RESUMEN

Sickle cell disease (SCD) comprises a group of genetic disorders characterized by the presence of the hemoglobin (Hb) S in homozygosis or in heterozygosis with some other Hb variant or in interaction with thalassemia. SCD is characterized by a very complex pathophysiology, which determines a wide variability of clinical manifestations, including a chronic state of hypercoagulability responsible for the increased risk of thromboembolic events. ADAMTS13 and von Willebrand factor (VWF) play an important role in arterial and venous thrombosis. Thus, the aim of this study was to understand how the ADAMTS13-VWF axis behaves in sickle cell disease, as well as whether there is an association of these markers with the use of hydroxyurea (HU). This is a cross-sectional study conducted with 40 patients diagnosed with SCD and 40 healthy individuals. The analysis of the ADAMTS13-VWF axis was comparatively performed between groups of patients and controls and, afterwards, between patients with SCD who were users and non-users of HU. ADAMTS13 activity, ADAMTS13 activity/VWF:Ag, and ADAMTS13:Ag/VWF:Ag ratios were significantly lower and VWF:Ag levels significantly higher in SCD patients when compared to the controls. There was no statistically significant difference in ADAMTS13:Ag and VWF collagen binding (VWF:CB) levels between the groups evaluated. Among the categories of HU use, there was no statistically significant difference in any of the evaluated markers. As a conclusion, we could observe that the ADAMTS13-VWF axis is altered in SCD when compared to healthy individuals and that there is no association between these markers and the use of HU.

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RESUMEN

Hydroxyurea (HU) is used as a therapy in sickle cell anemia (SCA). Many studies have established that HU improves patient quality of life by reducing symptoms. However, the effect of HU on erythrocytes is not well-described. We evaluated several parameters related to oxidative stress and total lipid content of erythrocytes in patients with SCA. The patient cohort consisted of 7 SCA patients treated with HU, 17 untreated SCA patients, and 15 healthy subjects. Erythrocytes from patients with SCA displayed increased oxidative stress relative to the control group, including higher thiobarbituric acid reactive substances (TBARS), Fe3+ content, and osmotic fragility, and decreased total cholesterol. We observed that treatment of SCA patients with HU increased Fe3+ content and activity of glutathione peroxidase, and decreased glutathione reductase activity, glutathione levels, total cholesterol, and phospholipid content comaperaded to patients untreated with HU. Thus, HU alters biochemical characteristics of erythrocytes; future studies will determine whether they are beneficial or not.

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RESUMEN

Modelo do estudo: Observacional transversal. Objetivo: Avaliar a associação entre a presença de anemia ferropriva com variáveis socioeconômicas e rendimento escolar. Método: Foram incluídas no estudo 124 crianças com idade entre seis e oito anos, estudantes do ensino fundamental de escolas municipais, as quais foram divididas em dois grupos de acordo com a presença (n=32) ou ausência de anemia (n=92). Os níveis de hemoglobina e ferro sérico foram determinados por método colorimétrico, a contagem de hemácias foi realizada utilizando a câmara de Neubauer, o hematócrito foi avaliado utilizando centrífuga de microhematócrito, e foram calculados os índices hematimétricos volume corpuscular médio, hemoglobina corpuscular média e concentração de hemoglobina corpuscular média. O desempenho escolar das crianças foi fornecido pelas escolas participantes e as variáveis socioeconômicas foram obtidas através de preenchimento de ficha clínica e do questionário socioeconômico da Associação Brasileira das Empresas de Pesquisa pelos pais ou responsáveis. Resultados: A prevalência de anemia ferropriva nos escolares foi de 25,8% que é considerada pelos parâmetros da OMS uma prevalência moderada. Foi observada uma maior proporção de crianças sem anemia que apresentaram melhores conceitos escolares e que pertencem aos níveis socioeconômicos mais altos do que de crianças com anemia. Contudo, não foram observadas diferenças estatisticamente significativas entre os grupos com relação ao rendimento escolar e as variáveis socioeconômicas. Conclusão: Uma prevalência moderada de anemia ferropriva foi encontrada nas crianças com idade entre seis e oitos anos, entretanto, não foi observada uma associação significativa entre a anemia ferropriva com variáveis socioeconômicas e o rendimento escolar. (AU)

Study design: Cross-sectional observational. Objective: Evaluate the association between the occurence of iron-deficiency anemia with socioeconomic variables and school performance. Method: They were included in the study 124 children aged between six and eight years old, municipal elementary school students, which were divided in two groups according to the presence (n=32) or absence of anemia (n=92). Hemoglobin and serum iron levels were determined by colorimetric method, red blood cells count was performed using Neubauer chamber, hematocrit was evaluated using microhematocrit centrifuge, and mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration hematimetric indexes were calculated. The school performance of children was provided by participating schools and socioeconomic variables were obtained by filling out the clinic file and the socioeconomic questionnaire of Brazilian Association of Research Companies by parents or guardians. Results: The prevalence of iron-deficiency anemia in school children was 25.8%, which is considered to be moderate. The proportion of better school grades was higher in children without anemia and in those belonging to the upper socioeconomic levels. However, it was not observed statistically differences between groups regarding school performance and socioeconomic variables. Conclusion: A moderate prevalence of iron-deficiency anemia was found in children aged between six and eight years old, however, it was not observed a significant association between irondeficiency anemia with socioeconomic variables and school performance. (AU)

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