Standardization method for measurement of hydroxyurea by Ultra High Efficiency Liquid Chromatography in plasma of patients with sickle cell disease

Sickle cell anemia (SCA) is a recessively inherited disease characterized by chronic hemolytic anemia, chronic inflammation, and acute episodes of hemolysis. Hydroxyurea (HU) is widely used to increase the levels of fetal hemoglobin (HbF). The objective of this study was to standardize and validate a method for the quantification of HU in human plasma by using ultra high performance liquid chromatography (UPLC) in order to determine the plasma HU levels in adult patients with SCA who had been treated with HU. We used an analytical reverse phase column (Nucleosil C18) with a mobile phase consisting of acetonitrile/water (16.7/83.3). The retention times of HU, urea, and methylurea were 6.7, 7.7, and 11.4 min, respectively. All parameters of the validation process were defined. To determine the precision and accuracy of quality controls, HU in plasma was used at concentrations of 100, 740, and 1600 µM, with methylurea as the internal standard. Linearity was assessed in the range of 50-1600 µM HU in plasma, obtaining a correlation coefficient of 0.99. The method was accurate and precise and can be used for the quantitative determination of HU for therapeutic monitoring of patients with SCA treated with HU.A anemia falciforme (AF) é uma doença hereditária recessiva caracterizada por anemia hemolítica crônica, inflamação crônica e episódios agudos de hemólise. Hidroxiureia (HU) é amplamente utilizada para aumentar os níveis de hemoglobina fetal (Hb F). O objetivo consiste em padronizar e validar um método para a quantificação de HU no plasma humano utilizando Cromatografia Líquida de Ultra Alta Eficiência (UPLC), a fim de determinar os níveis de HU em pacientes adultos com AF, tratados com HU. Utilizou-se coluna analítica de fase inversa (Nucleosil C18), fase móvel constituída por acetonitrila/água (16,7/83,3). Os tempos de retenção da HU, uréia e metiluréia foram respectivamente de 6,7, 7,7 e 11,4 minutos. Definiram-se todos os parâmetros do processo de validação. Para determinar a precisão e exatidão dos controles de qualidade utilizaram-se concentrações de 100, 740 e 1600 mM de HU no plasma, empregando como padrão interno a metiluréia. A linearidade foi avaliada no intervalo de 50 1600 mM de HU no plasma, obtendo-se coeficiente de correlação de 0,99. O método foi considerado exato e preciso e pode ser realizado com o propósito de determinação quantitativa de HU para monitorização terapêutica de pacientes com AF tratados com esse fármaco

Prolonged response to recombinant human erythropoietin treatment in patients with myelodysplastic syndrome at a single referral centre in Brazil

OBJECTIVES: To evaluate the effects of epoetin (EPO) alfa treatment on overall survival, event-free survival and response duration in patients with myelodysplastic syndrome (MDS) who were treated at a haematological referral centre in northeastern Brazil. METHODS: This was a retrospective cohort study of 36 patients diagnosed with MDS and treated with EPO alfa at 30,000 to 60,000 IU per week. Clinical data were collected from medical records. The events assessed were non-response to treatment and progression to acute myeloid leukaemia (AML). Statistical analyses were performed using GraphPad Prism 7 and SPSS 24 software. RESULTS: The overall survival of patients who received EPO alfa treatment was 51.64%, with a median of 65 months of treatment, and the overall survival of this group was 100% during the first 24 months. We detected a 43.5-month median event-free survival, with a response rate of 80.5%. We observed responses from 25 to 175 months. Patients with transfusion dependence and those with a high-risk stratification, as determined by the International Prognostic Scoring System (IPSS), the Revised International Prognostic Scoring System (IPSSR), the WHO classification-based Prognostic Scoring System (WPSS) and the WHO 2016, had a lower event-free survival than other patients. CONCLUSIONS: Despite the wide use of EPO alfa in the treatment of anaemia in patients with MDS, the median response duration is approximately only 24 months. Our data provide encouraging results concerning the benefits of using EPO alfa for the improvement of the quality of life, as patients treated with EPO showed higher overall survival, event-free survival rates and longer response durations than have been previously described in the literature

Methemoglobin measure in adult patients with sickle-cell anemia: influence of hydroxyurea therapy

Introduction: Hemoglobin S (HbS) is unstable hemoglobin that easily oxidizes, causing methemoglobin (MetHb) increased production in patients with sickle-cell anemia (SCA). Objectives: To determine MetHb levels and the influence of hydroxyurea (HU) therapy on this marker in patients with SCA. Materials and methods: Blood samples from 53 patients with SCA at the steady-state, with and without HU therapy, and 30 healthy individuals were collected to evaluate MetHb levels. The MetHb measurement was performed by spectrophotometry. Complete blood count, HU measurements, and fetal hemoglobin (HbF) and HbS concentrations were taken from medical records. Results: MetHb levels were statically higher in patients with SCA when compared to control group (p < 0.001). There was no statistical difference in MetHb level between SCA patients, either using or not HU. We obtained a positive correlation between MetHb measurements and HbS concentration (r = 0.2557; p = 0.0323). Conclusion: HbS presence favored hemoglobin breaking down, and consequently increased MetHb production. Treatment with HU, however, did not influence the levels of this marker

Cytotoxicity and DNA damage in the neutrophils of patients with sickle cell anaemia treated with hydroxyurea

A hidroxiuréia (HU) constitui o avanço mais importante no tratamento da anemia falciforme (AF) por prevenir complicações e aumentar a qualidade de vida dos pacientes. Entretanto, alguns aspectos do tratamento com HU permanecem obscuros, incluindo a sua ação e potencial toxicidade em outras células sanguíneas, tais como neutrófilos. Este estudo utilizou a mensuração da lactato desidrogenase (LDH) e do metil tiazoltetrazólio (MTT) e o ensaio do cometa para investigar a citotoxicidade e índice de dano (ID) ao DNA em neutrófilos de pacientes com AF em uso do medicamento. Nos ensaios de LDH e MTT, observou-se além de ausência de toxicidade, uma ação citoprotetora no grupo de pacientes tratados, Grupo SSHU (n=21, 11 mulheres e 10 homens, com idades entre 19-63 anos), quando comparados aos pacientes sem tratamento, Grupo SS (n=20, 13 mulheres e 07 homens, 18-69 anos), e grupo de indivíduos saudáveis (AA) usado como controle (n=52, 28 mulheres e 24 homens, 19-60 anos), com redução significativa (pHydroxyurea (HU) is the most important advance in the treatment of sickle cell anaemia (SCA) for preventing complications and improving quality of life for patients. However, some aspects of treatment with HU remain unclear, including their effect on and potential toxicity to other blood cells such as neutrophils. This study used the measurement of Lactate Dehydrogenase (LDH) and Methyl ThiazolTetrazolium (MTT) and the comet assay to investigate the cytotoxicity and damage index (DI) of the DNA in the neutrophils of patients with SCA using HU.In the LDH and MTT assays, a cytoprotective effect was observed in the group of patients treated, as well as an absence of toxicity. When compared to patients without the treatment, the SS group (n=20, 13 women and 07 men, aged 18-69 years), and the group of healthy individuals (AA) used as a control group (n=52, 28 women and 24 men, aged 19-60 years), The SSHU group (n=21, 11 women and 10 men, aged 19-63 years) showed a significant reduction (

Levothyroxine Replacement Improves Oxidative Status in Primary Hypothyroidism

Objective: Although hypothyroidism has been linked to oxidative stress, data regarding the relationship between thyroid hormone levels and oxidative stress is still inconsistent. This study was designed to evaluate the effect of levothyroxine replacement on oxidative stress in women with primary hypothyroidism.Design: A total of 25 female patients with primary hypothyroidism were included. Oxidative stress markers were measured before and after levothyroxine replacement treatment in all patients.Methods: Oxidative stress was evaluated through the measurement of oxidants (thiobarbituric acid reactive substances [TBARS] and nitrite/nitrate levels), and antioxidants (superoxide dismutase and catalase activity).Results: Antioxidant catalase activity (63.77 ± 23.8 vs. 50.12 ±12.75 atv/min; p = 0.03) was significantly increased and the levels of TBARS (3.02 ± 0.86 vs. 3.55 ± 0.87 μM; p = 0.03) were significantly decreased in the state of euthyroidism after levothyroxine replacement compared to the hypothyroidism before levothyroxine treatment. No significant change in neither nitrite/nitrate concentration (p = 0.18) nor in superoxide dismutase activity (p = 0.93) after L-T4 adjustment was found.Conclusions: Our data demonstrate that levothyroxine replacement improved oxidative status in patients with primary hypothyroidism, indexed by the significantly decreased levels of malonaldehyde (MDA) and increased catalase (CAT) activity

Cytotoxicity and DNA damage in the neutrophils of patients with sickle cell anaemia treated with hydroxyurea

Hydroxyurea (HU) is the most important advance in the treatment of sickle cell anaemia (SCA) for preventing complications and improving quality of life for patients. However, some aspects of treatment with HU remain unclear, including their effect on and potential toxicity to other blood cells such as neutrophils. This study used the measurement of Lactate Dehydrogenase (LDH) and Methyl ThiazolTetrazolium (MTT) and the comet assay to investigate the cytotoxicity and damage index (DI) of the DNA in the neutrophils of patients with SCA using HU.In the LDH and MTT assays, a cytoprotective effect was observed in the group of patients treated, as well as an absence of toxicity. When compared to patients without the treatment, the SS group (n=20, 13 women and 07 men, aged 18-69 years), and the group of healthy individuals (AA) used as a control group (n=52, 28 women and 24 men, aged 19-60 years), The SSHU group (n=21, 11 women and 10 men, aged 19-63 years) showed a significant reduction (p20 months), demonstrating that despite the cytoprotective effects in terms of cell viability, the use of HU can induce DNA damage in neutrophils

Análise dos haplótipos da anemia falciforme em Fortaleza revela as origens étnicas da população cearense Analysis of sickle cell anemia haplotypes in Fortaleza reveals the ethnic origins of Ceará state population

Os haplótipos ligados ao gene da &#946;S-globina foram analisados em uma amostra de 68 cromossomos de pacientes de Fortaleza, capital do Ceará, com anemia falciforme (AF), com a finalidade de fornecer informações sobre a distribuição das frequências dos haplótipos, contribuindo para o estudo das origens da formação étnica da população cearense. A distribuição dos haplótipos do gene da &#946;S-globina foi 66,2% do tipo Bantu, 22% do Benin e 11,8% do atípico. Houve diferença estatisticamente significativa entre o presente estudo e os resultados de outros pesquisadores no Ceará. A distribuição das frequências dos haplótipos do gene da &#946;S-globina no presente estudo está condizente com a história da formação da população brasileira. Conforme dados históricos sobre as origens da população negra trazida ao Ceará, o haplótipo Bantu seria o mais prevalente, seguido pelo Benin e Senegal. Estes resultados são relevantes para o estudo das rotas de tráfico dos escravos no Brasil e para entendermos as origens étnicas da população brasileira.In a sample of 68 chromosomes from sickle cell anemia patients from the population of Fortaleza, capital of Ceará State - Brazil, the haplotypes connected with &#946;S-globin gene were analyzed with the aim to provide further information on haplotype frequency distribution, which ultimately contributed to the investigation into the ethnic origins of the state's population. The haplotype distribution of &#946;S-globin gene was 66.2% Bantu type, 22% Benin type and 11.8% atypical. There was a significant statistical difference between the results of the present study and those achieved by other researchers in Ceará. The distribution of haplotype frequencies of &#946;S-globin gene in the present study is consistent with the history of the Brazilian population origins. According to historical data on the origins of the slave population brought to Ceará State, Bantu haplotype would be the most prevalent, followed by Benin and Senegal. These results are relevant to the study of the slave traffic routes in Brazil and to understand the ethnic origins of Brazilian population