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1.
Br J Haematol ; 196(2): 380-389, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34775608

RESUMO

Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.


Assuntos
Talassemia/epidemiologia , Adolescente , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Comorbidade , Gerenciamento Clínico , Suscetibilidade a Doenças , Feminino , Predisposição Genética para Doença , Humanos , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/terapia , Masculino , Pessoa de Meia-Idade , Vigilância em Saúde Pública , Estudos Retrospectivos , Fatores Sociodemográficos , Talassemia/diagnóstico , Talassemia/etiologia , Talassemia/terapia , Estados Unidos/epidemiologia , Adulto Jovem
2.
Pediatr Blood Cancer ; 65(7): e27067, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29637688

RESUMO

BACKGROUND: Nontransfusion-dependent thalassemia (NTDT) refers to a diverse group of thalassemia mutations and clinical phenotypes that do not require chronic transfusions. It is increasingly prevalent in the United States. PROCEDURE: This study reviews the epidemiology and clinical characteristics of 138 patients with NTDT treated at four US thalassemia centers from 1997 to 2014. Data on laboratory results, transfusions, and clinical complications were collected from patient charts. RESULTS: Overall, 84 patients with α-thalassemia (62 deletional hemoglobin H; 22 nondeletional hemoglobin H), 39 with ß-thalassemia (26 with homozygous or double heterozygous ß mutations; 13 with single ß mutations with or without α triplication), and 15 with E/ß-thalassemia (12 E/ß0 ; three E/ß+ ) were identified. At study entry, the median age for patients with α-thalassemia was 2.3 years; 9.2 years for patients with ß-thalassemia and 2.2 years for patients with E/ß-thalassemia. Most patients with α-thalassemia were Asian. Patients with ß-thalassemia were predominantly Caucasian (46%) or of African descent (36%). Twenty percent of patients were born outside the United States and 5% were transfused before immigration. Complications varied by genotype and age. Individuals with nondeletional hemoglobin H were severely affected and, despite their young age, had many complications. Iron overload increased with age and was more common in patients who received transfusions. CONCLUSIONS: NTDT in the United States is a multi-ethnic disease with different genotypic mutations and phenotypic manifestations. A higher than expected proportion of patients was Black/African American. NTDT-related complications are common and increase with age, supporting a need for early diagnosis.


Assuntos
Talassemia/epidemiologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Genótipo , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Fenótipo , Talassemia/complicações , Talassemia/genética , Estados Unidos/epidemiologia , Adulto Jovem
3.
Am J Hematol ; 92(12): 1356-1361, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28940308

RESUMO

Our phase I, open-label, multi-center, dose-escalation study evaluated the pharmacokinetics (PK) of SP-420, a tridentate oral iron chelating agent of the desferrithiocin class, in patients with transfusion dependent ß-thalassemia. SP-420 was administered as a single dose of 1.5 (n = 3), 3 (n = 3), 6 (n = 3), 12 (n = 3), and 24 (n = 6) mg/kg or as a twice-daily dose of 9 mg/kg (n = 6) over 14-28 days. There was a near dose-linear increase in the mean plasma SP-420 concentrations and in the mean values for Cmax and AUC0-τ over the dose range evaluated. The median tmax ranged from 0.5 to 2.25 h and was not dose dependent. The study was prematurely terminated by the sponsor due to renal adverse events (AE) including proteinuria, increase in serum creatinine, and one case of Fanconi syndrome. Other adverse effects included hypersensitivity reactions and gastrointestinal disturbances. Based on current dose administration, the renal AE observed outweighed the possible benefits from chelation therapy. However, additional studies assessing efficacy and safety of lower doses or less frequent dosing of SP-420 over longer durations with close monitoring would be necessary to better explain the findings of our study and characterize the safety of the study drug.


Assuntos
Cicloexanonas/farmacocinética , Di-Hidropiridinas/efeitos adversos , Quelantes de Ferro/efeitos adversos , Quelantes de Ferro/farmacocinética , Tiazóis/efeitos adversos , Tiazóis/farmacocinética , Talassemia beta/terapia , Adolescente , Adulto , Transfusão de Sangue , Cicloexanonas/efeitos adversos , Cicloexanonas/uso terapêutico , Di-Hidropiridinas/uso terapêutico , Relação Dose-Resposta a Droga , Humanos , Quelantes de Ferro/administração & dosagem , Nefropatias/induzido quimicamente , Pessoa de Meia-Idade , Sideróforos/uso terapêutico , Sideróforos/toxicidade , Tiazóis/uso terapêutico , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico
4.
J Health Psychol ; 21(5): 579-89, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-24801328

RESUMO

Emotion context sensitivity is the ability to respond emotionally in a manner that is functionally appropriate for the context in which the emotion arises. This study examined the relationship between emotion context sensitivity and treatment adherence in adults with the chronic illness Thalassemia. Emotional responses were measured by examining the frequency of positive and negative emotional words used to answer two interview questions that created two different emotional contexts. Consistent with previous research on adaptive and contextually appropriate emotions, negative emotion words were related to adherence in the context of the disease itself, while positive emotion words were related to adherence in the context of coping.


Assuntos
Adaptação Psicológica , Emoções , Idioma , Talassemia/psicologia , Cooperação e Adesão ao Tratamento/psicologia , Adulto , Doença Crônica , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Talassemia/terapia
6.
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
7.
Transfusion ; 54(7): 1773-81, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24611697

RESUMO

BACKGROUND: In the absence of curative treatment, such as stem cell transplant, regular transfusions remain the mainstay of therapy for individuals with thalassemia major, a syndrome that results from marked ineffective erythropoiesis and the resultant anemia. The primary objectives of transfusion therapy are twofold: to suppress ineffective erythropoiesis and to ensure appropriate growth and development through childhood. In practice, a number of different transfusion protocols are in use across the developed world, with on-demand transfusion still being the paradigm in most of the developing world with limited resources. STUDY DESIGN AND METHODS: To investigate perceived differences in transfusion practice, a self-reported electronic survey was disseminated to eight US thalassemia treatment centers in February 2011. The survey was divided into sections ranging from laboratory and clinical practices to emerging transfusion-transmitted diseases. RESULTS: The survey response rate was 100%. The total number of transfused patients was 411. One-hundred percent of institutions used leukoreduced blood. No centers routinely provided cytomegalovirus-seronegative red blood cells (RBCs). Half the centers provided irradiated RBCs; only one routinely provided washed RBCs, and none transfused RBCs of defined storage age. Seventy-five percent of centers routinely phenotyped thalassemia patients' RBC antigens; 50% prophylactically matched for Rh and K antigens. The frequency of antibody investigations varied widely, and 25% of centers routinely medicated patients before transfusion. CONCLUSION: Eight thalassemia centers in the United States were surveyed to determine the uniformity of transfusion practice. The variability of the results was surprising. Consequently, we performed a literature review and propose an evidence-based protocol for routine transfusion therapy for patients with thalassemia.


Assuntos
Transfusão de Eritrócitos , Prática Clínica Baseada em Evidências , Guias de Prática Clínica como Assunto , Prática Profissional , Talassemia/terapia , Preservação de Sangue/métodos , Preservação de Sangue/normas , Segurança do Sangue/métodos , Segurança do Sangue/normas , Coleta de Dados , Transfusão de Eritrócitos/métodos , Transfusão de Eritrócitos/normas , Transfusão de Eritrócitos/estatística & dados numéricos , Prática Clínica Baseada em Evidências/normas , Humanos , Prática Profissional/normas , Prática Profissional/estatística & dados numéricos , Inquéritos e Questionários , Talassemia/epidemiologia , Estados Unidos/epidemiologia
8.
Blood ; 123(10): 1483-6, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24429337

RESUMO

We conducted a pilot trial to investigate the safety and effectiveness of mobilizing CD34(+) hematopoietic progenitor cells (HPCs) in adults with ß-thalassemia major. We further assessed whether thalassemia patient CD34(+) HPCs could be transduced with a globin lentiviral vector under clinical conditions at levels sufficient for therapeutic implementation. All patients tolerated granulocyte colony-stimulating factor well with minimal side effects. All cell collections exceeded 8 × 10(6) CD34(+) cells/kg. Using clinical grade TNS9.3.55 vector, we demonstrated globin gene transfer averaging 0.53 in 3 validation runs performed under current good manufacturing practice conditions. Normalized to vector copy, the vector-encoded ß-chain was expressed at a level approximating normal hemizygous protein output. Importantly, stable vector copy number (0.2-0.6) and undiminished vector expression were obtained in NSG mice 6 months posttransplant. Thus, we validated a safe and effective procedure for ß-globin gene transfer in thalassemia patient CD34(+) HPCs, which we will implement in the first US trial in patients with severe inherited globin disorders. This trial is registered at www.clinicaltrials.gov as #NCT01639690.


Assuntos
Técnicas de Transferência de Genes , Terapia Genética , Mobilização de Células-Tronco Hematopoéticas , Transplante de Células-Tronco Hematopoéticas , Globinas beta/genética , Talassemia beta/genética , Talassemia beta/terapia , Animais , Antígenos CD34/metabolismo , Ensaio de Unidades Formadoras de Colônias , Modelos Animais de Doenças , Células Precursoras Eritroides/metabolismo , Expressão Gênica , Vetores Genéticos/genética , Xenoenxertos , Humanos , Camundongos , Transdução Genética , Globinas beta/biossíntese , Talassemia beta/metabolismo
9.
Int J Behav Med ; 21(1): 160-8, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23086716

RESUMO

BACKGROUND: Although research has demonstrated the detrimental effects of excessive negative affect on treatment adherence and morbidity in chronic illness, rarely have researchers investigated the benefits of awareness of negative emotional experiences during treatment. PURPOSE: In this investigation, we examined the association of negative affect differentiation (the ability to report negative emotional experiences as separate and distinct from each other,) to treatment adherence in adult patients with the congenital blood disorder thalassemia. METHOD: Negative affect differentiation was assessed during a 12-16-week treatment-based diary and adherence was operationalized as attendance at routine screenings over 12 months. Participants were adult patients (n = 32; age M = 31.63, SD = 7.72; 72 % female) with transfusion-dependent thalassemia in treatment in a large metropolitan hospital in the Northeastern USA. RESULTS: The results indicate that negative affect differentiation is significantly associated with greater adherence to treatment, even when controlling for disease burden and level of psychological distress. CONCLUSION: Although preliminary, this investigation suggests that differentiated processing of negative emotional experiences during illness can lead to adaptive treatment-related behavior. As such, it may present a new avenue for research and intervention targeting the improvement of adherence during treatment for chronic illness.


Assuntos
Negativismo , Cooperação do Paciente/psicologia , Talassemia/psicologia , Talassemia/terapia , Adaptação Psicológica , Adulto , Conscientização , Doença Crônica , Comorbidade , Emoções , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estresse Psicológico/diagnóstico
10.
Transfusion ; 54(4): 972-81; quiz 971, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23889533

RESUMO

BACKGROUND: Transfusions are the primary therapy for thalassemia but have significant cumulative risks. In 2004, the Centers for Disease Control and Prevention (CDC) established a national blood safety monitoring program for thalassemia. This report summarizes the population and their previous nonimmune and immune transfusion complications. STUDY DESIGN AND METHODS: The CDC Thalassemia Blood Safety Network is a consortium of centers longitudinally following patients. Enrollment occurred from 2004 through 2012. Demographics, transfusion history, infectious exposures, and transfusion and nontransfusion complications were summarized. Logistic regression analyses of factors associated with allo- and autoimmunization were employed. RESULTS: The race/ethnicity of these 407 thalassemia patients was predominantly Asian or Caucasian. The mean ± SD age was 22.3 ± 13.2 years and patients had received a mean ± SD total number of 149 ± 103.4 units of red blood cells (RBCs). Multiorgan dysfunction was common despite chelation. Twenty-four percent of transfused patients had previous exposure to possible transfusion-associated pathogens including one case of babesia. As 27% were immigrants, the infection source cannot be unequivocally linked to transfusion. Transfusion reactions occurred in 48%, including allergic, febrile, and hemolytic; 19% were alloimmunized. Common antigens were E, Kell, and C. Years of transfusion was the strongest predictor of alloimmunization. Autoantibodies occurred in 6.5% and were associated with alloimmunization (p < 0.0001). Local institutional policies, not patient characteristics, were major determinants of blood preparation and transfusion practices. CONCLUSION: Hemosiderosis, transfusion reactions, and infections continue to be major problems in thalassemia. New pathogens were noted. National guidelines for RBC phenotyping and preparation are needed to decrease transfusion-related morbidity.


Assuntos
Transfusão de Eritrócitos/efeitos adversos , Talassemia/terapia , Adolescente , Adulto , Segurança do Sangue/estatística & dados numéricos , Centers for Disease Control and Prevention, U.S. , Criança , Pré-Escolar , Transfusão de Eritrócitos/estatística & dados numéricos , Feminino , Humanos , Lactente , Estudos Longitudinais , Masculino , Estados Unidos/epidemiologia , Adulto Jovem
11.
Am J Hematol ; 88(9): 771-3, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23757266

RESUMO

Improved survival in thalassemia has refocused attention on quality of life, including family planning. Understanding the issues associated with infertility and adverse pregnancy outcomes may impact clinical care of patients with thalassemia. We report the number and outcomes of pregnancies among subjects enrolled in Thalassemia Clinical Research Network (TCRN) registries and examine variables associated with successful childbirth. We identified 129 pregnancies in 72 women among the 264 women, age 18 years or older in our dataset. Over 70% of pregnancies resulted in live births and 73/83 (88%) of live births occurred at full term. Most pregnancies (78.2%) were conceived without reproductive technologies. Most (59.3%) pregnancies occurred while on chronic transfusion programs, however only 38.9% were on iron chelation. Four women developed heart problems. Iron burden in women who had conceived was not significantly different from age- and diagnosis-matched controls that had never been pregnant. There was also no difference in pregnancy outcomes associated with diagnosis, transfusion status, diabetes or Hepatitis C infection. Pregnancies occurred in 27.3% of women with thalassemia of child-bearing age in the TCRN registries, a notable increase from our previous 2004 report. With optimal health maintenance, successful pregnancies may be achievable.


Assuntos
Nascido Vivo/epidemiologia , Sistema de Registros , Natimorto/epidemiologia , Talassemia beta/epidemiologia , Adulto , Transfusão de Sangue , Feminino , Nível de Saúde , Humanos , Ferro/metabolismo , Quelantes de Ferro/uso terapêutico , Pessoa de Meia-Idade , América do Norte/epidemiologia , Gravidez , Técnicas de Reprodução Assistida/estatística & dados numéricos , Reino Unido/epidemiologia , Talassemia beta/terapia
12.
Am J Hematol ; 88(8): 652-6, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23640778

RESUMO

Cardiovascular magnetic resonance (CMR) and hepatic magnetic resonance imaging (MRI) have become reliable noninvasive tools to monitor iron excess in thalassemia major (TM) patients. However, long-term studies are lacking. We reviewed CMR and hepatic MRI T2* imaging on 54 TM patients who had three or more annual measurements. They were managed on various chelation regimens. Patients were grouped according to their degree of cardiac siderosis: severe (T2*, <10 msec), mild to moderate (T2* = 10-20 msec), and no cardiac siderosis (T2*, >20 msec). We looked at the change in cardiac T2*, liver iron concentration (LIC) and left ventricular ejection fraction (LVEF) at years 3 and 5. In patients with severe cardiac siderosis, cardiac T2* (mean ± SD) improved from 6.9 ± 1.6 at baseline to 13.6 ± 10.0 by year 5, mean ΔT2* = 6.7 (P = 0.04). Change in cardiac T2* at year 3 was not significant in the severe group. Patients with mild to moderate cardiac siderosis had mean cardiac T2* of 14.6 ± 2.9 at baseline which improved to 26.3 ± 9.5 by year 3, mean ΔT2* = 1.7 (P = 0.01). At baseline, median LICs (mg/g dry weight) in patients with severe, mild-moderate, and no cardiac siderosis were 3.6, 2.8, and 3.3, whereas LVEFs (mean ± SD) (%) were 56.3 ± 10.1, 60 ± 5, and 66 ± 7.6, respectively. No significant correlation was noted between Δ cardiac T2* and Δ LIC, Δ cardiac T2*, and Δ LVEF at years 3 and 5. Throughout the observation period, patients with no cardiac siderosis maintained their cardiac T2* above 20 msec. The majority of patients with cardiac siderosis improve cardiac T2* over time with optimal chelation.


Assuntos
Cardiopatias , Coração , Hemossiderose , Fígado , Miocárdio/metabolismo , Talassemia beta , Adolescente , Adulto , Criança , Feminino , Seguimentos , Coração/diagnóstico por imagem , Coração/fisiopatologia , Cardiopatias/diagnóstico por imagem , Cardiopatias/etiologia , Cardiopatias/metabolismo , Cardiopatias/fisiopatologia , Hemossiderose/diagnóstico por imagem , Hemossiderose/etiologia , Hemossiderose/fisiopatologia , Humanos , Quelantes de Ferro/administração & dosagem , Fígado/diagnóstico por imagem , Fígado/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Monitorização Fisiológica/métodos , Radiografia , Volume Sistólico , Talassemia beta/complicações , Talassemia beta/diagnóstico por imagem , Talassemia beta/tratamento farmacológico , Talassemia beta/metabolismo , Talassemia beta/fisiopatologia
13.
Pediatr Blood Cancer ; 60(9): 1507-12, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23637051

RESUMO

BACKGROUND: Deferasirox is a once-daily, oral iron chelator that was developed out of a need for a long-acting, conveniently-administered chelator for patients with transfusional hemosiderosis. The approved mode of administration requires taking deferasirox on an empty stomach with water, apple juice, or orange juice to limit variation in bioavailability. This required administration schedule might not be palatable for patients. Additionally, approximately one-quarter of patients experience mild to moderate gastrointestinal (GI) symptoms, which may pose additional challenges, particularly in the younger and older age ranges. We present a trial to assess the palatability and safety of various administration modes of deferasirox in pediatric and adult patients. PROCEDURES: Participants rated palatability in a 4-week run-in phase, where deferasirox was administered per label. Subsequently, patients rated several administration modes during a 3-month assessment phase. RESULTS: Palatability was more favorable during the assessment phase, with 47% of patient ratings for palatability being favorable while only 38% were favorable during the run-in phase. The most highly rated choice was deferasirox taken with a soft food at breakfast. In addition, there was an indication of improved GI tolerability during the assessment phase (symptoms were reported in 37% of patients during run-in and 32% during the assessment phase; rates of diarrhea decreased significantly). Although trough PK values increased, no major new toxicities were observed. CONCLUSIONS: These data indicate that different administration options may improve palatability and GI tolerability, which could have a positive impact on treatment adherence. (ClinicalTrials.gov number, NCT00845871)


Assuntos
Benzoatos/administração & dosagem , Bebidas , Interações Alimento-Droga , Alimentos , Hemossiderose/tratamento farmacológico , Quelantes de Ferro/administração & dosagem , Triazóis/administração & dosagem , Adolescente , Transfusão de Sangue , Criança , Pré-Escolar , Deferasirox , Feminino , Doenças Hematológicas/terapia , Hemossiderose/etiologia , Humanos , Masculino
14.
J Cardiovasc Magn Reson ; 15: 38, 2013 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-23688265

RESUMO

BACKGROUND: Established heart failure in thalassaemia major has a poor prognosis and optimal management remains unclear. METHODS: A 1 year prospective study comparing deferoxamine (DFO) monotherapy or when combined with deferiprone (DFP) for patients with left ventricular ejection fraction (LVEF) <56% was conducted by the Thalassemia Clinical Research Network (TCRN). All patients received DFO at 50-60 mg/kg 12-24 hr/day sc or iv 7 times weekly, combined with either DFP 75 at mg/kg/day (combination arm) or placebo (DFO monotherapy arm). The primary endpoint was the change in LVEF by CMR. RESULTS: Improvement in LVEF was significant in both study arms at 6 and 12 months (p = 0.04), normalizing ventricular function in 9/16 evaluable patients. With combination therapy, the LVEF increased from 49.9% to 55.2% (+5.3% p = 0.04; n = 10) at 6 months and to 58.3% at 12 months (+8.4% p = 0.04; n = 7). With DFO monotherapy, the LVEF increased from 52.8% to 55.7% (+2.9% p = 0.04; n = 6) at 6 months and to 56.9% at 12 months (+4.1% p = 0.04; n = 4). The LVEF trend did not reach statistical difference between study arms (p = 0.89). In 2 patients on DFO monotherapy during the study and in 1 patient on combined therapy during follow up, heart failure deteriorated fatally. The study was originally powered for 86 participants to determine a 5% difference in LVEF improvement between treatments. The study was prematurely terminated due to slow recruitment and with the achieved sample size of 20 patients there was 80% power to detect an 8.6% difference in EF, which was not demonstrated. Myocardial T2* improved in both arms (combination +1.9 ± 1.6 ms p = 0.04; and DFO monotherapy +1.9 ± 1.4 ms p = 0.04), but with no significant difference between treatments (p = 0.65). Liver iron (p = 0.03) and ferritin (p < 0.001) both decreased significantly in only the combination group. CONCLUSIONS: Both treatments significantly improved LVEF and myocardial T2*. Although this is the largest and only randomized study in patients with LV decompensation, further prospective evaluation is needed to identify optimal chelation management in these high-risk patients.


Assuntos
Desferroxamina/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Quelantes de Ferro/uso terapêutico , Piridonas/uso terapêutico , Sideróforos/uso terapêutico , Talassemia beta/tratamento farmacológico , Adulto , Deferiprona , Quimioterapia Combinada , Feminino , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/etiologia , Insuficiência Cardíaca/fisiopatologia , Humanos , Líbano , Masculino , Ontário , Estudos Prospectivos , Recuperação de Função Fisiológica , Volume Sistólico/efeitos dos fármacos , Fatores de Tempo , Resultado do Tratamento , Estados Unidos , Função Ventricular Esquerda/efeitos dos fármacos , Adulto Jovem , Talassemia beta/complicações , Talassemia beta/diagnóstico
15.
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
17.
Nat Med ; 19(4): 437-45, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23502961

RESUMO

Regulation of erythropoiesis is achieved by the integration of distinct signals. Among them, macrophages are emerging as erythropoietin-complementary regulators of erythroid development, particularly under stress conditions. We investigated the contribution of macrophages to physiological and pathological conditions of enhanced erythropoiesis. We used mouse models of induced anemia, polycythemia vera and ß-thalassemia in which macrophages were chemically depleted. Our data indicate that macrophages contribute decisively to recovery from induced anemia, as well as the pathological progression of polycythemia vera and ß-thalassemia, by modulating erythroid proliferation and differentiation. We validated these observations in primary human cultures, showing a direct impact of macrophages on the proliferation and enucleation of erythroblasts from healthy individuals and patients with polycythemia vera or ß-thalassemia. The contribution of macrophages to stress and pathological erythropoiesis, which we have termed stress erythropoiesis macrophage-supporting activity, may have therapeutic implications.


Assuntos
Eritropoese/fisiologia , Macrófagos/fisiologia , Policitemia Vera/fisiopatologia , Talassemia beta/fisiopatologia , Animais , Ácido Clodrônico/farmacologia , Modelos Animais de Doenças , Contagem de Eritrócitos , Eritropoese/efeitos dos fármacos , Feminino , Hematócrito , Hemoglobinas/análise , Humanos , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Reticulócitos/fisiologia , Estresse Fisiológico/fisiologia
18.
PLoS One ; 8(2): e55709, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23409025

RESUMO

BACKGROUND: Fetal hemoglobin level is a heritable complex trait that strongly correlates swith the clinical severity of sickle cell disease. Only few genetic loci have been identified as robustly associated with fetal hemoglobin in patients with sickle cell disease, primarily adults. The sole approved pharmacologic therapy for this disease is hydroxyurea, with effects largely attributable to induction of fetal hemoglobin. METHODOLOGY/PRINCIPAL FINDINGS: In a multi-site observational analysis of children with sickle cell disease, candidate single nucleotide polymorphisms associated with baseline fetal hemoglobin levels in adult sickle cell disease were examined in children at baseline and induced by hydroxyurea therapy. For baseline levels, single marker analysis demonstrated significant association with BCL11A and the beta and epsilon globin loci (HBB and HBE, respectively), with an additive attributable variance from these loci of 23%. Among a subset of children on hydroxyurea, baseline fetal hemoglobin levels explained 33% of the variance in induced levels. The variant in HBE accounted for an additional 13% of the variance in induced levels, while variants in the HBB and BCL11A loci did not contribute beyond baseline levels. CONCLUSIONS/SIGNIFICANCE: These findings clarify the overlap between baseline and hydroxyurea-induced fetal hemoglobin levels in pediatric disease. Studies assessing influences of specific sequence variants in these and other genetic loci in larger populations and in unusual hydroxyurea responders are needed to further understand the maintenance and therapeutic induction of fetal hemoglobin in pediatric sickle cell disease.


Assuntos
Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Antidrepanocíticos/uso terapêutico , Hemoglobina Fetal/genética , Hidroxiureia/uso terapêutico , Polimorfismo de Nucleotídeo Único , Adolescente , Alelos , Anemia Falciforme/metabolismo , Antidrepanocíticos/administração & dosagem , Criança , Feminino , Hemoglobina Fetal/metabolismo , Genótipo , Humanos , Hidroxiureia/administração & dosagem , Masculino , Estudos Prospectivos
19.
AIDS Res Hum Retroviruses ; 29(7): 1006-9, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23409829

RESUMO

Thalassemia is an inherited genetic disorder requiring multiple transfusions to treat anemia caused by low hemoglobin levels. Thus, thalassemia patients are at risk for infection with blood-borne pathogens, including human T cell lymphotropic viruses (HTLV) that are transmitted by transfusion of cellular blood products. Here, we examined the prevalence of HTLV among 234 U.S. thalassemia patients using sera collected in 2008. Sera were tested for antibodies to HTLV-1/2 using enzyme immunoassay (EIA) and a confirmatory western blot (WB) that differentiates between HTLV-1 and HTLV-2. Demographic information and clinical information were collected at study enrollment, including HIV and hepatitis C virus (HCV) status. Three patients (1.3%) were WB positive; two were HTLV-1 and one could not be serotyped as HTLV-1/2. All three HTLV-positive persons were HIV-1 negative and one was HCV seropositive. The HTLV seroprevalence was higher than that of HIV-1 (0.85%) and lower than HCV (18.8%) in this population. All three patients (ages 26-46 years) were diagnosed with ß-thalassemia shortly after birth and have since been receiving multiple transfusions annually. Two of the HTLV-positive patients confirmed receiving transfusions before HTLV blood screening was implemented in 1988. We identified a substantial HTLV-1 seroprevalence in U.S. thalassemia patients that is much greater than that seen in blood donors. Our findings highlight the importance of HTLV testing of patients with thalassemia and other diseases requiring multiple transfusions, especially in recipients of unscreened transfusions. In addition, appropriate counseling and follow-up of HTLV-infected patients are warranted.


Assuntos
Infecções por HTLV-I/complicações , Talassemia beta/complicações , Adulto , Feminino , Anticorpos Anti-HTLV-I/sangue , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-I/transmissão , Infecções por HTLV-II/complicações , Hepatite C/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Reação Transfusional , Estados Unidos/epidemiologia , Talassemia alfa/complicações
20.
Haematologica ; 98(1): 129-35, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22875626

RESUMO

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


Assuntos
Benzoatos/administração & dosagem , Desferroxamina/administração & dosagem , Triazóis/administração & dosagem , Talassemia beta/tratamento farmacológico , Talassemia beta/metabolismo , Adulto , Deferasirox , Quimioterapia Combinada , Feminino , Humanos , Ferro/sangue , Ferro/urina , Quelantes de Ferro/administração & dosagem , Masculino
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