RESUMO
BACKGROUND: Hemolysis may occur in vivo, under pathological conditions, or in vitro, related to pre-analytical errors. Hemolyzed samples may produce unreliable results, leading to errors in diagnostic and monitoring evaluations. This study aims to evaluate the interference of in vitro hemolysis on the interpretation of the parameters of the blood cell-counting performed by the impedance method. METHODS: Peripheral blood samples were collected in anticoagulant K2-EDTA and subsequently divided into three 1.0 mL aliquots. The first aliquot was not subjected to any intervention, and the second and third aliquots were passed 5 and 10 times through a small-gauge needle to produce scalar amounts of hemolysis. Hematological tests were performed by Hemacounter 60-RT 7600® . RESULTS: Comparison of the samples with different degrees of hemolysis showed a decrease in red blood cells count and hematocrit counts and increase in mean corpuscular hemoglobin concentration and platelet count in samples with a high degree of hemolysis. According to the accepted clinical point of view, the samples with a high degree of hemolysis exceeded the desirable bias, presenting decrease in red blood cells count, hematocrit and mean corpuscular volume, and increase in red cell distribution width, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet counts. However, samples with a mild degree of hemolysis showed only a slight increase in mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, and platelet count. CONCLUSION: This study demonstrated that in vitro hemolysis can decrease the clinical and analytical reliability of the assessment of the blood count.
Assuntos
Contagem de Células Sanguíneas/métodos , Hematócrito/métodos , Hemólise/fisiologia , Anticoagulantes/farmacologia , Feminino , Hemoglobinas/metabolismo , Humanos , Masculino , Adulto JovemRESUMO
ABSTRACT Down syndrome (DS) is one of the most leading causes of intellectual disability. The aim of this study was to compare biochemical and hematological parameters, triglyceride/high-density lipoprotein cholesterol (HDL-C) and neutrophil/lymphocyte ratios in individuals with intellectual disabilities (ID) associated or not with DS. The main result is the lower HDL-C level in individuals with DS than in the ID group, suggesting a modification in the lipid profile whose origin would lie in genetic alterations. However, further researches are important to analyze if there is any link between trisomy 21 and the reduction of plasma HDL-C levels in individuals with DS.
RESUMO A síndrome de Down (SD) é uma das principais causas de deficiência intelectual. Os objetivos deste estudo foram comparar parâmetros bioquímicos e hematológicos, bem como encontrar a relação triglicerídeo/colesterol da lipoproteína de alta densidade (HDL-C) e a razão neutrófilo/linfócito em indivíduos com deficiência intelectual (DI) associada ou não à SD. O principal resultado foi a diminuição do HDL-C em indivíduos com SD quando comparados àqueles com DI, sugerindo que essa modificação no perfil lipídico pode se relacionar com alterações genéticas. Portanto, pesquisas adicionais são importantes para analisar se existe ligação entre a trissomia 21 e a redução dos níveis de HDL-C em indivíduos com SD.
RESUMO
Manual reticulocyte counts were examined under light microscopy, using the property whereby supravital stain precipitates residual ribosomal RNA versus the automated flow methods, with the suggestion that in the latter there is greater precision and an ability to determine both mature and immature reticulocyte fractions. Three hundred and forty-one venous blood samples of patients were analyzed of whom 224 newborn and the rest adults; 51 males and 66 females, with ages between 0 and 89 years, as part of the laboratory routine for hematological examinations at the Clinical Laboratory of the Hospital Universitário do Oeste do Paraná. This work aimed to compare manual and automated methodologies for reticulocyte countings and evaluate random and systematic errors. The results obtained showed that the difference between the two methods was very small, with an estimated 0·4% systematic error and 3·9% random error. Thus, it has been confirmed that both methods, when well conducted, can reflect precisely the reticulocyte counts for adequate clinical use.
Assuntos
Citometria de Fluxo/métodos , Microscopia/métodos , Contagem de Reticulócitos/métodos , Contagem de Reticulócitos/normas , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Automação , Criança , Pré-Escolar , Feminino , Citometria de Fluxo/normas , Humanos , Lactente , Recém-Nascido , Masculino , Microscopia/normas , Pessoa de Meia-Idade , RNA Ribossômico , Reprodutibilidade dos Testes , Contagem de Reticulócitos/instrumentação , Adulto JovemRESUMO
Reticulocyte counts are widely used in laboratories to evaluate bone marrow erythropoietic activity and have great diagnostic and prognostic importance in the treatment of anemias. Reticulocytes are supravitally stained with new methylene blue or brilliant cresyl blue, which highlight the characteristic aspect of the reticulum visible by light microscopy. Known criteria were observed for good manual reticulocyte counting with special attention being paid to the preparation of reticulocyte slides, to counting fields without overlapping cells, and to the number of evaluated cells. The aim of this study was to evaluate the inter-observer variation and also to analyze the statistical error of manual reticulocyte counting. The Intraclass correlation coefficient (ICC) according to Bartko was used to evaluate the level of agreement among 12 laboratory technicians who evaluated the same 25 blood smears. The results of statistical analyses showed that the amount of random error, defined as (1-r2), varied from 4 percent to 60 percent among the technicians. Although imprecision occurred, the overall profiles were quite similar, and intraclass correlation coefficients indicated that the results obtained have clinical significance.
A contagem do reticulócitos é usada extensamente na rotina laboratorial para avaliar a atividade eritropoiética da medula óssea, e é de grande importância no diagnóstico e no prognóstico na terapia de anemias hemolíticas. São coradas com o azul de metileno novo e o azul cresil brilhante, o que conferem o aspecto característico de retículo quando observado ao microscópioótico. Critérios conhecidos foram observados para um bom desempenho da contagem manual de reticulócitos, principalmente, atenção especial nas películas do sangue durante a montagem das lâminas; contagem nos campos que não contém sobreposição celular; e também no número de células avaliadas. O objetivo deste estudo foi avaliar a variação interobservadores, analisar o erro estatístico da contagem manual dos reticulócitos, e demonstrar as limitações deste método. A análise de correlação intraclasses segundo Bartko [Psychol Rep 19:3,1966; 34:418,1974] foi usada para avaliar a concordância entre 12 observadores em um total de 25 lâminas do sangue, com contagens variadas de reticulócitos. Os resultados das análises estatísticas indicam que o erro casual, calculado como (1-r2) variou de 4 a 60 por cento entre os observadores. Embora ocorra imprecisão entre os observadores, o perfil geral entre eles é similar, e o coeficiente de correlação intraclasse indicou que os resultados obtidos são clinicamente úteis.