Sickling Cells, Cyclic Nucleotides, and Protein Kinases: The Pathophysiology of Urogenital Disorders in Sickle Cell Anemia

Sickle cell anemia is one of the best studied inherited diseases, and despite being caused by a single point mutation in the HBB gene, multiple pleiotropic effects of the abnormal hemoglobin S production range from vaso-occlusive crisis, stroke, and pulmonary hypertension to osteonecrosis and leg ulcers. Urogenital function is not spared, and although priapism is most frequently remembered, other related clinical manifestations have been described, such as nocturia, enuresis, increased frequence of lower urinary tract infections, urinary incontinence, hypogonadism, and testicular infarction. Studies on sickle cell vaso-occlusion and priapism using both in vitro and in vivo models have shed light on the pathogenesis of some of these events. The authors review what is known about the deleterious effects of sickling on the genitourinary tract and how the role of cyclic nucleotides signaling and protein kinases may help understand the pathophysiology underlying these manifestations and develop novel therapies in the setting of urogenital disorders in sickle cell disease

[beta Thalassemia Major And Pregnancy During Adolescence: Report Of Two Cases].

Beta thalassemia major is a rare hereditary blood disease in which impaired synthesis of beta globin chains causes severe anemia. Medical treatment consists of chronic blood transfusions and iron chelation. We describe two cases of adolescents with beta thalassemia major with unplanned pregnancies and late onset of prenatal care. One had worsening of anemia with increased transfusional requirement, fetal growth restriction, and placental senescence. The other was also diagnosed with hypothyroidism and low maternal weight, and was admitted twice during pregnancy due to dengue shock syndrome and influenza H1N1-associated respiratory infection. She also developed fetal growth restriction and underwent vaginal delivery at term complicated by uterine hypotonia. Both patients required blood transfusions after birth and chose medroxyprogesterone as a contraceptive method afterwards. This report highlights the importance of medical advice on contraceptive methods for these women and the role of a specialized prenatal follow-up in association with a hematologist.37291-29

Urinary bladder dysfunction in transgenic sickle cell disease mice

FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOBackground Urological complications associated with sickle cell disease (SCD), include nocturia, enuresis, urinary infections and urinary incontinence. However, scientific evidence to ascertain the underlying cause of the lower urinary tract symptoms in SCD is lacking. Objective Thus, the aim of this study was to evaluate urinary function, in vivo and ex vivo, in the Berkeley SCD murine model (SS). Methods Urine output was measured in metabolic cage for both wild type and SS mice (25-30 g). Bladder strips and urethra rings were dissected free and mounted in organ baths. In isolated detrusor smooth muscle (DSM), relaxant response to mirabegron and isoproterenol (1 nM-10 mu M) and contractile response to (carbachol (CCh; 1 nM-100 mu M), KCl (1 mM-300mM), CaCl2 (1 mu M-100mM), alpha,beta-methylene ATP (1, 3 and 10 mu M) and electrical field stimulation (EFS; 1-32 Hz) were measured. Phenylephrine (Phe; 10nM-100 mu M) was used to evaluate the contraction mechanism in the urethra rings. Cystometry and histomorphometry were also performed in the urinary bladder. Results SS mice present a reduced urine output and incapacity to produce typical bladder contractions and bladder emptying (ex vivo), compared to control animals. In DSM, relaxation in response to a selective beta 3-adrenergic agonist (mirabegron) and to a non-selective beta-adrenergic (isoproterenol) agonist were lower in SS mice. Additionally, carbachol, alpha,beta-methylene ATP, KCl, extracellular Ca2+ and electrical-field stimulation promoted smaller bladder contractions in SS group. Urethra contraction induced by phenylephrine was markedly reduced in SS mice. Histological analyses of SS mice bladder revealed severe structural abnormalities, such as reductions in detrusor thickness and bladder volume, and cell infiltration. Conclusions Taken together, our data demonstrate, for the first time, that SS mice display features of urinary bladder dysfunction, leading to impairment in urinary continence, which may have an important role in the pathogenesis of the enuresis and infections observed the SCD patients.Urological complications associated with sickle cell disease (SCD), include nocturia, enuresis, urinary infections and urinary incontinence. However, scientific evidence to ascertain the underlying cause of the lower urinary tract symptoms in SCD is lacking. Objective Thus, the aim of this study was to evaluate urinary function, in vivo and ex vivo, in the Berkeley SCD murine model (SS). Methods Urine output was measured in metabolic cage for both wild type and SS mice (25-30 g). Bladder strips and urethra rings were dissected free and mounted in organ baths. In isolated detrusor smooth muscle (DSM), relaxant response to mirabegron and isoproterenol (1 nM-10 mu M) and contractile response to (carbachol (CCh; 1 nM-100 mu M), KCl (1 mM-300mM), CaCl2 (1 mu M-100mM), alpha,beta-methylene ATP (1, 3 and 10 mu M) and electrical field stimulation (EFS; 1-32 Hz) were measured. Phenylephrine (Phe; 10nM-100 mu M) was used to evaluate the contraction mechanism in the urethra rings. Cystometry and histomorphometry were also performed in the urinary bladder. Results SS mice present a reduced urine output and incapacity to produce typical bladder contractions and bladder emptying (ex vivo), compared to control animals. In DSM, relaxation in response to a selective beta 3-adrenergic agonist (mirabegron) and to a non-selective beta-adrenergic (isoproterenol) agonist were lower in SS mice. Additionally, carbachol, alpha,beta-methylene ATP, KCl, extracellular Ca2+ and electrical-field stimulation promoted smaller bladder contractions in SS group. Urethra contraction induced by phenylephrine was markedly reduced in SS mice. Histological analyses of SS mice bladder revealed severe structural abnormalities, such as reductions in detrusor thickness and bladder volume, and cell infiltration. Conclusions Taken together, our data demonstrate, for the first time, that SS mice display features of urinary bladder dysfunction, leading to impairment in urinary continence, which may have an important role in the pathogenesis of the enuresis and infections observed the SCD patients108115FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOCNPQ – CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICOFAPESP [2008/57441-0]CNPq [481761/2008-0]sem informaçãosem informaçã

Association Of Nitric Oxide Synthase And Matrix Metalloprotease Single Nucleotide Polymorphisms With Preeclampsia And Its Complications.

Preeclampsia is one of the leading causes of maternal and neonatal morbidity and mortality in the world, but its appearance is still unpredictable and its pathophysiology has not been entirely elucidated. Genetic studies have associated single nucleotide polymorphisms in genes encoding nitric oxide synthase and matrix metalloproteases with preeclampsia, but the results are largely inconclusive across different populations. To investigate the association of single nucleotide polymorphisms (SNPs) in NOS3 (G894T, T-786C, and a variable number of tandem repetitions VNTR in intron 4), MMP2 (C-1306T), and MMP9 (C-1562T) genes with preeclampsia in patients from Southeastern Brazil. This prospective case-control study enrolled 77 women with preeclampsia and 266 control pregnant women. Clinical data were collected to assess risk factors and the presence of severe complications, such as eclampsia and HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome. We found a significant association between the single nucleotide polymorphism NOS3 T-786C and preeclampsia, independently from age, height, weight, or the other SNPs studied, and no association was found with the other polymorphisms. Age and history of preeclampsia were also identified as risk factors. The presence of at least one polymorphic allele for NOS3 T-786C was also associated with the occurrence of eclampsia or HELLP syndrome among preeclamptic women. Our data support that the NOS3 T-786C SNP is associated with preeclampsia and the severity of its complications.10e013669

Hb H disease resulting from the association of an α0-thalassemia allele [-(α)20.5] with an unstable α-globin variant [Hb Icaria]: First report on the occurrence in Brazil

Hb H Disease is caused by the loss or inactivation of three of the four functional α-globin genes. Patients present chronic hemolytic anemia and splenomegaly. In some cases, occasional blood transfusions are required. Deletions are the main cause of this type of thalassemia ( α-thalassemia). We describe here an unusual case of Hb H disease caused by the combination of a common α0 deletion [-( α) 20.5 ] with a rare point mutation (c.427T > A), thus resulting in an elongated and unstable α-globin variant, Hb Icaria, (X142K), with 31 additional amino-acid residues. Very high levels of Hb H and Hb Bart's were detected in the patient's red blood cells (14.7 and 19.0%, respectively). This is the first description of this infrequent association in the Brazilian population

Pregnancy in sickle cell disease – do we know what to expect?

sem informação365313314sem informaçã

Pregnancy in sickle cell disease – do we know what to expect?

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Aspects of iron metabolism regulation in hemoglobinopathies

Orientador: Fernando Ferreira CostaTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências MédicasResumo: As hemoglobinopatias são distúrbios hereditários em que uma mutação genética leva a alteração da produção normal de hemoglobina, tal como na anemia falciforme e nas talassemias ß. Na maioria dessas doenças, ocorre anemia com necessidade transfusional variável, o que pode acarretar sobrecarga corporal de ferro. Na talassemia ß intermediária, ocorre aumento espontâneo e desproporcional da absorção do ferro, com consequente excesso desse metal mesmo na ausência de transfusões. Com a evolução da terapia transfusional e o aumento da expectativa de vida desses pacientes, o conhecimento sobre a regulação do metabolismo do ferro tornou-se fundamental para melhor controle da sobrecarga de ferro. O principal regulador desse metabolismo é a hepcidina, um polipeptídeo produzido majoritariamente pelo fígado, porém também sintetizado por células do sistema fagocítico-mononuclear, em que seu papel é pouco conhecido. Uma citocina capaz de suprimir a produção de hepcidina é o GDF-15 (fator de crescimento e diferenciação 15). Neste estudo, com a avaliação de amostras de sangue de 103 pacientes com anemia falciforme, talassemia ß intermediária, anemia por deficiência de cobalamina ou outros tipos de anemia, constatou-se que o aumento dos níveis desse fator ocorre tanto em quadros de hemólise crônica quanto na presença de eritropoese ineficaz, constituindo um sinal da medula óssea modulador da absorção de ferro nos estados de aumento da eritropoese. Entretanto, evidenciou-se que a associação de supressão da hepcidina com altos níveis de GDF-15 ocorre nas hemoglobinopatias, mas não nas demais causas de anemia. Na anemia megaloblástica, a ausência de sobrecarga de ferro com níveis normais de hepcidina ao diagnóstico e sua queda durante o tratamento sugerem regulação da hepcidina independente de GDF-15 neste tipo de anemia. A análise da razão hepcidina/ferritina mostrou-se mais fidedigna que os níveis de hepcidina circulante na identificação dos estados em que há propensão a absorção aumentada de ferro por alta atividade eritropoética, e sugerem que o estado inflamatório crônico da anemia falciforme poderia exercer um fator protetor contra sobrecarga de ferro, quando comparados a talassemia intermediária, pela elevação relativa da produção de hepcidina. Além disso, observou-se uma correlação negativa entre a expressão gênica de hepcidina (gene HAMP) em monócitos humanos e os níveis de GDF-15, denotando um provável efeito regulatório semelhante ao descrito em hepatócitos. Não se identificou correlação entre essa expressão nos monócitos e marcadores de sobrecarga de ferro, corroborando a hipótese de a hepcidina ter outra função nessas células, não relacionada diretamente à absorção de ferro. Pacientes com anemia falciforme em uso de hidroxiureia apresentaram maiores níveis de expressão de hepcidina monocítica e obteve-se evidência in vitro de uma ação estimuladora dessa expressão por esse fármaco, caracterizando a hidroxiureia com potencial atividade agonista de hepcidina, de futuro interesse em estudos de sua aplicação clínica nos estados em que exista deficiência monocítica dessa proteína. Trata-se do primeiro estudo avaliando comparativamente hemoglobinopatias e outros tipos de anemia com e sem componente eritropoético ineficaz do ponto de vista dos reguladores da absorção de ferro, além de caracterizar, pela primeira vez, a expressão de hepcidina extra-hepática nos distúrbios da síntese de hemoglobinaAbstract: Hemoglobinopathies are inherited diseases in which a genetic mutation leads to abnormal production of hemoglobin, such as in sickle cell anemia or in the ß-thalassemias. In the majority of these disorders, anemia causes variable degrees of transfusion dependency, which may lead to iron overload. In ß-thalassemia intermedia, an increase in iron absorption occurs spontaneously and regardless from the total body iron stores, generating iron overload even in the absence of repeated transfusions. Owing to advances in transfusion medicine and to the improvement in the overall life expectancy of patients with hemoglobin disorders, further knowledge on the regulation of iron metabolism has become increasingly important for appropriate management of iron overload. The main regulator of iron metabolism is hepcidin, a polypeptide mainly produced by the liver, although its synthesis also occurs in phagocytic-mononuclear cells, in which its role is less known. Growth differentiation factor 15 (GDF-15) is a cytokine capable of downregulating hepcidin production. This study analyzed 103 blood samples from patients with sickle cell anemia, ß-thalassemia intermedia, cobalamin deficiency anemia and other types of anemia, showing elevation of GDF-15 plasmatic levels both in chronic hemolytic states and ineffective erythropoiesis, thus characterizing it as a signalling molecule produced by the bone marrow to stimulate iron absorption in the presence of increased erythropoietic activity. Nevertheless, hepcidin suppression was only associated with high levels of GDF- 15 in the hemoglobinopathies. In megaloblastic anemia, absence of iron overload with normal hepcidin levels, associated with their reduction during treatment, suggest that hepcidin regulation occurs independently from GDF-15 in thie type of anemia. Analysis of hepcidin/ferritin ratio proved to be more reliable to identify patients prone to increased iron absorption due to erythropoietic hyperactivity than hepcidin levels themselves and suggests that the chronic inflammatory state in sickle cell anemia may protect from iron overload by relatively increasing hepcidin levels in comparison to levels found in thalassemia intermedia. Moreover, we found a negative correlation between GDF-15 levels and HAMP monocytic expression, a regulatory mechanism similar to what has been observed in hepatic cell lines. In further analyses of the present study, no correlation between hepcidin expression and iron overload markers was observed in monocytes from patients with hemoglobinopathies, corroborating the hypothesis that the monocytic counterpart of hepcidin could have a different function, unrelated to iron regulation. Patients with sickle cell anemia under hydroxyurea treatment have been shown to present with higher levels of hepcidin expression in monocytes, and a cell culture model managed to demonstrate the upregulating effect of hydroxyurea in vitro, thus highlighting the possibility of exploring this drug in the future as a potential hepcidin agonist and, therefore, as a therapeutic intervention in diseases with impaired monocytic hepcidin production. This is the first study of molecules involved in iron metabolism regulation comparing hemoglobinopathies and other anemia types with and without ineffective erythropoiesis. Furthermore, this is the first characterization of extra-hepatic hepcidin expression in hemoglobin disordersDoutoradoBiologia Estrutural, Celular, Molecular e do DesenvolvimentoDoutor em Fisiopatologia Medic

Myocardial iron overload in sickle cell disease : a rare but potentially fatal complication of transfusion

Sickle cell disease (SCD) is a frequent indication for chronic transfusion, which can cause iron overload. Excess iron often affects the liver, but not the heart in SCD. Magnetic resonance (MR) is recommended to detect myocardial iron overload (MIO) but its elevated cost requires optimized indication. We aimed to compile all published data on MIO in SCD upon the description of a fatal case of severe MIO in our institution, and to determine associated risk factors. We performed a systematic review using the PRISMA guidelines in two databases (PubMed and Web of Science). Inclusion criteria were publication in English, patients diagnosed with SCD, and reporting ferritin and MIO by MR. Twenty publications reported on 865 SCD adult and pediatric patients, with at least 10 other cases of MIO. The prevalence of MIO in chronically transfused SCD patients can be estimated to be 3% or less, and is associated with high transfusion burden, top-up transfusions, and low adherence to iron chelation. Cardiac siderosis in SCD is rarely reported, and increased awareness with better use of the available screening tools are necessary. Prospective studies should define the recommended chelation regimens depending on the severity of MIO333170175COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPES2014/00984-3; 4570/201

Iron overload disorders

Abstract Iron overload disorders represent a variety of conditions that lead to increased total body iron stores and resultant end‐organ damage. An elevated ferritin and transferrin‐iron saturation can be commonly encountered in the evaluation of elevated liver enzymes. Confirmatory homeostatic iron regulator (HFE) genetic testing for C282Y and H63D, mutations most encountered in hereditary hemochromatosis, should be pursued in evaluation of hyperferritinemia. Magnetic resonance imaging with quantitative assessment of iron content or liver biopsy (especially if liver disease is a cause of iron overload) should be used as appropriate. A secondary cause for iron overload should be considered if HFE genetic testing is negative for the C282Y homozygous or C282Y/H63D compound heterozygous mutations. Differential diagnosis of secondary iron overload includes hematologic disorders, iatrogenic causes, or chronic liver diseases. More common hematologic disorders include thalassemia syndromes, myelodysplastic syndrome, myelofibrosis, sideroblastic anemias, sickle cell disease, or pyruvate kinase deficiency. If iron overload has been excluded, evaluation for causes of hyperferritinemia should be pursued. Causes of hyperferritinemia include chronic liver disease, malignancy, infections, kidney failure, and rheumatic conditions, such as adult‐onset Still's disease or hemophagocytic lymphohistiocytosis. In this review, we describe the diagnostic testing of patients with suspected hereditary hemochromatosis, the evaluation of patients with elevated serum ferritin levels, and signs of secondary overload and treatment options for those with secondary iron overload