Unique identifier: NCT01496963.


Assuntos
Cateterismo Cardíaco , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/epidemiologia , Talassemia beta/epidemiologia , Adulto , Estudos de Casos e Controles , Estudos Transversais , Ecocardiografia , Hipertensão Pulmonar Primária Familiar , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Prevalência , Pressão Propulsora Pulmonar , Fatores de Risco
5.
Haematologica ; 100(4): 452-7, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25480500

RESUMO

Clinical and hematologic characteristics of beta(ß)-thalassemia are determined by several factors resulting in a wide spectrum of severity. Phenotype modulators are: HBB mutations, HBA defects and fetal hemoglobin production modulators (HBG2:g.-158C>T polymorphism, HBS1L-MYB intergenic region and the BCL11A). We characterized 54 genetic variants at these five loci robustly associated with the amelioration of beta-thalassemia phenotype, to build a predictive score of severity using a representative cohort of 890 ß-thalassemic patients. Using Cox proportional hazard analysis on a training set, we assessed the effect of these loci on the age at which patient started regular transfusions, built a Thalassemia Severity Score, and validated it on a testing set. Discriminatory power of the model was high (C-index=0.705; R(2)=0.343) and the validation conducted on the testing set confirmed its predictive accuracy with transfusion-free survival probability (P<0.001) and with transfusion dependency status (Area Under the Receiver Operating Characteristic Curve=0.774; P<0.001). Finally, an automatized on-line calculation of the score was made available at http://tss.unica.it. Besides the accurate assessment of genetic predictors effect, the present results could be helpful in the management of patients, both as a predictive score for screening and a standardized scale of severity to overcome the major-intermedia dichotomy and support clinical decisions.


Assuntos
Variação Genética , Globinas beta/genética , Talassemia beta/diagnóstico , Talassemia beta/genética , Transfusão de Sangue , DNA Intergênico , Feminino , Estudos de Associação Genética , Loci Gênicos , Humanos , Estimativa de Kaplan-Meier , Masculino , Mutação , Fenótipo , Polimorfismo de Nucleotídeo Único , Prognóstico , Estudos Retrospectivos , Índice de Gravidade de Doença , Talassemia beta/mortalidade , Talassemia beta/terapia
6.
Ann Hepatol ; 14(3): 389-95, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25864220

RESUMO

UNLABELLED: BACKGROUND AND RATIONALE FOR THE STUDY: Genome-wide association studies have identified host genetic variation to be critical for spontaneous clearance and treatment response in patients infected with hepatitis C virus. Recently, the role of the IFNL3 polymorphisms in influencing the spontaneous clearance of HCV, the response to interferon and the progression of liver fibrosis, was also demonstrated in patients with thalassemia major infected by genotype 1b. In the present study we retrospectively analyzed 368 anti-HCV positive patients with beta-thalassemia at two Italian major centers in Cagliari and Torino. RESULTS: C/C variant of polymorphism rs12979860 was related to response to interferon treatment and, above all, to spontaneous clearance of the virus. However, the positive predictive power was stronger for viral persistence than spontaneous clearance and in such respect the TT allele was more predictive than CC. The methylation associated polymorphism rs4803221 had independent effects with respect to rs12979860 and the haplotype tagged by SNP rs12979860 and rs4803221 significantly could improve the viral clearance prediction in infected patients. Neither necroinflammation or bilirubin values in the chronic phase of the hepatitis C were related to IFNL3 polymorphisms. No relation among IFNL3 polymorphisms and fibrosis stage directly shown by the liver biopsy was found. CONCLUSIONS: Also in thalassemia the SNPs on chromosome 19q13 closely associates with spontaneous and treatment-induced HCV clearance. The viral clearance prediction is significantly improved by the haplotype tagged by SNP rs12979860 and rs4803221. Neither necroinflammation, bilirubin values or fibrosis stage seem to be related to IFNL3 polymorphisms.


Assuntos
DNA/genética , Hepatite C Crônica/genética , Interleucinas/genética , Polimorfismo Genético , Talassemia beta/genética , Feminino , Genótipo , Hepacivirus/genética , Hepatite C Crônica/complicações , Hepatite C Crônica/metabolismo , Humanos , Interferons , Interleucinas/metabolismo , Masculino , RNA Viral/análise , Estudos Retrospectivos , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/metabolismo
7.
Circulation ; 128(3): 281-308, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23775258

RESUMO

This aim of this statement is to report an expert consensus on the diagnosis and treatment of cardiac dysfunction in ß-thalassemia major (TM). This consensus statement does not cover other hemoglobinopathies, including thalassemia intermedia and sickle cell anemia, in which a different spectrum of cardiovascular complications is typical. There are considerable uncertainties in this field, with a few randomized controlled trials relating to treatment of chronic myocardial siderosis but none relating to treatment of acute heart failure. The principles of diagnosis and treatment of cardiac iron loading in TM are directly relevant to other iron-overload conditions, including in particular Diamond-Blackfan anemia, sideroblastic anemia, and hereditary hemochromatosis. Heart failure is the most common cause of death in TM and primarily results from cardiac iron accumulation. The diagnosis of ventricular dysfunction in TM patients differs from that in nonanemic patients because of the cardiovascular adaptation to chronic anemia in non-cardiac-loaded TM patients, which includes resting tachycardia, low blood pressure, enlarged end-diastolic volume, high ejection fraction, and high cardiac output. Chronic anemia also leads to background symptomatology such as dyspnea, which can mask the clinical diagnosis of cardiac dysfunction. Central to early identification of cardiac iron overload in TM is the estimation of cardiac iron by cardiac T2* magnetic resonance. Cardiac T2* <10 ms is the most important predictor of development of heart failure. Serum ferritin and liver iron concentration are not adequate surrogates for cardiac iron measurement. Assessment of cardiac function by noninvasive techniques can also be valuable clinically, but serial measurements to establish trends are usually required because interpretation of single absolute values is complicated by the abnormal cardiovascular hemodynamics in TM and measurement imprecision. Acute decompensated heart failure is a medical emergency and requires urgent consultation with a center with expertise in its management. The first principle of management of acute heart failure is control of cardiac toxicity related to free iron by urgent commencement of a continuous, uninterrupted infusion of high-dose intravenous deferoxamine, augmented by oral deferiprone. Considerable care is required to not exacerbate cardiovascular problems from overuse of diuretics or inotropes because of the unusual loading conditions in TM. The current knowledge on the efficacy of removal of cardiac iron by the 3 commercially available iron chelators is summarized for cardiac iron overload without overt cardiac dysfunction. Evidence from well-conducted randomized controlled trials shows superior efficacy of deferiprone versus deferoxamine, the superiority of combined deferiprone with deferoxamine versus deferoxamine alone, and the equivalence of deferasirox versus deferoxamine.


Assuntos
American Heart Association , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/terapia , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Consenso , Insuficiência Cardíaca/fisiopatologia , Humanos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/tratamento farmacológico , Estados Unidos
8.
Blood Cells Mol Dis ; 52(1): 46-9, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23896219

RESUMO

α-Thalassemia commonly results from deletions or point mutations in one or both α-globin genes located on chromosome 16p13.3 giving rise to complex and variable genotypes and phenotypes. Rarely, unusual non-deletion defects or atypical deletions down-regulate the expression of the α-globin gene. In the last decade of the program for ß-thalassemia carrier screening and genetic counseling in Sardinia, the association of new techniques of molecular biology such as gene sequencing and Multiplex Ligation-dependent Probe Amplification (MLPA) to conventional methods has allowed to better define several thalassemic genotypes and the complex variability of the α-cluster with its flanking regions, with a high frequency of different genotypes and compound heterozygosity for two α mutations even in the same family. The exact molecular definition of the genotypes resulting from the interactions among the large number of α-thalassemia determinants and with ß-thalassemia, is important for a correct correlation of genotype-phenotype and to prevent underdiagnosis of carrier status which could hamper the effectiveness of a screening program particularly in those regions where a high frequency of hemoglobinopathies is present.


Assuntos
Genótipo , Mutação , Polimorfismo Genético , alfa-Globinas/genética , Talassemia alfa/genética , Talassemia beta/genética , Alelos , Portador Sadio , Cromossomos Humanos Par 16 , Frequência do Gene , Estudos de Associação Genética , Testes Genéticos , Heterozigoto , Humanos , Itália , Fenótipo , Índice de Gravidade de Doença , Talassemia alfa/diagnóstico , Talassemia beta/diagnóstico
9.
Blood ; 119(14): 3263-8, 2012 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-22251482

RESUMO

This was a 24-week, multicenter phase-2 study designed to assess safety, tolerability, and pharmacodynamics of FBS0701, a novel oral chelator, in adults with transfusional iron overload. Fifty-one patients, stratified by transfusional iron intake, were randomized to FBS0701 at either 14.5 or 29 mg/kg/d (16 and 32 mg/kg/d salt form). FBS0701 was generally well tolerated at both doses. Forty-nine patients (96%) completed the study. There were no drug-related serious adverse events. No adverse events (AEs) showed dose-dependency in frequency or severity. Treatment-related nausea, vomiting, abdominal pain, and diarrhea were each noted in < 5% of patients. Mean serum creatinine did not change significantly from Baseline or between dose groups. Transaminases wer increased in 8 (16%), three of whom acquired HCV on-study from a single blood bank while five had an abnormal baseline ALT. The 24 week mean change in liver iron concentration (ΔLIC) at 14.5 mg/kg/d was +3.1 mg/g (dw); 29% achieved a decrease in LIC. Mean ΔLIC at 29 mg/kg/d was -0.3 mg/g (dw); 44% achieved a decrease in LIC (P < .03 for ΔLIC between doses). The safety and tolerability profile at therapeutic doses compare favorably to other oral chelators.


Assuntos
Etil-Éteres/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Tiazóis/uso terapêutico , Reação Transfusional , Adolescente , Adulto , Creatinina/metabolismo , Relação Dose-Resposta a Droga , Etil-Éteres/efeitos adversos , Etil-Éteres/farmacologia , Feminino , Hemoglobinopatias/complicações , Hemoglobinopatias/terapia , Humanos , Ferro/análise , Ferro/metabolismo , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/farmacologia , Sobrecarga de Ferro/diagnóstico , Fígado/metabolismo , Masculino , Pessoa de Meia-Idade , Tiazóis/efeitos adversos , Tiazóis/farmacologia , Resultado do Tratamento , Adulto Jovem
10.
Blood ; 120(5): 970-7, 2012 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-22589472

RESUMO

Nontransfusion-dependent thalassemia (NTDT) patients may develop iron overload and its associated complications despite receiving only occasional or no transfusions. The present 1-year, randomized, double-blind, placebo-controlled THALASSA (Assessment of Exjade in Nontransfusion-Dependent Thalassemia) trial assessed the efficacy and safety of deferasirox in iron-overloaded NTDT patients. A total of 166 patients were randomized in a 2:1:2:1 ratio to starting doses of 5 or 10 mg/kg/d of deferasirox or placebo. The means ± SD of the actual deferasirox doses received over the duration of the study in the 5 and 10 mg/kg/d starting dose cohorts were 5.7 ± 1.4 and 11.5 ± 2.9 mg/kg/d, respectively. At 1 year, the liver iron concentration (LIC) decreased significantly compared with placebo (least-squares mean [LSM] ± SEM, -2.33 ± 0.7 mg Fe/g dry weight [dw], P = .001, and -4.18 ± 0.69 mg Fe/g dw, P < .001) for the 5 and 10 mg/kg/d deferasirox groups, respectively (baseline values [means ± SD], 13.11 ± 7.29 and 14.56 ± 7.92 mg Fe/g dw, respectively). Similarly, serum ferritin decreased significantly compared with placebo by LSM -235 and -337 ng/mL for the deferasirox 5 and 10 mg/kg/d groups, respectively (P < .001). In the placebo patients, LIC and serum ferritin increased from baseline by 0.38 mg Fe/g dw and 115 ng/mL (LSM), respectively. The most common drug-related adverse events were nausea (n = 11; 6.6%), rash (n = 8; 4.8%), and diarrhea (n = 6; 3.6%). This is the first randomized study showing that iron chelation with deferasirox significantly reduces iron overload in NTDT patients with a frequency of overall adverse events similar to placebo.


Assuntos
Benzoatos/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Talassemia/tratamento farmacológico , Triazóis/uso terapêutico , Adolescente , Adulto , Idoso , Algoritmos , Benzoatos/efeitos adversos , Benzoatos/farmacologia , Transfusão de Sangue , Criança , Deferasirox , Método Duplo-Cego , Feminino , Humanos , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/farmacologia , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/complicações , Masculino , Pessoa de Meia-Idade , Placebos , Estudos Prospectivos , Talassemia/complicações , Resultado do Tratamento , Triazóis/efeitos adversos , Triazóis/farmacologia , Adulto Jovem
11.
Haematologica ; 99(1): 76-84, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23872310

RESUMO

ß-thalassemia and sickle cell disease are widespread fatal genetic diseases. None of the existing clinical treatments provides a solution for all patients. Two main strategies for treatment are currently being investigated: (i) gene transfer of a normal ß-globin gene; (ii) reactivation of the endogenous γ-globin gene. To date, neither approach has led to a satisfactory, commonly accepted standard of care. The δ-globin gene produces the δ-globin of hemoglobin A2. Although expressed at a low level, hemoglobin A2 is fully functional and could be a valid substitute of hemoglobin A in ß-thalassemia, as well as an anti-sickling agent in sickle cell disease. Previous in vitro results suggested the feasibility of transcriptional activation of the human δ-globin gene promoter by inserting a Kruppel-like factor 1 binding site. We evaluated the activation of the Kruppel-like factor 1 containing δ-globin gene in vivo in transgenic mice. To evaluate the therapeutic potential we crossed the transgenic mice carrying a single copy activated δ-globin gene with a mouse model of ß-thalassemia intermedia. We show that the human δ-globin gene can be activated in vivo in a stage- and tissue-specific fashion simply by the insertion of a Kruppel-like factor 1 binding site into the promoter. In addition the activated δ-globin gene gives rise to a robust increase of the hemoglobin level in ß-thalassemic mice, effectively improving the thalassemia phenotype. These results demonstrate, for the first time, the therapeutic potential of the δ-globin gene for treating severe hemoglobin disorders which could lead to novel approaches, not involving gene addition or reactivation, to the cure of ß-hemoglobinopathies.


Assuntos
Ativação Transcricional , Talassemia beta/genética , Globinas delta/genética , Animais , Modelos Animais de Doenças , Eritrócitos/citologia , Eritrócitos/metabolismo , Eritropoese/genética , Expressão Gênica , Ordem dos Genes , Genes Reporter , Loci Gênicos , Humanos , Ferro/metabolismo , Camundongos , Camundongos Transgênicos , Fenótipo , Regiões Promotoras Genéticas , Talassemia beta/terapia , Globinas delta/química , Globinas delta/metabolismo
12.
Br J Haematol ; 163(3): 400-3, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24033185

RESUMO

This study aimed to verify the impact of heart magnetic resonance imaging on chelation choices and patient compliance in a single-institution cohort as well as its predictive value for heart failure and arrhythmias. Abnormal cardiac T2* values determined changes in treatment in most subjects. Heart T2* was confirmed to be highly predictive over 1 year for heart failure and arrhythmias. The choice of chelation regimens known to remove heart iron efficiently was not sufficient by itself to influence the risk. Compliance with treatment had a more remarkable role.


Assuntos
Arritmias Cardíacas/etiologia , Terapia por Quelação/métodos , Insuficiência Cardíaca/etiologia , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/diagnóstico , Imageamento por Ressonância Magnética , Miocárdio/patologia , Cooperação do Paciente , Talassemia beta/patologia , Adulto , Área Sob a Curva , Arritmias Cardíacas/epidemiologia , Arritmias Cardíacas/prevenção & controle , Benzoatos/administração & dosagem , Benzoatos/uso terapêutico , Deferasirox , Deferiprona , Desferroxamina/administração & dosagem , Desferroxamina/uso terapêutico , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Feminino , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/prevenção & controle , Humanos , Ferro/análise , Quelantes de Ferro/administração & dosagem , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/patologia , Sobrecarga de Ferro/prevenção & controle , Masculino , Miocárdio/química , Valor Preditivo dos Testes , Piridonas/administração & dosagem , Piridonas/uso terapêutico , Curva ROC , Risco , Estudos de Amostragem , Reação Transfusional , Triazóis/administração & dosagem , Triazóis/uso terapêutico , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Talassemia beta/terapia
13.
Br J Haematol ; 161(6): 872-83, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23600689

RESUMO

We conducted a cross-sectional study on 924 ß-thalassaemia major patients (mean age 30·1 years) treated at nine Italian centres using the WEBTHAL software, to evaluate real-life application of iron overload assessment and management standards. Serum ferritin <2500 ng/ml was a risk factor for never having liver iron concentration (LIC) measurement, while absence of cardiac disease and siderosis were risk factors for a delay in LIC measurement >2 years. Patients who never had a cardiac MRI (CMR) T2* measurement were <18 years, had iron intake ≤0·4 mg/kg per day, or a serum ferritin <2500 ng/ml. A history of normal CMR T2* was the main risk factor for a delay in subsequent assessment of >2 years. Deferoxamine (22·8%) was more commonly used in patients with Hepatitis C Virus or high serum creatinine. Deferiprone (20·6%) was less commonly prescribed in patients with elevated alanine aminotransferase; while a deferoxamine + deferiprone combination (17·9%) was more commonly used in patients with serum ferritin >2500 ng/ml or CMR T2* <20 ms. Deferasirox (38·3%) was more commonly prescribed in patients <18 years, but less commonly used in those with heart disease or high iron intake. These observations largely echoed guidelines at the time, although some practices are expected to change in light of evolving evidence.


Assuntos
Gerenciamento Clínico , Sobrecarga de Ferro/etiologia , Software , Talassemia beta/complicações , Adulto , Benzoatos/administração & dosagem , Benzoatos/uso terapêutico , Estudos Transversais , Deferasirox , Deferiprona , Desferroxamina/administração & dosagem , Desferroxamina/uso terapêutico , Feminino , Humanos , Ferro/metabolismo , Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/tratamento farmacológico , Itália , Fígado/metabolismo , Masculino , Piridonas/administração & dosagem , Piridonas/uso terapêutico , Triazóis/administração & dosagem , Triazóis/uso terapêutico , Adulto Jovem
14.
Blood ; 118(16): 4454-8, 2011 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-21821711

RESUMO

Increased hemoglobin A(2) (HbA(2); ie, levels > 3.9%) is the most important feature of ß-thalassemia carriers. However, it is not uncommon to find persons with borderline HbA(2) (levels, 3.3%-3.8%), who pose a relevant screening problem. Several genotypes have been associated with borderline HbA(2), but sometimes the reasons for this unusual phenotype are unknown. In this paper, we report, for the first time, that mutations of KLF1 result in HbA(2) levels in the borderline range. Six different KLF1 mutations were identified in 52 of 145 subjects with borderline HbA(2) and normal mean corpuscular volume and mean corpuscular hemoglobin. Two mutations (T327S and T280_H283del) are here reported for the first time. The prevalent mutation in Sardinians is S270X, which accounts for 80.8% of the total. The frequent discovery of KLF1 mutations in these atypical carriers may contribute significantly to the thalassemia screening programs aimed at identification of at risk couples.


Assuntos
Hemoglobina A2/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Mutação , Talassemia beta/diagnóstico , Talassemia beta/genética , Índices de Eritrócitos , Feminino , Humanos , Masculino , Linhagem , Talassemia beta/metabolismo
15.
Haematologica ; 98(1): 129-35, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22875626

RESUMO

Patients with ß-thalassemia require iron chelation therapy to protect against progressive iron overload and non-transferrin-bound iron. Some patients fail to respond adequately to deferoxamine and deferasirox monotherapy while others have side effects which limit their use of these drugs. Since combining deferiprone and deferoxamine has an additive effect, placing all patients into net negative iron balance, we investigated the possibility that combining deferasirox and deferoxamine would lead to similar results. We conducted 34-day metabolic iron balance studies in six patients in whom the relative effectiveness of deferasirox (30 mg/kg/day) and deferoxamine (40 mg/kg/day) was compared, alone and in combination. Patients consumed fixed low-iron diets; daily urinary and stool iron excretion were determined by atomic absorption. Red blood cell transfusions were given prior to each drug treatment to minimize the effects of ineffective erythropoiesis. Serial safety measures, hematologic parameters, serum chemistries, ferritin levels and urinalyses were determined. All patients were in negative iron balance when treated with deferoxamine alone while four of six patients remained in positive balance when deferasirox monotherapy was evaluated. Daily use of both drugs had a synergistic effect in two patients and an additive effect in three others. Five of six patients would be in negative iron balance if they used the combination of drugs just 3 days a week. No significant or drug-related changes were observed in the blood work-ups or urinalyses performed. We conclude that supplementing the daily use of deferasirox with 2 - 3 days of deferoxamine therapy would place all patients into net negative iron balance thereby providing a convenient way to tailor chelation therapy to the individual needs of each patient.


Assuntos
Benzoatos/administração & dosagem , Desferroxamina/administração & dosagem , Triazóis/administração & dosagem , Talassemia beta/tratamento farmacológico , Talassemia beta/metabolismo , Adulto , Deferasirox , Quimioterapia Combinada , Feminino , Humanos , Ferro/sangue , Ferro/urina , Quelantes de Ferro/administração & dosagem , Masculino
16.
Ann Hematol ; 92(11): 1485-93, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23775581

RESUMO

Patients with non-transfusion-dependent thalassemia (NTDT) often develop iron overload that requires chelation to levels below the threshold associated with complications. This can take several years in patients with high iron burden, highlighting the value of long-term chelation data. Here, we report the 1-year extension of the THALASSA trial assessing deferasirox in NTDT; patients continued with deferasirox or crossed from placebo to deferasirox. Of 133 patients entering extension, 130 completed. Liver iron concentration (LIC) continued to decrease with deferasirox over 2 years; mean change was -7.14 mg Fe/g dry weight (dw) (mean dose 9.8 ± 3.6 mg/kg/day). In patients originally randomized to placebo, whose LIC had increased by the end of the core study, LIC decreased in the extension with deferasirox with a mean change of -6.66 mg Fe/g dw (baseline to month 24; mean dose in extension 13.7 ± 4.6 mg/kg/day). Of 166 patients enrolled, 64 (38.6 %) and 24 (14.5 %) patients achieved LIC <5 and <3 mg Fe/g dw by the end of the study, respectively. Mean LIC reduction was greatest in patients with the highest pretreatment LIC. Deferasirox progressively decreases iron overload over 2 years in NTDT patients with both low and high LIC. Safety profile of deferasirox over 2 years was consistent with that in the core study.


Assuntos
Benzoatos/uso terapêutico , Transfusão de Sangue , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Talassemia/tratamento farmacológico , Triazóis/uso terapêutico , Estudos Cross-Over , Deferasirox , Método Duplo-Cego , Humanos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/epidemiologia , Estudos Prospectivos , Talassemia/sangue , Talassemia/epidemiologia , Fatores de Tempo , Resultado do Tratamento
17.
Eur J Haematol ; 90(6): 501-7, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23414443

RESUMO

BACKGROUND: Transfusion-acquired hepatitis C virus (HCV) remains an important problem among patients with thalassemia. In this study, we evaluated the natural history of post-transfusional hepatitis C in thalassemia major, paying special attention to spontaneous viral clearance, to factors influencing the chronicity rate and fibrosis progression. DESIGN AND METHODS: A prospective study to evaluate the incidence and etiology of transfusion-related hepatitis was started in 1980. In patients who developed hepatitis C, HCV RNA, ALT, and ferritin were measured over time. The correlation between interleukin-28B gene polymorphisms and viral clearance was also analyzed. RESULTS: Seventy-three of 135 patients (62.2%) acquired HCV. An extended follow-up (22 to 30 yr) with HCV RNA assessment was available in 52 patients. Of them, 23 (44.2%) cleared the virus. The proportion of IL-28B genotypes was different between the subjects who cleared the virus and the subjects who did not. Fibrosis progression was similar in HCV RNA-positive and HCV RNA-negative patients. Liver iron was the only factor associated with the fibrosis. CONCLUSIONS: In thalassemia patients with HCV infection, liver iron does not play a major role in influencing the chronicity rate, whereas it is significantly associated with the fibrosis.


Assuntos
Transfusão de Sangue , Patógenos Transmitidos pelo Sangue , Hepacivirus , Hepatite C Crônica , Interleucinas , Polimorfismo Genético , RNA Viral , Talassemia beta , Criança , Pré-Escolar , Feminino , Seguimentos , Hepacivirus/genética , Hepacivirus/metabolismo , Hepatite C Crônica/sangue , Hepatite C Crônica/genética , Humanos , Lactente , Interferons , Interleucinas/sangue , Interleucinas/genética , Ferro/metabolismo , Fígado/metabolismo , Fígado/virologia , Masculino , Estudos Prospectivos , RNA Viral/sangue , RNA Viral/genética , Estudos Retrospectivos , Talassemia beta/sangue , Talassemia beta/genética , Talassemia beta/virologia
18.
Am J Hematol ; 88(6): 503-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23553596

RESUMO

The 1-year THALASSA study enrolled 166 patients with various non-transfusion-dependent thalassemia (NTDT) syndromes, degrees of iron burden and patient characteristics, and demonstrated the overall efficacy and safety of deferasirox in reducing liver iron concentration (LIC) in these patients. Here, reduction in LIC with deferasirox 5 and 10 mg/kg/day starting dose groups is shown to be consistent across the following patient subgroups-baseline LIC/serum ferritin, age, gender, race, splenectomy (yes/no), and underlying NTDT syndrome (ß-thalassemia intermedia, HbE/ß-thalassemia or α-thalassemia). These analyses also evaluated deferasirox dosing strategies for patients with NTDT. Greater reductions in LIC were achieved in patients dose-escalated at Week 24 from deferasirox 10 mg/kg/day starting dose to 20 mg/kg/day. Patients who received an average actual dose of deferasirox >12.5-≤17.5 mg/kg/day achieved a greater LIC decrease compared with the ≥7.5-≤12.5 mg/kg/day and >0-<7.5 mg/kg/day subgroups, demonstrating a dose-response efficacy. LIC reduction across patient subgroups was generally consistent with the primary efficacy analysis with a similar safety profile.


Assuntos
Benzoatos/administração & dosagem , Quelantes de Ferro/administração & dosagem , Fígado/efeitos dos fármacos , Fígado/metabolismo , Talassemia/tratamento farmacológico , Talassemia/metabolismo , Triazóis/administração & dosagem , Adulto , Benzoatos/efeitos adversos , Deferasirox , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Ferritinas/sangue , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/metabolismo , Masculino , Talassemia/sangue , Triazóis/efeitos adversos , Adulto Jovem
19.
Circulation ; 123(14): 1519-28, 2011 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-21444881

RESUMO

BACKGROUND: Measurement of myocardial iron is key to the clinical management of patients at risk of siderotic cardiomyopathy. The cardiovascular magnetic resonance relaxation parameter R2* (assessed clinically via its reciprocal, T2*) measured in the ventricular septum is used to assess cardiac iron, but iron calibration and distribution data in humans are limited. METHODS AND RESULTS: Twelve human hearts were studied from transfusion-dependent patients after either death (heart failure, n=7; stroke, n=1) or transplantation for end-stage heart failure (n=4). After cardiovascular magnetic resonance R2* measurement, tissue iron concentration was measured in multiple samples of each heart with inductively coupled plasma atomic emission spectroscopy. Iron distribution throughout the heart showed no systematic variation between segments, but epicardial iron concentration was higher than in the endocardium. The mean ± SD global myocardial iron causing severe heart failure in 10 patients was 5.98 ± 2.42 mg/g dry weight (range, 3.19 to 9.50 mg/g), but in 1 outlier case of heart failure was 25.9 mg/g dry weight. Myocardial ln[R2*] was strongly linearly correlated with ln[Fe] (R²=0.910, P<0.001), leading to [Fe]=45.0×(T2*)⁻¹·²² for the clinical calibration equation with [Fe] in milligrams per gram dry weight and T2* in milliseconds. Midventricular septal iron concentration and R2* were both highly representative of mean global myocardial iron. CONCLUSIONS: These data detail the iron distribution throughout the heart in iron overload and provide calibration in humans for cardiovascular magnetic resonance R2* against myocardial iron concentration. The iron values are of considerable interest in terms of the level of cardiac iron associated with iron-related death and indicate that the heart is more sensitive to iron loading than the liver. The results also validate the current clinical practice of monitoring cardiac iron in vivo by cardiovascular magnetic resonance of the midseptum.


Assuntos
Ferro/metabolismo , Imageamento por Ressonância Magnética/métodos , Miocárdio/metabolismo , Miocárdio/patologia , Adolescente , Adulto , Cadáver , Criança , Feminino , Átrios do Coração/metabolismo , Átrios do Coração/patologia , Valvas Cardíacas/metabolismo , Valvas Cardíacas/patologia , Ventrículos do Coração/metabolismo , Ventrículos do Coração/patologia , Humanos , Sobrecarga de Ferro/metabolismo , Masculino , Pessoa de Meia-Idade , Septo Interventricular/metabolismo , Septo Interventricular/patologia , Adulto Jovem
20.
Blood Cells Mol Dis ; 48(2): 121-3, 2012 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-22169218

RESUMO

Mutations in TMPRSS6 gene cause iron-refractory iron deficiency anemia, a rare autosomal recessive disorder characterized by hypochromic microcytic anemia not responsive to oral iron therapy and partially responsive to parenteral iron administration. Here we report a female infant homozygous for a loss of function mutation in TMPRSS6 gene, who responded to oral iron therapy when supplemented with ascorbic acid.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Ácido Ascórbico/administração & dosagem , Ferro/administração & dosagem , Administração Oral , Anemia Ferropriva/sangue , Anemia Ferropriva/genética , Índices de Eritrócitos , Feminino , Humanos , Lactente , Proteínas de Membrana/genética , Mutação , Serina Endopeptidases/genética
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