Browsing by Author "Miranda, Armandina"
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- AEQ na quantificação da hemoglobina: desempenho analítico a longo prazo de trinta laboratórios portuguesesPublication . Miranda, Armandina; Correia, Helena; Cardoso, Ana; Brito, Cristina; Clemente, Vera; Silva, Susana; Meijer, Piet; Faria, AnaÉ importante para os laboratórios clínicos avaliarem o desempenho dos seus métodos ao longo do tempo. O principal objetivo deste estudo foi a aplicação de um modelo de regressão linear para avaliação a longo prazo, do desempenho dos laboratórios na quantificação da hemoglobina, comparando os resultados individuais do laboratório com a média de consenso de cada ensaio, após a exclusão de outliers. Para avaliar o desempenho do laboratório foram calculados o coeficiente de variação analítico a longo prazo (LCVa) e o Bias total analítico. O modelo de regressão linear foi aplicado aos resultados quantitativos da hemoglobina para avaliar o desempenho analítico a longo prazo de trinta laboratórios que participam no programa de avaliação externa da qualidade PNAEQ (2014-2016), utilizando os resultados de doze amostras controlo de sangue em EDTA, com diferentes concentrações de hemoglobina. Os participantes foram selecionados aleatoriamente, sendo incluídos laboratórios hospitalares e ambulatórios. As variáveis introduzidas para avaliar o desempenho a longo prazo neste modelo foram o CV analítico a longo prazo (LCVa) e o Bias total analítico. Dois laboratórios foram excluídos da análise. Foi determinado o número de laboratórios que cumpriram os objetivos de desempenho analítico definido com base na variação biológica. A mediana do LCVa foi de 1,4% (variação de 0,4% -3,4%). O LCVa foi 0,58 vezes inferior à variação biológica total (teste de diagnóstico) para todos os laboratórios (100%) e foi 0,5 vezes inferior à variação biológica intraindividual (teste de monitorização) em 62% dos laboratórios. A mediana do Bias total foi de 1,1% (variação de 0,1% -3,3%), sendo que 83% dos laboratórios apresentaram um Bias total inferior a 0,25 da variação biológica total. A participação em programas de avaliação externa da qualidade é de extrema importância, uma vez que fornece informações ao laboratório sobre o desempenho do seu método tanto numa única análise, bem como ao longo do tempo e permite a avaliação da necessidade de melhoria.
- Alfa-talassémia delecional e fenótipo hematológico: parâmetros associados às diferentes deleções na casuística de 2015 a 2019Publication . Gaspar, Gisela; Ramalho, Rita de Mira; Seuanes, Filomena; Feliciano, Carla; Duarte, Guida; Copeto, Sandra; Costa, Alcina; Santos, João Xavier; Miranda, ArmandinaAs talassémias são caracterizadas por um desequilíbrio quantitativo nas cadeias globinicas devido à redução ou supressão da síntese de uma das cadeias. Foram avaliados retrospetivamente os resultados de 496 casos suspeitos de α-talassémia delecional e correlacionados com os dados hematológicos. A pesquisa de deleções causadoras de α-talassémia foi efetuada por Gap e Multiplex Gap-PCR. A maioria dos casos (n=190) apresentou um genótipo normal (αα /αα), seguido de heterozigotia (-α 3 ,7 /αα) (n=148) e homozigotia (-α 3 ,7 /α 3 ,7 ) (n=141) para a deleção de 3,7kb. Detetaram-se ainda 5 casos de heterozigotia para a deleção de 4,2Kb (-α 4,2 /αα), 4 de dupla heterozigotia ( α 3 ,7 /α 4,2 ), 7 de heterozigotia α 0 (-- S E A /αα ), e 1 de Hb H (-- S E A /-α 3 ,7 ). Os resultados evidenciaram que o VGM e o HGM são excelentes índices hematológicos de rastreio e seleção dos testes moleculares, sendo o seu valor tanto mais baixo quanto maior o número de genes delecionados. Os resultados obtidos são ainda concordantes com o descrito na literatura e reforçam que o valor de cut-off de 25 pg (HGM), tem sensibilidade adequada para inferir da presença de uma deleção α 0 -talassémia. A deteção da deleção α 0 assume particular importância na prevenção da ocorrência de Hb Bart’s na descendência de um casal de portadores. O diagnóstico de α-talassémia é efetuado por métodos moleculares, no entanto os índices hematológicos são importantes marcadores preditivos do número de genes alfa delecionados e da relação fenótipo / genótipo.
- Alpha-thalassemia due to novel deletions and complex rearrangements in the subtelomeric region of chromosome 16pPublication . Ferrão, José; Silva, Marisa; Gonçalves, Lúcia; Gomes, Susana; Loureiro, Pedro; Coelho, Andreia; Miranda, Armandina; Seuanes, Filomena; Batalha Reis, Ana; Pina, Francisca; Maia, Raquel; Kjollerstrom, Paula; Monteiro, Estela; F. Lacerda, João; Lavinha, João; Gonçalves, João; Faustino, PaulaIntroduction: Inherited deletions removing the α-globin genes and/or their upstream regulatory elements (MCSs) give rise to alpha-thalassemia, one of the most common genetic recessive disorders worldwide. The pathology is characterized by microcytic hypochromic anemia due to reduction of the α-globin chain synthesis, which are essential for hemoglobin tetramerization. Material and Methods: In order to clarify the suggestive α-thalassemia phenotype in eleven patients, we performed Multiplex Ligation-dependent Probe Amplification with commercial and synthetic engineered probes, gap-PCR, and Sanger sequencing to search for deletions in the subtelomeric region of chromosome 16p. Results: We have identified five distinct large deletions, two of them novel, and one indel. The deletions range from approximately 3.3 to 323 kb, and i) remove the whole α-globin cluster; or ii) remove exclusively the upstream regulatory elements leaving the α-globin genes structurally intact. The indel consists in the loss of MCS-R2 (HS-40), which is the most important distal regulatory element for the α-globin gene expression, and the insertion of 39 bp, seemingly resulting from a complex rearrangement involving two DNA segments (probably from chromosome 3q) bridging the deletion breakpoints with a CC-bp orphan sequence in between. Finally, in one patient no α-globin deletion or point mutation were found. This patient revealed to be a very unusual case of acquired alpha-thalassemia associated with a myelodysplastic syndrome. Conclusions: Our study widens the spectrum of molecular lesions by which α-thalassemia may occur and emphasizes the importance of diagnosing large α-zero-deletions to provide patients with appropriate genetic counseling.
- Alpha-thalassemia due to novel deletions and complex rearrangements in the subtelomeric region of chromosome 16pPublication . Ferrão, José; Silva, Marisa; Gonçalves, Lúcia; Gomes, Susana; Loureiro, Pedro; Coelho, Andreia; Miranda, Armandina; Seuanes, Filomena; Batalha Reis, Ana; Valtonen-André, Camila; Sonesson, Annika; Pina, Francisca; Maia, Raquel; Kjollerstrom, Paula; Monteiro, Estela; F. Lacerda, João; Lavinha, João; Gonçalves, João; Faustino, PaulaIntroduction: Inherited deletions removing the α-globin genes and/or their upstream regulatory elements (MCSs) give rise to alpha-thalassemia, one of the most common genetic recessive disorders worldwide. The pathology is characterized by microcytic hypochromic anemia due to reduction of the α-globin chain synthesis, which are essential for hemoglobin tetramerization. Material and Methods: In order to clarify the suggestive α-thalassemia phenotype in eleven patients, we performed Multiplex Ligation-dependent Probe Amplification with commercial and synthetic probes, gap-PCR, and Sanger sequencing to search for deletions in the subtelomeric region of chromosome 16p. Results: We have identified six distinct large deletions, three of them novel, and one indel. The deletions range from approximately 3.3 to 323 kb, and i) remove the whole α-globin cluster; or ii) remove exclusively the upstream regulatory elements leaving the α-globin genes structurally intact. The indel consists in the loss of MCS-R2 (HS-40), which is the most important distal regulatory element for the α-globin gene expression, and the insertion of 39 nt, seemingly resulting from a complex rearrangement involving two DNA segments (probably from chromosome 3q), bridging the deletion breakpoints with a CC-bp orphan sequence in between. Finally, in one patient no α-globin deletion or point mutation were found. This patient revealed to have acquired alpha-thalassemia associated with a myelodysplastic syndrome. Conclusions: Our study widens the spectrum of molecular lesions by which α-thalassemia may occur and emphasizes the importance of diagnosing large α0-deletions to provide patients with appropriate genetic counseling.
- An integrated solution using bench spreadsheets to monitor Quality control indicators and performance in medicine laboratoriesPublication . Miranda, Armandina; Costa, Sandra; Costa, Alcina; Alvim, Marta; Correia, Helena; Carletto, Aline; Faria, Ana PaulaLaboratory Quality Control (LQC) in medical laboratories is a tool to monitor the procedures of pre analytical, intra analytical and post analytical phases. The data statistic analyze allow the quantification of the random errors using the variation coefficients (CV%) obtained by Internal Quality Control (IQC) and the systematic errors (bias%), from the results of External Quality Control (EQC). These results are combined to calculate the Total Error (TE) and Measurement of Uncertainty (MAU), that allows the knowledge of the precision and accuracy and follow the performance of laboratory by comparison with the quality specifications. The main objective is to present a tool as a bench spreadsheet developed in National Institute of Health Doctor Ricardo Jorge (INSA), aiming to help the national and portuguese speaking countries laboratories, to calculate the main indicators of the LQC: TE, Sigma level and MU using IQC and EQC results, in a simplified way.
- Análise retrospetiva do desempenho dos participantes no Programa de Morfologia do Sangue Periférico - PNAEQ 2012-2017Publication . Silva, Susana Pereira; Pereira, Edna; Correia, Helena; Miranda, Armandina; Cardoso, Ana; Silva, Cândido; Ismail, Sara; Barreira, Rui; Miranda, Ana; Batalha Reis, Ana; Faria, Ana PaulaO exame morfológico do sangue periférico é essencial para o diagnóstico clínico de doenças hematológicas e doenças não hematológicas com expressão morfológica no sangue periférico. A avaliação do desempenho dos profissionais deve ser uma prática implementada pelos laboratórios. A participação em programas de avaliação externa da qualidade, em que são enviadas amostras de doentes selecionadas pelos membros do Grupo de Trabalho de Hematologia do Programa Nacional de Avaliação Externa da Qualidade (PNAEQ), permite a avaliação e formação tendo como objetivo a melhoria do desempenho dos profissionais. No programa de Morfologia de Sangue Periférico do PNAEQ são enviados três ensaios anuais com três amostras cada. O Grupo de Trabalho de Hematologia foi formalizado em 2013 e conta com a colaboração de peritos nacionais, dos laboratórios de Centros Hospitalares Lisboa Norte e Ocidental e do Instituto Português de Oncologia de Lisboa, que contribuem voluntariamente com amostras de doentes, assim como com comentários complementares formativos. O objetivo deste trabalho é avaliar o desempenho dos participantes de laboratórios hospitalares e de ambulatório, no período 2012-2017, quanto à identificação das alterações morfológicas e hipóteses de diagnóstico[1] nas amostras esfregaços de sangue periférico.
- Ancestry of the major long-range regulatory site of the α-globin genes in the Portuguese population with the common 3.7 kb α-thalassemia deletionPublication . Pena, Rita; Lopes, Pedro; Gaspar, Gisela; Miranda, Armandina; Faustino, PaulaBackground: The α-Major Regulatory Element (α-MRE), also known as HS-40, is located upstream of the α-globin gene cluster and has a crucial role in the long-range regulation of the α-globin gene expression. This enhancer is polymorphic and several haplotypes were identified in different populations, with haplotype D almost exclusively found in African populations. The purpose of this research was to identify the HS-40 haplotype associated with the 3.7 kb α-thalassemia deletion (-α3.7del) in the Portuguese population, and determine its ancestry and influence on patients' hematological phenotype. Methods and results: We selected 111 Portuguese individuals previously analyzed by Gap-PCR to detect the presence of the -α3.7del: 50 without the -α3.7del, 34 heterozygous and 27 homozygous for the -α3.7del. The HS-40 region was amplified by PCR followed by Sanger sequencing. Four HS-40 haplotypes were found (A to D). The distribution of HS-40 haplotypes and genotypes are significantly different between individuals with and without the -α3.7del, being haplotype D and genotype AD the most prevalent in patients with this deletion in homozygosity. Furthermore, multiple correspondence analysis revealed that individuals without the -α3.7del are grouped with other European populations, while samples with the -α3.7del are separated from these and found more closely related to the African population. Conclusion: This study revealed for the first time an association of the HS-40 haplotype D with the -α3.7del in the Portuguese population, and its likely African ancestry. These results may have clinical importance as in vitro analysis of haplotype D showed a decrease in its enhancer activity on α-globin gene.
- Ancestry of the major long-range regulatory site of the α-globin genes in the Portuguese population with the common 3.7kb α-thalassemia deletionPublication . Pena, Rita; Lopes, Pedro; Gaspar, Gisela; Miranda, Armandina; Faustino, PaulaThe α-major regulatory element (known as HS-40) has a crucial role in the long-range regulation of the α-globin gene expression. This element is genetically polymorphic and six haplotypes (A to F) have been identified in different populations, with haplotype D almost exclusively found in African populations. This study aimed to identify the HS-40 haplotype associated with the common 3.7kb α-thalassemia deletion (-α3.7del) in the Portuguese population, and investigate its ancestry. We searched for the -α3.7del in 111 selected Portuguese individuals by Gap-PCR. In addition, a DNA fragment containing the HS-40 was amplified by PCR and Sanger sequenced. Statistical analysis was performed using R software. Fifty individuals have the wild-type α-globin genotype (group I), 34 are heterozygous for the -α3.7del (group II) and 27 are homozygous (group III). Regarding the HS-40, four haplotypes were found (A to D). The distribution of HS-40 haplotypes and genotypes are significantly different between groups with and without the -α3.7del (p<0.001), being haplotype D and genotype AD the most prevalent in group III. Furthermore, multiple correspondence analysis revealed that individuals without the -α3.7del are grouped with other European populations, while samples with the -α3.7del are split from these and found more related to the African population. This study revealed for the first time an association of a specific HS-40 haplotype with the -α3.7del in the Portuguese population, and its likely African ancestry. These results may have a clinical importance as in vitro analysis of haplotype D showed a descrease in its enhancer activity on α-globin genes.
- Ancestry of the α-MRE Associated with the 3.7kb α-Thalassemia Deletion in the Portuguese PopulationPublication . Pena, Rita; Lopes, Pedro; Gaspar, Gisela; Miranda, Armandina; Faustino, PaulaThe α-major regulatory element (α-MRE), also known as HS-40, is located upstream of the α-globin gene cluster and has a crucial role in the long-range regulation of the α-globin gene expression. It is genetically polymorphic and six haplotypes (A to F) have been identified in different populations. The D haplotype was primary described in African populations and is nearly absent in other populations. The aims of this study were to identify the α-MRE haplotype associated with the common 3.7kb α-thalassemia deletion (-α3.7del) in the Portuguese population, and to investigate its ancestry. We searched for the -α3.7del in 111 selected Portuguese individuals by Gap-PCR. In addition, a DNA fragment containing the α-MRE was amplified by PCR and Sanger sequenced. Statistical analysis was performed using R software. Fifty individuals have the wild-type α-globin genotype (group I), 34 are heterozygous for the -α3.7del (group II) and 27 are homozygous (group III). Regarding the α-MRE, four haplotypes were found (A to D). The ancestral A haplotype is predominant in all groups. The B haplotype is the second most frequent in groups I and II, whereas in group III haplotype D is the second most prevalent. Concerning genotypes, the α-MRE AA and AB are the most common in group I, while genotype AD is more prevalent in group III. In fact, 71.4% of AD individuals are homozygous for the -α3.7del. Moreover, the distribution of α-MRE haplotypes and genotypes are significantly different between groups with and without the -α3.7del (p<0.001). Furthermore, multiple correspondence analysis revealed that individuals without the -α3.7del are grouped with other European populations, while samples with the -α3.7del are split from these and found to be more closely related to the African population. This study revealed for the first time an association of a specific α-MRE haplotype with the common -α3.7del in the Portuguese population, and its likely African ancestry. These results may have clinical importance as the D haplotype has an alteration in the consensus sequence for the AP-1/NF-E2 binding site and in vitro experiments showed a decrease in its enhancer activity on α-globin genes.
- Anemia de células falciformes: avaliação da hemoglobina fetal num grupo de crianças angolanas antes e após tratamento com hidroxiureiaPublication . Almeida, Priscilla; Costa, Alcina; Seuanes, Filomena; Romão, Raquel; Brito, Miguel; Silva, Isabel Moreira da; Miranda, Armandina