RESUMO
OBJECTIVES: Fabry disease (FD) is a rare disease associated with sphingolipid accumulation. Sphingolipids are components of plasma membranes that are important in podocyte function and accumulate in various glomerular diseases such as focal segmental glomerulosclerosis (FSGS). Both FD and FSGS can cause podocyte damage and are classified as podocytopathies. In this respect, FD and FSGS share the same pathophysiologic pathways. Previous screening studies have shown that a significant proportion of end-stage renal disease (ESRD) patients receiving hemodialysis (HD) have unsuspected FD, and the prevalence of low alpha-galactosidase A (αGLA) enzyme activity in these patients is higher than that in the normal population. We aimed to compare αGLA enzyme activity in patients with biopsy-proven FSGS and ESRD receiving HD. METHODS: The records of 232 patients [62 FSGS (F/M: 33/29); 170 HD (M/F: 93/79)] were evaluated retrospectively. The screening was performed based on the αGLA enzyme activity on a dried blood spot, with the confirmation of plasma LysoGb3 levels, and the known GLA mutations were tested in patients with low enzyme activities. The two groups were compared using these parameters. RESULTS: The mean level of αGLA enzyme activity was found to be lower in FSGS patients than in the HD group (2.88±1.2 µmol/L/h versus 3.79±1.9 µmol/L/h, p<0.001). There was no significant relationship between the two groups with regard to the plasma LysoGb3 levels (2.2±1.22 ng/ml versus 1.7±0.66 ng/ml, p: 0.4). In the analysis of GLA mutations, a D313Y mutation [C(937G>T) in exon p] was found in one patient from the FSGS group. CONCLUSIONS: We found that αGAL activity in patients with FSGS is lower than that in patients undergoing HD. The low enzyme activity in patients with FSGS may be explained by considering the similar pathogenesis of FSGS and FD, which may also lead to sphingolipid deposition and podocyte injury.
Assuntos
Falência Renal Crônica/terapia , alfa-Galactosidase/sangue , Feminino , Glomerulosclerose Segmentar e Focal/sangue , Glomerulosclerose Segmentar e Focal/epidemiologia , Humanos , Falência Renal Crônica/epidemiologia , Masculino , Prevalência , Estudos RetrospectivosRESUMO
OBJECTIVES: Fabry disease (FD) is a rare disease associated with sphingolipid accumulation. Sphingolipids are components of plasma membranes that are important in podocyte function and accumulate in various glomerular diseases such as focal segmental glomerulosclerosis (FSGS). Both FD and FSGS can cause podocyte damage and are classified as podocytopathies. In this respect, FD and FSGS share the same pathophysiologic pathways. Previous screening studies have shown that a significant proportion of end-stage renal disease (ESRD) patients receiving hemodialysis (HD) have unsuspected FD, and the prevalence of low alpha-galactosidase A (αGLA) enzyme activity in these patients is higher than that in the normal population. We aimed to compare αGLA enzyme activity in patients with biopsy-proven FSGS and ESRD receiving HD. METHODS: The records of 232 patients [62 FSGS (F/M: 33/29); 170 HD (M/F: 93/79)] were evaluated retrospectively. The screening was performed based on the αGLA enzyme activity on a dried blood spot, with the confirmation of plasma LysoGb3 levels, and the known GLA mutations were tested in patients with low enzyme activities. The two groups were compared using these parameters. RESULTS: The mean level of αGLA enzyme activity was found to be lower in FSGS patients than in the HD group (2.88±1.2 μmol/L/h versus 3.79±1.9 μmol/L/h, p<0.001). There was no significant relationship between the two groups with regard to the plasma LysoGb3 levels (2.2±1.22 ng/ml versus 1.7±0.66 ng/ml, p: 0.4). In the analysis of GLA mutations, a D313Y mutation [C(937G>T) in exon p] was found in one patient from the FSGS group. CONCLUSIONS: We found that αGAL activity in patients with FSGS is lower than that in patients undergoing HD. The low enzyme activity in patients with FSGS may be explained by considering the similar pathogenesis of FSGS and FD, which may also lead to sphingolipid deposition and podocyte injury.
Assuntos
Humanos , Masculino , Feminino , alfa-Galactosidase/sangue , Falência Renal Crônica/terapia , Glomerulosclerose Segmentar e Focal/sangue , Glomerulosclerose Segmentar e Focal/epidemiologia , Prevalência , Estudos Retrospectivos , Falência Renal Crônica/epidemiologiaRESUMO
BACKGROUND: Fabry disease is a lysosomal storage disease caused by enzyme α-galactosidase A deficiency as a result of mutations in the GLA gene. Cardiac involvement is characterized by progressive left ventricular hypertrophy. OBJECTIVE: To estimate the prevalence of Fabry disease in a population with left ventricular hypertrophy. METHODS: The patients were assessed for the presence of left ventricular hypertrophy defined as a left ventricular mass index ≥ 96 g/m2 for women or ≥ 116 g/m2 for men. Severe aortic stenosis and arterial hypertension with mild left ventricular hypertrophy were exclusion criteria. All patients included were assessed for enzyme α-galactosidase A activity using dry spot testing. Genetic study was performed whenever the enzyme activity was decreased. RESULTS: A total of 47 patients with a mean left ventricular mass index of 141.1 g/m2 (± 28.5; 99.2 to 228.5 g/m2] were included. Most of the patients were females (51.1%). Nine (19.1%) showed decreased α-galactosidase A activity, but only one positive genetic test - [GLA] c.785G>T; p.W262L (exon 5), a mutation not previously described in the literature. This clinical investigation was able to establish the association between the mutation and the clinical presentation. CONCLUSION: In a population of patients with left ventricular hypertrophy, we documented a Fabry disease prevalence of 2.1%. This novel case was defined in the sequence of a mutation of unknown meaning in the GLA gene with further pathogenicity study. Thus, this study permitted the definition of a novel causal mutation for Fabry disease - [GLA] c.785G>T; p.W262L (exon 5).
Assuntos
Doença de Fabry/enzimologia , Doença de Fabry/epidemiologia , Hipertrofia Ventricular Esquerda/enzimologia , Hipertrofia Ventricular Esquerda/epidemiologia , Mutação , alfa-Galactosidase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Teste em Amostras de Sangue Seco , Feminino , Estudos de Associação Genética , Testes Genéticos , Humanos , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Prevalência , alfa-Galactosidase/sangueRESUMO
AbstractBackground:Fabry disease is a lysosomal storage disease caused by enzyme α-galactosidase A deficiency as a result of mutations in the GLA gene. Cardiac involvement is characterized by progressive left ventricular hypertrophy.Objective:To estimate the prevalence of Fabry disease in a population with left ventricular hypertrophy.Methods:The patients were assessed for the presence of left ventricular hypertrophy defined as a left ventricular mass index ≥ 96 g/m2 for women or ≥ 116 g/m2 for men. Severe aortic stenosis and arterial hypertension with mild left ventricular hypertrophy were exclusion criteria. All patients included were assessed for enzyme α-galactosidase A activity using dry spot testing. Genetic study was performed whenever the enzyme activity was decreased.Results:A total of 47 patients with a mean left ventricular mass index of 141.1 g/m2 (± 28.5; 99.2 to 228.5 g/m2] were included. Most of the patients were females (51.1%). Nine (19.1%) showed decreased α-galactosidase A activity, but only one positive genetic test − [GLA] c.785G>T; p.W262L (exon 5), a mutation not previously described in the literature. This clinical investigation was able to establish the association between the mutation and the clinical presentation.Conclusion:In a population of patients with left ventricular hypertrophy, we documented a Fabry disease prevalence of 2.1%. This novel case was defined in the sequence of a mutation of unknown meaning in the GLA gene with further pathogenicity study. Thus, this study permitted the definition of a novel causal mutation for Fabry disease - [GLA] c.785G>T; p.W262L (exon 5).
ResumoFundamento:A doença de Fabry é uma doença lisossomal de sobrecarga provocada pela deficiência da enzima α-galactosidase A como resultado de mutações no gene GLA. O envolvimento cardíaco carateriza-se por hipertrofia ventricular esquerda progressiva.Objetivo:Estimar a prevalência da doença de Fabry numa população com hipertrofia ventricular esquerda.Métodos:Os doentes foram avaliados para a presença de hipertrofia ventricular esquerda definida por massa do ventrículo esquerdo indexada como ≥ 96 g/m2 para mulheres ou ≥ 116 g/m2 para homens. Estenose aórtica severa e hipertensão arterial, com hipertrofia ventricular esquerda discreta, foram critério de exclusão. Todos os doentes incluídos foram avaliados para a atividade da enzima α-galactosidase A com testes de gota seca. No caso de atividade enzimática diminuída, realizava-se estudo genético.Resultados:Foram incluídos 47 doentes com uma média de massa indexada de 141,1 g/m2 (± 28,5; 99,2 a 228,5 g/m2]. A maioria (51,1%) dos doentes era do sexo feminino. Nove deles (19,1%) tinham diminuição da atividade da α-galactosidase A, mas apenas um teste genético foi positivo − [GLA] c.785G>T; p.W262L (éxon 5), uma mutação não descrita na literatura. O trabalho de investigação clínica permitiu estabelecer uma associação entre a mutação e a apresentação clínica.Conclusão:Em uma população de doentes com hipertrofia ventricular esquerda, documentamos uma prevalência de doença de Fabry de 2,1%. O novo caso foi definido na sequência de uma mutação de significado indeterminado no gene GLA com posterior estudo de patogenicidade. Este estudo permitiu, assim, definir uma nova mutação causal para doença de Fabry - [GLA] c.785G>T; p.W262L (éxon 5).
Assuntos
Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Fabry/enzimologia , Doença de Fabry/epidemiologia , Hipertrofia Ventricular Esquerda/enzimologia , Hipertrofia Ventricular Esquerda/epidemiologia , Mutação , alfa-Galactosidase/genética , Teste em Amostras de Sangue Seco , Estudos de Associação Genética , Testes Genéticos , Prevalência , Portugal/epidemiologia , alfa-Galactosidase/sangueRESUMO
Fabry disease is an X-linked lysosomal disorder (LD) due to deficiency of the enzyme α-galactosidase A (αGal), which leads to the accumulation of neutral glycosphingolipids, mainly globotriaosylceramide (Gb3). Several mechanisms contribute to the diverse physiopathological alterations observed in this disease, and it has been suggested that an underlying proinflammatory state could play a significant role. The aim of this study is to investigate the presence of a proinflammatory state in the different subsets of peripheral blood mononuclear cells (PBMC) and to understand the mechanisms that contribute to its onset and perpetuation. We have shown that cultured PBMC from Fabry patients present a higher proinflammatory cytokine expression and production. Moreover, we determined that among PBMC, dendritic cells and monocytes present a basal proinflammatory cytokine production profile, which is further exacerbated with an inflammatory stimulus. Finally we established that normal, monocyte-derived dendritic cells and macrophages display the same proinflammatory profile when cultured in the presence of Gb3 and an inhibitor of αGal. Furthermore, this effect can be abolished using a TLR4 blocking antibody, indicating that TLR4 is necessary in the process. In summary, our results demonstrate the presence of a proinflammatory state involving two key subsets of innate immunity, and provide direct evidence of Gb3 having a proinflammatory role, likely mediated by TLR4, a finding that could help in the understanding of the underlying causes of the inflammatory pathogenesis of Fabry disease.
Assuntos
Citocinas/metabolismo , Doença de Fabry/sangue , Triexosilceramidas/sangue , alfa-Galactosidase/sangue , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Células Dendríticas/metabolismo , Doença de Fabry/enzimologia , Doença de Fabry/imunologia , Doença de Fabry/patologia , Feminino , Humanos , Inflamação/metabolismo , Inflamação/patologia , Leucócitos Mononucleares/metabolismo , Macrófagos/metabolismo , Masculino , Pessoa de Meia-Idade , Receptor 4 Toll-Like/metabolismo , Triexosilceramidas/imunologiaRESUMO
Fabry disease (FD) is an X-linked inborn error of glycosphingolipid catabolism that results from mutations in the alpha-galactosidase A (GLA) gene. Evaluating the enzymatic activity in male individuals usually performs the diagnosis of the disease, but in female carriers the diagnosis based only on enzyme assays is often inconclusive. In this work, we analyzed 568 individuals from 102 families with suspect of FD. Overall, 51 families presented 38 alterations in the GLA gene, among which 19 were not previously reported in literature. The alterations included 17 missense mutations, 7 nonsense mutations, 7 deletions, 6 insertions and 1 in the splice site. Six alterations (R112C, R118C, R220X, R227X, R342Q and R356W) occurred at CpG dinucleotides. Five mutations not previously described in the literature (A156D, K237X, A292V, I317S, c.1177_1178insG) were correlated with low GLA enzyme activity and with prediction of molecular damages. From the 13 deletions and insertions, 7 occurred in exons 6 or 7 (54%) and 11 led to the formation of a stop codon. The present study highlights the detection of new genomic alterations in the GLA gene in the Brazilian population, facilitating the selection of patients for recombinant enzyme-replacement trials and offering the possibility to perform prenatal diagnosis.
Assuntos
Doença de Fabry/diagnóstico , Doença de Fabry/genética , Mutação , alfa-Galactosidase/genética , Brasil , Éxons , Família , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Sítios de Splice de RNA , Análise de Sequência de DNA , alfa-Galactosidase/sangueRESUMO
OBJECTIVES: To compare alpha-galactosidase A activity in dried blood spots on filter paper, plasma, and leukocytes of Fabry disease patients and healthy controls, and to develop a miniaturization approach of the techniques to measure activity using plasma and leukocytes. DESIGN AND METHODS: Blood was collected from healthy controls and Fabry disease patients. Two drops were spotted on filter paper. Plasma and leukocytes were separated from the remaining sample. Enzyme activity was assessed by fluorometry. RESULTS: Significant positive correlation between standard and miniaturized techniques was observed. Alpha-galactosidase activity differed for male and female subjects when analyzed using filter paper and plasma. New reference and cutoff values were established based on the differences in alpha-galactosidase activity between genders. A good correlation was observed across biological materials assessed. CONCLUSIONS: The establishment of specific values for men and women increases reliability of commonly used techniques to screen and diagnose Fabry disease.
Assuntos
Doença de Fabry/sangue , Leucócitos/enzimologia , alfa-Galactosidase/sangue , Adolescente , Adulto , Coleta de Amostras Sanguíneas , Estudos de Casos e Controles , Teste em Amostras de Sangue Seco , Doença de Fabry/diagnóstico , Doença de Fabry/enzimologia , Feminino , Humanos , Masculino , Papel , Plasma , Valores de Referência , Sensibilidade e Especificidade , Adulto JovemRESUMO
Fabry disease is an X-linked disease of glycosphingolipid (GL) metabolism. The accumulation of GL in tissues can affect multiple organ systems. Initial symptoms includes episodes of severe pain in the extremities, cornea verticillata and skin lesions. In late stages, kidney, heart and brain can be involved. This report attempts for importance of cornea verticillata in the diagnosis of Fabry disease in a young patient with pain in the lower limb extremities.
A doença de Fabry é um erro inato no metabolismo de glicosfingolipides (GL) ligado ao cromossomo X. O acúmulo de GL nos tecidos pode afetar múltiplos órgãos e sistemas. Os sintomas iniciais incluem episódios de dor nas extremidades, córnea verticilata e lesões na pele. Em estágios avançados, os rins, coração e cérebro podem ser envolvidos. Este relato de caso enfatiza para importância da córnea verticilata para o diagnóstico de doença de Fabry em paciente jovem com dor nos membros inferiores.
Assuntos
Adolescente , Humanos , Masculino , Doença de Fabry/diagnóstico , alfa-Galactosidase/sangue , Biomarcadores/sangue , Opacidade da Córnea/complicações , Opacidade da Córnea/diagnóstico , Doença de Fabry/genéticaRESUMO
OBJECTIVES: To analyze the effect of blood collection and storage conditions on activity of α-galactosidase A, arylsulfatase B and α-glucosidase. DESIGN AND METHODS: Blood was collected in EDTA, heparin, or direct spotting on filter paper and stored at different temperatures (-20, 4, 25 and 37°C) and storage times (3, 10, 17 and 180 days). The influence of filter paper size was also assessed (3.0 and 1.2mm). RESULTS: No statistically significant difference was observed between the three collection methods. α-Glucosidase A activity significantly decreased after the 10th day, while arylsulfatase B activity only differed significantly after the 180th day, and α-galactosidase A activity remained constant throughout this storage time. Excellent correlation coefficients were observed for the two filter paper sizes used. CONCLUSIONS: Both paper sizes may be employed. Filter paper specimens should be transported under refrigeration as soon as possible after blood collection.
Assuntos
Coleta de Amostras Sanguíneas/métodos , Filtração , N-Acetilgalactosamina-4-Sulfatase/sangue , Papel , alfa-Galactosidase/sangue , alfa-Glucosidases/sangue , Humanos , Temperatura , Fatores de TempoRESUMO
Fabry disease is an X-linked disease of glycosphingolipid (GL) metabolism. The accumulation of GL in tissues can affect multiple organ systems. Initial symptoms includes episodes of severe pain in the extremities, cornea verticillata and skin lesions. In late stages, kidney, heart and brain can be involved. This report attempts for importance of cornea verticillata in the diagnosis of Fabry disease in a young patient with pain in the lower limb extremities.