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Objectives: Our study evaluated the association of the polymorphism rs724016 in the ZBTB38 gene, previously associated with height in other populations, with predictors of height, clinical outcomes, and laboratory parameters in sickle cell anemia (SCA). Methods: Cross-sectional study with individuals with SCA and aged between 3 and 20 years. Clinical, laboratory, molecular, and bone age (BA) data were evaluated. Levels of IGF-1 and IGFBP-3 were adjusted for BA, target height (TH) was calculated as the mean parental height standard deviation score (SDS), and predicted adult height (PAH) SDS was calculated using BA. Results: We evaluated 80 individuals with SCA. The homozygous genotype of the G allele of rs724016 was associated with a lower height SDS (p < 0.001) and, in a additive genetic model, was negatively associated with HbF levels (p = 0.016). Lower adjusted IGF-1 levels were associated with co-inheritance of alpha-thalassemia and with the absence of HU therapy. Elevated HbF levels were associated with a lower deficit in adjusted growth potential (TH minus PAH). Conclusion: Our analysis shows that SNP rs724016 in the ZBTB38 is associated with shorter height and lower HbF levels, an important modifier of SCA.
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INTRODUCTION: Sickle cell anemia (SCA) is a hematological genetic disorder caused by a mutation in the gene of the ß-globin. Pharmacological treatments will continue to be an important approach, including the strategy to induce fetal hemoglobin (HbF). AREAS COVERED: Here, we analyzed the articles described in the literature regarding the drug discovery of HbF inducers. The main approaches for such strategy will be discussed, highlighting those most promising. EXPERT OPINION: The comprehension of the mechanisms involved in the ß-globin regulation is the main key to design new drugs to induce HbF. Among the strategies, gamma-globin regulation by epigenetic enzymes seems to be a promising approach to be pursued, although the comprehension of the selectivity role for those new drugs is crucial to reduce adverse effects. The low druggability of transcription factors and their vital role in embryonic human development are critical points that should be taken in account for drug design. The guanylate cyclase and the NO/cGMP signaling pathway seem to be promising not only for HbF induction, but also for the protective effects in the cardiovascular system. The association of drugs acting through different mechanisms to induce HbF seems to be promising for the discovery of new drugs.
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Hemoglobina Fetal , Globinas beta , Humanos , Hemoglobina Fetal/genética , Hemoglobina Fetal/metabolismo , Hemoglobina Fetal/farmacologia , Globinas beta/farmacologia , Fatores de Transcrição , Transdução de SinaisRESUMO
Hemoglobin S is caused by a nucleotide change in HBB gene (HBB:c.20A>T, p.Glu6Val), is presented in diverse forms: simple carriers (HbSA), homozygotes (HbSS) also known as sickle cell anemia, and compound heterozygotes with other ß-hemoglobinopathies. It is worldwide distributed, in Mexico, is frequently observed in the southern states Guerrero, Oaxaca and Chiapas. Elevated fetal hemoglobin (HbF) is associated with mild phenotype; single-nucleotide variants (SNVs) in modifier genes, such as BCL11A, HBG2, HBBP1 pseudogene and HBS1L-MYB intergenic region, upregulate HbF synthesis. The aim of this study was to identify HbF regulating genetic variants in HbSS and HbSA Mexican subjects. We studied 39 individuals (HbSS = 24, 61%, HbSA = 15, 39%) from Chiapas (67%) and Guerrero (33%), peripheral blood was collected in ethylenediamine tetraacetic acid (EDTA) for molecular and hematological studies, DNA was isolated by salting-out technic and genotyping was performed through allelic discrimination by real time polymerase chain reaction (RT-PCR) using Taqman® probes for 15 SNV (in BCL11A: rs6706648, rs7557939, rs4671393, rs11886868, rs766432, rs7599488, rs1427407; HBS1L-MYB: rs28384513, rs7776054, rs9399137, rs4895441, rs9402686, rs1320963; HBG2: rs7482144; and HBBP1: rs10128556). The obtained data were analyzed using IMB SPSS v.22.0 software. All minor alleles were observed in frequencies over 0.05, the most frequent was rs9402686 (0.82), while the less frequent was rs101028556 (0.08). In HbSS group, the mean fetal hemoglobin was 11.9 ± 5.9% and was significantly elevated in BCL11A rs11886868 wildtype homozygotes and in carriers of HBS1L-MYB intergenic region rs7776054 (p = 0.04 and p = 0.03, respectively). In conclusion, in HbSS Mexican patients, two SNVs were observed related to increased HbF; BCL11A rs11886868 and HBS1L-MYB rs7776054.
Sickle cell anemia (SCA) is one of the most common types of hemoglobinopathies in people of African ancestry, it is caused by homozygosity of HbS mutation (HBB:c.20A>T). It is known that fetal hemoglobin plays a key role in decreasing HbS polymerization which damages the erythrocyte structure and is responsible for the characteristic hemolytic crises endured by these patients. Single-nucleotide variant (SNV) in genes that regulate fetal hemoglobin (HbF) after birth have been associated with its increment, thus ameliorating the hematologic phenotype of this pathology and other ß-hemoglobinopathies. Therefore, in this study, we identified, for the first time in Mexican patients with SCA (HbSS) and HbS carriers (HbSA), the presence of 15 SNVs on BCL11A, HBS1L-MYB and HBG2; all HbSS patients had anemia and elevated HbF; 2 variants were related to increased HbF rs11688888C of BCL11A and rs7776054G of HBSIL-MYB; and finally, all minor alleles were found at a frequency higher than 0.05.
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Anemia Falciforme , Hemoglobina Fetal , DNA Intergênico , Ácido Edético , Hemoglobina Fetal/genética , Hemoglobina Falciforme/genética , Heterozigoto , Homozigoto , Humanos , México , Nucleotídeos , Polimorfismo de Nucleotídeo Único , Proteínas Repressoras/genéticaRESUMO
INTRODUCTION: The hematological and clinical features vary markedly between the different genotypes of sickle cell disease. Even within the single genotype of homozygous sickle cell disease (HbSS), there is marked variability that is presumed to result from interacting genetic and environmental factors. AREAS COVERED: The classification of the different genotypes of sickle cell disease with approximate prevalence at birth in different communities and some of the major clinical and hematological differences. This assessment includes three potential genetic factors influencing hematology and clinical outcome in HbSS, the beta globin haplotype, alpha thalassemia, and persistence of fetal hemoglobin (HbF). EXPERT OPINION: The author is a clinician with experience of sickle cell disease primarily in Jamaica but also in Greece, Uganda, Saudi Arabia, and India. It is therefore necessarily an account of clinical data and does not address current debates on molecular mechanisms. Most data derive from Jamaica where efforts have been made to reduce any symptomatic bias by long-term follow-up of patients all over the Island and further reduced by a cohort study based on newborn screening, which has been in operation for over 48 years.
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Anemia Falciforme , Talassemia alfa , Anemia Falciforme/diagnóstico , Anemia Falciforme/epidemiologia , Anemia Falciforme/genética , Variação Biológica da População , Estudos de Coortes , Hemoglobina Fetal/genética , Haplótipos , Hemoglobina Falciforme/genética , Humanos , Recém-Nascido , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Globinas beta/genéticaRESUMO
Abstract Introduction: Sickle cell anemia (SCA) is a Mendelian disorder with a heterogeneous clinical course. The reasons for this phenotypic diversity are not entirely established, but it is known that high fetal hemoglobin levels lead to a milder course of the disease. Additionally, genetic variants in the intergenic region HBS1L-MYB promote high levels of fetal hemoglobin into adulthood. Objective: In the present study, we investigated the HMIP1 C-839A (rs9376092) polymorphism, located at the HBS1L-MYB intergenic region block 1, in SCA patients. Method: We analyzed 299 SCA patients followed in two reference centers in Brazil. The HMIP1 C-839A (rs9376092) genotypes were determined by allele specific polymerase chain reactions. Clinical and laboratory data were obtained from patient interviews and medical records. Results: The median fetal hemoglobin levels were higher in patients with the HMIP1 C-839A (rs9376092) AA genotype (CC = 6.4%, CA = 5.6% and AA = 8.6%), but this difference did not reach significance (p = 0.194). No association between HMIP1 C-839A (rs9376092) genotypes and other clinical and laboratorial features was detected (p > 0.05). Conclusion: In summary, our data could not support the previously related association between the HMIP1 C-893A (rs9376092) polymorphism and differential fetal hemoglobin levels.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Hemoglobina Fetal , Anemia Falciforme , Polimorfismo GenéticoRESUMO
Fetal hemoglobin (HbF) induction constitutes a valuable and validated approach to treat the symptoms of sickle cell disease (SCD). Here, we synthesized pomalidomide-nitric oxide (NO) donor derivatives (3a-f) and evaluated their suitability as novel HbF inducers. All compounds demonstrated different capacities of releasing NO, ranging 0.3-30.3%. Compound 3d was the most effective HbF inducer for CD34+ cells, exhibiting an effect similar to that of hydroxyurea. We investigated the mode of action of compound 3d for HbF induction by studying the in vitro alterations in the levels of transcription factors (BCL11A, IKAROS, and LRF), inhibition of histone deacetylase enzymes (HDAC-1 and HDAC-2), and measurement of cGMP levels. Additionally, compound 3d exhibited a potent anti-inflammatory effect similar to that of pomalidomide by reducing the TNF-α levels in human mononuclear cells treated with lipopolysaccharides up to 58.6%. Chemical hydrolysis studies revealed that compound 3d was stable at pH 7.4 up to 24 h. These results suggest that compound 3d is a novel HbF inducer prototype with the potential to treat SCD symptoms.
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Anemia Falciforme/tratamento farmacológico , Talidomida/análogos & derivados , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Relação Estrutura-Atividade , Talidomida/síntese química , Talidomida/química , Talidomida/uso terapêuticoRESUMO
INTRODUCTION: Sickle cell anemia (SCA) is a Mendelian disorder with a heterogeneous clinical course. The reasons for this phenotypic diversity are not entirely established, but it is known that high fetal hemoglobin levels lead to a milder course of the disease. Additionally, genetic variants in the intergenic region HBS1L-MYB promote high levels of fetal hemoglobin into adulthood. OBJECTIVE: In the present study, we investigated the HMIP1 C-839A (rs9376092) polymorphism, located at the HBS1L-MYB intergenic region block 1, in SCA patients. METHOD: We analyzed 299 SCA patients followed in two reference centers in Brazil. The HMIP1 C-839A (rs9376092) genotypes were determined by allele specific polymerase chain reactions. Clinical and laboratory data were obtained from patient interviews and medical records. RESULTS: The median fetal hemoglobin levels were higher in patients with the HMIP1 C-839A (rs9376092) AA genotype (CC=6.4%, CA=5.6% and AA=8.6%), but this difference did not reach significance (p=0.194). No association between HMIP1 C-839A (rs9376092) genotypes and other clinical and laboratorial features was detected (p>0.05). CONCLUSION: In summary, our data could not support the previously related association between the HMIP1 C-893A (rs9376092) polymorphism and differential fetal hemoglobin levels.
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Sickle Cell Disease (SCD) is an inherited disorder of red blood cells that is caused by a single mutation in the ß -globin gene. The disease, which afflicts millions of patients worldwide mainly in low income countries, is characterized by high morbidity, mortality and low life expectancy. The new pharmacological and non-pharmacological strategies for SCD is urgent in order to promote treatments able to reduce patient's suffering and improve their quality of life. Since the FDA approval of HU in 1998, there have been few advances in discovering new drugs; however, in the last three years voxelotor, crizanlizumab, and glutamine have been approved as new therapeutic alternatives. In addition, new promising compounds have been described to treat the main SCD symptoms. Herein, focusing on drug discovery, we discuss new strategies to treat SCD that have been carried out in the last ten years to discover new, safe, and effective treatments. Moreover, non-pharmacological approaches, including red blood cell exchange, gene therapy and hematopoietic stem cell transplantation will be presented.
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Anemia Falciforme , Transplante de Células-Tronco Hematopoéticas , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/genética , Eritrócitos , Terapia Genética , Humanos , Qualidade de VidaRESUMO
Hydroxyurea has long been used for the treatment of sickle cell anemia (SCA), and its clinical effectiveness is related to the induction of fetal hemoglobin (HbF), a major modifier of SCA phenotypes. However, there is substantial variability in response to hydroxyurea among patients with SCA. While some patients show an increase in HbF levels and an ameliorated clinical condition under low doses of hydroxyurea, other patients present a poor effect or even develop toxicity. However, the effects of genetic polymorphisms on increasing HbF levels in response to hydroxyurea in patients with SCA (Hb SS) have been less explored. Therefore, we performed a systematic review to assess whether single-nucleotide polymorphisms (SNPs) affect HbF levels in patients with SCA treated with hydroxyurea. Moreover, we performed pathway analysis using the set of genes with SNPs found to be associated with changes in HbF levels in response to hydroxyurea among the included studies. The systematic literature search was conducted on Medline/PubMed, EMBASE, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Scopus, and Web of Science. Seven cohort studies were included following our inclusion and exclusion criteria. From the 728 genetic polymorphisms examined in the included studies, 50 different SNPs of 17 genes were found to be associated with HbF changes in patients with SCA treated with hydroxyurea, which are known to affect baseline HbF but are not restricted to them. Enrichment analysis of this gene set revealed reactome pathways with the lowest adjusted p-values and highest combined scores related to VEGF ligand-receptor interactions (R-HSA-194313; R-HSA-195399) and the urea cycle (R-HSA-70635). Pharmacogenetic studies of response to hydroxyurea therapy in patients with SCA are still scarce and markedly heterogeneous regarding candidate genes and SNPs examined for association with HbF changes and outcomes, suggesting that further studies are needed. The reviewed findings highlighted that similar to baseline HbF, changes in HbF levels upon hydroxyurea therapy are likely to be regulated by multiple loci. There is evidence that SNPs in intron 2 of BCL11A affect HbF changes in response to hydroxyurea therapy, a potential application that might improve the clinical management of SCA. Systematic Review Registration: (https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=208790).
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Induction of fetal hemoglobin production with hydroxyurea is an effective strategy in sickle cell disease and beta thalassemias, but up to 20% of patients do not respond to or cannot tolerate it. Benserazide is used in the treatment of Parkinson's disease and was noticed to induce gamma globin in preclinical models. We hypothesized that chronic treatment with benserazide-containing medication may be associated with increase in HbF production and in circulating F-cells. Blood samples were collected from 50 subjects including 35 patients on benserazide for Parkinson's disease, 10 healthy controls, and 5 patients with sickle cell anemia as positive controls for high fetal hemoglobin. We found a strong correlation between HbF and circulating F-cells in the entire population, but we found no significant increase in HbF and F-cell percentage in patients taking benserazide up to 700 mg daily. No hematologic abnormalities attributable to benserazide use after up to 22 years were detected. Our data support long-term safety and tolerability of benserazide at doses ten times higher than used in preclinical models to induce fetal hemoglobin. Further clinical trials enrolling patients with sickle cell disease and thalassemia are warranted to provide insight into its efficacy to treat those populations.
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Antiparkinsonianos/farmacologia , Benserazida/farmacologia , Hemoglobina Fetal/análise , Doença de Parkinson/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Falciforme/sangue , Anemia Falciforme/tratamento farmacológico , Antiparkinsonianos/uso terapêutico , Antidrepanocíticos/farmacologia , Antidrepanocíticos/uso terapêutico , Benserazida/uso terapêutico , Estudos Transversais , Feminino , Humanos , Hidroxiureia/farmacologia , Hidroxiureia/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/sangue , Adulto JovemRESUMO
Resveratrol (RVT) derivatives (10a-i) were designed, synthesized, and evaluated for their potential as gamma-globin inducers in treating Sickle Cell Disease (SCD) symptoms. All compounds were able to release NO at different levels ranging from 0 to 26.3%, while RVT did not demonstrate this effect. In vivo, the antinociceptive effect was characterized using an acetic acid-induced abdominal contortion model. All compounds exhibited different levels of protection, ranging from 5.9 to 37.3%; the compound 10a was the most potent among the series. At concentrations between 3.13 and 12.5 µM, the derivative 10a resulted in a reduction of 41.1-64.3% in the TNF-α levels in the supernatants of macrophages that were previously LPS-stimulated. This inhibitory effect was higher than that of RVT used as the control. In addition, the compound 10a and RVT induced double the production of the gamma-globin chains (γG + γA), compared to the vehicle, using CD34+ cells. Compound 10a also did not induce membrane perturbation and it was not mutagenic in the in vivo assay. Thus, compound 10a emerged as a new prototype of the gamma-globin-inducer group with additional analgesic and anti-inflammatory activities and proving to be a useful alternative to treat SCD symptoms.
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Analgésicos/síntese química , Resveratrol/análogos & derivados , Analgésicos/uso terapêutico , Animais , Células Cultivadas , Constrição Patológica/induzido quimicamente , Constrição Patológica/tratamento farmacológico , Modelos Animais de Doenças , Humanos , Interleucina-1beta/metabolismo , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Masculino , Camundongos , Óxido Nítrico/metabolismo , Resveratrol/farmacologia , Resveratrol/uso terapêutico , Relação Estrutura-Atividade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Fetal hemoglobin (HbF) ameliorates clinical severity of sickle cell anemia (SCA). The major loci regulating HbF levels are HBB cluster, BCL11A, and HMIP-2 (HBS1L-MYB). However, the impact of noncoding single-nucleotide polymorphisms (SNPs) in these loci on clinical outcomes and their functional role on regulating HbF levels should be better elucidated. Therefore, we performed comprehensive association analyses of 14 noncoding SNPs in five loci with HbF levels and with clinical outcomes in a cohort of 250 children with SCA from Southeastern Brazil, and further performed functional annotation of these SNPs. We found SNPs independently associated with HbF levels: rs4671393 in BCL11A (ß-coefficient = 0.28), rs9399137 in HMIP-2A (ß-coefficient = 0.16), and rs4895441 in HMIP-2B (ß-coefficient = 0.15). Patients carrying minor (HbF-boosting) alleles for rs1427407, rs93979137, rs4895441, rs9402686, and rs9494145 showed reduced count of reticulocytes (p < 0.01), while those carrying the T allele of rs9494145 showed lower white blood cell count (p = 0.002). Carriers of the minor allele for rs9402686 showed higher peripheral saturation of oxygen (p = 0.002). Patients carrying minor alleles in BCL11A showed lower risk of transfusion incidence rate ratio (IRR ≥ 1.3; p < 0.0001). This effect was independent of HbF effect (p = 0.005). Carriers of minor alleles for rs9399137 and rs9402686 showed lower risk of acute chest syndrome (IRR > 1.3; p ≤ 0.01). Carriers of the reference allele for rs4671393 showed lower risk of infections (IRR = 1.16; p = 0.01). In conclusion, patients carrying HbF-boosting alleles of BCL11A and HMIP-2 were associated with milder clinical phenotypes. Higher HbF concentration may underlie this effect.
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Anemia Falciforme/diagnóstico , Anemia Falciforme/genética , Hemoglobina Fetal/metabolismo , Proteínas de Ligação ao GTP/genética , Genes myb , Polimorfismo de Nucleotídeo Único , Proteínas Repressoras/genética , Alelos , Anemia Falciforme/sangue , Anemia Falciforme/epidemiologia , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Feminino , Hemoglobina Fetal/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Lactente , Recém-Nascido , Masculino , Prognóstico , Estudos RetrospectivosRESUMO
IMPACT STATEMENT: Sickle cell disease (SCD) is one of the most common inherited diseases and is associated with a reduced life expectancy and acute and chronic complications, including frequent painful vaso-occlusive episodes that often require hospitalization. At present, treatment of SCD is limited to hematopoietic stem cell transplant, transfusion, and limited options for pharmacotherapy, based principally on hydroxyurea therapy. This review highlights the importance of intracellular cGMP-dependent signaling pathways in SCD pathophysiology; modulation of these pathways with soluble guanylate cyclase (sGC) stimulators or phosphodiesterase (PDE) inhibitors could potentially provide vasorelaxation and anti-inflammatory effects, as well as elevate levels of anti-sickling fetal hemoglobin.
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Anemia Falciforme/tratamento farmacológico , GMP Cíclico/metabolismo , Anemia Falciforme/fisiopatologia , Hemoglobina Fetal/metabolismo , Hemoglobina Falciforme/química , Humanos , Hidroxiureia/química , Hidroxiureia/uso terapêutico , Modelos Biológicos , Óxido Nítrico/metabolismo , Estresse Oxidativo , Inibidores de Fosfodiesterase/uso terapêutico , Transdução de SinaisRESUMO
La anemia de células falciformes es una enfermedad genética frecuente en la que la herencia de dos genes mutantes de la hemoglobina, uno de cada progenitor, produce un trastorno de la hemoglobina. Es una enfermedad crónica con exacerbaciones agudas que causan efectos a largo plazo en la educación, la vida familiar, la integración social y la calidad de vida del paciente. La clínica se resume en vaso oclusión e isquemia tisular, anemia hemolítica y la susceptibilidad a infecciones. Se presenta el caso de un hombre de raza negra, de 28 años cursando con crisis dolorosa vaso-oclusiva, trastorno hemolítico y síndrome anémico de volúmenes normales.
Sickle cell anemia is a common genetic disease in which the inheritance of two mutant hemoglobin genes, one from each parent produces a hemoglobinopathy. It is a chronic disease with acute exacerbations that cause long-term effects on education, family life, social integration and the patient's quality of life. The clinic is summarized in vaso-occlusion and tissue ischemia, hemolytic anemia and susceptibility to infections. We present the case of a 28 years old black male, suffering from a vaso-occlusive crisis, hemolytic disorder and normocytic anemic syndrome.
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RESUMO: Objetivo: Descrever a prevalência das hemoglobinopatias da população adulta brasileira, segundo exames laboratoriais da Pesquisa Nacional de Saúde. Métodos: Estudo descritivo realizado com os dados laboratoriais da Pesquisa Nacional de Saúde coletados entre os anos de 2014 e 2015. A pesquisa de hemoglobinopatias foi feita pelo método da cromatografia líquida de alto desempenho. Os resultados dos exames individuais foram interpretados fornecendo os parâmetros normais, homozigotos ou heterozigotos para hemoglobina S, C e D, além de outras eventuais hemoglobinopatias. Foram estimadas prevalências das hemoglobinopatias segundo sexo, cor da pele, região, idade e escolaridade. Resultados: Houve presença de hemoglobinopatias em 3,7% da população. As principais foram o traço falciforme (2,49%), a talassemia menor (0,30%) e a suspeita de talassemia maior (0,80%). Em relação ao traço falciforme e à suspeita de talassemia maior, houve diferença estatisticamente significativa para a variável cor da pele (p < 0,05). As prevalências encontradas para traço falciforme segundo cor de pele foram: preta (4,1%), parda (3,6%), branca (1,2%) e outras (1,7%). Conclusão: As hemoglobinopatias mais prevalentes foram o traço falciforme e a talassemia menor, predominando entre pretos e pardos. O estudo ajuda na identificação das hemoglobinopatias e no aconselhamento genético na preconcepção.
ABSTRACT: Objective: To describe the prevalence of hemoglobinopathies in the Brazilian adult population, according to laboratory tests from the National Health Survey. Methods: A descriptive study was carried out with National Health Survey laboratory data collected between 2014 and 2015. The hemoglobinopathies test was performed using the High Performance Liquid Chromatography method. The results of the individual tests were interpreted as providing normal, homozygous or heterozygous results for S, C and D hemoglobin, in addition to other possible hemoglobinopathies. Prevalence of hemoglobinopathies according to gender, skin color, region, age and schooling was estimated. Results: Hemoglobinopathies were present in 3.7% of the population. The main ones were the sickle cell trait (2.49%), thalassemia minor (0.30%) and suspected thalassemia major (0.80%). In relation to the sickle cell trait and suspected thalassemia major, there was a statistically significant difference for the skin color variable (p<0.05). The prevalences found for sickle cell trait according to skin color was: 4.1% among dark-skinned blacks, 3.6% among light-skinned blacks, 1.2% among whites, and 1.7% among others. Conclusion: The most prevalent hemoglobinopathies were the sickle cell trait and minor thalassemia, and were predominate among light- and dark-skinned black people. The study helps in identifying hemoglobinopathies and in genetic counseling in pre-conception.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Adulto Jovem , Traço Falciforme/epidemiologia , Inquéritos Epidemiológicos/métodos , Talassemia beta/epidemiologia , Fatores Socioeconômicos , Brasil/epidemiologia , Prevalência , Estudos Transversais , Inquéritos Epidemiológicos/estatística & dados numéricos , Cromatografia Líquida de Alta Pressão , Distribuição por Sexo , Distribuição por Idade , Pessoa de Meia-IdadeRESUMO
N-oxide derivatives 5(a-b), 8(a-b), and 11(a-c) were designed, synthesized and evaluated in vitro and in vivo as potential drugs that are able to ameliorate sickle cell disease (SCD) symptoms. All of the compounds demonstrated the capacity to releasing nitric oxide at different levels ranging from 0.8 to 30.1%, in vivo analgesic activity and ability to reduce TNF-α levels in the supernatants of monocyte cultures. The most active compound (8b) protected 50.1% against acetic acid-induced abdominal constrictions, while dipyrone, which was used as a control only protected 35%. Compounds 8a and 8b inhibited ADP-induced platelet aggregation by 84% and 76.1%, respectively. Both compounds increased γ-globin in K562â¯cells at 100⯵M. The mechanisms involved in the γ-globin increase are related to the acetylation of histones H3 and H4 that is induced by these compounds. In vitro, the most promising compound (8b) was not cytotoxic, mutagenic and genotoxic.
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Anemia Falciforme/tratamento farmacológico , Descoberta de Drogas , Histonas/metabolismo , Oxidiazóis/farmacologia , gama-Globinas/biossíntese , Ácido Acético/antagonistas & inibidores , Ácido Acético/farmacologia , Acetilação , Anemia Falciforme/metabolismo , Relação Dose-Resposta a Droga , Humanos , Células K562 , Estrutura Molecular , Óxido Nítrico/metabolismo , Oxidiazóis/síntese química , Oxidiazóis/química , Relação Estrutura-AtividadeRESUMO
ABSTRACT Introduction: Patients with sickle-cell disease (SCD) present chronic hemolysis with increased serum biomarkers. Genetic polymorphisms of the BLC11A gene modulate fetal hemoglobin (HbF), thus reducing hemolysis Objective: To associate the polymorphisms of BCL11A gene with the hemolysis markers: reticulocyte, bilirubin, uric acid, lactate dehydrogenase (LDH), and methemoglobin (MetHb) in SCD patients. Methods: The study included 45 patients with SCD of both sexes using hydroxyurea (HU), treated at a Hospital in Fortaleza, Ceará, Brazil, along with 80 healthy individuals as the control group. MetHb, uric acid, and bilirubin measurements were carried out with the spectrophotometric method, and LDH with a kinetic method, a reticulocyte count by a manual method; and evaluation of BCL11A polymorphisms, in real time polymerase chain reaction (PCR). Data were analyzed using the statistical software GraphPad Prism. The level of significance was set at < 5%. Results: In region rs7557939 of the BCL11A gene genotype, A/G showed a significant increase of MetHb (p = 0.0297), and the A/A genotype showed high concentration of LDH (p = 0.0316) in the same region. The use of HU at doses ≥ 10 mg/kg/day showed a decrease of LDH (p = 0.02), and treatment for > 50 months was linked to the reticulocyte count (p = 0.0155). Conclusion: Polymorphisms in the rs7557939 region of the BCL11A gene appear to somehow interfere in the clinical setting of patients with SCD, suggesting relation with the concentration of MetHb and LDH. This study pioneered an investigation into the association of hemolysis biomarkers with BCL11A gene polymorphisms in SCD.
RESUMO Introdução: Pacientes com anemia falciforme (AF) apresentam hemólise crônica com biomarcadores séricos aumentados. Os polimorfismos genéticos do gene BLC11A modulam a hemoglobina fetal (HbF), reduzindo, assim, a hemólise. Objetivo: Associar os polimorfismos do gene BCL11A aos marcadores de hemólise: reticulócitos, bilirrubina, ácido úrico, lactato desidrogenase (LDH) e meta-hemoglobina (MetHb) em pacientes com AF. Métodos: O estudo incluiu 45 pacientes com AF que utilizavam hidroxiureia (HU), tratados em um hospital de Fortaleza, Ceará, Brasil, e 80 indivíduos saudáveis como grupo-controle. A dosagem de MetHb, ácido úrico e bilirrubina foi realizada por método espectrofotométrico; LDH, pelo método cinético; contagem de reticulócitos, pelo método manual; e avaliação de polimorfismos BCL11A, por reação em cadeia da polimerase (PCR) em tempo real. Os dados foram analisados usando o software estatístico GraphPad Prism. O nível de significância foi < 5%. Resultados: Na região rs7557939 do gene BCL11A, o genótipo A/G mostrou aumento significativo de MetHb (p = 0,0297), e o genótipo A/A esteve relacionado com a alta concentração de LDH (p = 0,0316). Pacientes em uso de HU em doses ≥ 10 mg/kg/dia apresentaram diminuição de LDH (p = 0,02), e o tratamento por mais de 50 meses foi relacionado com a contagem de reticulócitos (p = 0,0155). Conclusão: Polimorfismos na região rs7557939 do gene BCL11A parecem interferir de alguma forma nas manifestações clínicas de pacientes com AF, o que sugere uma relação com a concentração de MetHb e LDH. Este estudo foi pioneiro na investigação da associação de biomarcadores de hemólise com polimorfismos do gene BCL11A na AF.
RESUMO
The gene for hereditary persistence of fetal hemoglobin (HPFH) in the Caribbean is much more common than previously estimated. To avoid labeling persons with the benign syndrome Hb S (HBB: c.20A>T)/HPFH as a disease and wasting scarce resources, parental studies are recommended when newborn screening reveals a pattern consistent with an SS phenotype.