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BACKGROUND: Knowledge of the diversity of invasion ligands in malaria parasites in endemic regions is essential to understand how natural selection influences genetic diversity of these ligands and their feasibility as possible targets for future vaccine development. In this study the diversity of four genes for merozoite invasion ligands was studied in Ecuadorian isolates of Plasmodium vivax. METHODS: Eighty-eight samples from P. vivax infected individuals from the Coast and Amazon region of Ecuador were obtained between 2012 and 2015. The merozoite invasion genes pvmsp-1-19, pvdbpII, pvrbp1a-2 and pvama1 were amplified, sequenced, and compared to the Sal-1 strain. Polymorphisms were mapped and genetic relationships between haplotypes were determined. RESULTS: Only one nonsynonymous polymorphism was detected in pvmsp-1-19, while 44 nonsynonymous polymorphisms were detected in pvdbpII, 56 in pvrbp1a-2 and 33 in pvama1. While haplotypes appeared to be more related within each area of study and there was less relationship between parasites of the coastal and Amazon regions of the country, diversification processes were observed in the two Amazon regions. The highest haplotypic diversity for most genes occurred in the East Amazon of the country. The high diversity observed in Ecuadorian samples is closer to Brazilian and Venezuelan isolates, but lower than reported in other endemic regions. In addition, departure from neutrality was observed in Ecuadorian pvama1. Polymorphisms for pvdbpII and pvama1 were associated to B-cell epitopes. CONCLUSIONS: pvdbpII and pvama1 genetic diversity found in Ecuadorian P. vivax was very similar to that encountered in other malaria endemic countries with varying transmission levels and segregated by geographic region. The highest diversity of P. vivax invasion genes in Ecuador was found in the Amazonian region. Although selection appeared to have small effect on pvdbpII and pvrbp1a-2, pvama1 was influenced by significant balancing selection.
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Malária Vivax , Plasmodium vivax , Humanos , Equador , Antígenos de Protozoários/genética , Proteínas de Protozoários/genética , Reticulócitos , Ligantes , Malária Vivax/epidemiologia , Polimorfismo Genético , Seleção Genética , Variação GenéticaRESUMO
Objetivo: determinar la relación entre el Ret-He con diferentes categorías según la concentración de hemoglobina en candidatos a donar sangre. Materiales y Métodos: Se realizó un estudio transversal a partir de la revisión de 227 historias clínicas de candidatos a donar sangre durante el mes de diciembre del 2021 en el Servicio de Banco de Sangre y Hemoterapia del Hospital Cayetano Heredia. Se categorizó en 3 grupos según los niveles de hemoglobina: Grupo 1: ≥12,5 g/dl (mujeres) - ≥13,5 g/dl (varones). Grupo 2: 12 g/dl ≥ mujeres <12.5 g/dl y 13 g/dl ≥ varones<13.5 g/dl. Grupo 3: <12 g/dl (mujeres) - <13 g/dl (varones). Se tomaron datos de hematocrito, hemoglobina, VCM, HCM, CHCM y Ret-He. Para el análisis bivariado se utilizó el análisis de varianza (ANOVA) y se consideró un nivel de significancia del 5 %. Resultados: La mediana de Ret-He fue mayor en el grupo 1 que en el grupo 2 (33.5 frente a 32.5; p=0.002) y en el grupo 3 (33.5 frente a 27.8; p<0.001). Se encontró relación estadísticamente significativa entre los grupos estudiados y Ret-He (p<0.001), además de una correlación positiva moderada fuerte entre Ret-He y los índices eritrocitarios. Conclusiones: Se encontró una asociación significativa entre los grupos basados en categorías de hemoglobina y la Ret-He en candidatos a donar sangre.
Objective: to determine the relationship between Ret-He with different categories according to hemoglobin concentration in candidates for blood donation. Methods: A cross-sectional study was carried out based on the review of 227 medical records of candidates to donate blood during the month of December 2021 in the Blood Bank and Hemotherapy Service of the Cayetano Heredia Hospital. They were categorized into 3 groups according to hemoglobin levels: Group 1: ≥12.5 g/dl (females) - ≥13.5 g/dl (males). Group 2: 12 g/dl ≥ females <12.5 g/dl and 13 g/dl ≥ males<13.5 g/dl. Group 3: <12 g/dl (females) - <13 g/dl (males). Hematocrit, hemoglobin, VCM, HCM, CHCM and Ret-He data were collected. For the bivariate analysis, analysis of variance (ANOVA) was used and a significance level of 5% was considered. Results: The median Ret-He was higher in group 1 than in group 2 (33.5 vs. 32.5; p=0.002) and in group 3 (33.5 vs. 27.8; p<0.001). A statistically significant relationship was found between the groups studied and Ret-He (p<0.001), in addition to a moderate-strong positive correlation between Ret-He and erythrocyte indices. Conclusions: An association was found between groups based on hemoglobin categories and Ret-He in blood donation candidates.
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Abstract Introduction During pregnancy, women are at an increased risk of developing iron-deficiency anemia. Objective The objective of this study was to assess the diagnostic performance of the reticulocyte hemoglobin equivalent (RET-He) in the early detection of iron-deficiency anemia in a group of pregnant women and to establish a reference range for this parameter in a group of control individuals. Method: A total of 60 patients and 130 control subjects were included in the study. Blood samples collected from the subjects were submitted to a complete blood count and a serum ferritin test and the data were analyzed by comparing the groups and ROC curves. Results The reference range found for the RET-He was between 29.75pg and 38.24pg, with a median of 35pg. The receiver operating characteristic (ROC) curve analysis for the ferritin parameter showed an area under the curve of 0.732 for the RET-He, 0.586 for hemoglobin, 0.551 for the mean corpuscular hemoglobin concentration and 0.482 for the mean corpuscular volume. Conclusion Early diagnosis of iron deficiency anemia in pregnancy is essential to prevent damage to both maternal and fetal health. The RET-He presents an excellent potential as an auxiliary tool for the diagnosis of iron deficiency in pregnant women.
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Humanos , Feminino , Gravidez , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Adulto Jovem , Gravidez , Deficiências de Ferro , Reticulócitos , Hemoglobinas , Anemia Ferropriva , HematologiaRESUMO
INTRODUCTION: During pregnancy, women are at an increased risk of developing iron-deficiency anemia. OBJECTIVE: The objective of this study was to assess the diagnostic performance of the reticulocyte hemoglobin equivalent (RET-He) in the early detection of iron-deficiency anemia in a group of pregnant women and to establish a reference range for this parameter in a group of control individuals. METHOD: A total of 60 patients and 130 control subjects were included in the study. Blood samples collected from the subjects were submitted to a complete blood count and a serum ferritin test and the data were analyzed by comparing the groups and ROC curves. RESULTS: The reference range found for the RET-He was between 29.75pg and 38.24pg, with a median of 35pg. The receiver operating characteristic (ROC) curve analysis for the ferritin parameter showed an area under the curve of 0.732 for the RET-He, 0.586 for hemoglobin, 0.551 for the mean corpuscular hemoglobin concentration and 0.482 for the mean corpuscular volume. CONCLUSION: Early diagnosis of iron deficiency anemia in pregnancy is essential to prevent damage to both maternal and fetal health. The RET-He presents an excellent potential as an auxiliary tool for the diagnosis of iron deficiency in pregnant women.
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INTRODUCTION: Reticulocytes are erythroid precursors that develop into mature erythrocytes, and they are an important tool to assess erythropoietic activity, as their count indicates the balance between the cells released from the bone marrow, their stage of maturity, and their rate of development into mature erythrocytes. Considering the described biological variability of the absolute reticulocyte count (ARC) and the immature reticulocyte fraction (IRF) and the limited information available on these hematological parameters in children, this study determined the reference intervals (RIs) of these parameters in a healthy pediatric population. METHODS: A retrospective, observational, and analytical study was designed to establish RIs for the ARC and the IRF according to age and sex. An indirect sampling method was applied to a mixed database of complete blood counts from children aged 2 months to 18 years, using the truncated maximum likelihood indirect method for reference interval estimation. Percentiles were calculated to obtain bimodal RIs. RESULTS: From a total of 190,812 samples, 6,814 were selected. Gender stratification was not necessary for the ARC and the IRF but they required partitioning into six and two age groups, respectively. CONCLUSION: This study determined, by an indirect sampling method, RIs for the ARC and the IRF in a pediatric population according to age and sex.
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Reticulócitos , Criança , Citometria de Fluxo/métodos , Humanos , Valores de Referência , Contagem de Reticulócitos/métodos , Estudos RetrospectivosRESUMO
Novos parâmetros hematológicos, como a fração de reticulócitos imaturos (IRF), tendem a se tornar ferramentas importantes na prática clínica. O IRF identifica os reticulócitos mais imaturos, que contêm grande quantidade de ácido ribonucleico, sendo um importante parâmetro para avaliar a atividade da medula óssea, em tempo real, para o diagnóstico diferencial das anemias, acompanhamento do seu tratamento, e para o acompanhamento ou recuperação da medula óssea em diversas condições clínicas. No entanto, ainda há um longo caminho a percorrer antes que a IRF possa ser usada na prática clínica. Assim sendo, é urgente estabelecer os valores de referência e padronizar as metodologias utilizadas pelos diferentes analisadores hematológicos e como expressar seus resultados. Esta revisão narrativa fornece uma perspectiva crítica sobre o IRF e seu potencial para o uso clínico, bem como suas limitações.
New hematological parameters, such as immature reticulocyte fraction (IRF), tend to become important tools in clinical practice. IRF identifies the most immature reticulocytes that contain a large amount of ribonucleic acid, being an important parameter to evaluate bone marrow activity in real time for differential diagnosis of anemias, monitoring of its treatment, and for follow-up or bone marrow recovery in various clinical conditions. However, there is still a long way to go before IRF can be used in clinical practice. Thus, it is urgent to establish reference values and to standardize of the methodologies used by different hematological analyzers and how to express the results. This narrative review provides a critical perspective on IRF, its potential of clinical use and limitations.
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OBJECTIVES: Because published data about the variability of reticulocyte counts in children are scarce, the interindividual biological variability of the automated reticulocyte count and its maturation fractions according to age and sex were analyzed. METHODS: A retrospective, observational, analytical study was designed to establish and compare normal values of the automated reticulocyte count and its maturation fractions in different age and sex groups. The sample was drawn from results of CBC counts performed in children aged between 2 months and 18 years using an indirect sampling methodology. RESULTS: A total of 9,362 CBC counts were analyzed. Automated reticulocyte count decreased between 2 months and 3 years of age and slowly increased thereafter, showing higher values in girls up to the age of 9 years, and equalized by sex thereafter. Immature reticulocyte fraction increased until 7 months of age; decreased progressively until 4 years of age; and then showed a discreet but constant rise, with significantly higher values in boys older than 1 year. The low-fluorescence fraction was relatively steady, with significantly higher values in girls aged 8 months and older. CONCLUSIONS: The automated reticulocyte count and its maturation fractions show significant variations related to age and sex in pediatric patients.
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Reticulócitos , Fatores Etários , Criança , Pré-Escolar , Feminino , Citometria de Fluxo , Humanos , Individualidade , Lactente , Masculino , Valores de Referência , Contagem de Reticulócitos , Reticulócitos/citologia , Estudos RetrospectivosRESUMO
ABSTRACT Introduction: Anemia is a complication with impact on morbidity and mortality in chronic kidney disease (CKD) patients. Current markers for the diagnosis and monitoring of anemia in CKD are limited by the interrelation between erythropoiesis, iron stores, inflammation, and the resistance to treatment with erythropoiesis stimulant agents (ESA). Objective: The aim of this study was to analyze the role of immature reticulocyte fraction (IRF) and hemoglobin concentration in reticulocytes (RET-He) by the hematology analyser Sysmex XN-5000 in the monitoring of CKD anemia in peritoneal dialysis patients. Methods: This was a prospective, observational multicenter study which compared IRF and RET-He with parameters recommended by the guidelines. Inflammatory biomarkers were analyzed by the Luminex® Multiplexing Instruments system. Thirty-five patients (59 ± 13 years old; 51% men) were included in the analysis. Results: Hemoglobin was 12.2 ± 2 g/dl; 87% had resistance to ESA. Patients with erythropoietin resistance index (ERI) in the upper quartile presented a significantly higher of IRF and a lower percentage of iron deficiency (12%) compared to ferritin (82%) and transferrin saturation index (STI) (51%). Interleukin-6 (IL-6) levels correlated with the percentage of medium fluorescence reticulocyte (MFR) (r = 0.45, p < 0.03). Hemoglobin values after 60 and 180 days were consistently higher in the group of patients with a IRF% lower than 10.5. Conclusion: IRF and RET-He may add value in the iron deficiency investigation, as well as in the identification of patients with ERI. Due to the restricted number of patients analyzed in this study, future studies should be encouraged in larger populations and with prospective follow-up, to validate our findings.
RESUMEN Introducción: La anemia es una complicación con impacto en la morbimortalidad en pacientes con enfermedad renal crónica (ERC). Los biomarcadores usados para el diagnóstico y seguimiento de la anemia en la ERC están limitados por la interrelación entre eritropoyesis, depósitos de hierro, inflamación y resistencia al tratamiento con agentes estimulantes de la eritropoyesis (AEE). Objetivo: El objetivo de este estudio fue analizar el papel de la fracción de reticulocitos inmaduros (IRF) y el equivalente de hemoglobina en reticulocitos (RET-He) mediante el analizador hematológico Sysmex XN-5000 en el seguimiento de la anemia por ERC en pacientes en diálisis peritoneal. Métodos: Estudio prospectivo, observacional multicéntrico que comparó IRF y RET-He con los parámetros recomendados por las guías. Los biomarcadores inflamatorios fueron analizados por el sistema Luminex® Multiplexing Instruments. Este estudio incluyó a 35 pacientes (59 ± 13 años; 51% hombres). Resultados: La hemoglobina fue de 12,2 ± 2 g/dl; el 87% tenía resistencia a AEE. Los pacientes con índice de resistencia a la eritropoyetina (IRE) en el cuartil superior tenían un IRF significativamente más alto y un porcentaje más bajo de deficiencia de hierro (12%) en comparación con la ferritina (82%) y las ITS (51%). Los niveles de interleucina-6 (IL-6) se correlacionaron con el porcentaje de reticulocitos de fluorescencia media (MFR) (r = 0,45, p < 0,03). Los valores de hemoglobina después de 60 y 180 días, fueron consistentemente más altos en el grupo de pacientes con IRF% inferior a 10,5. Conclusión: IRF y RET-He pueden agregar valor en la investigación de ferropenia, así como en la identificación de pacientes con ERI. Debido al número limitado de pacientes analizados en este estudio, se deben impulsar estudios futuros en poblaciones más grandes y con seguimiento prospectivo, para validar nuestros hallazgos.
RESUMO Introdução: Anemia é uma complicação com impacto na morbidade e na mortalidade de pacientes com doença renal crônica (DRC). Os biomarcadores utilizados no diagnóstico e no monitoramento de anemia na DRC são limitados devido à inter-relação entre eritropoiese, estoque de ferro, inflamação e resistência à terapêutica com agentes estimuladores da eritropoiese (AEE). Objetivo: O objetivo deste estudo foi analisar o papel dos marcadores fração de reticulócitos imaturos (IRF) e concentração de hemoglobina nos reticulócitos (RET-He) do analisador hematológico Sysmex XN 5000 no monitoramento da anemia em pacientes em diálise peritoneal. Métodos: Estudo prospectivo, observacional e multicêntrico que comparou IRF e RET-He com parâmetros laboratoriais recomendados pelos guidelines. Biomarcadores inflamatórios foram analisados pelo sistema Luminex® Multiplexing Instruments. Este estudo incluiu 35 pacientes (59 ± 13 anos; 51% homens). Resultados: Os valores de hemoglobina foram 12,2 ± 2 g/dl; 87% apresentaram resistência a AEE. Pacientes com índice de resistência à eritropoietina (IRE) no quartil superior apresentaram valores significativamente maiores de IRF e menor porcentagem de deficiência de ferro (12%) em comparação com pacientes com ferritina (82%) e índice de saturação de transferrina (IST) (51%). Os níveis de interleucina 6 (IL-6) correlacionaram-se com a porcentagem de reticulócitos de fluorescência média (MFR) (r = 0,45, p < 0,03). Valores de hemoglobina após 60 e 180 dias foram consistentemente mais altos no grupo de pacientes com IRF% menor que 10,5. Conclusão: IRF e RET-He podem agregar valor na investigação da deficiência de ferro, bem como na identificação do índice de existência à eritropoietina (ERI). Devido ao número restrito de pacientes analisados neste trabalho, estudos futuros devem ser estimulados em populações maiores e com acompanhamento prospectivo, para validação dos nossos achados.
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Introducción: El término hemólisis hace referencia a la destrucción de los eritrocitos y ocurre en un amplio rango de condiciones clínicas fisiológicas y patológicas. Es empleado para definir situaciones en la que la vida media de los eritrocitos está disminuida por causas mecánicas, tóxicas, autoinmunes o infecciosas. Objetivo: Describir los principales marcadores de hemólisis que se encuentran variablemente alterados en las diferentes formas de anemias hemolíticas. Métodos: Se realizó una revisión de la literatura, en inglés y español, a través del sitio web PubMed y el motor de búsqueda Google Académico de artículos publicados en los últimos 10 años. Se hizo un análisis y resumen de la información. Análisis y síntesis de la información: La hemoglobina es el marcador más directo de la gravedad clínica en las enfermedades hemolíticas. Sus valores pueden estar muy próximos a los valores de referencia en las formas ligeras (Hb > 100 g/L) o significativamente reducidos en las moderadas (Hb entre 80-100 g/L), graves (Hb entre 60-80 g/L) y muy graves (Hb < 60 g/L). Sin embargo, existen otros marcadores esenciales para diferenciar las formas de presentación aguda y crónica, la hemólisis extravascular de la intravascular y la presencia de signos extrahematológicos tales como: los reticulocitos y esquistocitos, la deshidrogenasa láctica, la haptoglobina, la bilirrubina, la ferritina y la hemosiderinuria. Conclusiones: Los parámetros hemolíticos pueden estar diferencialmente alterados en varias condiciones lo cual ayuda en la realización del diagnóstico diferencial de las anemias hemolíticas(AU)
Introduction: The term hemolysis refers to the destruction of erythrocytes, a process occurring in a wide range of physiological and pathological clinical conditions. The term is used to define situations in which mean erythrocyte lifespan is reduced due to mechanical, toxic, autoimmune or infectious causes. Objective: Describe the main markers of hemolysis found to be variably altered in the different forms of hemolytic anemias. Methods: A review was conducted of the literature about the topic published in English and Spanish in the website PubMed and the search engine Google Scholar in the last 10 years. Data were analyzed and summarized. Data analysis and synthesis: Hemoglobin is the most direct marker of clinical severity in hemolytic diseases. Its values may be very close to reference levels in mild disease (Hb > 100 g/l), whereas they will be significantly reduced in moderate (Hb 80-100 g/l), severe (Hb 60-80 g/l) and very severe disease (Hb < 60 g/l). However, other markers are also essential to distinguish acute from chronic presentation, extravascular from intravascular hemolysis, and the presence of extrahematological signs such as reticulocytes and schistocytes, lactate dehydrogenase, haptoglobin, bilirubin, ferritin and hemosiderinuria. Conclusions: Differentially altered hemolytic parameters may be found in several conditions, which makes them useful for the differential diagnosis of hemolytic anemias(AU)
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Humanos , Biomarcadores , Anemia Hemolítica Congênita/diagnóstico , Diagnóstico DiferencialRESUMO
OBJECTIVES: Since hematologic values vary with age in children, we evaluated the agreement between the "traditional" reticulocyte production index (RPI) and an RPI by age (RPI/A)-adjusted normal values. METHODS: A retrospective, observational, and analytical study was performed on CBCs of children with anemia younger than 18 years. The agreement and clinical repercussions of the RPI values were analyzed with an RPI/A developed with theoretical values for different ages. RESULTS: A total of 5,503 tests were analyzed and no systematic error between the two indices was found; however, there were significant proportional differences at higher values that resulted in lower RPI/A in children younger than 15 days and higher RPI/A in children aged 15 days and older. No agreement was observed at any age. The proportion of arregenerative anemia diagnosed using RPI/A was higher in children younger than 15 days and lower in those 15 days and older. CONCLUSIONS: RPI is not an adequate tool for evaluating the erythropoietic capacity of bone marrow in the pediatric population. The disagreement between the results can be explained by the difference in normal hematologic values between children and adults.
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Contagem de Reticulócitos/normas , Reticulócitos , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Valores de Referência , Estudos RetrospectivosRESUMO
A anemia é uma complicação importante na doença renal crônica (DRC), culminando com o aumento da morbidade e mortalidade, tornando-se fundamental a busca de marcadores hematológicos que permitam seu diagnóstico precoce. Este artigo teve como objetivo revisar na literatura estudos que investigaram a associação entre o conteúdo de hemoglobina contida nos reticulócitos com a anemia em pacientes com DRC em tratamento dialítico e gerar evidências de sua importância na prática clínica. Foi realizada a busca nas bases de dados eletrônicas: Medline e Web of Science. O período de busca definido foi de janeiro de 1997 a dezembro de 2017. O conteúdo de hemoglobina dos reticulócitos avalia a hemoglobina contida nos reticulócitos, sendo que estes, após liberação da medula óssea, permanecem no sangue periférico de um a quatro dias antes de completar sua maturação, conferindo-lhe maior especificidade em refletir a disponibilidade de ferro aos precursores hematopoiéticos, além de fornecer uma avaliação precoce da resposta eritropoética frente ao tratamento de ferro IV. Os artigos selecionados nessa revisão demonstraram que o conteúdo de hemoglobina do reticulócito, além de refletir precocemente a disponibilidade de ferro aos precursores hematopoiéticos, o mesmo não sofre interferência de citocinas inflamatórias, tornando-o um marcador eficaz no monitoramento da cinética do ferro em pacientes em diálise.
Anemia is an important complication in chronic kidney disease (CKD), culminating with the increase in morbidity and mortality, making it fundamental to search for hematological markers that allow its early diagnosis. This review aimed to review in the literature studies that investigated the association between hemoglobin content in reticulocytes and anemia in patients with CKD in dialysis and to generate evidence of its importance in clinical practice. The hemoglobin content of the reticulocytes evaluates the hemoglobin contained in the reticulocytes, which, after release of the bone marrow, remain in the peripheral blood 1 to 4 days before their maturation completes, giving it greater specificity in reflecting the availability of iron to the reticulocytes. Hematopoietic precursors, in addition to providing an early assessment of the erythropoietic response to IV iron treatment. The articles selected in this review have demonstrated that the reticulocyte hemoglobin content in addition to early reflection of the availability of iron to the hematopoietic precursors does not suffer interference from inflammatory cytokines, making it an effective marker in the monitoring of iron kinetics in dialysis patients.
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Reticulócitos , Diálise , Insuficiência Renal Crônica , AnemiaRESUMO
Resumen Introducción: El contenido de hemoglobina de reticulocitos (CHr), es un parámetro en la biometría hematológica automatizada que proporciona información sobre el contenido de hierro, por ello se ha utilizado como un marcador de la biodisponibilidad del hierro en la eritropoyesis, permite su detección en una etapa temprana de la anemia ferropénica y otras patologías como inflamación crónica, enfermedad renal crónica; además realizar monitoreo de terapias con eritropoyetina y hierro. Objetivo: Exponer la aplicabilidad de la CHr como un parámetro en el diagnóstico precoz de la anemia por deficiencia de hierro, así como su medición e interpretación. Materiales y métodos: Se realizó la revisión de artículos científicos en inglés y español en las bases de datos PubMed, ScienceDirect, LILACS y Medline, usando descriptores validados en Medical Subject Headings (MeSH), considerando periodo de publicabilidad del 80% inferior a 5 años. Resultados: Se describe la importancia, aplicabilidad, determinación e interpretación de este parámetro como biomarcador específico hemático temprano en el diagnóstico de deficiencia de hierro antes de presentarse cambios morfológicos eritroides. Conclusiones: La CHr es un parámetro de gran utilidad en el diagnóstico temprano de anemia ferropénica y otras patologías como deficiencia funcional de hierro, estados de inflamación crónica y enfermedad renal crónica.
Abstract Introduction: The reticulocyte hemoglobin content (CHr) is a parameter in automated hematological biometrics, which can provide information on the iron content. So it has been used as a marker of the bioavailability of iron in the erythropoiesis, it allows its detection at an early stage of iron deficiency anemia and other pathologies such as chronic inflammation, chronic kidney disease; in addition to monitoring therapy with erythropoietin and iron. Objective: To expose the applicability of CHr as a parameter in the early diagnosis of iron deficiency anemia, as well as its measurement and interpretation. Materials and methods: The review of scientific articles in English and Spanish was carried out in the PubMed, ScienceDirect, LILACS and Medline databases, using descriptors validated in Medical Subject Headings (MeSH), considering the publication period of 80% less than 5 years. Results: The importance, applicability, determination and interpretation of this parameter is described as an early specific biomarker in the blood in the diagnosis of iron deficiency before presenting morphological changes occurring during terminal erythroid differentiation. Conclusions: CHr is a very useful parameter in the early diagnosis of iron deficiency anemia and other pathologies such as functional deficiency, chronic inflammation states and chronic renal disease.
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Reticulócitos , Biomarcadores , Anemia , FerroRESUMO
Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti-CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.
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Instabilidade Cromossômica , Citometria de Fluxo/métodos , Glioblastoma/genética , Micronúcleos com Defeito Cromossômico , Reticulócitos/patologia , Separação Celular/métodos , Feminino , Glioblastoma/sangue , Glioblastoma/patologia , Humanos , Masculino , Gradação de Tumores , Fatores de Risco , Manejo de Espécimes/métodosRESUMO
Resumen Introducción. La cuantificación de la inestabilidad cromosómica es un parámetro importante para evaluar la genotoxicidad y la radiosensibilidad. Las técnicas convencionales requieren cultivos celulares o laboriosos análisis microscópicos de cromosomas o núcleos. La citometría de flujo en reticulocitos ha surgido como una alternativa para los estudios in vivo, ya que reduce los tiempos de análisis e incrementa hasta en 20 veces el número de células analizables. Objetivos. Estandarizar los parámetros de citometría de flujo requeridos para seleccionar y cuantificar reticulocitos micronucleados (RET-MN) a partir de muestras de sangre periférica, y cuantificar la frecuencia de esta subpoblación anormal como medida de inestabilidad citogenética en sendas poblaciones de voluntarios sanos (n=25) y pacientes (n=25) recién diagnosticados con gliomas de alto grado antes de iniciar el tratamiento. Materiales y métodos. Las células sanguíneas se marcaron con anti-CD71-PE para reticulocitos, anti- CD61-FITC para la exclusión de plaquetas y yoduro de propidio para detectar el ADN en reticulocitos. La fracción celular MN-RETCD71+ se seleccionó y se cuantificó con un citómetro de flujo automático. Resultados. Se describió detalladamente la estandarización de los parámetros citométricos, con énfasis en la selección y la cuantificación de la subpoblación celular MN-RETCD71+. Se establecieron los niveles basales de MN-RETCD71+ en la población de control y en los pacientes se encontró un incremento de 5,2 veces antes de iniciar el tratamiento (p<0,05). Conclusión. Los resultados evidenciaron la utilidad de la citometría de flujo acoplada a la marcación de las células RETCD71+ como método eficiente para cuantificar la inestabilidad cromosómica in vivo. Se sugieren posibles razones del incremento de micronúcleos en células RETCD71+ de pacientes con gliomas.
Abstract Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti- CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.
Assuntos
Feminino , Humanos , Masculino , Reticulócitos/patologia , Glioblastoma/genética , Instabilidade Cromossômica , Micronúcleos com Defeito Cromossômico , Citometria de Fluxo/métodos , Manejo de Espécimes/métodos , Separação Celular/métodos , Fatores de Risco , Glioblastoma/sangue , Glioblastoma/patologia , Gradação de TumoresRESUMO
Marketed formulations of erythropoietin (EPO) ior®EPOCIM, MIRCERA® and two newly developed pegylated-EPO analogues (PEG-EPO 32 and 40â¯kDa) formulations were intravenously administered to New Zealand rabbits. A semi-mechanistic Pharmacokinetic/Pharmacodynamic (PK/PD) model describing in a simultaneous and integrated form the time course of reticulocytes, red blood cells and hemoglobin was built to account for the time course of hematopoiesis stimulation after erythropoietin administration. Data analysis was performed based on the population approach with the software NONMEM version 7.3. Erythropoietin disposition of each of the administered formulations was best described with a two compartment model and linear elimination. Different formulations show different clearance and apparent volume of distribution of the central compartment but share estimates of inter-compartmental clearance and apparent peripheral volume of distribution. A semi-mechanistic model including cell proliferation, maturation, and homeostatic regulation provided a good description of the data regardless the type of erythropoietin formulation administered. The system-, and drug-related parameters showed consistency and differed across formulations, respectively. A single IV administration of PEG-EPO 32 and 40â¯kDa formulations in New Zealand rabbits achieves a median change of 27% and 22% on RET levels, and of 47% and 63% on RBC and HGB levels, respectively compared to MIRCERA®. The administration of new branched PEG-chains formulations improves PK and PD properties of EPO, in terms of increasing elimination half-lives and pharmacological activity on RET, RBC and HGB compared to commercially available formulations (ior®EPOCIM and MIRCERA®).
Assuntos
Eritropoetina/farmacocinética , Hematínicos/farmacocinética , Hematopoese/efeitos dos fármacos , Modelos Biológicos , Polietilenoglicóis/farmacocinética , Animais , Disponibilidade Biológica , Composição de Medicamentos , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Eritropoetina/administração & dosagem , Eritropoetina/sangue , Eritropoetina/química , Hematínicos/administração & dosagem , Hematínicos/sangue , Hematínicos/química , Hemoglobinas/metabolismo , Injeções Intravenosas , Modelos Lineares , Masculino , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/química , Coelhos , Proteínas Recombinantes/farmacocinética , Reticulócitos/efeitos dos fármacos , Reticulócitos/metabolismoRESUMO
Elucidating receptor-ligand and protein-protein interactions represents an attractive alternative for designing effective Plasmodium vivax control methods. This article describes the ability of P. vivax rhoptry neck proteins 2 and 4 (RON2 and RON4) to bind to human reticulocytes. Biochemical and cellular studies have shown that two PvRON2- and PvRON4-derived conserved regions specifically interact with protein receptors on reticulocytes marked by the CD71 surface transferrin receptor. Mapping each protein fragment's binding region led to defining the specific participation of two 20 amino acid-long regions selectively competing for PvRON2 and PvRON4 binding to reticulocytes. Binary interactions between PvRON2 (ligand) and other parasite proteins, such as PvRON4, PvRON5, and apical membrane antigen 1 (AMA1), were evaluated and characterised by surface plasmon resonance. The results revealed that both PvRON2 cysteine-rich regions strongly interact with PvAMA1 Domains II and III (equilibrium constants in the nanomolar range) and at a lower extent with the complete PvAMA1 ectodomain and Domains I and II. These results strongly support that these proteins participate in P. vivax's complex invasion process, thus providing new pertinent targets for blocking P. vivax merozoites' specific entry to their target cells.
Assuntos
Antígenos CD/metabolismo , Adesão Celular , Interações Hospedeiro-Patógeno , Plasmodium vivax/fisiologia , Proteínas de Protozoários/metabolismo , Receptores da Transferrina/metabolismo , Reticulócitos/parasitologia , Humanos , Ligação Proteica , Mapeamento de Interação de Proteínas , Ressonância de Plasmônio de SuperfícieRESUMO
CONTEXT: The recombinant human erythropoietin (rHuEPO) stimulates the erythropoiesis process. Because this glycoprotein has a short half-life, it needs to be administrated two to three times a week. One of the technics to solve this issue is the PEGgilation. AIMS: To evaluate the pharmacokinetics (PK) and pharmacodynamics of two new branched PEGylated erythropoietins (i.e., an asymmetric 32 kDa-PEG2-rHuEPO and a symmetric 40 kDa-PEG2-rHuEPO molecule) compared to non-PEGylated ior®EPOCIM and MIRCERA®. METHODS: Serum concentrations of both PEGylated and non-PEGylated erythropoietins were measured at various time points in order to determine PK parameters using non-compartmental analysis approach. The reticulocyte (%), erythrocyte count and hemoglobin levels were ascertained in order to compare the effect of these molecules after administrating a single intravenous dose (10 µg/kg) of each product in male New Zealand rabbits. RESULTS: Both branched PEGylated erythropoietin forms exhibited half-lives that were significantly longer than ior®EPOCIM (p<0.05), but not statistically different to MIRCERA®. The mean elimination half-life increased from 4 h (ior®EPOCIM) to 131 h for the 32 kDa-PEG2-rHuEPO and 119 h for the 40 kDa-PEG2-rHuEPO. Conversely, MIRCERA® exhibits a half-life of 64 h. Both PEGylated erythropoietin products significantly enhanced the stimulating effect on reticulocytes and erythrocytes formation, as well as on hemoglobin levels, when compared to ior®EPOCIM treatment up to 42 days post-dose. CONCLUSIONS: The PEGylation strategy employed in this study is an effective method to modify the pharmacokinetics and pharmacodynamics of rHuEPO molecule achieving higher half-lives and, therefore, longer in vivo bioactivity. Both of the branched PEGylated-EPO forms tested are promising candidates for human testing.
CONTEXTO: La eritropoyetina humana recombinante (rHuEPO) estimula la formación de eritrocitos en la medula ósea. Esta glicoproteína terapéutica presenta rápida eliminación en el organismo. Una de las estrategias tecnológicas para resolver esta problemática es la PEGgilación. OBJETIVOS: Evaluar la farmacocinética y la farmacodinámica de dos nuevas eritropoyetinas PEGiladas ramificadas (una asimétrica de 32 kDa-PEG2-rHuEPO y otra simétrica de 40 kDa-PEG2-rHuEPO) en comparación con ior®EPOCIM y el producto de referencia MIRCERA®. MÉTODOS: Se midieron las concentraciones séricas de eritropoyetina PEGilada y no PEGilada, a diferentes tiempos, para determinar los parámetros farmacocinéticos usando el método de análisis no compartimental. Se determinaron los % de reticulocitos, los niveles de eritrocitos y hemoglobina para comparar el efecto de estas moléculas después de administrar a dosis única 10 µg/kg por vía intravenosa en conejos Nueva Zelanda machos. RESULTADOS: Las eritropoyetinas PEGiladas ramificadas presentaron semividas significativamente superiores a ior®EPOCIM (p<0.05), pero no fueron estadísticamente diferentes a MIRCERA®. El t1/2 aumentó de 4 h (ior®EPOCIM) a 131 h para la 32 kDa-PEG2-rHuEPO y 119 h para la 40 kDa-PEG2-rHuEPO, respectivamente. Ambas eritropoyetinas PEGiladas mejoraron significativamente el efecto estimulante sobre la formación de reticulocitos y eritrocitos, así como los niveles de hemoglobina, en comparación con ior®EPOCIM hasta 42 días después de la dosis. CONCLUSIONES: La estrategia de PEGilación, empleada en este estudio, es un método efectivo para modificar la farmacocinética y farmacodinamia de moléculas de eritropoyetinas. Esta tecnología permitió aumentar la semivida de estas moléculas, así como prolongar su bioactividad in vivo. Ambas formas ramificadas de rHuEPO PEGiladas son candidatos prometedores para su uso clínico.
RESUMO
RESUMEN Introducción: La eritropoyetina es una alfa globulina glicosilada con producción renal en más del 90% en la vida adulta. Es la principal hormona en el mantenimiento constante de la masa eritrocitaria, aunque existen modificaciones en sus niveles asociados con el tabaquismo, anemias, EPOC y la migración de bajas a medianas o altas alturas. Esto último desencadena un proceso hipóxico que puede llegar a producir mal agudo de montaña. Objetivo: Describir el comportamiento de la eritropoyetina, el recuento de reticulocitos y su influencia, en procesos de adaptación a la altura. Metodología: Estudio descriptivo de corte transversal que incluyó 11 participantes provenientes de bajas alturas a quienes se les determinó la concentración sérica de eritropoyetina y el recuento de reticulocitos en un periodo de 28 días. Resultados: Ocho de los participantes presentaron un ascenso progresivo en los niveles séricos de eritropoyetina, uno mantuvo una curva plana y dos presentaron comportamiento atípico respecto a lo reportado en la literatura. Conclusión: La eritropoyetina es un factor fundamental que marca el comienzo de la eritropoyesis, cuya finalidad es mejorar el aporte de oxígeno en procesos de adaptación a la altura. Además, la hipoxia es un factor determinante en el inicio y desarrollo del mal agudo de montaña. El recuento de reticulocitos depende del estímulo proliferativo y anti-apoptótico de la eritropoyetina, así como de las concentraciones séricas de vitamina B12, hierro y ácido fólico.
ABSTRACT Introduction: EPO is a glycosylated alpha globulin produced in more than 90% by kidneys through adult life, being a key hormone that regulated the erythrocytic mass. However, there are some modifications in the levels of this hormone that may be related to smoking, anemia, EPOC and migration to from low to higher altitudes, inducing hypoxic processes. Depending on the individual, it may produced the disease named as acute mountain sickness. Objective: To describe erythropoietin level modifications, reticulocytes count and its influence, on the adaptive process to altitude. Methodology: This is a transversal descriptive study including 11 participants from low altitudes places, whose EPO serum concentration and reticulocytes count was determined during 28 days. Results: Eight participants presented a progressive increase in EPO serum levels, one participant exhibited a constant level and two more showed atypical results according to previous literature. Conclusion: EPO is a key factor for determining the erythropoiesis beginning, as its objective is to improve the oxygen provision during altitude adaptation processes by increasing its concentration in blood due to hypoxic stimulus. Besides, hypoxia is a determinant factor in the beginning and development of acute mountain sickness. The reticulocytes count depends also on the EPO proliferative and anti-apoptotic stimulus, and on the serum concentrations of B12 vitamin, iron and folic acid.
Assuntos
Humanos , Eritropoetina , Reticulócitos , Eritropoese , Doença da Altitude , HipóxiaRESUMO
Objective: The aim of this study was to evaluate the effectiveness of mature red cell and reticulocyte parameters to identify three conditions: iron deficiency anemia, anemia of chronic disease, and anemia of chronic disease associated with absolute iron deficiency. Methods: Peripheral blood cells from 117 adult patients with anemia were classified accord- ing to iron status, inflammation, and hemoglobinopathies as: iron deficiency anemia (n = 42), anemia of chronic disease (n = 28), anemia of chronic disease associated with iron deficiency anemia (n = 22), and heterozygous β-thalassemia (n = 25). The percentage of microcytic eryth-rocytes, hypochromic erythrocytes, and the levels of hemoglobin in both reticulocytes and mature red cells were determined. Receiver operating characteristic analysis was used to evaluate the accuracy of the parameters in differentiating anemia. Results: There was no difference between the groups of iron deficiency and anemia of chronic disease associated with absolute iron deficiency for any of the parameters. The percentage of hypochromic erythrocytes was the best parameter to identify absolute iron deficiency in patients with anemia of chronic disease (area under curve = 0.785; 95% confidence interval: 0.661-0.909 with sensitivity of 72.7%, and specificity of 70.4%; cut-off value 1.8%). The formula microcytic erythrocyte count minus hypochromic erythrocyte count was very accurate to differentiate iron deficiency anemia from heterozygous β-thalassemia (area under curve = 0.977; 95% confidence interval: 0.950-1.005 with a sensitivity of 96.2%, and specificity of 92.7%; cut-off value 13.8). Conclusion: The erythrocyte and reticulocyte indices are moderately good to identify absolute iron deficiency in patients with anemia of chronic disease.
Assuntos
Humanos , Masculino , Feminino , Adulto , Anemia Ferropriva , Eritrócitos , ReticulócitosRESUMO
Introduction: The importance of local references values has been well described in the literature; this is because the characteristics of the population may influence the laboratory tests. Objective: To establish the reference range for traditional and extended red blood cell parameters and reticulocyte indices in order to investigate its application in patients with chronic kidney disease (CKD). Materials and methods: 249 blood donors (125 males and 124 females) were selected to establish the reference values. The hemodialysis sample consisted of 62 patients with terminal CKD (48 male and 14 female). All analyzes were performed using the Sysmex XE-5000 automated hematology analyzer. Results: Differences between reference values was observed in relation to gender: red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular hemoglobin concentration (MCHC), percentage of hyperchromic red blood cells (%HYPER), percentage of microcytosis (%MICRO), percentage of macrocytosis (%MACRO), absolute reticulocyte count (RET), reticulocyte hemoglobin content (RET-He), immature reticulocyte fraction (IFR), low fluorescence reticulocytes (LFR), medium fluorescence reticulocytes (MFR), and high fluorescence reticulocytes (HFR). Individuals with CKD presented RBC, HGB, HCT, MCHC, red cell distribution width expressed as coefficient of variation (RDW-CV), percentage of hypochromic red blood cells (%HYPO), percentage of reticulocytes (RET%), RET (female group), IFR, LFR, MFR, and HFR results compatible with the anemic state, which can be observed in 91.8% of patients. All studied parameters were in the area under the curve (AUC) > 0.4. In male group, %HYPO (AUC: 0.806) and IFR (AUC: 0.762) presented higher AUC values, while female group presented %HYPO (AUC: 0.806), %HYPER (AUC: 0.815), and IFR (AUC: 0.660). Conclusion: The medical advancement, the development of new techniques and hematological parameters have revealed important information ...
Introdução: A importância dos valores de referências locais tem sido bastante descrita na literatura, isso porque características da população podem influenciar os testes laboratoriais. Objetivos: Estabelecer o intervalo de referência para parâmetros eritrocitários tradicionais e estendidos e índices reticulocitários a fim de investigar sua aplicação em pacientes com doença renal crônica (DRC). Materiais e métodos: Dos doadores de sangue, 249 pacientes foram selecionados para estabelecimento dos valores de referência (125 homens e 124 mulheres); dos pacientes em hemodiálise, a amostra foi composta por 62 indivíduos com DRC terminal (48 homens e 14 mulheres). Todas as análises foram realizadas no avaliador hematológico Sysmex XE-5000. Resultados: Foi observada uma distinção entre os valores de referência em relação ao gênero: células vermelhas do sangue (RBC), hemoglobina (HGB), hematócrito (HCT), concentração de hemoglobina corpuscular média (CHCM), porcentagem de eritrócitos hiper-hemoglobinizados (%HIPER), porcentagem de microcitose (%MICRO), porcentagem de macrocitose (%MACRO), contagem absoluta de reticulócitos (RET), contagem relativa de reticulócitos (RET-He), fração de reticulócitos imaturos (IFR), reticulócitos de baixa fluorescência (LFR), reticulócitos de média fluorescência (MFR) e reticulócitos de alta fluorescência (HFR). Os indivíduos com DRC apresentaram resultados de RBC, HGB, HCT, CHCM, coeficiente de variação do tamanho dos eritrócitos (RDW-CV), %HIPO, RET%, RET (grupo das mulheres), IFR, LFR, MFR e HFR compatíveis com o estado anêmico, que pode ser observado em 91,8%. Todos os parâmetros estudados apresentaram área sob a curva (AUC) > 0,4. Para o grupo dos homens, a %HIPO (AUC: 0,806) e a IFR (AUC: 0,762) apresentaram melhores valores de AUC; já para o grupo das mulheres foram a %HIPO (AUC: 0,806), a %HIPER (AUC: 0,815) e a IFR (AUC: 0,660). Conclusão: Avanço da medicina e surgimento de novas técnicas e parâmetros ...