RESUMO
INTRODUCTION: Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia. METHODS: We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011. RESULTS: We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation. CONCLUSIONS: Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.
RESUMO
Abstract Introduction Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia. Methods We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011. Results We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation. Conclusions Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.
Assuntos
Humanos , Criança , Talassemia , Sobrecarga de Ferro , Terapia por QuelaçãoRESUMO
BACKGROUND: Patients with thalassemia major present chronic hemolysis and require regular blood transfusions which may cause iron overload cardiomyopathy and chronic heart failure. Hemochromatosis is characterized by excessive iron accumulation in tissues, and heart involvement is the main cause of death in patients with thalassemia. OBJECTIVE: The aim of this study was to evaluate cardiac structure and function by conventional Doppler echocardiography and tissue Doppler imaging in patients with TM and no clinical evidence of heart failure. METHODS: This is a prospective observational study including 18 patients with thalassemia major (TM) receiving regular blood transfusion. To separately evaluate anemia and blood transfusion effects, two gender, age, weight, and height-matched control groups were included: one with healthy individuals (Healthy, n=18) and one with iron deficient anemia patients (Anemia, n=18). Statistical analysis was performed using ANOVA followed by Tukey's test or Kruskal-Wallis's and Dunn's test. RESULTS: The following echocardiographic variables presented significantly higher values in TM than the Anemia and Healthy groups: left atrium volume index (Healthy: 16.4±6.08; Anemia: 17.9±7.02; TM: 24.1±8.30 cm³/m²); mitral septal E/Em ratio (Healthy: 6.55±1.60; Anemia: 6.74±0.74; TM: 8.10±1.31); and duration of reverse pulmonary vein flow [Healthy: 74.0 (59.0-74.0); Anemia: 70.5 (67.0-74.0); TM: 111 (87.0-120) ms]. The mitral E/A ratio was higher in TM than Anemia (Healthy: 1.80±0.40; Anemia: 1.80±0.24; TM: 2.03±0.34). No differences were found in left ventricular structures and systolic function indexes. CONCLUSION: Conventional Doppler echocardiography and tissue Doppler allow changes in left ventricular diastolic function to be identified in asymptomatic patients with thalassemia major.
Assuntos
Terapia por Quelação , Ecocardiografia Doppler/métodos , Quelantes de Ferro/uso terapêutico , Reação Transfusional , Função Ventricular , Talassemia beta/complicações , Adolescente , Adulto , Fatores Etários , Anemia/etiologia , Anemia/fisiopatologia , Criança , Métodos Epidemiológicos , Feminino , Hemocromatose/etiologia , Hemocromatose/fisiopatologia , Hemodinâmica , Hemólise/fisiologia , Humanos , Masculino , Fatores Sexuais , Adulto Jovem , Talassemia beta/fisiopatologia , Talassemia beta/terapiaRESUMO
In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox) providing good results in reducing cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA), presents a review of the literature regarding iron overload assessment (by imaging and laboratory exams) and the role of T2* magnetic resonance imaging (MRI) to control iron overload and iron chelation therapy, with evidence-based recommendations for each clinical situation. Based on this review, the authors propose an iron chelation protocol for patients with thalassemia under regular transfusions.
RESUMO
BACKGROUND: An association between class I and II alleles of the major histocompatibility complex and idiopathic chronic urticaria has previously been observed in different populations, but there are still no studies on Brazilian populations in this regard. OBJECTIVE: The involvement of the major histocompatibility complex classes I and II (loci A, B and DR) in Brazilian patients with idiopathic chronic urticaria and a positive autologous serum skin test was investigated and compared with a healthy population group. METHODS: DNA was extracted from the blood of 42 patients with idiopathic chronic urticaria and major histocompatibility complex classes I and II alleles were determined using the polymerase chain reaction and a laboratory test for oligonucleotide hybridization using a single-filament probe. The frequencies of these alleles in patients with chronic urticaria were compared with the frequencies in 1000 genetically unrelated voluntary blood donors from the same region of Brazil. The diagnosis of idiopathic chronic urticaria was based on the patients' clinical history and routine laboratory tests. Only the patients with positive autologous serum skin test were selected. The allele distribution resulted from the patient and control groups were analyzed using odds ratios and 95% confidence intervals. RESULTS: No statistically significant differences were found between the positive autologous serum skin test patients with chronic urticaria and the control group. CONCLUSIONS: We found that in this population group, there was no specific association between the HLA alleles studied and chronic urticaria. We believe that further population studies are needed in order to investigate the possible existence of this association.
Assuntos
Antígenos de Histocompatibilidade Classe II/análise , Antígenos de Histocompatibilidade Classe I/análise , Urticária/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Estudos de Casos e Controles , Doença Crônica , Feminino , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Testes Cutâneos , Urticária/imunologia , Adulto JovemRESUMO
PURPOSE: To assess the correlation between MRI findings of the pancreas with those of the heart and liver in patients with beta thalassemia; to compare the pancreas T2* MRI results with glucose and ferritin levels and labile plasma iron (LPI). MATERIALS AND METHODS: We retrospectively evaluated chronically transfused patients, testing glucose with enzymatic tests, serum ferritin with chemiluminescence, LPI with cellular fluorescence, and T2* MRI to assess iron content in the heart, liver, and pancreas. MRI results were compared with one another and with serum glucose, ferritin, and LPI. Liver iron concentration (LIC) was determined in 11 patients' liver biopsies by atomic absorption spectrometry. RESULTS: 289 MRI studies were available from 115 patients during the period studied. 9.4% of patients had overt diabetes and an additional 16% of patients had impaired fasting glucose. Both pancreatic and cardiac R2* had predictive power (p<0.0001) for identifying diabetes. Cardiac and pancreatic R2* were modestly correlated with one another (r(2) = 0.20, p<0.0001). Both were weakly correlated with LIC (r(2) = 0.09, p<0.0001 for both) and serum ferritin (r(2) = 0.14, p<0.0001 and r(2) = 0.03, p<0.02, respectively). None of the three served as a screening tool for single observations. There is a strong log-log, or power-law, relationship between ratio of signal intensity (SIR) values and pancreas R2* with an r(2) of 0.91. CONCLUSIONS: Pancreatic iron overload can be assessed by MRI, but siderosis in other organs did not correlate significantly with pancreatic hemosiderosis.
Assuntos
Sobrecarga de Ferro/diagnóstico , Imageamento por Ressonância Magnética/métodos , Pâncreas/química , Pâncreas/patologia , Talassemia beta/patologia , Adolescente , Adulto , Biópsia , Glicemia/análise , Transfusão de Sangue , Criança , Feminino , Ferritinas/sangue , Humanos , Masculino , Curva ROC , Análise de Regressão , Estudos Retrospectivos , Talassemia beta/sangueRESUMO
UNLABELLED: ABSTRACTObjectives:To evaluate the use of magnetic resonance imaging in patients with ß-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. METHODS: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. RESULTS: The mean serum ferritin was 2,676.5 +/- 2,051.7 ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= -0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). CONCLUSION: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. There was no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values.
RESUMO
FUNDAMENTO: Pacientes com talassemia major (TM) apresentam hemólise crônica e necessitam de transfusões sanguíneas egularmente que podem causar cardiomiopatia por sobrecarga de ferro e insuficiência cardíaca crônica. A hemocromatose é caracterizada por acúmulo excessivo de ferro nos tecidos; acometimento do coração é a principal causa de óbito em pacientes com talassemia. OBJETIVO: Avaliar as estruturas e a função cardíaca por meio de ecocardiografia com Doppler convencional e Doppler tecidual em pacientes com TM, sem evidência clínica de insuficiência cardíaca. MÉTODOS: Trata-se de estudo observacional prospectivo de 18 pacientes com TM que recebem transfusão sanguínea regularmente. Para avaliar, separadamente, os efeitos da anemia e da transfusão sanguínea, dois grupos controles pareados por gênero, idade, peso e altura foram incluídos: um com indivíduos saudáveis (Saudável, n = 18) e outro com pacientes com anemia por deficiência de ferro (Anemia, n = 18). Análise estatística foi realizada utilizando ANOVA seguida pelo teste de Tukey ou Kruskal-Wallis e teste de Dunn. RESULTADOS: As seguintes variáveis ecocardiográficas apresentaram valores significativamente mais elevados no grupo TM do que nos grupos Anemia e Saudável: índice de volume do átrio esquerdo (Saudável: 16,4 ± 6,08; Anemia: 17,9 ± 7,02; TM: 24,1 ± 8,30 cm/m); razão E/Em septal mitral (Saudável: 6,55 ± 1,60; Anemia: 6,74 ± 0,74; TM: 8,10 ± 1,31) e duração do fluxo reverso em veias pulmonares [Saudável: 74,0 (59,0-74,0); Anemia: 70,5 (67,0-74,0); TM: 111 (87,0-120) ms]. Arazão E/A mitral foi maior no grupo TM do que no grupo Anemia (Saudável: 1,80 ± 0,40; Anemia: 1,80 ± 0,24; TM: 2,03 ± 0,34). Não foram encontradas diferenças entre os grupos em variáveis estruturais do ventrículo esquerdo e em índices de função sistólica. CONCLUSÃO: A ecocardiografia com Doppler convencional e o Doppler tecidual permite que alterações na função diastólica do ventrículo esquerdo sejam identificadas em pacientes assintomáticos com talassemia major.
BACKGROUND: Patients with thalassemia major present chronic hemolysis and require regular blood transfusions which may cause iron overload cardiomyopathy and chronic heart failure. Hemochromatosis is characterized by excessive iron accumulation in tissues, and heart involvement is the main cause of death in patients with thalassemia. OBJECTIVE: The aim of this study was to evaluate cardiac structure and function by conventional Doppler echocardiography and tissue Doppler imaging in patients with TM and no clinical evidence of heart failure. METHODS: This is a prospective observational study including 18 patients with thalassemia major (TM) receiving regular blood transfusion. To separately evaluate anemia and blood transfusion effects, two gender, age, weight, and height-matched control groups were included: one with healthy individuals (Healthy, n=18) and one with iron deficient anemia patients (Anemia, n=18). Statistical analysis was performed using ANOVA followed by Tukey's test or Kruskal-Wallis's and Dunn's test. RESULTS: The following echocardiographic variables presented significantly higher values in TM than the Anemia and Healthy groups: left atrium volume index (Healthy: 16.4±6.08; Anemia: 17.9±7.02; TM: 24.1±8.30 cm³/m²); mitral septal E/Em ratio (Healthy: 6.55±1.60; Anemia: 6.74±0.74; TM: 8.10±1.31); and duration of reverse pulmonary vein flow [Healthy: 74.0 (59.0-74.0); Anemia: 70.5 (67.0-74.0); TM: 111 (87.0-120) ms]. The mitral E/A ratio was higher in TM than Anemia (Healthy: 1.80±0.40; Anemia: 1.80±0.24; TM: 2.03±0.34). No differences were found in left ventricular structures and systolic function indexes. CONCLUSION: Conventional Doppler echocardiography and tissue Doppler allow changes in left ventricular diastolic function to be identified in asymptomatic patients with thalassemia major.
Assuntos
Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Adulto Jovem , Transfusão de Sangue/efeitos adversos , Terapia por Quelação , Ecocardiografia Doppler/métodos , Quelantes de Ferro/uso terapêutico , Função Ventricular , Talassemia beta/complicações , Fatores Etários , Anemia/etiologia , Anemia/fisiopatologia , Métodos Epidemiológicos , Hemodinâmica , Hemocromatose/etiologia , Hemocromatose/fisiopatologia , Hemólise/fisiologia , Fatores Sexuais , Talassemia beta/fisiopatologia , Talassemia beta/terapiaRESUMO
In the absence of an iron chelating agent, patients with beta-thalassemia on regular transfusions present complications of transfusion-related iron overload. Without iron chelation therapy, heart disease is the major cause of death; however, hepatic and endocrine complications also occur. Currently there are three iron chelating agents available for continuous use in patients with thalassemia on regular transfusions (desferrioxamine, deferiprone, and deferasirox) providing good results in reducing cardiac, hepatic and endocrine toxicity. These practice guidelines, prepared by the Scientific Committee of Associação Brasileira de Thalassemia (ABRASTA), presents a review of the literature regarding iron overload assessment (by imaging and laboratory exams) and the role of T2* magnetic resonance imaging (MRI) to control iron overload and iron chelation therapy, with evidence-based recommendations for each clinical situation. Based on this review, the authors propose an iron chelation protocol for patients with thalassemia under regular transfusions.
Assuntos
Humanos , Talassemia beta , Transfusão de Sangue , Terapia por Quelação , Protocolos Clínicos , Quelantes de Ferro , Distúrbios do Metabolismo do Ferro , Imageamento por Ressonância MagnéticaRESUMO
BACKGROUND: An association between class I and II alleles of the major histocompatibility complex and idiopathic chronic urticaria has previously been observed in different populations, but there are still no studies on Brazilian populations in this regard. OBJECTIVE: The involvement of the major histocompatibility complex classes I and II (loci A, B and DR) in Brazilian patients with idiopathic chronic urticaria and a positive autologous serum skin test was investigated and compared with a healthy population group. METHODS: DNA was extracted from the blood of 42 patients with idiopathic chronic urticaria and major histocompatibility complex classes I and II alleles were determined using the polymerase chain reaction and a laboratory test for oligonucleotide hybridization using a single-filament probe. The frequencies of these alleles in patients with chronic urticaria were compared with the frequencies in 1000 genetically unrelated voluntary blood donors from the same region of Brazil. The diagnosis of idiopathic chronic urticaria was based on the patients' clinical history and routine laboratory tests. Only the patients with positive autologous serum skin test were selected. The allele distribution resulted from the patient and control groups were analyzed using odds ratios and 95% confidence intervals. RESULTS: No statistically significant differences were found between the positive autologous serum skin test patients with chronic urticaria and the control group. CONCLUSIONS: We found that in this population group, there was no specific association between the HLA alleles studied and chronic urticaria. We believe that further population studies are needed in order to investigate the possible existence of this association.
FUNDAMENTOS: A associação entre os alelos do MHC classe I e II e a urticária crônica idiopática tem sido previamente constatada em diferentes populações, sendo que na população brasileira ainda não existem estudos a este respeito. OBJETIVOS: Foi estudado o envolvimento do MHC classe I e II (locci A, B e DR) em pacientes brasileiros com urticária crônica idiopática e teste cutâneo do soro autólogo positivo, comparando-se com um grupo populacional saudável. MÉTODOS: O DNA foi extraído do sangue de 42 pacientes com urticária crônica idiopática e o MHC classe I e II determinado por reação em cadeia da polimerase e teste laboratorial de hibridização de oligonucleotídeo com sonda de filamento único. A freqüência destes alelos em pacientes com urticária crônica idiopática foi comparada com a de 1000 doadores de sangue voluntários e geneticamente não relacionados, da mesma região do Brasil. O diagnóstico de urticária crônica idiopática foi baseado na história clínica do paciente e exames laboratoriais de rotina; foram selecionados apenas os pacientes com teste cutâneo do soro autólogo positivo. O resultado da distribuição alélica entre o grupo de pacientes e o grupo controle foi analisado através do odds rate com o cálculo do intervalo de confiança de 95% (95% IC). RESULTADOS: Não foram encontradas diferenças com significância estatística entre os pacientes com urticária crônica teste cutâneo do soro autólogo positivos e o grupo controle. CONCLUSÕES: Verificamos que neste grupo populacional estudado não houve associação específica entre os alelos HLA estudados e a urticária crônica; acreditamos na necessidade de outros estudos populacionais, para podermos verificar a possível existência desta associação.
Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem , Antígenos de Histocompatibilidade Classe I/análise , Antígenos de Histocompatibilidade Classe II/análise , Urticária/genética , Alelos , Estudos de Casos e Controles , Doença Crônica , Predisposição Genética para Doença , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe II/genética , Reação em Cadeia da Polimerase , Testes Cutâneos , Urticária/imunologiaRESUMO
Objectives: To evaluate the use of magnetic resonance imaging in patients with Beta-thalassemia and to compare T2* magnetic resonance imaging results with serum ferritin levels and the redox active fraction of labile plasma iron. Methods: We have retrospectively evaluated 115 chronically transfused patients (65 women). We tested serum ferritin with chemiluminescence, fraction of labile plasma iron by cellular fluorescence and used T2* MRI to assess iron content in the heart, liver, and pancreas. Hepatic iron concentration was determined in liver biopsies of 11 patients and the results were compared with liver T2* magnetic resonance imaging. Results: The mean serum ferritin was 2,676.5+/- 2,051.7ng/mL. A fraction of labile plasma iron was abnormal (> 0,6 Units/mL) in 48/83 patients (57%). The mean liver T2* value was 3.91 ± 3.95 ms, suggesting liver siderosis in most patients (92.1%). The mean myocardial T2* value was 24.96 ± 14.17 ms and the incidence of cardiac siderosis (T2* < 20 ms) was 36%, of which 19% (22/115) were severe cases (T2* < 10 ms). The mean pancreas T2* value was 11.12 ± 11.20 ms, and 83.5% of patients had pancreatic iron deposition (T2* < 21 ms). There was significant curvilinear and inverse correlation between liver T2* magnetic resonance imaging and hepatic iron concentration (r= -0.878; p < 0.001) and moderate correlation between pancreas and myocardial T2* MRI (r = 0.546; p < 0.0001). Conclusion: A high rate of hepatic, pancreatic and cardiac impairment by iron overload was demonstrated. Ferritin levels could not predict liver, heart or pancreas iron overload as measured by T2* magnetic resonance imaging. Therewas no correlation between liver, pancreas, liver and myocardial iron overload, neither between ferritin and fraction of labile plasma iron with liver, heart and pancreas T2* values.
Objetivo: Avaliar o acúmulo de ferro em diferentes órgãos por meio da ressonância nuclear magnética T2* e correlacionar os resultados aos níveis de ferritina sérica, ferro plasmático lábil e outros órgãos envolvidos. Métodos: Foram avaliados retrospectivamente 115 pacientes talassêmicos (sendo 65 mulheres). A concentração hepática de ferro foi determinada em biópsia de 11 pacientes; os resultados foram comparados com os valores de T2* fígado. Resultados: a ferritina sérica média foi de 2.676,5 +/- 2.051,7 ng/mL. O ferro plasmático lábil foi anormal (> 0,6 Unidades/mL) em 48/83 pacientes (57%). A média dos valores de T2* no fígado foi 3,91 ± 3,95 ms, sugerindo siderose hepática em 92,1% pacientes. A média do T2* cardíaco foi de 24,96 ± 14,17 ms e 36% dos pacientes apresentavam siderose cardíaca (T2* < 20ms), dos quais 19% (22/115) já apresentavam sobrecarga cardíaca grave (T2* < 10 ms). A média de T2* no pâncreas foi de 11,12 ± 11,20 ms, perfazendo um total de 83,5% de pacientes com sobrecarga de ferro pancreático (T2* < 21 ms). Houve correlação significativa, curvilínea e inversa entre T2* fígado e a concentração de ferro hepática (r = -0,878; p <0,001) e correlação moderada entre T2* pâncreas e T2* miocárdio (r = 0,546; p<0,0001). Conclusão: Uma elevada taxa de acometimento hepático, pancreático e cardíaco por sobrecarga férrica foi demonstrada. Os níveis de ferritina não puderam prever sobrecarga de ferro hepático, cardíaco ou pancreáticos medidos por meio da ressonância nuclear magnética T2*. Não houve correlação entre a sobrecarga de ferro no fígado, pâncreas e miocárdio, nem entre a ferritina e os níveis plasmáticos de ferro sérico e os valores de T2* no fígado, coração e pâncreas.
Assuntos
Biópsia , Transfusão de Sangue , Sobrecarga de Ferro , Imageamento por Ressonância MagnéticaRESUMO
A doença falciforme caracteriza-se por uma alteração genética que resulta na produção da hemoglobina S. A triagem neonatal para a HbS é de fundamental importância para o diagnóstico da anemia falciforme, possibilitando a instituição de tratamento preventivo, no sentido de diminuir a morbidade e mortalidade na infância. Embora o diagnóstico precoce, através do "Teste do Pezinho", esteja ocorrendo praticamente em todo o país, que medidas estão sendo tomadas após a confirmação do diagnóstico? Realizamos um estudo transversal e retrospectivo em 22.785 (96,97 por cento) de 23.497 nascidos vivos que foram submetidos ao exame de triagem neonatal. Todos os exames foram realizados no primeiro mês de vida. Foram diagnosticados quatro recém-nascidos com o padrão HbSS e dois HbSC. A primeira avaliação especializada ocorreu de 2 a 9 meses após o diagnóstico. Em apenas um caso houve a administração adequada das imunizações e da antibioticoterapia profilática. O tempo de realização do teste de triagem e a chegada dos resultados na Unidade coletora da amostra estão geralmente adequados. Levando-se em consideração a necessidade da instituição de um tratamento profilático em um centro especializado, é fundamental elaborar um fluxo que melhor articule todos os atores envolvidos, visando amenizar as prováveis consequências e sequelas desta doença.
Sickle disease is characterized by a genetic alteration which produces hemoglobin S. Neonatal screening for HbS has a major importance in the diagnosis of sickle anemia, thereby enabling preventive treatment in order to reduce childhood morbidity and mortality. Although early diagnosis by neonatal screening is being performed in practically the entire country, what measures are being taken after diagnostic confirmation? We carried out a cross-sectional retrospective study of 22,785 (96.97 percent) of 23,595 live births submitted to neonatal screening. All tests were performed within the first month of life. Four newborns with HbSS and two with HbSC were diagnosed. The first specialized evaluation occurred between 2 and 9 months after the disease had been identified. Only one case received correct immunization and prophylactic antibiotic therapy. The time between the screening test and the samples arriving at the collecting units was appropriate. Taking into account the necessity of establishing prophylactic treatment at specialized centers, effective communication between healthcare services is essential to safeguard against possible consequences and sequelae related to the disease.
Assuntos
Masculino , Feminino , Recém-Nascido , Diagnóstico Precoce , Doença da Hemoglobina SC , Triagem NeonatalRESUMO
O artigo aborda a avaliação da eficácia e a importância da reposição de ferro via endovenosa no combate da anemia ferropriva, pois alguns pacientes não toleram ou não respondem ao tratamento de reposição de ferro via oral.
Assuntos
Ferro , Terapêutica , Anemia Ferropriva , Injeções IntravenosasRESUMO
Lesão pulmonar aguda associada à transfusão (transfusion-related acute lung injury, TRALI) é uma complicação clínica grave relacionada à transfusão de hemocomponentes que contêm plasma. Recentemente, TRALI foi considerada a principal causa de morte associada à transfusão nos Estados Unidos e Reino Unido. É manifestada tipicamente por dispnéia, hipoxemia, hipotensão, febre e edema pulmonar não cardiogênico, que ocorre durante ou dentro de 6 h, após completada a transfusão. Embora o exato mecanismo não tenha sido totalmente elucidado, postula-se que TRALI esteja associada à infusão de anticorpos contra antígenos leucocitários (classes I ou II ou aloantígenos específicos de neutrófilos) e a mediadores biologicamente ativos presentes em componentes celulares estocados. A maioria dos doadores implicados em casos da TRALI são mulheres multíparas. TRALI, além de ser pouco diagnosticada, pode ainda ser confundida com outras situações de insuficiência respiratória aguda. Um melhor conhecimento sobre TRALI pode ser crucial na prevenção e tratamento desta severa complicação transfusional.
Transfusion-related acute lung injury (TRALI) is a serious clinical syndrome associated with the transfusion of plasma-containing blood components. Recently, TRALI has come to be recognized as the leading cause of transfusion-related death in the United States and United Kingdom. This complication typically presents as shortness of breath, hypoxemia, hypotension, fever and noncardiogeneic pulmonary edema, all occurring during or within 6 h after transfusion. Although the mechanism of TRALI has not been fully elucidated, it has been associated with human leukocyte antigen antibodies (class I, class II or neutrophil alloantigens) and with biologically active mediators in stored cellular blood components. Most of the donors implicated in cases of TRALI are multiparous women. Rarely diagnosed, TRALI can be confused with other causes of acute respiratory failure. Greater knowledge regarding TRALI on the part of clinicians could be crucial in preventing and treating this severe complication of blood transfusion.
Assuntos
Feminino , Humanos , Masculino , Transfusão de Sangue/efeitos adversos , Síndrome do Desconforto Respiratório/diagnóstico , Doadores de Sangue , Diagnóstico Diferencial , Europa (Continente)/epidemiologia , Antígenos HLA/imunologia , América do Norte/epidemiologia , Fatores de Risco , Síndrome do Desconforto Respiratório/epidemiologia , Síndrome do Desconforto Respiratório/etiologia , Síndrome do Desconforto Respiratório/fisiopatologiaRESUMO
Apesar da introdução da quelação parenteral de ferro com desferoxamina há mais de trinta anos, 50 por cento dos pacientes com talassemia major morrem antes dos 35 anos de idade, predominantemente por insuficiência cardíaca secundária a sobrecarga de ferro. Embora a desferrioxamina, possa reduzir ou estabilizar o acúmulo de ferro no corpo, um grande número de pacientes não recebe terapia adequada com este quelante devido principalmente à intolerância a um regime que requer administração parenteral prolongada, cinco a sete dias por semana. Para esses pacientes, a deferiprona, um quelante oralmente ativo, surge com uma alternativa de tratamento para o controle da sobrecarga de ferro. Um grande número de estudos clínicos demonstraram a segurança e eficácia da deferiprona. Estima-se que mais de 6 mil pacientes com sobrecarga de ferro já tenham sido tratados com este quelante, com alguns pacientes tomando a droga por mais de dez anos. A quantidade de ferro excretada induzida pela deferiprona é diretamente influenciada pela dose da droga e pelo grau de sobrecarga de ferro do paciente. Recentemente, demonstrou-se que desferrioxamina e deferiprona exibem capacidades quelantes diversas e que, usados simultaneamente ou numa terapia sequencial, promovem uma excreção de ferro adicional ou sinérgica com rápida redução na carga de ferro do corpo. Pela primeira vez é possível considerar esquemas de quelação individualizados baseados nas necessidades individuais de cada paciente
mode of administration which impairs the compliancewith the regime of repeatedly subcutaneous infusions.For these patients, the orally active iron chelatordeferiprone is an attractive alternative to control theoverloaded iron. It has been estimated that more thansix thousands patients have already been treated withdeferiprone, with some of them taking the chelator for10 years or more. The deferiprone-induced ironexcretion is directly related to the dose of deferiproneand the patients iron load. In most of transfusiondependentpatients, a dose of 75 mg/kg/day is sufficientto offset the transfusional iron-load. Recently, it hasbeen demonstrated that desferrioxamine anddeferiprone exhibit different chelating capabilities forthe removal of iron from the various body iron poolsand that the use of both chelators promote an additiveor synergistic iron excretion with rapid reduction inthe body iron load. It now is possible to consider tailormadechelation regimens based on individual patientneeds.
Assuntos
Humanos , Terapia por Quelação , Desferroxamina , TalassemiaRESUMO
Context: Patients with sickle cell anemia (SCA) are frequently transfused with red blood cells (RBC). Recently, we reported that the calculated risk of RBC alloimmunization per transfused unit in Brasilian patients with SCA is 1.15 per cent. We describe a delayed hemolytic transfusion reaction (DHTR) presenting as a painful crisis in a patient with SCA. Case report: A 35-year-old Brazilian female with homozygous SCA was admitted for a program of partial exchange transfusion prior to cholecystectomy. Her blood group was. O RhD positive and no atypical RBC alloantibody was detected using the indirect antiglobulin technique. Pre-transfusional hemoglobin (Hb) was 8.7 g/dl and isovolumic partial exchange transfusion was performed using 4 units of ABO compatible packed RBC. Five days after the last transfusion she developed generalized joint pain and fever of 39 degrees Celsius. Her Hb level dropped from 12.0 g/dL to 9.3 g/dL and the unconjugated bilirrubin level rose to mmol/L. She was joundiced and had hemoglobinuria. Hemoglobin electrophoresis showed 48.7 per cent HbS, 46.6 per cent HbA, 2.7 per cent HbA, and 2.0 per cent HbF. The patient's extended RBC phenotype was Cde, K-k+, Kp(a-b+), Fy (a-b-), M+N+s+. Le (a+b), Di(a-). An RBC alloantibody with specificity to the Rh system (anti-c, titer 1:16.384) was identified by the indirect antiglobulin test. The Rh phenotype of the RBC used in the last packed RBC transfusion was CcDEe. The patient discharged, asymptomatic, 7 days after admission.
Assuntos
Humanos , Feminino , Adulto , Dor/etiologia , Transfusão de Eritrócitos/efeitos adversos , Anemia Falciforme/terapia , Artropatias/etiologia , Fatores de TempoRESUMO
Os filtros de leucócitos säo eficazes em remover agentes infecciosos de hemocomponentes infectados. Neste estudo, foram avaliados os mecanismos de retençäo de Trypanosoma cruzi (T. cruzi) por filtros de leucócitos. Amostras de concentrado de glóbulos vermelhos (CGV) e concentrado de plaquetas (CP) foram contaminados com parasitas T. cruzi (cepa Y, 3,4 x 10(6)/ml), e filtrados com filtros experimentais de leucócitos, com capacidade de remoçäo de aproximadamente 3 log(10) leucócitos. A análise das fibras dos filtros através de microscopia eletrônica de transmissäo mostrou que os parasitas T. cruzi foram removidos dos CGV e CP contaminados por mecanismo físico, sem interaçäo com células sangüíneas. Além disso, foi demonstrado que os parasitas T. cruzi foram também removidos por adesäo direta às fibras dos filtros, sugerindo um mecanismo biológico, provavelmente mediado por proteínas da superfície do parasita