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1.
Br J Haematol ; 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31338833

RESUMO

Congenital sideroblastic anaemia (CSA) is a rare disease caused by germline mutations of genes involved in haem and iron-sulphur cluster formation, and mitochondrial protein biosynthesis. We performed a retrospective multicentre European study of a cohort of childhood-onset CSA patients to explore genotype/phenotype correlations. We studied 23 females and 20 males with symptoms of CSA. Among the patients, the most frequently mutated genes were ALAS2 (n = 10; 23·3%) and SLC25A38 (n = 8; 18·6%), causing isolated forms of microcytic anaemia of varying severity. Five patients with SLC19A2 mutations suffered from thiamine-responsive megaloblastic anaemia and three exhibited the 'anaemia, deafness and diabetes' triad. Three patients with TRNT1 mutations exhibited severe early onset microcytic anaemia associated with thrombocytosis, and two exhibited B-cell immunodeficiency, inflammatory syndrome and psychomotor delay. The prognoses of patients with TRNT1 and SLC2A38 mutations were generally dismal because of comorbidities or severe iron overload. No molecular diagnosis could be established in 14/43 cases. This study emphasizes the frequency of ALAS2 and SLC25A38 mutations and provides the largest comprehensive analysis to date of genotype/phenotype correlations in CSA. Further studies of CSA patients with data recorded in an international registry would be helpful to improve patient management and establish standardized guidelines.

2.
Haematologica ; 2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31097628

RESUMO

Allogeneic stem cell transplantation remains the only curative treatment for sickle-cell anemia, but the place of myeloablative conditioning remains to be defined. The aim of the present study was to analyze long-term outcomes, including chimerism, sickle-cell anemia-related events and biological data (hemoglobin, reticulocytes, HbS%), and fertility, in a French series of 234 SCA-patients younger than 30 years who received (1988-2012) a matched-sibling-donor stem cell transplantation following standardized myeloablative conditioning (Busulfan, Cyclophosphamide and rabbit anti-thymocyte globulin). Since the first report of the series (1988-2004), 151 new consecutive patients with sickle-cell anemia were similarly transplanted. Considering death, non-engraftment or rejection (donor cells<5%) as events, the 5-year event-free survival was 97.9% (95% confidence interval:95.5-100%), confirming at least 95% chance of cure since year 2000. In the overall cohort (n=234, median follow-up of 7.9 years), event-free survival was not associated with age, but chronic-graft-vs-host disease was independently associated with recipien's age>15 (hazard ratio=4.37,P=0.002) and lower (5-15 vs 20 mg/kg) anti-thymocyte globulin dose (hazard ratio=4.55,P=0.001). At one year, 44% of patients had mixed chimerism (5-95% donor cells), but those prepared with anti-thymocyte globulin had no graft rejection. No events related to sickle cell anemia occurred in patients with mixed chimerism, even those with 15-20% donor cells, but hemolytic anemia stigmata were observed with donor cells<50%. Currently, myeloablative transplantation with matched-sibling donor has a higher event-free survival (98%) in patients younger than 30 than that reported for non-myeloablative conditioning (88%). Nevertheless, the risk of chronic graft-vs-host disease in older patients and need for fertility preservation might be indications in patients older than 15 for a non-myeloablative conditioning.

3.
JAMA ; 321(3): 266-276, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30667500

RESUMO

Importance: In children with sickle cell anemia (SCA), high transcranial Doppler (TCD) velocities are associated with stroke risk, which is reduced by chronic transfusion. Whether matched sibling donor hematopoietic stem cell transplantation (MSD-HSCT) can reduce velocities in patients with SCA is unknown. Objective: To determine the association of MSD-HSCT with TCD velocities as a surrogate for the occurrence of ischemic stroke in children with SCA. Design, Setting, and Participants: Nonrandomized controlled intervention study conducted at 9 French centers. Patients with SCA were enrolled between December 2010 and June 2013, with 3-year follow-up ending in January 2017. Children with SCA were eligible if younger than 15 years, required chronic transfusions for persistently elevated TCD velocities, and had at least 1 sibling without SCA from the same 2 parents. Families agreed to HLA antigen typing and transplantation if a matched sibling donor was identified or to standard care in the absence of a matched sibling donor. Exposures: MSD-HSCT (n = 32), compared with standard care (n = 35) (transfusions for ≥1 year with potential switch to hydroxyurea thereafter), using propensity score matching. Main Outcomes and Measures: The primary outcome was the highest time-averaged mean of maximum velocities in 8 cerebral arteries, measured by TCD (TCD velocity) at 1 year. Twenty-five of 29 secondary outcomes were analyzed, including the highest TCD velocity at 3 years and normalization of velocities (<170 cm/s) and ferritin levels at 1 and 3 years. Results: Sixty-seven children with SCA (median age, 7.6 years; 35 girls [52%]) were enrolled (7 with stroke history). In the matched sample, highest TCD velocities at 1 year were significantly lower on average in the transplantation group (129.6 cm/s) vs the standard care group (170.4 cm/s; difference, -40.8 cm/s [95% CI, -62.9 to -18.6]; P < .001). Of the 25 analyzed secondary end points, 4 showed significant differences, including the highest TCD velocity at 3 years (112.4 cm/s in the transplantation group vs 156.7 cm/s in the standard care group; difference, -44.3 [95% CI, -71.9 to -21.1]; P = .001); normalization rate at 1 year (80.0% in the transplantation group vs 48.0% in the standard care group; difference, 32.0% [95% CI, 0.2% to 58.6%]; P = .045); and ferritin levels at 1 year (905 ng/mL in the transplantation group vs 2529 ng/mL in the standard care group; difference, -1624 [95% CI, -2370 to -879]; P < .001) and 3 years (382 ng/mL in the transplantation group vs 2170 ng/mL in the standard care group; difference, -1788 [95% CI, -2570 to -1006]; P < .001). Conclusions and Relevance: Among children with SCA requiring chronic transfusion because of persistently elevated TCD velocities, MSD-HSCT was significantly associated with lower TCD velocities at 1 year compared with standard care. Further research is warranted to assess the effects of MSD-HSCT on clinical outcomes and over longer follow-up. Trial Registration: ClinicalTrials.gov Identifier: NCT01340404.


Assuntos
Anemia Falciforme/terapia , Circulação Cerebrovascular/fisiologia , Transplante de Células-Tronco Hematopoéticas , Irmãos , Ultrassonografia Doppler Transcraniana , Aloenxertos , Anemia Falciforme/diagnóstico por imagem , Anemia Falciforme/fisiopatologia , Velocidade do Fluxo Sanguíneo , Criança , Feminino , Ferritinas/sangue , Doença Enxerto-Hospedeiro , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Masculino , Pontuação de Propensão , Qualidade de Vida , Condicionamento Pré-Transplante
4.
Haematologica ; 104(8): 1554-1564, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30655378

RESUMO

We describe the clinical, hematologic and genetic characteristics of a retrospective series of 126 subjects from 64 families with hereditary xerocytosis. Twelve patients from six families carried a KCNN4 mutation, five had the recurrent p.Arg352His mutation and one had a new deletion at the exon 7-intron 7 junction. Forty-nine families carried a PIEZO1 mutation, which was a known recurrent mutation in only one-third of the cases and private sequence variation in others; 12 new probably pathogenic missense mutations were identified. The two dominant features leading to diagnosis were hemolysis that persisted after splenectomy and hyperferritinemia, with an inconstant correlation with liver iron content assessed by magnetic resonance imaging. PIEZO1-hereditary xerocytosis was characterized by compensated hemolysis in most cases, perinatal edema of heterogeneous severity in more than 20% of families and a major risk of post-splenectomy thrombotic events, including a high frequency of portal thrombosis. In KCNN4-related disease, the main symptoms were more severe anemia, hemolysis and iron overload, with no clear sign of red cell dehydration; therefore, this disorder would be better described as a 'Gardos channelopathy'. These data on the largest series to date indicate that PIEZO1-hereditary xerocytosis and Gardos channelopathy are not the same disease although they share hemolysis, a high rate of iron overload and inefficient splenectomy. They demonstrate the high variability in clinical expression as well as genetic bases of PIEZO1-hereditary xerocytosis. These results will help to improve the diagnosis of hereditary xerocytosis and to provide recommendations on the clinical management in terms of splenectomy, iron overload and pregnancy follow-up.

5.
Haematologica ; 103(7): 1143-1149, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29599204

RESUMO

In this retrospective study, we evaluate long-term complications in nearly all ß-thalassemia-major patients who successfully received allogeneic hematopoietic stem cell transplantation in France. Ninety-nine patients were analyzed with a median age of 5.9 years at transplantation. The median duration of clinical follow up was 12 years. All conditioning regimens were myeloablative, most were based on busulfan combined with cyclophosphamide, and more than 90% of patients underwent a transplant from a matched sibling donor. After transplantation, 11% of patients developed thyroid dysfunction, 5% diabetes, and 2% heart failure. Hypogonadism was present in 56% of females and 14% of males. Female patients who went on to normal puberty after transplant were significantly younger at transplantation than those who experienced delayed puberty (median age 2.5 vs 8.7 years). Fertility was preserved in 9 of 27 females aged 20 years or older and 2 other patients became pregnant following oocyte donation. In addition to patient's age and higher serum ferritin levels at transplantation, time elapsed since transplant was significantly associated with decreased height growth in multivariate analysis. Weight growth increased after transplantation particularly in females, 36% of adults being overweight at last evaluation. A comprehensive long-term monitoring, especially of endocrine late effects, is required after hematopoietic stem cell transplantation for thalassemia.

6.
Clin Immunol ; 188: 52-57, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29330115

RESUMO

Evans syndrome (ES) is defined by the combination of autoimmune hemolytic anemia and immune thrombocytopenia. Clinical presentation includes manifestations of immune dysregulation, found in primary immune deficiencies, autoimmune lymphoproliferative syndrome with FAS (ALPS-FAS), Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) and Lipopolysaccharide-Responsive vesicle trafficking Beige-like and Anchor protein (LRBA) defects. We report the clinical history and genetic results of 18 children with ES after excluding ALPS-FAS. Thirteen had organomegaly, five lymphocytic infiltration of non-lymphoid organs, nine hypogammaglobulinemia and fifteen anomalies in lymphocyte phenotyping. Seven patients had genetic defects: three CTLA4 mutations (c.151C>T; c.109+1092_568-512del; c.110-2A>G) identified by Sanger sequencing and four revealed by Next Generation Sequencing: LRBA (c.2450+1C>T), STAT3 gain-of-function (c.2147C>T; c.2144C>T) and KRAS (c.37G>T). No feature emerged to distinguish patients with or without genetic diagnosis. Our data on pediatric-onset ES should prompt physicians to perform extensive screening for mutations in the growing pool of genes involved in primary immune deficiencies with autoimmunity.

7.
Adv Exp Med Biol ; 1013: 89-122, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29127678

RESUMO

Allogeneic hematopoietic stem cell transplantation (HSCT) can cure single gene disorders such as thalassemia and sickle cell anemia (SCA). These non-malignant diseases have in common severe hemolytic anemia and high proliferative bone marrow, requiring frequent transfusions. The risk of rejection is high and graft-vs-host disease is not desirable. Important progress has been made in the management of these diseases, including leukocyte depletion of blood products, and chelation therapy, for both diseases, and erythrocytapheresis and hydroxycarbamide for SCA. However, morbidity and quality of life are still of concern. Results have also significantly improved for HSCT, with the reduction of rejection by using anti-thymocyte globulin (ATG), which also decreases the risk of chronic graft-vs-host disease. Current data show a more than 90% chance of cure with myeloablative conditioning in children with hemoglobinopathy and a geno-identical donor. Results are similar whether the cell source is cord blood or bone marrow. Because of the risk of conditioning-related infertility, ovarian and/or testis cryopreservation should be discussed. Non-myeloablative conditioning regimens have also been successfully developed in adults with SCA and organ dysfunction, making cure possible. These encouraging results should incite to perform HLA typing early in families with hemoglobinopathies, and to systematically propose sibling cord blood cryopreservation for those without geno-identical donor.


Assuntos
Anemia Falciforme/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Talassemia beta/terapia , Adulto , Soro Antilinfocitário/administração & dosagem , Criança , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Teste de Histocompatibilidade , Humanos , Imunossupressores/administração & dosagem , Qualidade de Vida , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Resultado do Tratamento
8.
Contemp Clin Trials ; 62: 91-104, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28821470

RESUMO

BACKGROUND: Children with sickle cell anemia (SCA) have an 11% risk of stroke by the age of 18. Chronic transfusion applied in patients detected to be at risk by transcranial Doppler allows a significant reduction of stroke risk. However, chronic transfusion exposes to several adverse events, including alloimmunization and iron overload, and is not curative. Hematopoietic stem cell transplantation allows termination of the transfusion program, but its benefit has not been demonstrated. DESIGN: DREPAGREFFE (NCT01340404) is a multicenter, prospective trial enrolling SCA children younger than 15years receiving chronic transfusion due to a history of abnormal transcranial Doppler (velocities ≥200cm/s). Only those with at least one non-SCA sibling and parents accepting HLA-typing and transplantation with a genoidentical donor were eligible. Chronic transfusion was pursued in patients with no available donor, whereas others were transplanted. Comparison between the 2 arms (transfusion vs transplantation) was analyzed using both genetic randomization and propensity-score matching as a sensitivity analysis. The primary end-point was the velocity measure at 1year. Secondary endpoints were the incidence of stroke, silent cerebral infarcts and stenoses, cognitive performance in comparison with siblings, allo-immunization, iron-overload, phosphatidyl-serine, angiogenesis/hypoxia, brain injury-related factor expression, quality of life and cost. OBJECTIVES: To show that genoidentical transplantation decreases velocities significantly more than chronic transfusion in SCA children at risk of stroke. DISCUSSION: DREPAGREFFE is the first prospective study to evaluate transplantation in SCA children. It compares the outcome of cerebral vasculopathy following genoidentical transplantation versus chronic transfusion using genetic randomization and causal inference methods.


Assuntos
Anemia Falciforme/complicações , Anemia Falciforme/terapia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/métodos , Acidente Vascular Cerebral/etiologia , Reação Transfusional , Adolescente , Transfusão de Sangue/economia , Transfusão de Sangue/métodos , Criança , Pré-Escolar , Cognição , Feminino , Transplante de Células-Tronco Hematopoéticas/economia , Humanos , Sobrecarga de Ferro/etiologia , Masculino , Estudos Prospectivos , Qualidade de Vida , Projetos de Pesquisa , Acidente Vascular Cerebral/diagnóstico por imagem , Ultrassonografia Doppler Transcraniana
9.
Blood ; 126(11): 1273-80, 2015 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-26148990

RESUMO

The Gardos channel is a Ca(2+)-sensitive, intermediate conductance, potassium selective channel expressed in several tissues including erythrocytes and pancreas. In normal erythrocytes, it is involved in cell volume modification. Here, we report the identification of a dominantly inherited mutation in the Gardos channel in 2 unrelated families and its association with chronic hemolysis and dehydrated cells, also referred to as hereditary xerocytosis (HX). The affected individuals present chronic anemia that varies in severity. Their red cells exhibit a panel of various shape abnormalities such as elliptocytes, hemighosts, schizocytes, and very rare stomatocytic cells. The missense mutation concerns a highly conserved residue among species, located in the region interacting with Calmodulin and responsible for the channel opening and the K(+) efflux. Using 2-microelectrode experiments on Xenopus oocytes and patch-clamp electrophysiology on HEK293 cells, we demonstrated that the mutated channel exhibits a higher activity and a higher Ca(2+) sensitivity compared with the wild-type (WT) channel. The mutated channel remains sensitive to inhibition suggesting that treatment of this type of HX by a specific inhibitor of the Gardos channel could be considered. The identification of a KCNN4 mutation associated with chronic hemolysis constitutes the first report of a human disease caused by a defect of the Gardos channel.


Assuntos
Anemia Hemolítica Congênita/genética , Hidropisia Fetal/genética , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/genética , Proteínas Mutantes/genética , Mutação de Sentido Incorreto , Adulto , Sequência de Aminoácidos , Anemia Hemolítica Congênita/sangue , Animais , Pré-Escolar , Eritrócitos Anormais/metabolismo , Feminino , Genes Dominantes , Células HEK293 , Humanos , Hidropisia Fetal/sangue , Técnicas In Vitro , Lactente , Recém-Nascido , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/sangue , Canais de Potássio Ativados por Cálcio de Condutância Intermediária/química , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Proteínas Mutantes/sangue , Proteínas Mutantes/química , Oócitos/metabolismo , Fragilidade Osmótica , Técnicas de Patch-Clamp , Linhagem , Gravidez , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Xenopus laevis
10.
Br J Haematol ; 171(4): 615-24, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26205481

RESUMO

The level of circulating platelet-, erythrocyte-, leucocyte- and endothelial-derived microparticles detected by high-sensitivity flow cytometry was investigated in 37 ß-thalassaemia major patients receiving a regular transfusion regimen. The phospholipid procoagulant potential of the circulating microparticles and the microparticle-dependent tissue factor activity were evaluated. A high level of circulating erythrocyte- and platelet-microparticles was found. In contrast, the number of endothelial microparticles was within the normal range. Platelet microparticles were significantly higher in splenectomized than in non-splenectomized patients, independent of platelet count (P < 0·001). Multivariate analysis indicated that phospholipid-dependent procoagulant activity was influenced by both splenectomy (P = 0·001) and platelet microparticle level (P < 0·001). Erythrocyte microparticles were not related to splenectomy, appear to be devoid of proper procoagulant activity and no relationship between their production and haemolysis, dyserythropoiesis or oxidative stress markers could be established. Intra-microparticle labelling with anti-HbF antibodies showed that they originate only partially (median of 28%) from thalassaemic erythropoiesis. In conclusion, when ß-thalassaemia major patients are intensively transfused, the procoagulant activity associated with thalassaemic erythrocyte microparticles is probably diluted by transfusions. In contrast, platelet microparticles, being both more elevated and more procoagulant, especially after splenectomy, may contribute to the residual thrombotic risk reported in splenectomized multi-transfused ß-thalassaemia major patients.


Assuntos
Plaquetas/fisiologia , Transfusão de Sangue , Micropartículas Derivadas de Células/fisiologia , Trombofilia/sangue , Talassemia beta/sangue , Adolescente , Adulto , Autoanticorpos/sangue , Autoanticorpos/imunologia , Plaquetas/ultraestrutura , Micropartículas Derivadas de Células/classificação , Terapia Combinada , Diabetes Mellitus/etiologia , Membrana Eritrocítica/ultraestrutura , Feminino , Hemoglobina Fetal/imunologia , Citometria de Fluxo , Humanos , Hipogonadismo/etiologia , Ferro/sangue , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/etiologia , Masculino , Lipídeos de Membrana/sangue , Pessoa de Meia-Idade , Estresse Oxidativo , Fosfatidilserinas/sangue , Risco , Esplenectomia , Trombofilia/etiologia , Reação Transfusional , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/cirurgia , Talassemia beta/terapia
11.
Hemoglobin ; 39(3): 156-61, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25806420

RESUMO

Sickle cell disease presents a great clinical variability that remains largely misunderstood. New disease protective genetic modifiers acting mainly through an increased Hb F level have recently been described. We studied relations between clinical and hematological phenotypes and known sickle cell disease genetic modifiers in patients from Mayotte Island, a remote French territory located in the Indian Ocean. Eighty-two children with sickle cell disease were enrolled; their median age was 5.9 years (range 1-18). Clinical and hematological features of sickle cell disease were retrospectively collected. Genetic studies included determination of ß-globin genotypes [Hb SS, Hb S-ß(0)-thalassemia (Hb S-ß(0)-thal), Hb S-ß(+)-thal], ß(S)-globin locus haplotype, α-thalassemia (α-thal), and single nucleotide polymorphisms (SNPs) located in quantitative trait loci for Hb F expression (XmnI polymorphism, BCL11A rs4671393 and rs11886868, intergenic region of HBS1L-MYB rs28384513, rs4895441 and rs9399137). Univariate and multivariate analyses were conducted. Twenty-eight percent of the patients had Hb S-ß-thal (eight different mutations in 21 patients), 55.0% had the -α(3.7) (rightward) deletion and 88.0% of the homozygous Hb SS patients were carrying a homozygous Bantu haplotype. In the multivariate model, the prognosis role of the SNP BCL11A rs4671393 was confirmed in the studied population showing a significant association with an elevated Hb F level and with a low hospitalization rate. The -α(3.7) deletion, XmnI polymorphism and intergenic region HBS1L-MYB SNPs were not significantly linked to any clinical criteria of severity. This report, the first to describe the main features of children with sickle cell disease on Mayotte Island, highlights the protective effect of the BCL11A polymorphism in this population.


Assuntos
Anemia Falciforme/genética , Genes Modificadores , Adolescente , Anemia Falciforme/diagnóstico , Anemia Falciforme/terapia , Criança , Pré-Escolar , Estudos de Coortes , Índices de Eritrócitos , Feminino , Regulação da Expressão Gênica , Estudos de Associação Genética , Genótipo , Hemoglobina Falciforme/genética , Humanos , Lactente , Masculino , Fenótipo , Polimorfismo de Nucleotídeo Único , Locos de Características Quantitativas , Talassemia alfa/diagnóstico , Talassemia alfa/genética , Talassemia beta/diagnóstico , Talassemia beta/genética
12.
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
13.
Rev Prat ; 64(8): 1132-7, 2014 Oct.
Artigo em Francês | MEDLINE | ID: mdl-25510144

RESUMO

Beta-thalassemia syndromes are autosomal recessive disorders related to the inability to produce beta-globin chains. Thalassemia major is by definition a transfusion dependent anemia and iron overload is the leading cause of death and morbidity. Beta-thalassemia is rarely encountered in France where patients mainly originated from Mediterranean countries and South East Asia. Recently, two major advances have substantially improved the disease management: oral iron chelation therapy and the introduction of cardiac MRI for monitoring cardiac iron. Hematopoietic stem cell transplantation remains, in clinical practice, the only curative approach and is proposed to children having an HLA-identical sibling. Diagnosis of thalassemia trait is important in order to propose genetic counseling to couples at risk. Thalassemia intermedia is a clinical entity where anemia is mild or moderate, requiring no or occasional transfusion. Clinical severity increases with age with a more severe anemia, thrombotic complications and extra-medullary hematopoiesis. Iron overload, optimally monitored with liver MRI, occurs in adult patients and is related to increased iron hyper-absorption.


Assuntos
Talassemia beta/terapia , Humanos , Talassemia beta/complicações
14.
Blood ; 124(18): 2867-71, 2014 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-25193871

RESUMO

Mutations in genes encoding proteins that are involved in mitochondrial heme synthesis, iron-sulfur cluster biogenesis, and mitochondrial protein synthesis have previously been implicated in the pathogenesis of the congenital sideroblastic anemias (CSAs). We recently described a syndromic form of CSA associated with B-cell immunodeficiency, periodic fevers, and developmental delay (SIFD). Here we demonstrate that SIFD is caused by biallelic mutations in TRNT1, the gene encoding the CCA-adding enzyme essential for maturation of both nuclear and mitochondrial transfer RNAs. Using budding yeast lacking the TRNT1 homolog, CCA1, we confirm that the patient-associated TRNT1 mutations result in partial loss of function of TRNT1 and lead to metabolic defects in both the mitochondria and cytosol, which can account for the phenotypic pleiotropy.


Assuntos
Anemia Sideroblástica/congênito , Anemia Sideroblástica/genética , Deficiências do Desenvolvimento/complicações , Febre/complicações , Doenças Genéticas Ligadas ao Cromossomo X/genética , Síndromes de Imunodeficiência/complicações , Mutação/genética , RNA Nucleotidiltransferases/genética , Alelos , Anemia Sideroblástica/complicações , Anemia Sideroblástica/enzimologia , Deficiências do Desenvolvimento/genética , Febre/genética , Doenças Genéticas Ligadas ao Cromossomo X/complicações , Doenças Genéticas Ligadas ao Cromossomo X/enzimologia , Células HEK293 , Humanos , Síndromes de Imunodeficiência/genética
15.
Br J Haematol ; 166(4): 557-65, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24779895

RESUMO

This study aimed to describe kinetics of complete donor chimerism occurrence (cDC, >99·9% donor) after unrelated cord blood transplantation (UCBT), to identify its predictive factors and its impact on post-transplant outcome. Ninety-four children who received single UCBT after a myeloablative conditioning regimen had blood chimerism evaluation at predefined post-transplant dates, using a real-time polymerase chain reaction method with 0·1% sensitivity. Cumulative incidence of cDC at 1 year post-transplantation was 61·8%. Three predictive factors were identified in multivariate analysis: history of malignant disease (P = 0·03), older age (above 2·16 years, the first quartile of age, P = 0·0055) and higher level of cord/recipient human leucocyte antigen mismatch (4/6 vs. 5-6/6, P < 0·001) increased the probability of post-transplant cDC. Although graft cell dose had a strong impact on haematological recovery, it did not apparently influence cDC occurrence. Early cDC (i.e. more than 99·9% donor chimerism on days 15-30 post-transplant) appeared useful to predict engraftment (P = 0·003) as well as acute and chronic graft-versus-host disease (GvHD). Severe acute or chronic GvHD never occurred in patients with DC ≤99·9%, suggesting than even minimal residual host haematopoiesis is associated with a very low risk of GvHD after UCBT.


Assuntos
Transplante de Células-Tronco de Sangue do Cordão Umbilical/efeitos adversos , Quimeras de Transplante/fisiologia , Adolescente , Aloenxertos/fisiologia , Criança , Pré-Escolar , Feminino , Doença Enxerto-Hospedeiro/etiologia , Hematopoese/fisiologia , Humanos , Lactente , Masculino , Antígenos de Histocompatibilidade Menor , Estudos Prospectivos , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Resultado do Tratamento
16.
Haematologica ; 99(5): 811-20, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24790059

RESUMO

Thalassemia major and sickle cell disease are the two most widely disseminated hereditary hemoglobinopathies in the world. The outlook for affected individuals has improved in recent years due to advances in medical management in the prevention and treatment of complications. However, hematopoietic stem cell transplantation is still the only available curative option. The use of hematopoietic stem cell transplantation has been increasing, and outcomes today have substantially improved compared with the past three decades. Current experience world-wide is that more than 90% of patients now survive hematopoietic stem cell transplantation and disease-free survival is around 80%. However, only a few controlled trials have been reported, and decisions on patient selection for hematopoietic stem cell transplantation and transplant management remain principally dependent on data from retrospective analyses and on the clinical experience of the transplant centers. This consensus document from the European Blood and Marrow Transplantation Inborn Error Working Party and the Paediatric Diseases Working Party aims to report new data and provide consensus-based recommendations on indications for hematopoietic stem cell transplantation and transplant management.


Assuntos
Anemia Falciforme/terapia , Transplante de Células-Tronco Hematopoéticas , Talassemia beta/terapia , Anemia Falciforme/diagnóstico , Criança , Humanos , Talassemia beta/diagnóstico
17.
J Clin Virol ; 58(4): 722-5, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24183312

RESUMO

BACKGROUND: Emerging viral infections in humans are appearing at an increasing rate. Recently, we identified a new Marseillevirus, named Giant Blood Marseillevirus (GBM), by performing viral metagenomics on asymptomatic blood donors. OBJECTIVES: To study and compare the prevalence of Marseillevirus between asymptomatic blood donors and thalassemia patients. DESIGN: Here, we present a combined molecular and serological study on 174 asymptomatic blood donors and 22 patients with thalassemia who receive repeated blood transfusions to estimate the prevalence of Marseillevirus in these two populations. RESULTS: We identified Marseillevirus genomic DNA in 4% of donors, whereas 9.1% of the thalassemia patients were positive for this virus. Moreover, IgG seropositivity was detected in 22.7% of patients in the thalassemia group, whereas this seropositivity was observed in 12.6% of the blood donor population. CONCLUSION: These results suggest that Marseillevirus infection is not rare in healthy persons and may be transmitted by transfusion, thus raising speculation regarding the long-term consequences of this viral infection, particularly in patients requiring repeated blood transfusions.


Assuntos
Doadores de Sangue , Infecções por Vírus de DNA/transmissão , Vírus de DNA/isolamento & purificação , Talassemia/terapia , Reação Transfusional , Adolescente , Adulto , Idoso , Anticorpos Antivirais/sangue , Infecções Assintomáticas/epidemiologia , Transfusão de Sangue/estatística & dados numéricos , Distribuição de Qui-Quadrado , Criança , Infecções por Vírus de DNA/sangue , Infecções por Vírus de DNA/epidemiologia , Infecções por Vírus de DNA/virologia , DNA Viral/sangue , Feminino , França/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Adulto Jovem
18.
C R Biol ; 336(3): 164-72, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23643400

RESUMO

In this report, we review the recent advances in evaluation and treatment of transfusional iron overload (IO). Results of the French thalassaemia registry are described. According to the disease, thalassaemia major or sickle cell anaemia, mechanisms and toxicity of iron overload, knowledge about IO long-term outcome and chelation treatment results, respective value of IO markers, differ. The recent tools evaluating organ specific IO and the diversification of iron chelator agents make possible to individualize chelation therapy in clinical practice. The severity of IO and the level of transfusional iron intake, the preferential localization of IO (heart/liver) as well as the tolerance and adherence profiles of the patient can now be taken into account. Introduction of cardiac magnetic resonance imaging for the quantification of myocardial iron and use of oral chelators have already been reported as decreasing the cardiac mortality rate related to IO in thalassaemia major patients. Long-term observation of patients under oral chelators will show if morbidity is also improving via a more continuous control of toxic iron and/or a better accessibility to cellular iron pools.


Assuntos
Anemia Falciforme/terapia , Sobrecarga de Ferro/etiologia , Talassemia/terapia , Reação Transfusional , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/complicações , Terapia por Quelação , Criança , Ensaios Clínicos Fase II como Assunto , Quimioterapia Combinada , Ferritinas/sangue , França/epidemiologia , Humanos , Ferro/análise , Ferro/farmacocinética , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/patologia , Sobrecarga de Ferro/prevenção & controle , Fígado/química , Imagem por Ressonância Magnética , Adesão à Medicação , Miocárdio/metabolismo , Miocárdio/patologia , Sistema de Registros , Talassemia/sangue , Talassemia/complicações , Talassemia/epidemiologia
19.
Blood ; 122(1): 112-23, 2013 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-23553769

RESUMO

Congenital sideroblastic anemias (CSAs) are a heterogeneous group of inherited disorders identified by pathological erythroid precursors with perinuclear mitochondrial iron deposition in bone marrow. An international collaborative group of physicians and laboratory scientists collated clinical information on cases of CSA lacking known causative mutations, identifying a clinical subgroup of CSA associated with B immunodeficiency, periodic fevers, and development delay. Twelve cases from 10 families were identified. Median age at presentation was 2 months. Anemia at diagnosis was sideroblastic, typically severe (median hemoglobin, 7.1 g/dL) and markedly microcytic (median mean corpuscular volume, 62.0 fL). Clinical course involved recurrent febrile illness and gastrointestinal disturbance, lacking an infective cause. Investigation revealed B-cell lymphopenia (CD19⁺ range, 0.016-0.22 × 109/L) and panhypogammaglobulinemia in most cases. Children displayed developmental delay alongside variable neurodegeneration, seizures, cerebellar abnormalities, sensorineural deafness, and other multisystem features. Most required regular blood transfusion, iron chelation, and intravenous immunoglobulin replacement. Median survival was 48 months, with 7 deaths caused by cardiac or multiorgan failure. One child underwent bone marrow transplantation aged 9 months, with apparent cure of the hematologic and immunologic manifestations. We describe and define a novel CSA and B-cell immunodeficiency syndrome with additional features resembling a mitochondrial cytopathy. The molecular etiology is under investigation.


Assuntos
Anemia Sideroblástica/diagnóstico , Linfócitos B/imunologia , Deficiências do Desenvolvimento/diagnóstico , Febre Familiar do Mediterrâneo/diagnóstico , Síndromes de Imunodeficiência/diagnóstico , Anemia Sideroblástica/sangue , Anemia Sideroblástica/genética , Deficiências do Desenvolvimento/sangue , Deficiências do Desenvolvimento/genética , Febre Familiar do Mediterrâneo/sangue , Febre Familiar do Mediterrâneo/genética , Feminino , Perda Auditiva Neurossensorial/sangue , Perda Auditiva Neurossensorial/diagnóstico , Perda Auditiva Neurossensorial/genética , Humanos , Síndromes de Imunodeficiência/sangue , Síndromes de Imunodeficiência/genética , Lactente , Recém-Nascido , Masculino , Doenças do Sistema Nervoso/sangue , Doenças do Sistema Nervoso/diagnóstico , Doenças do Sistema Nervoso/genética , Linhagem , Fenótipo , Síndrome
20.
Biol Blood Marrow Transplant ; 19(1): 62-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22892550

RESUMO

Although hematopoietic stem cell transplantation (HSCT) offers curative potential for beta-thalassemia major (beta-TM), it is associated with a variable but significant incidence of graft rejection. We studied the French national experience for improvement over time and the potential benefit of antithymocyte globulin (ATG). Between December 1985 and December 2007, 108 patients with beta-TM underwent HSCT in 21 different French transplantation centers. The majority of patients received a matched sibling transplant (n = 96) and a busulfan- and cyclophosphamide-based conditioning regimen (n = 95), also with ATG in 57 cases. Ninety-five of the 108 patients survived, with a median follow-up of 12 years. Probabilities of 15-year survival and thalassemia-free survival after first HSCT were 86.8% and 69.4%, respectively. Graft failure occurred in 24 patients, 11 of whom underwent a second HSCT. The use of ATG was associated with a decrease in rejection rate from 35% to 10%. Thalassemia-free survival improved significantly with time, reaching 83% in the 54 patients undergoing HSCT after 1994 (median time of HSCT). In view of the increased risk of graft rejection after matched sibling HSCT, current French national guidelines recommend, for all children at risk for beta-TM, the systematic addition of ATG to the myeloablative conditioning regimen and special attention to optimize transfusion and chelation therapy in the pretransplantation period.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Estudos Retrospectivos , Condicionamento Pré-Transplante , Talassemia beta/mortalidade , Talassemia beta/terapia , Adolescente , Adulto , Bussulfano/administração & dosagem , Pré-Escolar , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Feminino , Seguimentos , França/epidemiologia , Humanos , Lactente , Masculino , Agonistas Mieloablativos/administração & dosagem , Irmãos , Taxa de Sobrevida , Transplante Homólogo
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