RESUMEN
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.
Asunto(s)
Transfusión Sanguínea , Cardiomiopatías/metabolismo , Cardiomiopatías/patología , Insuficiencia Cardíaca/metabolismo , Insuficiencia Cardíaca/patología , Hemosiderosis/metabolismo , Hemosiderosis/patología , Hierro/análisis , Miocardio/química , Miocardio/patología , Talasemia beta/terapia , Adolescente , Adulto , Autopsia , Compuestos Azo/química , Transfusión Sanguínea/mortalidad , Cardiomiopatías/mortalidad , Cardiomiopatías/cirugía , Causas de Muerte , Niño , Colágeno/análisis , Colorantes/química , Femenino , Fibrosis , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Hemosiderosis/mortalidad , Hemosiderosis/cirugía , Humanos , Masculino , Persona de Mediana Edad , Índice de Severidad de la Enfermedad , Espectrofotometría Atómica , Coloración y Etiquetado/métodos , Adulto Joven , Talasemia beta/sangre , Talasemia beta/diagnóstico , Talasemia beta/mortalidadRESUMEN
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.
Asunto(s)
Agranulocitosis/inducido químicamente , Piridonas/efectos adversos , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Ensayos Clínicos como Asunto/estadística & datos numéricos , Deferiprona , Femenino , Humanos , Quelantes del Hierro/efectos adversos , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , Recuento de Leucocitos , Masculino , Persona de Mediana Edad , Neutropenia/inducido químicamente , Neutrófilos/citología , Educación del Paciente como Asunto , Vigilancia de Productos Comercializados/estadística & datos numéricos , Piridonas/uso terapéutico , Factores de Riesgo , Factores Sexuales , Talasemia/complicaciones , Adulto JovenRESUMEN
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.
Asunto(s)
Transfusión Sanguínea , Hemocromatosis/sangre , Hierro/sangre , Síndromes Mielodisplásicos/sangre , Transferrina/metabolismo , Talasemia beta/sangre , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Síndromes Mielodisplásicos/terapia , Talasemia beta/terapiaRESUMEN
BACKGROUND: Patients with non-transfusion-dependent thalassemia (NTDT) present with a spectrum of disease severities. Since there are multiple pathophysiologies in such patients, tailoring treatment remains essential. Therefore, one simple, reliable tool would be beneficial to assess disease severity and tailor therapy, particularly for internal medicine specialists who may treat a variety of NTDT patients with a multitude of complications. This would allow for standardization of assessments leading to timely interventions and prevention of complications. METHODS: A working group of NTDT experts was formed to develop a new disease severity scoring system for adult and pediatric patients with NTDT, based on parameters considered to be most pertinent in defining disease severity. RESULTS: 20 parameters were selected for inclusion in the disease severity scoring system. An additional six parameters, largely related to growth and development, were selected specifically for pediatric patients (≤ 16 years of age). Consensus of expert opinion was used to establish the selected methods of assessment for each parameter, based on feasibility and availability of technology, cost containment, and avoidance of patient risk. CONCLUSION: We propose that this new disease severity scoring system for adult and pediatric NTDT patients could be developed into a practical tool for widespread clinical use.
Asunto(s)
Alanina Transaminasa/sangre , Bilirrubina/sangre , Hemoglobinas/metabolismo , Hierro/sangre , Talasemia beta/sangre , Adolescente , Adulto , Arritmias Cardíacas/epidemiología , Enfermedades Óseas Metabólicas/epidemiología , Niño , Colecistectomía , Colecistitis/epidemiología , Colelitiasis/epidemiología , Comorbilidad , Insuficiencia Cardíaca/epidemiología , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Humanos , Hipertensión Pulmonar/epidemiología , Úlcera de la Pierna/epidemiología , Cirrosis Hepática/epidemiología , Osteoporosis/epidemiología , Recuento de Plaquetas , Índice de Severidad de la Enfermedad , Esplenomegalia/epidemiología , Volumen Sistólico , Trombosis/epidemiología , Talasemia beta/epidemiologíaRESUMEN
We report genome-wide association study results for the levels of A1, A2 and fetal hemoglobins, analyzed for the first time concurrently. Integrating high-density array genotyping and whole-genome sequencing in a large general population cohort from Sardinia, we detected 23 associations at 10 loci. Five signals are due to variants at previously undetected loci: MPHOSPH9, PLTP-PCIF1, ZFPM1 (FOG1), NFIX and CCND3. Among the signals at known loci, ten are new lead variants and four are new independent signals. Half of all variants also showed pleiotropic associations with different hemoglobins, which further corroborated some of the detected associations and identified features of coordinated hemoglobin species production.
Asunto(s)
Genoma Humano/genética , Estudio de Asociación del Genoma Completo/métodos , Técnicas de Genotipaje/métodos , Hemoglobinas/genética , Análisis de Secuencia de ADN/métodos , Adulto , Femenino , Variación Genética , Genotipo , Humanos , Islas , Italia , Masculino , Persona de Mediana Edad , Familia de Multigenes , Polimorfismo de Nucleótido Simple , Globinas alfa/genética , Globinas beta/genéticaRESUMEN
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.
Asunto(s)
ADN/genética , Hepatitis C Crónica/genética , Interleucinas/genética , Polimorfismo Genético , Talasemia beta/genética , Femenino , Genotipo , Hepacivirus/genética , Hepatitis C Crónica/complicaciones , Hepatitis C Crónica/metabolismo , Humanos , Interferones , Interleucinas/metabolismo , Masculino , ARN Viral/análisis , Estudios Retrospectivos , Adulto Joven , Talasemia beta/complicaciones , Talasemia beta/metabolismoAsunto(s)
Eritropoyesis , Hepcidinas/metabolismo , Hierro/metabolismo , Talasemia alfa/metabolismo , Talasemia beta/metabolismo , Factor 15 de Diferenciación de Crecimiento/sangre , Factor 15 de Diferenciación de Crecimiento/metabolismo , Hemólisis , Hepcidinas/sangre , Humanos , Sobrecarga de Hierro/metabolismo , Talasemia alfa/sangre , Talasemia alfa/diagnóstico , Talasemia beta/sangre , Talasemia beta/diagnósticoRESUMEN
Haemoglobinopathies constitute the commonest recessive monogenic disorders worldwide, and the treatment of affected individuals presents a substantial global disease burden. Carrier identification and prenatal diagnosis represent valuable procedures that identify couples at risk for having affected children, so that they can be offered options to have healthy offspring. Molecular diagnosis facilitates prenatal diagnosis and definitive diagnosis of carriers and patients (especially 'atypical' cases who often have complex genotype interactions). However, the haemoglobin disorders are unique among all genetic diseases in that identification of carriers is preferable by haematological (biochemical) tests rather than DNA analysis. These Best Practice guidelines offer an overview of recommended strategies and methods for carrier identification and prenatal diagnosis of haemoglobinopathies, and emphasize the importance of appropriately applying and interpreting haematological tests in supporting the optimum application and evaluation of globin gene DNA analysis.
Asunto(s)
Hemoglobinopatías/diagnóstico , Hemoglobinopatías/genética , Guías de Práctica Clínica como Asunto , Diagnóstico Prenatal/normas , Alelos , Femenino , Pruebas Genéticas/normas , Variación Genética , Estudio de Asociación del Genoma Completo , Genotipo , Hematología/normas , Hemoglobina A/genética , Humanos , Análisis de Secuencia por Matrices de Oligonucleótidos , Embarazo , Análisis de Secuencia de ADNRESUMEN
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.
Asunto(s)
Variación Genética , Globinas beta/genética , Talasemia beta/diagnóstico , Talasemia beta/genética , Transfusión Sanguínea , ADN Intergénico , Femenino , Estudios de Asociación Genética , Sitios Genéticos , Humanos , Estimación de Kaplan-Meier , Masculino , Mutación , Fenotipo , Polimorfismo de Nucleótido Simple , Pronóstico , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Talasemia beta/mortalidad , Talasemia beta/terapiaRESUMEN
OBJECTIVE: To evaluate the long-term effect of Deferiprone (DFP) in reducing brain iron overload and improving neurological manifestations in patients with NBIA. METHODS: 6 NBIA patients (5 with genetically confirmed PKAN), received DFP solution at 15 mg/kg po bid. They were assessed by UPDRS/III and UDRS scales and blinded video rating, performed at baseline and every six months. All patients underwent brain MRI at baseline and during follow up. Quantitative assessment of brain iron was performed with T2* relaxometry, using a gradient multi-echo T2* sequence. RESULTS: After 48 months of treatment clinical rating scales and blinded video rating indicated a stabilization in motor symptoms in 5/6 Pts. In the same subjects MRI evaluation showed reduced hypointensity in the globus pallidus (GP); quantitative assessment confirmed a significant increment in the T2* value, and hence reduction of the iron content of the GP. CONCLUSION: The data from our 4-years follow-up study confirm the safety of DFP as a chelator agent for iron accumulation. The clinical stabilization observed in 5/6 of our patients suggests that DFP may be a reasonable therapeutic option for the treatment of the neurological manifestations linked with iron accumulation and neurodegeneration, especially in adult patients at early stage of the disease. (Clinicaltrials.gov identifier: NTC00907283).
Asunto(s)
Quelantes del Hierro/uso terapéutico , Trastornos del Metabolismo del Hierro/tratamiento farmacológico , Distrofias Neuroaxonales/tratamiento farmacológico , Neurodegeneración Asociada a Pantotenato Quinasa/tratamiento farmacológico , Piridonas/uso terapéutico , Adulto , Deferiprona , Femenino , Humanos , Trastornos del Metabolismo del Hierro/diagnóstico , Estudios Longitudinales , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Distrofias Neuroaxonales/diagnóstico , Neurodegeneración Asociada a Pantotenato Quinasa/diagnóstico , Índice de Severidad de la Enfermedad , Adulto JovenAsunto(s)
Algoritmos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Hierro/sangre , Talasemia beta/sangre , Talasemia beta/complicaciones , Preescolar , Transfusión de Eritrocitos , Humanos , Lactante , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Curva ROC , Talasemia beta/terapiaRESUMEN
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.
Asunto(s)
Activación Transcripcional , Talasemia beta/genética , Globinas delta/genética , Animales , Modelos Animales de Enfermedad , Eritrocitos/citología , Eritrocitos/metabolismo , Eritropoyesis/genética , Expresión Génica , Orden Génico , Genes Reporteros , Sitios Genéticos , Humanos , Hierro/metabolismo , Ratones , Ratones Transgénicos , Fenotipo , Regiones Promotoras Genéticas , Talasemia beta/terapia , Globinas delta/química , Globinas delta/metabolismoRESUMEN
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.
Asunto(s)
Genotipo , Mutación , Polimorfismo Genético , Globinas alfa/genética , Talasemia alfa/genética , Talasemia beta/genética , Alelos , Portador Sano , Cromosomas Humanos Par 16 , Frecuencia de los Genes , Estudios de Asociación Genética , Pruebas Genéticas , Heterocigoto , Humanos , Italia , Fenotipo , Índice de Severidad de la Enfermedad , Talasemia alfa/diagnóstico , Talasemia beta/diagnósticoAsunto(s)
Duplicación de Gen , Globinas alfa/genética , Talasemia beta/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Argentina , Niño , Preescolar , Femenino , Heterocigoto , Humanos , Italia/etnología , Masculino , Persona de Mediana Edad , Familia de Multigenes , Fenotipo , Adulto JovenRESUMEN
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.
Asunto(s)
Cateterismo Cardíaco , Hipertensión Pulmonar/diagnóstico , Hipertensión Pulmonar/epidemiología , Talasemia beta/epidemiología , Adulto , Estudios de Casos y Controles , Estudios Transversales , Ecocardiografía , Hipertensión Pulmonar Primaria Familiar , Femenino , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Análisis Multivariante , Valor Predictivo de las Pruebas , Prevalencia , Presión Esfenoidal Pulmonar , Factores de RiesgoRESUMEN
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.
Asunto(s)
Arritmias Cardíacas/etiología , Terapia por Quelación/métodos , Insuficiencia Cardíaca/etiología , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/diagnóstico , Imagen por Resonancia Magnética , Miocardio/patología , Cooperación del Paciente , Talasemia beta/patología , Adulto , Área Bajo la Curva , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/prevención & control , Benzoatos/administración & dosificación , Benzoatos/uso terapéutico , Deferasirox , Deferiprona , Deferoxamina/administración & dosificación , Deferoxamina/uso terapéutico , Relación Dosis-Respuesta a Droga , Quimioterapia Combinada , Femenino , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/prevención & control , Humanos , Hierro/análisis , Quelantes del Hierro/administración & dosificación , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/patología , Sobrecarga de Hierro/prevención & control , Masculino , Miocardio/química , Valor Predictivo de las Pruebas , Piridonas/administración & dosificación , Piridonas/uso terapéutico , Curva ROC , Riesgo , Muestreo , Reacción a la Transfusión , Triazoles/administración & dosificación , Triazoles/uso terapéutico , Adulto Joven , Talasemia beta/complicaciones , Talasemia beta/tratamiento farmacológico , Talasemia beta/terapiaRESUMEN
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.
Asunto(s)
American Heart Association , Insuficiencia Cardíaca/etiología , Insuficiencia Cardíaca/terapia , Talasemia beta/complicaciones , Talasemia beta/tratamiento farmacológico , Consenso , Insuficiencia Cardíaca/fisiopatología , Humanos , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/complicaciones , Sobrecarga de Hierro/tratamiento farmacológico , Estados UnidosRESUMEN
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.
Asunto(s)
Benzoatos/uso terapéutico , Transfusión Sanguínea , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Talasemia/tratamiento farmacológico , Triazoles/uso terapéutico , Estudios Cruzados , Deferasirox , Método Doble Ciego , Humanos , Sobrecarga de Hierro/sangre , Sobrecarga de Hierro/epidemiología , Estudios Prospectivos , Talasemia/sangre , Talasemia/epidemiología , Factores de Tiempo , Resultado del TratamientoRESUMEN
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.