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1.
Artigo em Inglês | MEDLINE | ID: mdl-37690980

RESUMO

INTRODUCTION: Despite knowledge advances on extramedullary haematopoiesis (EMH) in thalassemic patients, the real picture remains an open issue. OBJECTIVES: To assess EMH prevalence in patients with thalassemia major (TM) and intermedia (TI), to describe magnetic resonance imaging (MRI) findings and to explore clinical risk factors. METHODS: In this cross-sectional study, images and clinical records of 184 consecutive patients with thalassemia who underwent T2* MRI between 2004 and 2011 were reviewed. Association of EMH with survival was investigated for patients with available follow-up charts. RESULTS: EMH was detected in 16/168 (9.5%) patients with TM (aged 19-49 years) and in 3/16 (18.8%) with TI (aged 36-41 years). Most (88%) had paravertebral thoracic and/or abdominal masses. Age was significantly associated with EMH risk (hazard ratio, [HR] 1.10/year; confidence interval [CI]: 1.03-1.18; p-value < 0.001), while lower pancreatic iron content by T2*MRI (HR: 0.94/ms; CI: 0.89-0.99; p-value = 0.049) was a protective factor. Estimated survival rate was superior for EMH-positive (n = 19) when compared to EMH-negative patients (n = 75) (p-value = 0.013). CONCLUSIONS: The prevalence of EMH was 10.3% (19/184), presented mainly as tumoral masses of 3 to 10 cm. Age was a risk factor for EMH development, while lower pancreatic iron might be a protective factor in this cohort.

2.
Am J Hematol ; 98(9): 1415-1424, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37401738

RESUMO

Children with transfusion-dependent thalassemia (TDT) require regular blood transfusions that, without iron-chelation therapy, lead to iron-overload toxicities. Current practice delays chelation therapy (late-start) until reaching iron overload (serum ferritin ≥1000 µg/L) to minimize risks of iron-depletion. Deferiprone's distinct pharmacological properties, including iron-shuttling to transferrin, may reduce risks of iron depletion during mild-to-moderate iron loads and iron overload/toxicity in children with TDT. The early-start deferiprone (START) study evaluated the efficacy/safety of early-start deferiprone in infants/young children with TDT. Sixty-four infants/children recently diagnosed with beta-thalassemia and serum ferritin (SF) between 200 and 600 µg/L were randomly assigned 1:1 to receive deferiprone or placebo for 12 months or until reaching SF-threshold (≥1000 µg/L at two consecutive visits). Deferiprone was initiated at 25 mg/kg/day and increased to 50 mg/kg/day; some recipients' dosages increased to 75 mg/kg/day based on iron levels. The primary endpoint was the proportion of patients ≥SF-threshold by month 12. Monthly transferrin saturation (TSAT) assessment evaluated iron-shuttling. At baseline, there was no significant difference in mean age (deferiprone: 3.03 years, placebo: 2.63 years), SF (deferiprone: 513.8 µg/L, placebo: 451.7 µg/L), or TSAT (deferiprone: 47.98%, placebo: 43.43%) between groups. At month 12, there was no significant difference in growth or adverse event (AE) rates between groups. No deferiprone-treated patients were iron-depleted. At month 12, 66% of patients receiving deferiprone remained below SF threshold versus 39% of placebo (p = .045). Deferiprone-treated patients showed higher TSAT levels and reached ≥60% TSAT threshold faster. Early-start deferiprone was well-tolerated, not associated with iron depletion, and efficacious in reducing iron overload in infants/children with TDT. TSAT results provide the first clinical evidence of deferiprone shuttling iron to transferrin.


Assuntos
Sobrecarga de Ferro , Talassemia beta , Humanos , Criança , Lactente , Pré-Escolar , Ferro , Talassemia beta/tratamento farmacológico , Quelantes de Ferro/efeitos adversos , Transferrina , Ferritinas , Piridonas/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia
3.
Hematol., Transfus. Cell Ther. (Impr.) ; 45(1): 7-15, Jan.-Mar. 2023. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1421549

RESUMO

Abstract Introduction Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia. Methods We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011. Results We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation. Conclusions Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.


Assuntos
Humanos , Criança , Talassemia , Sobrecarga de Ferro , Terapia por Quelação
4.
Hematol Transfus Cell Ther ; 45(1): 7-15, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34090847

RESUMO

INTRODUCTION: Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia. METHODS: We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011. RESULTS: We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation. CONCLUSIONS: Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.

5.
Blood Adv ; 7(4): 611-619, 2023 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-36018224

RESUMO

Long-term safety and efficacy data on the iron chelator deferiprone in sickle cell disease (SCD) and other anemias are limited. FIRST-EXT was a 2-year extension study of FIRST (Ferriprox in Patients With Iron Overload in Sickle Cell Disease Trial), a 1-year, randomized noninferiority study of deferiprone vs deferoxamine in these populations. Patients who entered FIRST-EXT continued to receive, or were switched to, deferiprone. Altogether, 134 patients were enrolled in FIRST-EXT (mean age: 16.2 years), with mean (SD) exposure to deferiprone of 2.1 (0.8) years over the 2 studies. The primary end point was safety. Secondary end points were change in liver iron concentration (LIC), cardiac T2∗, serum ferritin (SF), and the proportion of responders (≥20% improvement in efficacy measure). The most common adverse events considered at least possibly related to deferiprone were neutropenia (9.0%) and abdominal pain (7.5%). LIC (mg/g dry weight) decreased over time, with mean (SD) changes from baseline at each time point (year 1, -2.64 [4.64]; year 2, -3.91 [6.38]; year 3, -6.64 [7.72], all P < .0001). Mean SF levels (µg/L) decreased significantly after year 2 (-771, P = .0008) and year 3 (-1016, P = .0420). Responder rates for LIC and SF increased each year (LIC: year 1, 46.5%; year 2, 57.1%; year 3, 66.1%; SF: year 1, 35.2%; year 2, 55.2%; year 3, 70.9%). Cardiac T2∗ remained normal in all patients. In conclusion, long-term therapy with deferiprone was not associated with new safety concerns and led to continued and progressive reduction in iron load in individuals with SCD or other anemias. The trial was registered at www.clinicaltrials.gov as #NCT02443545.


Assuntos
Anemia Falciforme , Sobrecarga de Ferro , Adolescente , Humanos , Anemia Falciforme/terapia , Ferritinas , Ferro/metabolismo , Quelantes de Ferro , Piridonas/efeitos adversos
8.
Blood Adv ; 6(4): 1243-1254, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-34847228

RESUMO

Many people with sickle cell disease (SCD) or other anemias require chronic blood transfusions, which often causes iron overload that requires chelation therapy. The iron chelator deferiprone is frequently used in individuals with thalassemia syndromes, but data in patients with SCD are limited. This open-label study assessed the efficacy and safety of deferiprone in patients with SCD or other anemias receiving chronic transfusion therapy. A total of 228 patients (mean age: 16.9 [range, 3-59] years; 46.9% female) were randomized to receive either oral deferiprone (n = 152) or subcutaneous deferoxamine (n = 76). The primary endpoint was change from baseline at 12 months in liver iron concentration (LIC), assessed by R2* magnetic resonance imaging (MRI). The least squares mean (standard error) change in LIC was -4.04 (0.48) mg/g dry weight for deferiprone vs -4.45 (0.57) mg/g dry weight for deferoxamine, with noninferiority of deferiprone to deferoxamine demonstrated by analysis of covariance (least squares mean difference 0.40 [0.56]; 96.01% confidence interval, -0.76 to 1.57). Noninferiority of deferiprone was also shown for both cardiac T2* MRI and serum ferritin. Rates of overall adverse events (AEs), treatment-related AEs, serious AEs, and AEs leading to withdrawal did not differ significantly between the groups. AEs related to deferiprone treatment included abdominal pain (17.1% of patients), vomiting (14.5%), pyrexia (9.2%), increased alanine transferase (9.2%) and aspartate transferase levels (9.2%), neutropenia (2.6%), and agranulocytosis (0.7%). The efficacy and safety profiles of deferiprone were acceptable and consistent with those seen in patients with transfusion-dependent thalassemia. This trial study was registered at www://clinicaltrials.gov as #NCT02041299.


Assuntos
Anemia Falciforme , Sobrecarga de Ferro , Talassemia , Adolescente , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Transfusão de Sangue , Deferiprona/uso terapêutico , Desferroxamina/efeitos adversos , Feminino , Humanos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Masculino , Piridonas/efeitos adversos , Talassemia/complicações , Talassemia/tratamento farmacológico , Transferases
9.
Am J Hematol ; 93(2): 262-268, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29119631

RESUMO

Iron overload is inevitable in patients who are transfusion dependent. In young children with transfusion-dependent thalassemia (TDT), current practice is to delay the start of iron chelation therapy due to concerns over toxicities, which have been observed when deferoxamine was started too early. However, doing so may increase the risk of iron accumulation that will be manifested as toxicities later in life. This study investigated whether deferiprone, a chelator with a lower affinity for iron than deferoxamine, could postpone transfusional iron overload while maintaining a good safety profile. Recently diagnosed TDT infants (N = 64 their age ranged from 10 to 18 (median 12) months, 54.7% males; receiving ≤6 transfusions; serum ferittin (SF) >400 to < 1000 ng/mL were randomized to "early start deferiprone" (.ES-DFP) at a low dose (50 mg/kg/day) or to "delay chelation" (DC), and remained in the study until their serum ferritin (SF) level reached ≥1000 µg/L. 61 patients continued the study Levels of transferrin saturation (TSAT) and labile plasma iron (LPI) were measured as well. By approximately 6 months postrandomization, 100% of the subjects in DC group had achieved SF > 1000 µg/L and TSAT > 70% compared with none in the ES-DFP group. LPI level > 0.6 µM was observed in 97% vs. 40% of the DS and ES groups, respectively, (P < 0.001). The time to reach SF > 1000 µg/L was delayed by 6 months in the ES-DFP group (P < 0.001) without escalating DFP dose. No unexpected, serious, or severe adverse events were seen in the ES-DFP group.


Assuntos
Terapia por Quelação/métodos , Deferiprona/uso terapêutico , Quelantes de Ferro/uso terapêutico , Talassemia/terapia , Transfusão de Sangue , Deferiprona/efeitos adversos , Feminino , Ferritinas/sangue , Humanos , Lactente , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Masculino , Resultado do Tratamento
10.
Sci Rep ; 7(1): 1398, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28469157

RESUMO

Parkinson's disease (PD) is associated with increased iron levels in the substantia nigra (SNc). This study evaluated whether the iron chelator, deferiprone, is well tolerated, able to chelate iron from various brain regions and improve PD symptomology. In a randomised double-blind, placebo controlled trial, 22 early onset PD patients, were administered deferiprone, 10 or 15 mg/kg BID or placebo, for 6 months. Patients were evaluated for PD severity, cognitive function, depression rating and quality of life. Iron concentrations were assessed in the substantia nigra (SNc), dentate and caudate nucleus, red nucleus, putamen and globus pallidus by T2* MRI at baseline and after 3 and 6 months of treatment. Deferiprone therapy was well tolerated and was associated with a reduced dentate and caudate nucleus iron content compared to placebo. Reductions in iron content of the SNc occurred in only 3 patients, with no changes being detected in the putamen or globus pallidus. Although 30 mg/kg deferiprone treated patients showed a trend for improvement in motor-UPDRS scores and quality of life, this did not reach significance. Cognitive function and mood were not adversely affected by deferiprone therapy. Such data supports more extensive clinical trials into the potential benefits of iron chelation in PD.


Assuntos
Química Encefálica/efeitos dos fármacos , Quelantes de Ferro/uso terapêutico , Ferro/metabolismo , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Piridonas/uso terapêutico , Idoso , Encéfalo/diagnóstico por imagem , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Deferiprona , Método Duplo-Cego , Feminino , Humanos , Inflamação/sangue , Inflamação/induzido quimicamente , Ferro/urina , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico por imagem , Estudos Prospectivos , Piridonas/sangue
11.
PLoS One ; 11(5): e0154842, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27191165

RESUMO

UNLABELLED: Antiretrovirals suppress HIV-1 production yet spare the sites of HIV-1 production, the HIV-1 DNA-harboring cells that evade immune detection and enable viral resistance on-drug and viral rebound off-drug. Therapeutic ablation of pathogenic cells markedly improves the outcome of many diseases. We extend this strategy to HIV-1 infection. Using drug-based lead discovery, we report the concentration threshold-dependent antiretroviral action of the medicinal chelator deferiprone and validate preclinical findings by a proof-of-concept double-blind trial. In isolate-infected primary cultures, supra-threshold concentrations during deferiprone monotherapy caused decline of HIV-1 RNA and HIV-1 DNA; did not allow viral breakthrough for up to 35 days on-drug, indicating resiliency against viral resistance; and prevented, for at least 87 days off-drug, viral rebound. Displaying a steep dose-effect curve, deferiprone produced infection-independent deficiency of hydroxylated hypusyl-eIF5A. However, unhydroxylated deoxyhypusyl-eIF5A accumulated particularly in HIV-infected cells; they preferentially underwent apoptotic DNA fragmentation. Since the threshold, ascertained at about 150 µM, is achievable in deferiprone-treated patients, we proceeded from cell culture directly to an exploratory trial. HIV-1 RNA was measured after 7 days on-drug and after 28 and 56 days off-drug. Subjects who attained supra-threshold concentrations in serum and completed the protocol of 17 oral doses, experienced a zidovudine-like decline of HIV-1 RNA on-drug that was maintained off-drug without statistically significant rebound for 8 weeks, over 670 times the drug's half-life and thus clearance from circulation. The uniform deferiprone threshold is in agreement with mapping of, and crystallographic 3D-data on, the active site of deoxyhypusyl hydroxylase (DOHH), the eIF5A-hydroxylating enzyme. We propose that deficiency of hypusine-containing eIF5A impedes the translation of mRNAs encoding proline cluster ('polyproline')-containing proteins, exemplified by Gag/p24, and facilitated by the excess of deoxyhypusine-containing eIF5A, releases the innate apoptotic defense of HIV-infected cells from viral blockade, thus depleting the cellular reservoir of HIV-1 DNA that drives breakthrough and rebound. TRIAL REGISTRATION: ClinicalTrial.gov NCT02191657.


Assuntos
Fármacos Anti-HIV/uso terapêutico , Infecções por HIV/tratamento farmacológico , Piridonas/uso terapêutico , Adolescente , Adulto , Fármacos Anti-HIV/administração & dosagem , Fármacos Anti-HIV/efeitos adversos , Fármacos Anti-HIV/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Células Cultivadas , Deferiprona , Relação Dose-Resposta a Droga , Método Duplo-Cego , Descoberta de Drogas , Feminino , HIV-1/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Piridonas/farmacologia
12.
Hemoglobin ; 38(2): 119-26, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24502375

RESUMO

Southern China has one of the world's largest population of patients needing transfusions. Transfusion and chelation are not uniformly available and no magnetic resonance imaging (MRI) assessment data exists to date. A total of 153 young ß-thalassemia major (ß-TM) patients were assessed using a validated 1.5T scanner in Hong Kong, People's Republic of China (PRC). Their median age was 13 (range 7 to 30), and most patients were young (22.0% age <10, 73.0% age <15, 88.0% age <18). Erratic health care made estimation of total transfusion and chelation exposure impossible. Despite their early age, 24.0% had severe cardiac hemosiderosis [T2*<10 milliseconds (ms)], at ages as early as 8 years old. Median heart iron was 1.68 mg/g dry weight (range 0.19-7.66) and increased with age (p = 0.017), while liver iron was 22.2 mg/g dry weight (range 3.15 to 39.2). Serum ferritin levels were poor predictors of heart and liver, or pancreatic R* and pituitary R* values. Magnetic resonance imaging scans are needed to screen very young ß-TM patients with immediate risk of premature cardiac death in developing nations and triage them to more intensive treatment. This is particularly important in countries with a large number of patients and limited resources. Our data suggests that in developing countries, there is no lower limit for thalassemia MRI scanning programs.


Assuntos
Sobrecarga de Ferro/diagnóstico , Avaliação das Necessidades/normas , Garantia da Qualidade dos Cuidados de Saúde/normas , Talassemia beta/diagnóstico , Adolescente , Adulto , Criança , China/epidemiologia , Ferritinas/sangue , Cardiopatias/diagnóstico , Cardiopatias/epidemiologia , Hemossiderose/diagnóstico , Hemossiderose/epidemiologia , Humanos , Sobrecarga de Ferro/epidemiologia , Sobrecarga de Ferro/terapia , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem , Talassemia beta/epidemiologia , Talassemia beta/terapia
13.
Pediatr Blood Cancer ; 61(5): 879-84, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24376176

RESUMO

BACKGROUND: A risk associated with the iron chelator deferiprone is the development of neutropenia or agranulocytosis. Accordingly, the product label recommends weekly blood monitoring and immediate interruption of treatment upon detection of an absolute neutrophil count (ANC) <1.5 × 10(9)/L, out of concern that continued therapy might lead to a more severe drop. However, it is uncertain how these recommendations are followed under real-life conditions and, if they are not followed, whether continuation of therapy results in increased incidence of agranulocytosis. PROCEDURE: This non-interventional surveillance program assessed the monitoring of deferiprone therapy in clinical practice. A total of 294 patients with transfusion-dependent anemias received deferiprone, as monotherapy or with another chelator, for up to 1 year. The participating physicians were not given any instructions about treatment and monitoring beyond being referred to the information in the package insert. RESULTS: ANC monitoring was conducted at an average interval of 5 ± 4 weeks, and deferiprone was not always interrupted upon detection of neutropenia. One patient (0.3%) experienced agranulocytosis, and nine others (3%) experienced a total of 11 episodes of neutropenia. All neutropenia episodes resolved; median time to resolution was similar whether or not treatment was interrupted; and no case of neutropenia progressed to agranulocytosis. CONCLUSIONS: These data indicate that less frequent ANC monitoring and continuation of deferiprone therapy during neutropenia are not associated with prolonged neutropenia or with progression to agranulocytosis.


Assuntos
Agranulocitose/prevenção & controle , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Neutropenia/prevenção & controle , Guias de Prática Clínica como Assunto , Padrões de Prática Médica , Piridonas/uso terapêutico , Adolescente , Adulto , Agranulocitose/induzido quimicamente , Transfusão de Sangue , Criança , Pré-Escolar , Deferiprona , Feminino , Seguimentos , Humanos , Lactente , Sobrecarga de Ferro/complicações , Masculino , Pessoa de Meia-Idade , Neutropenia/induzido quimicamente , Neutrófilos , Estudos Prospectivos , Resultado do Tratamento , Adulto Jovem
14.
Pharmacoeconomics ; 31(9): 807-22, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23868464

RESUMO

BACKGROUND: Patients with ß-thalassaemia major experience chronic iron overload due to regular blood transfusions. Chronic iron overload can be treated using iron-chelating therapies such as desferrioxamine (DFO), deferiprone (DFP) and deferasirox (DFX) monotherapy, or DFO-DFP combination therapy. OBJECTIVES: This study evaluated the relative cost effectiveness of these regimens over a 5-year timeframe from a UK National Health Service (NHS) perspective, including personal and social services. METHODS: A Markov model was constructed to evaluate the cost effectiveness of the treatment regimens over 5 years. Based on published randomized controlled trial evidence, it was assumed that all four treatment regimens had a comparable effect on serum ferritin concentration (SFC) and liver iron concentration (LIC), and that DFP was more effective for reducing cardiac morbidity and mortality. Published utility scores for route of administration were used, with subcutaneously administered DFO assumed to incur a greater quality of life (QoL) burden than the oral chelators DFP and DFX. Healthcare resource use, drug costs (2010/2011 costs), and utilities associated with adverse events were also considered, with the effect of varying all parameters assessed in sensitivity analysis. Incremental costs and quality-adjusted life-years (QALYs) were calculated for each treatment, with cost effectiveness expressed as incremental cost per QALY. Assumptions that DFP conferred no cardiac morbidity, mortality, or morbidity and mortality benefit were also explored in scenario analysis. RESULTS: DFP was the dominant strategy in all scenarios modelled, providing greater QALY gains at a lower cost. Sensitivity analysis showed that DFP dominated all other treatments unless the QoL burden associated with the route of administration was greater for DFP than for DFO, which is unlikely to be the case. DFP had >99 % likelihood of being cost effective against all comparators at a willingness-to-pay threshold of £20,000 per QALY. CONCLUSIONS: In this analysis, DFP appeared to be the most cost-effective treatment available for managing chronic iron overload in ß-thalassaemia patients. Use of DFP in these patients could therefore result in substantial cost savings.


Assuntos
Quelantes de Ferro/economia , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/economia , Piridonas/economia , Piridonas/uso terapêutico , Talassemia beta/complicações , Talassemia beta/economia , Análise Custo-Benefício/economia , Deferiprona , Custos de Medicamentos , Custos de Cuidados de Saúde , Humanos , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/complicações , Modelos Econômicos , Piridonas/efeitos adversos , Qualidade de Vida , Anos de Vida Ajustados por Qualidade de Vida , Reino Unido , Talassemia beta/tratamento farmacológico
15.
Einstein (Säo Paulo) ; 9(2)abr.-jun. 2011. tab, mapas
Artigo em Inglês, Português | LILACS | ID: lil-594925

RESUMO

Objectives: To evaluate the use of magnetic resonance imaging in patients with Beta-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. Methods: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. Results: The mean serum ferritin was 2,676.5+/- 2,051.7ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= -0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). Conclusion: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. Therewas no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values.


Objetivo: Avaliar o acúmulo de ferro em diferentes órgãos por meio da ressonância nuclear magnética T2* e correlacionar os resultados aos níveis de ferritina sérica, ferro plasmático lábil e outros órgãos envolvidos. Métodos: Foram avaliados retrospectivamente 115 pacientes talassêmicos (sendo 65 mulheres). A concentração hepática de ferro foi determinada em biópsia de 11 pacientes; os resultados foram comparados com os valores de T2* fígado. Resultados: a ferritina sérica média foi de 2.676,5 +/- 2.051,7 ng/mL. O ferro plasmático lábil foi anormal (> 0,6 Unidades/mL) em 48/83 pacientes (57%). A média dos valores de T2* no fígado foi 3,91 ± 3,95 ms, sugerindo siderose hepática em 92,1% pacientes. A média do T2* cardíaco foi de 24,96 ± 14,17 ms e 36% dos pacientes apresentavam siderose cardíaca (T2* < 20ms), dos quais 19% (22/115) já apresentavam sobrecarga cardíaca grave (T2* < 10 ms). A média de T2* no pâncreas foi de 11,12 ± 11,20 ms, perfazendo um total de 83,5% de pacientes com sobrecarga de ferro pancreático (T2* < 21 ms). Houve correlação significativa, curvilínea e inversa entre T2* fígado e a concentração de ferro hepática (r = -0,878; p <0,001) e correlação moderada entre T2* pâncreas e T2* miocárdio (r = 0,546; p<0,0001). Conclusão: Uma elevada taxa de acometimento hepático, pancreático e cardíaco por sobrecarga férrica foi demonstrada. Os níveis de ferritina não puderam prever sobrecarga de ferro hepático, cardíaco ou pancreáticos medidos por meio da ressonância nuclear magnética T2*. Não houve correlação entre a sobrecarga de ferro no fígado, pâncreas e miocárdio, nem entre a ferritina e os níveis plasmáticos de ferro sérico e os valores de T2* no fígado, coração e pâncreas.


Assuntos
Biópsia , Transfusão de Sangue , Sobrecarga de Ferro , Imageamento por Ressonância Magnética
16.
Einstein (Sao Paulo) ; 9(2): 165-72, 2011 Jun.
Artigo em Inglês, Português | MEDLINE | ID: mdl-26760810

RESUMO

UNLABELLED: ABSTRACTObjectives:To evaluate the use of magnetic resonance imaging in patients with ß-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. METHODS: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. RESULTS: The mean serum ferritin was 2,676.5 +/- 2,051.7 ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= -0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). CONCLUSION: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. There was no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values.

17.
J Pediatr Hematol Oncol ; 32(8): 601-5, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20921906

RESUMO

Limited data are available on the use of deferiprone in children younger than 10 years of age. This study evaluated the safety and efficacy of a new liquid formulation of deferiprone for the treatment of transfusional iron overload in children 1-10 years old. One hundred children (91 thalassemia major, 8 Hb E-ß thalassemia, and 1 sickle cell disease) were enrolled for a 6-month treatment with deferiprone (50 to 100 mg/kg/d). The safety profile was similar to or better than that reported in earlier studies with deferiprone tablets in older children and adults. No unexpected adverse reactions were observed. Gastrointestinal intolerance (GI) was observed in 11% and an increased serum ALT in 12% of the children. Both events were transient. Mild neutropenia, observed in 6% of patients, did not progress to agranulocytosis and resolved despite continuous deferiprone treatment. Two patients experienced agranulocytosis that resolved without complications upon discontinuation of therapy. Deferiprone use was associated with a significant decline in mean serum ferritin level from 2532±1463 µg/L at baseline to 2176±1144 µg/L (P<0.0005). The results of this study show a favorable benefit/risk ratio of deferiprone oral solution for the treatment of young children with transfusional iron overload.


Assuntos
Quelantes de Ferro/administração & dosagem , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Piridonas/administração & dosagem , Reação Transfusional , Talassemia beta/terapia , Administração Oral , Agranulocitose/induzido quimicamente , Anemia Falciforme/terapia , Química Farmacêutica , Criança , Pré-Escolar , Deferiprona , Feminino , Humanos , Lactente , Quelantes de Ferro/efeitos adversos , Masculino , Piridonas/efeitos adversos
18.
Haematologica ; 91(9): 1241-3, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16956824

RESUMO

We compared the safety and efficacy of alternating deferoxamine and deferiprone with that of deferoxamine monotherapy. Sixty transfusion-dependent thalassemia patients regularly treated with deferoxamine were randomized to continue deferoxamine alone or to receive an alternating therapy for one year. Both arms resulted in equivalent decreases of serum ferritin and liver iron concentration. There was no significant difference in the proportion of patients with adverse events in the two therapy groups although the nature of the adverse events differed according to the chelation regimen.


Assuntos
Desferroxamina/administração & dosagem , Sobrecarga de Ferro/tratamento farmacológico , Piridonas/administração & dosagem , Talassemia/tratamento farmacológico , Adolescente , Adulto , Deferiprona , Desferroxamina/efeitos adversos , Quimioterapia Combinada , Feminino , Humanos , Masculino , Piridonas/efeitos adversos , Talassemia/complicações , Resultado do Tratamento
19.
Rev. bras. hematol. hemoter ; 25(3): 177-188, July-Sept. 2003. tab, graf
Artigo em Português | LILACS | ID: lil-355440

RESUMO

Apesar da introdução da quelação parenteral de ferro com desferoxamina há mais de trinta anos, 50 por cento dos pacientes com talassemia major morrem antes dos 35 anos de idade, predominantemente por insuficiência cardíaca secundária a sobrecarga de ferro. Embora a desferrioxamina, possa reduzir ou estabilizar o acúmulo de ferro no corpo, um grande número de pacientes não recebe terapia adequada com este quelante devido principalmente à intolerância a um regime que requer administração parenteral prolongada, cinco a sete dias por semana. Para esses pacientes, a deferiprona, um quelante oralmente ativo, surge com uma alternativa de tratamento para o controle da sobrecarga de ferro. Um grande número de estudos clínicos demonstraram a segurança e eficácia da deferiprona. Estima-se que mais de 6 mil pacientes com sobrecarga de ferro já tenham sido tratados com este quelante, com alguns pacientes tomando a droga por mais de dez anos. A quantidade de ferro excretada induzida pela deferiprona é diretamente influenciada pela dose da droga e pelo grau de sobrecarga de ferro do paciente. Recentemente, demonstrou-se que desferrioxamina e deferiprona exibem capacidades quelantes diversas e que, usados simultaneamente ou numa terapia sequencial, promovem uma excreção de ferro adicional ou sinérgica com rápida redução na carga de ferro do corpo. Pela primeira vez é possível considerar esquemas de quelação individualizados baseados nas necessidades individuais de cada paciente


mode of administration which impairs the compliancewith the regime of repeatedly subcutaneous infusions.For these patients, the orally active iron chelatordeferiprone is an attractive alternative to control theoverloaded iron. It has been estimated that more thansix thousands patients have already been treated withdeferiprone, with some of them taking the chelator for10 years or more. The deferiprone-induced ironexcretion is directly related to the dose of deferiproneand the patient’s iron load. In most of transfusiondependentpatients, a dose of 75 mg/kg/day is sufficientto offset the transfusional iron-load. Recently, it hasbeen demonstrated that desferrioxamine anddeferiprone exhibit different chelating capabilities forthe removal of iron from the various body iron poolsand that the use of both chelators promote an additiveor synergistic iron excretion with rapid reduction inthe body iron load. It now is possible to consider tailormadechelation regimens based on individual patientneeds.


Assuntos
Humanos , Terapia por Quelação , Desferroxamina , Talassemia
20.
Blood ; 102(5): 1583-7, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-12763939

RESUMO

The identification of a safe, orally active iron chelator is critically important for the prevention of morbidity and early death in patients receiving regular red cell transfusions. Based on our findings in a 1-year multicenter, prospective study of the safety and efficacy of deferiprone in patients with thalassemia major, we have extended the treatment period to 4 years. The mean dose of the chelator was 73 mg/kg per day during 531 patient-years. The rates of agranulocytosis (absolute neutrophil count [ANC] < 500 x 10(9)/L) and milder forms of neutropenia (ANC, 500-1500 x 10(9)/L) were 0.2 and 2.8 per 100 patient-years, respectively. Neutropenia occurred significantly more commonly in patients with intact spleens. Gastrointestinal and joint symptoms decreased significantly after the first year of therapy, and led to discontinuation of deferiprone in only one patient in years 2 to 4. The mean alanine aminotransferase (ALT) value of 71 U/L after 4 years of therapy was significantly higher than the baseline value of 61 U/L. Trend analysis showed no increase in the ALT levels or the percentage of patients with ALT levels greater than twice the upper limit of the reference range. Ferritin levels did not change significantly from the values at the time of change from deferoxamine to deferiprone in either the intention-to-treat analysis or in the 84 patients who completed 4 years of therapy. Because of concerns regarding the effectiveness of the studied dose of deferiprone, 47 patients discontinued therapy, whereas 15 patients interrupted therapy because of concerns regarding low iron levels. The results of this study help to define the safety and effectiveness of long-term therapy with deferiprone.


Assuntos
Quelantes de Ferro/administração & dosagem , Quelantes de Ferro/efeitos adversos , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Talassemia beta/tratamento farmacológico , Administração Oral , Adolescente , Adulto , Agranulocitose/induzido quimicamente , Alanina Transaminase/sangue , Criança , Deferiprona , Ferritinas/sangue , Gastroenteropatias/induzido quimicamente , Humanos , Artropatias/induzido quimicamente , Neutropenia/induzido quimicamente , Pacientes Desistentes do Tratamento , Estudos Prospectivos , Resultado do Tratamento
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