RESUMO
Sickle cell disease (SCD) is characterized by increased hemolysis, which results in plasma heme overload and ultimately cardiovascular complications. Here, we hypothesized that increased heme in SCD causes upregulation of heme oxygenase 1 (Hmox1), which consequently drives cardiomyopathy through ferroptosis, an iron-dependent non-apoptotic form of cell death. First, we demonstrated that the Townes SCD mice had higher levels of hemopexin-free heme in the serum and increased cardiomyopathy, which was corrected by hemopexin supplementation. Cardiomyopathy in SCD mice was associated with upregulation of cardiac Hmox1, and inhibition or induction of Hmox1 improved or worsened cardiac damage, respectively. Because free iron, a product of heme degradation through Hmox1, has been implicated in toxicities including ferroptosis, we evaluated the downstream effects of elevated heme in SCD. Consistent with Hmox1 upregulation and iron overload, levels of lipid peroxidation and ferroptotic markers increased in SCD mice, which were corrected by hemopexin administration. Moreover, ferroptosis inhibitors decreased cardiomyopathy, whereas a ferroptosis inducer erastin exacerbated cardiac damage in SCD and induced cardiac ferroptosis in nonsickling mice. Finally, inhibition or induction of Hmox1 decreased or increased cardiac ferroptosis in SCD mice, respectively. Together, our results identify ferroptosis as a key mechanism of cardiomyopathy in SCD.
Assuntos
Anemia Falciforme/complicações , Cardiomiopatias/etiologia , Ferroptose , Heme Oxigenase-1/metabolismo , Heme/metabolismo , Proteínas de Membrana/metabolismo , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Animais , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Feminino , Masculino , Camundongos , Camundongos Transgênicos , Miocárdio/metabolismo , Miocárdio/patologiaRESUMO
Silent cerebral infarcts and arteriopathy are common and progressive in individuals with sickle cell anemia. However, most data describing brain lesions in sickle cell anemia are cross-sectional or derive from pediatric cohorts with short follow-up. We investigated the progression of silent cerebral infarct and cerebral vessel stenosis on brain MRI and MRA, respectively, by describing the incidence of new or worsening lesions over a period of up to 25 years among young adults with sickle cell anemia and explored risk factors for progression. Forty-four adults with sickle cell anemia (HbSS or HbSß0thalassemia), exposed to chronic transfusions (n = 12) or hydroxyurea (n = 32), median age 19.2 years (range 18.0-31.5), received a screening brain MRI/MRA and their results were compared with a clinical exam performed during childhood and adolescence. We used exact log-rank test to compare MRI and MRA progression among any two groups. The hazard ratio (HR) and 95% confidence interval (CI) were calculated from Cox regression analyses. Progression of MRI and MRA occurred in 12 (27%) and 4 (9%) young adults, respectively, relative to their pediatric exams. MRI progression risk was high among participants with abnormal pediatric exams (HR: 11.6, 95% CI: 2.5-54.7) and conditional or abnormal transcranial Doppler ultrasound velocities (HR: 3.9, 95% CI: 1.0-15.1). Among individuals treated with hydroxyurea, high fetal hemoglobin measured in childhood was associated with lower hazard of MRI progression (HR: 0.86, 95% CI: 0.76-0.98). MRA progression occurred more frequently among those with prior stroke (HR: 8.6, 95% CI: 1.2-64), abnormal pediatric exam (P = 0.00084), and elevated transcranial Doppler ultrasound velocities (P = 0.004). Brain MRI/MRA imaging in pediatrics can identify high-risk patients for CNS disease progression in young adulthood, prompting consideration for early aggressive treatments.
Assuntos
Anemia Falciforme/patologia , Encéfalo/irrigação sanguínea , Doenças do Sistema Nervoso Central/patologia , Infarto Cerebral/patologia , Acidente Vascular Cerebral/patologia , Adolescente , Adulto , Anemia Falciforme/tratamento farmacológico , Antidrepanocíticos/uso terapêutico , Transfusão de Sangue Autóloga , Encéfalo/patologia , Progressão da Doença , Transfusão de Eritrócitos , Feminino , Humanos , Hidroxiureia/uso terapêutico , Angiografia por Ressonância Magnética , Masculino , Fatores de Risco , Ultrassonografia Doppler Transcraniana , Adulto JovemRESUMO
BACKGROUND: Sickle cell disease (SCD), the most common monogenic disorder, affects more than 300 000 births annually, with 44 000 in India. Although the clinical phenotype of SCD is considered to be milder in aboriginal populations in India, there is a paucity of data on outcomes. To determine the severity of SCD in this population, we studied mortality rates and causes of mortality in a longitudinal cohort of patients with SCD in a remote aboriginal community in India receiving community-based comprehensive care. PROCEDURES: Causes of death were analyzed in this cohort from January 2008 to December 2018. Details were collected from hospital records and in case of deaths at home by utilizing the WHO verbal autopsy questionnaire. RESULTS: The cohort consisted of 157 patients belonging to the Paniya, Betta Kurumba, Kattunyakan, and Mullu Kurumba tribes. During the study period, there were 22 deaths, all from the Paniya tribe. Twelve deaths (54.5%) occurred in the hospital and the remaining at home (45.5%), reflecting a crude mortality rate of 140 per 1000 population. Twenty-five percent of deaths occurred in the 6-18 age group. There were no deaths in the 0-5 age group. The median age of death was 25 years, which was 30 years less than in the non-SCD aboriginal population. The leading causes of death were acute chest syndrome, anemia, and sepsis among the SCD patients and stroke and suicides in the non-SCD aboriginal population. CONCLUSION: SCD is a severe disease among the Gudalur Valley's aboriginal population with a significant risk of premature mortality.
Assuntos
Anemia Falciforme/mortalidade , Havaiano Nativo ou Outro Ilhéu do Pacífico/estatística & dados numéricos , Adolescente , Adulto , Anemia Falciforme/epidemiologia , Anemia Falciforme/patologia , Criança , Pré-Escolar , Participação da Comunidade , Feminino , Seguimentos , Humanos , Índia/epidemiologia , Lactente , Recém-Nascido , Masculino , Prognóstico , Estudos Retrospectivos , Taxa de Sobrevida , Adulto JovemRESUMO
Suboptimal vitamin A status (serum retinol <30 µg/dL) is associated with poor clinical outcomes in children with the hemoglobin-SS disease (HbSS), and supplementation with the recommended daily allowance of retinol is ineffective in improving vitamin A status. In a single-center randomized blinded dose-finding pilot study, we compared vitamin A and nutritional status in children with HbSS to healthy children and explored the impact of high-dose supplementation on the primary outcome serum vitamin A status. Exploratory outcomes included hematologic, nutritional, immunologic, and muscle function status in children with HbSS. A mixed-effects linear regression model evaluated associations between vitamin A dose, serum retinol, and exploratory outcomes. Twenty healthy children participated, and 22 subjects with HbSS were randomized to oral 3000 or 6000 IU/d retinol for 8 weeks; 21 subjects completed all evaluations. Serum retinol, growth, and nutritional status were all suboptimal in HbSS subjects at baseline, and supplementation did not change vitamin A status. Fetal hemoglobin (Δ=2.5, 95% confidence interval [CI], 0.5-4.3), mean corpuscular volume (Δ=2.7, 95% CI, 0.7-4.7), mean corpuscular hemoglobin (Δ=1.4, 95% CI, 0.5-2.3), and mean corpuscular hemoglobin concentration (Δ=0.5, 95% CI, 0.1-0.9) all improved with supplementation. Mild improvements in erythrocyte indices, growth status, and muscle function occurred independent of hydroxyurea use.
Assuntos
Anemia Falciforme/tratamento farmacológico , Suplementos Nutricionais , Índices de Eritrócitos/efeitos dos fármacos , Vitamina A/administração & dosagem , Adolescente , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Estudos de Casos e Controles , Método Duplo-Cego , Feminino , Seguimentos , Hemoglobina Falciforme/metabolismo , Humanos , Masculino , Estado Nutricional , Projetos Piloto , PrognósticoRESUMO
Ischemia-reperfusion (I/R) injury is a serious condition which is associated with myocardial infarction, stroke, acute kidney injury, trauma, circulatory arrest, sickle cell disease, and sleep apnea and can lead to high morbidity and mortality. Salts of zinc (Zn) are commonly used by humans and have protective effects against gastric, renal, hepatic, muscle, myocardial, or neuronal ischemic injury. The present review evaluates molecular mechanisms underlying the protective effects of Zn supplement against I/R injury. Data of this review have been collected from the scientific articles published in databases such as Science Direct, Scopus, PubMed, and Scientific Information Database from 1991 to 2019. Zn supplementation increased the decreased parameters including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), glutathione (GSH), metallothionein (MT), protein sulfhydryl (P-SH), and nuclear factor-erythroid 2-related factor-2 (Nrf2) expression and decreased the increased elements such as endoplasmic reticulum (ER) stress, mitochondrial permeability transition pore (mPTP) opening, malondialdehyde (MDA), serum level of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and microRNAs-(122 and 34a), apoptotic factors, and histopathological changes. Zn also increases phosphatidylinositol 3-kinase (PI3K)/Akt and glycogen synthase kinase-3ß (GSK-3ß) phosphorylation and preserves protein kinase C isoforms. It is suggested that Zn can be administered before elective surgeries for prevention of side effects of I/R injury.
Assuntos
Traumatismo por Reperfusão/tratamento farmacológico , Zinco/farmacologia , Injúria Renal Aguda/tratamento farmacológico , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Animais , Suplementos Nutricionais , Parada Cardíaca Induzida , Humanos , Infarto do Miocárdio/tratamento farmacológico , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Síndromes da Apneia do Sono/tratamento farmacológico , Síndromes da Apneia do Sono/metabolismo , Síndromes da Apneia do Sono/patologia , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Ferimentos e Lesões/tratamento farmacológico , Ferimentos e Lesões/metabolismo , Ferimentos e Lesões/patologia , Zinco/administração & dosagemRESUMO
Sickle cell disease (SCD) is a recessively inherited blood disorder caused by abnormal ß-globin production. The ß-globin mutation changes erythrocyte morphology into a sickle shape and increases erythrocyte vulnerability to hemolysis. Oxidative stress and concomitant inflammation eventually result in damage to multiple organs. Nrf2 is a master regulator of the oxidative stress response, homeostasis, and metabolism. Keap1 modulates Nrf2 protein levels; Nrf2 inducers alter nuclear Nrf2 levels by interacting with Keap1. Genetic modification of Keap1 helps to reduce inflammation and tissue damage in SCD model mice through Nrf2 induction. Here, we investigated the benefits of a mild and safe Nrf2 agonist, sulforaphane (SFN), in ameliorating SCD pathology in a murine model. SFN is a phytochemical and is found in cruciferous vegetables as its inert precursor, glucoraphanin. We found that dietary SFN administration for 14 days or 2 months increased the expression of Nrf2-dependent cytoprotective genes, but SFN uptake did not have deleterious effects on the food consumption and growth of SCD model mice. SFN ameliorated the liver damage of SCD mice, which could be validated by the rescue of liver function and the significantly reduced liver necrotic area. SFN administration also helped to eliminate heme released from lysed sickle cells. These results indicate that dietary supplementation with SFN relieves SCD symptoms by inducing Nrf2 and support our contention that SFN is a potential drug for the long-term treatment of children with SCD.
Assuntos
Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/metabolismo , Suplementos Nutricionais , Isotiocianatos/farmacologia , Hepatopatias/tratamento farmacológico , Hepatopatias/metabolismo , Fígado/metabolismo , Anemia Falciforme/genética , Anemia Falciforme/patologia , Animais , Modelos Animais de Doenças , Feminino , Heme/genética , Heme/metabolismo , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/genética , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fígado/patologia , Hepatopatias/genética , Hepatopatias/patologia , Masculino , Camundongos , Camundongos Transgênicos , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , SulfóxidosRESUMO
OBJECTIVES: Deferasirox is an oral iron chelator with established dose-dependent efficacy for the treatment of iron overload secondary to transfusion. However, there is few data reporting the use of Desferasirox in adult patients with sickle cell disease (SCD) and transfusional iron overload. METHODS: We conducted a prospective, single center, nonrandomized study from January 2014 to March 2015 in Campinas, Brazil. Seven patients (five women, median age 50 y.o.) who were followed up on regular transfusion program were treated with a single daily dose of deferasirox (median dose 20â mg/kg). They were monitored for clinical symptoms, renal function and hepatotoxicity. RESULTS: One patient discontinued the study due to lack of compliance. Two patients reported mild to moderate adverse events (gastrointestinal disturbances). Five patients had the drug discontinued due to worsening of renal function. One patient had the drug discontinued due to severe hepatotoxicity that evolved to death; no patient finished the study. Discussion and conclusions: Deferasirox does not appear to be well tolerated in SCD patients older than 40 years, in which complications of the underlying disease are already fully installed. The choice of the ideal iron chelator for this population should include an evaluation of comorbidities and organic dysfunctions, as well as the need to find pharmacogenetic safety markers in this group of patients.
Assuntos
Anemia Falciforme/tratamento farmacológico , Deferasirox/uso terapêutico , Quelantes de Ferro/uso terapêutico , Adulto , Idoso , Anemia Falciforme/patologia , Deferasirox/farmacologia , Feminino , Humanos , Quelantes de Ferro/farmacologia , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
INTRODUCTION: Recent knowledge on the pathophysiology of sickle cell disease (SCD) have emphasized the role of hemolysis and nitric oxide (NO) depletion on the occurrence of acute and chronic complications. This new paradigm raises the possibility of innovative therapeutic approaches, including arginine supplementation. Areas covered: This review comments on the role of NO in the regulation of vascular tone, as well as its impaired metabolism in hemolytic diseases. Disturbances in these processes in SCD were detailed considering the functions of endothelial nitric oxide synthase (eNOS), arginase and asymmetric dimethylarginine (ADMA). Therapeutic approaches involving these pathways were discussed with emphasis on the effects of arginine therapy on the normalization of NO levels and its consequent clinical effects, mainly the decrease in the intensity of vaso-occlusive crises. Expert opinion: Considering the complex pathogenesis of the disease and the restricted access to curative therapies, the management of SCD must rely on a combination of therapies covering multiple pathways. Arginine supplementation, a low-cost approach, has shown promising results, which is particulary important considering most of the affected patients still live in unfavorable socioeconomic conditions. These findings should encourage further clinical trials, evaluating other outcomes and specific subpopulations, such as adult patients and compound heterozygotes.
Assuntos
Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/metabolismo , Arginina/uso terapêutico , Anemia Falciforme/complicações , Anemia Falciforme/patologia , Animais , Arginina/análogos & derivados , Arginina/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismoRESUMO
BACKGROUND: Sickle-cell disease increases the risk of malnutrition. Low arginine and nitric oxide bioavailability are implicated in morbidity related to sickle-cell disease. Simple interventions are required, especially in low-income settings. We aimed to test the hypotheses that: (1) supplementary arginine, citrulline, and daily chloroquine increase bioavailable arginine and flow-mediated dilatation (FMD; maximal diameter change; FMDmax%), a measure of nitric oxide-dependent endothelial function; and (2) protein energy supplementation in the form of ready-to-use supplementary food (RUSF) improves the height-for-age and body-mass index-for-age Z-scores in children with sickle-cell disease. METHODS: We performed a double-blind, random order crossover trial with two 4-month intervention periods (each followed by 4-month washout periods) in Muhimbili National Hospital in Dar-es-Salaam, Tanzania. We enrolled 119 children from the Muhimbili Sickle Cohort who were aged 8-12 years, naive to hydroxyurea, and had documented HbSS phenotype. Two formulations of RUSF (providing 500 kcal/day) were tested: basic (RUSF-b), with which children also received weekly chloroquine (150 mg or 225 mg chloroquine base, dependent on bodyweight); and vascular (RUSF-v), which was fortified with arginine and citrulline (designed to achieve mean intakes of 0·2 g/kg per day of arginine and 0·1 g/kg per day of citrulline), and with which children received daily chloroquine (maximum 3 mg chloroquine base/kg per day). Children were randomly allocated to receive either RUSF-b first or RUSF-v first and, after a washout period, were then given the other treatment. The primary outcomes in comparing the two RUSF formulations were mean plasma arginine, arginine to ornithine ratio, and arginine to asymmetric dimethylarginine ratio, and mean FMDmax%. The primary outcomes of the combined effect of both RUSF interventions were mean height-for-age Z-score and body-mass index-for-age Z-score. Analyses were done on the eligible intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT01718054; and with ISRCTN74331412. FINDINGS: Between Aug 9, 2012, and Feb 26, 2014, 145 children were randomised (71 children to RUSF-v first and 74 children to RUSF-b first) and 119 children were treated, of whom 114 children yielded complete data for all reported endpoints. The ratio of arginine to ornithine (mean of individual differences -8·67%, 95% CI -19·55 to 2·20; p=0·12) and the mean FMDmax% (1·00, -0·47 to 2·47; p=0·18) did not significantly differ between the RUSF-b and RUSF-v treatments. However, the arginine to asymmetric dimethylarginine ratio was significantly increased by RUSF-v compared with RUSF-b (56·26%, 31·13 to 81·38; p<0·0001). In planned analyses that used mixed effects models to estimate the effect of each intervention compared with the participants at baseline or during washout periods, the arginine to asymmetric dimethylarginine ratio increased following both RUSF-v treatment (86%; p<0·0001) and RUSF-b treatment (40%; p<0·0001). However, FMDmax% was higher after treatment with RUSF-v (0·92; p<0·0001) but not RUSF-b (0·39; p=0·22). Following either intervention (RUSF-b and RUSF-v, pooled) body-mass index-for-age Z-score (0·091; p=0·001) and height-for-age Z-score (0·013; p=0·081) increased compared with baseline and washout timepoints. In 83 participants in the treated population, there were 71 adverse events during the intervention, of which 21 (30%) were serious, and 81 adverse events during the washout periods, of which 26 (32%) were serious (p=0·31), including one patient who died in the second washout period. INTERPRETATION: RUSF providing 500 kcal/day results in small weight gains in children with sickle-cell disease. However, even without arginine and citrulline fortification, RUSF seems to ameliorate arginine dysregulation and might improve endothelial function. Long-term studies are required to assess whether these physiological effects translate to improved clinical outcomes and better growth and development in patients with sickle-cell disease. FUNDING: Wellcome Trust.
Assuntos
Anemia Falciforme/tratamento farmacológico , Suplementos Nutricionais/estatística & dados numéricos , Anemia Falciforme/patologia , Arginina , Criança , Cloroquina , Citrulina , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Masculino , TanzâniaRESUMO
BACKGROUND: In sickle cell disease (SCD), symptoms of vitamin D deficiency (VDD) and chronic pain can overlap. AIM: To examine the relationship between serum vitamin D levels and the frequency of acute pain episodes. METHODS: In this cross-sectional study, serum 25-hydroxyvitamin D (25-OHD) was assayed by high-performance liquid chromatography, and its influence on the number of significant pain episodes was examined by bivariate and logistic regression analyses. RESULTS: The mean (SD) serum 25-OHD level in 123 children with SCD (HbSS) was 105.8 (24.1) nmol/L (range 37.5-155.8). Fourteen patients (11.4%) either had a deficient (1.6%) or insufficient (9.8%) level. None had severe VDD. All the children with sub-optimal vitamin D experienced pain, as did 69.7% of those with normal vitamin D [14 (100%) vs 76 (69.7%), 95% CI 0.7-0.9, p = 0.04]. The mean serum vitamin D level in the 90 patients with at least one pain episode [103.1 (25.2) nmol/L] was significantly lower than the 113.1 (19.3) nmol/L in the 33 without a pain episode (95% CI 1.3-7.8, p = 0.04). The frequency of pain correlated inversely with the serum 25-OHD level. Serum levels of vitamin D (OR 1.2, 95% CI 1.3-1.7, p = 0.04) and fetal haemoglobin concentration (OR 1.6, 95% CI 1.1-1.4, p = 0.02) predicted significant pain episodes. CONCLUSION: In children with SCD, there is a possible association between depressed serum vitamin D levels and increased frequency of acute pain episodes. Vitamin D supplements should be considered in patients with low levels and frequent episodes of pain.
Assuntos
Anemia Falciforme/patologia , Dor/epidemiologia , Soro/química , Vitamina D/análogos & derivados , Adolescente , Criança , Pré-Escolar , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Feminino , Humanos , Lactente , Masculino , Nigéria , Vitamina D/sangueRESUMO
Chronic inflammation and reduced blood levels of omega-3 fatty acids (n-3) are known characteristics of sickle cell disease (SCD).The anti-inflammatory properties of n-3 fatty acids are well recognized. Omega-3 treated (n = 24), hydroxyurea (HU) treated (n = 18), and n-3 untreated (n=21) homozygous SCD patients (HbSS) and healthy (HbAA) controls (n = 25) matched for age (5-16 years), gender and socioeconomic status were studied. According to age (5-10) or (11-16) years, two or three capsules containing 277.8 mg docosahexaenoic (DHA) and 39.0mg eicosapentaenoic (EPA) or high oleic acid placebo (41%) were assigned to n-3 treated and n-3 untreated groups, respectively. Hydroxyurea treated group was on dosage more than 20 mg/kg/day. The effect of supplementation on systemic and blood cell markers of inflammation was investigated. The n-3 treated group had higher levels of DHA and EPA (p < 0.001) and lower white blood cell count and monocyte integrin (p < 0.05) compared with the n-3 untreated. No difference was detected between the two groups regarding C-reactive protein, granulocytes integrin and selectin, plasma tumour necrosis factor-α and interleukin-10. The n-3 treated group had lowered nuclear factor-kappa B (NF-κB) gene expression compared to n-3 untreated and HU treated groups (p < 0.05). This study provides evidence that supplementation with n-3 fatty acids may ameliorate inflammation and blood cell adhesion in patients with SCD.
Assuntos
Anemia Falciforme/dietoterapia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , NF-kappa B/antagonistas & inibidores , Adolescente , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/imunologia , Anemia Falciforme/patologia , Antidrepanocíticos/uso terapêutico , Proteína C-Reativa/imunologia , Proteína C-Reativa/metabolismo , Estudos de Casos e Controles , Adesão Celular/efeitos dos fármacos , Criança , Pré-Escolar , Método Duplo-Cego , Feminino , Humanos , Hidroxiureia/uso terapêutico , Inflamação/prevenção & controle , Integrinas/sangue , Integrinas/imunologia , Interleucina-10/sangue , Interleucina-10/imunologia , Contagem de Leucócitos , Masculino , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/patologia , NF-kappa B/sangue , NF-kappa B/imunologia , Ácido Oleico/administração & dosagem , Selectinas/sangue , Selectinas/imunologia , Classe Social , Fator de Necrose Tumoral alfa/sangue , Fator de Necrose Tumoral alfa/imunologiaRESUMO
The anemia of sickle cell disease is associated with a severe inflammatory vasculopathy and endothelial dysfunction, which leads to painful and life-threatening clinical complications. Growing evidence supports the anti-inflammatory properties of ω-3 fatty acids in clinical models of endothelial dysfunction. Promising but limited studies show potential therapeutic effects of ω-3 fatty acid supplementation in sickle cell disease. Here, we treated humanized healthy and sickle cell mice for 6 weeks with ω-3 fatty acid diet (fish-oil diet). We found that a ω-3 fatty acid diet: (i) normalizes red cell membrane ω-6/ω-3 ratio; (ii) reduces neutrophil count; (iii) decreases endothelial activation by targeting endothelin-1 and (iv) improves left ventricular outflow tract dimensions. In a hypoxia-reoxygenation model of acute vaso-occlusive crisis, a ω-3 fatty acid diet reduced systemic and local inflammation and protected against sickle cell-related end-organ injury. Using isolated aortas from sickle cell mice exposed to hypoxia-reoxygenation, we demonstrated a direct impact of a ω-3 fatty acid diet on vascular activation, inflammation, and anti-oxidant systems. Our data provide the rationale for ω-3 dietary supplementation as a therapeutic intervention to reduce vascular dysfunction in sickle cell disease.
Assuntos
Anemia Falciforme/dietoterapia , Anti-Inflamatórios/farmacologia , Vasos Sanguíneos/efeitos dos fármacos , Suplementos Nutricionais , Ácidos Graxos Ômega-3/farmacologia , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Animais , Vasos Sanguíneos/metabolismo , Vasos Sanguíneos/patologia , Modelos Animais de Doenças , Endotelina-1/antagonistas & inibidores , Endotelina-1/biossíntese , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Endotélio Vascular/patologia , Membrana Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/patologia , Humanos , Hipóxia/dietoterapia , Hipóxia/metabolismo , Hipóxia/patologia , Camundongos , Camundongos Transgênicos , Neutrófilos/efeitos dos fármacos , Neutrófilos/metabolismo , Neutrófilos/patologia , Oxigênio/efeitos adversosRESUMO
Sickle hemoglobin polymerization commences with a striking latency period, called a "delay time" followed by abrupt polymer formation. The delay time is exceedingly concentration dependent. This discovery (40 years ago) led to the "kinetic hypothesis," that is, that the pathophysiology was related to the relationship between the delay time and the capillary transit. The delay time is well described by a double-nucleation mechanism of polymer formation. In macroscopic volumes, the delay time is highly reproducible, but in small volumes such as erythrocytes, under certain conditions, the intrinsic delay time can be augmented by a stochastic delay owing to random waiting times for the first nucleus to form. This lengthens the average delay and adds further protection from vaso-occlusion. When oxygen removal is not sudden, the growth of polymers after the delay time is limited by the rate of oxygen removal, further lengthening the time before occlusion may occur. This is important if some polymers have remained in the cell after pulmonary transit as their presence otherwise would obliterate any delay. The difficulty of deforming a cell once polymerized rationalizes the "two-step" model of vaso-occlusion in which a postcapillary adhesion event is followed by a sickling logjam. The delay time that is required is therefore generalized to be the delay time for an erythrocyte to move beyond regions in the venuoles where adherent cells have reduced the available lumen. The measurements of delay times correlate well with the severity of sickling syndromes. They also correlate with the improvements owing to the administration of hydroxyurea.
Assuntos
Anemia Falciforme/sangue , Anemia Falciforme/diagnóstico , Eritrócitos Anormais/metabolismo , Hemoglobina Falciforme/metabolismo , Anemia Falciforme/tratamento farmacológico , Anemia Falciforme/patologia , Antidrepanocíticos/uso terapêutico , Movimento Celular/efeitos dos fármacos , Deformação Eritrocítica/efeitos dos fármacos , Eritrócitos Anormais/efeitos dos fármacos , Eritrócitos Anormais/patologia , Hemoglobina Falciforme/antagonistas & inibidores , Hemoglobina Falciforme/química , Humanos , Hidroxiureia/uso terapêutico , Cinética , Pulmão/irrigação sanguínea , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Oxigênio/sangue , Polimerização/efeitos dos fármacos , Índice de Gravidade de Doença , Fatores de TempoRESUMO
The aim of this study was to determine circulating omega-6, omega-3 polyunsaturated fatty acids and prostaglandin E2 (PGE2) levels in steady state sickle cell disease (SCD) patients. Blood was collected from healthy hemoglobin volunteers and steady state homozygous HbSS patients who had not received blood transfusions in the last 3 months. Plasma levels of arachidonic acid (AA, C20:4n-6), dihomo-gamma-linolenic acid (DGLA, C20:3n-6), eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3) were determined by an optimized multiple reaction monitoring method using ultrafast liquid chromatography coupled with tandem mass spectrometry. PGE2 was measured in serum samples by enzyme immunoassay. Plasma AA and DGLA were significantly increased while EPA and DHA were significantly decreased in SCD plasma compared to control. Serum PGE2 levels, AA/DHA and AA/EPA ratio was significantly higher in SCD patients when compared to control group. The significant increase in PGE2 levels, AA/EPA and AA/DHA ratio confirms the presence of a proinflammatory state in SCD patients.
Assuntos
Anemia Falciforme/patologia , Dinoprostona/sangue , Ácidos Graxos Ômega-3/sangue , Ácidos Graxos Ômega-6/sangue , Plasma/química , Adolescente , Adulto , Criança , Pré-Escolar , Cromatografia Líquida , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Espectrometria de Massas em Tandem , Adulto JovemRESUMO
Humans and mice with sickle cell disease (SCD) have rigid red blood cells (RBCs). Omega-3 fatty acids, such as docosahexanoic acid (DHA), may influence RBC deformability via incorporation into the RBC membrane. In this study, sickle cell (SS) mice were fed natural ingredient rodent diets supplemented with 3% DHA (DHA diet) or a control diet matched in total fat (CTRL diet). After 8weeks of feeding, we examined the RBCs for: 1) stiffness, as measured by atomic force microscopy; 2) deformability, as measured by ektacytometry; and 3) percent irreversibly sickled RBCs on peripheral blood smears. Using atomic force microscopy, it is found that stiffness is increased and deformability decreased in RBCs from SS mice fed CTRL diet compared to wild-type mice. In contrast, RBCs from SS mice fed DHA diet had markedly decreased stiffness and increased deformability compared to RBCs from SS mice fed CTRL diet. Furthermore, examination of peripheral blood smears revealed less irreversibly sickled RBCs in SS mice fed DHA diet as compared to CTRL diet. In summary, our findings indicate that DHA supplementation improves RBC flexibility and reduces irreversibly sickled cells by 40% in SS mice. These results point to potential therapeutic benefits of dietary omega-3 fatty acids in SCD.
Assuntos
Anemia Falciforme/dietoterapia , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Membrana Eritrocítica/efeitos dos fármacos , Anemia Falciforme/sangue , Anemia Falciforme/patologia , Animais , Modelos Animais de Doenças , Contagem de Eritrócitos , Deformação Eritrocítica/efeitos dos fármacos , Membrana Eritrocítica/patologia , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Microscopia de Força AtômicaRESUMO
Blood transfusion and iron chelation currently represent a supportive therapy to manage anemia, vasculopathy and vaso-occlusion crises in Sickle-Cell-Disease. Here we describe the first 5-year long-term randomized clinical trial comparing Deferiprone versus Deferoxamine in patients with Sickle-Cell-Disease. The results of this study show that Deferiprone has the same effectiveness as Deferoxamine in decreasing body iron burden, measured as repeated measurements of serum ferritin concentrations on the same patient over 5-years and analyzed according to the linear mixed-effects model (LMM) (p=0.822). Both chelators are able to decrease, significantly, serum ferritin concentrations, during 5-years, without any effect on safety (p=0.005). Moreover, although the basal serum ferritin levels were higher in transfused compared with non-transfused group (p=0.031), the changes over time in serum ferritin levels were not statistically significantly different between transfused and non-transfused cohort of patients (p=0.389). Kaplan-Meier curve, during 5-years of study, suggests that Deferiprone does not alter survival in comparison with Deferoxamine (p=0.38). In conclusion, long-term iron chelation therapy with Deferiprone was associated with efficacy and safety similar to that of Deferoxamine. Therefore, in patients with Sickle-Cell-Disease, Deferiprone may represent an effective long-term treatment option.
Assuntos
Anemia Falciforme/tratamento farmacológico , Desferroxamina/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico , Piridonas/uso terapêutico , Adolescente , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/mortalidade , Anemia Falciforme/patologia , Transfusão de Sangue , Criança , Deferiprona , Feminino , Ferritinas/sangue , Humanos , Ferro/sangue , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/mortalidade , Sobrecarga de Ferro/patologia , Itália , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise de SobrevidaRESUMO
OBJECTIVE: This study was conducted to determine the relationship of frontal lobe cortical thickness and basal ganglia volumes to measures of cognition in adults with sickle cell anemia (SCA). METHODS: Participants included 120 adults with SCA with no history of neurologic dysfunction and 33 healthy controls (HCs). Participants were enrolled at 12 medical center sites, and raters were blinded to diagnostic group. We hypothesized that individuals with SCA would exhibit reductions in frontal lobe cortex thickness and reduced basal ganglia and thalamus volumes compared with HCs and that these structural brain abnormalities would be associated with measures of cognitive functioning (Wechsler Adult Intelligence Scale, 3rd edition). RESULTS: After adjusting for age, sex, education level, and intracranial volume, participants with SCA exhibited thinner frontal lobe cortex (t = -2.99, p = 0.003) and reduced basal ganglia and thalamus volumes compared with HCs (t = -3.95, p < 0.001). Reduced volume of the basal ganglia and thalamus was significantly associated with lower Performance IQ (model estimate = 3.75, p = 0.004) as well as lower Perceptual Organization (model estimate = 1.44, p = 0.007) and Working Memory scores (model estimate = 1.37, p = 0.015). Frontal lobe cortex thickness was not significantly associated with any cognitive measures. CONCLUSIONS: Our findings suggest that basal ganglia and thalamus abnormalities may represent a particularly salient contributor to cognitive dysfunction in adults with SCA.
Assuntos
Anemia Falciforme/patologia , Cérebro/patologia , Transtornos Cognitivos/patologia , Imageamento por Ressonância Magnética/métodos , Adulto , Anemia Falciforme/complicações , Anemia Falciforme/fisiopatologia , Gânglios da Base/patologia , Gânglios da Base/fisiopatologia , Cérebro/fisiopatologia , Transtornos Cognitivos/etiologia , Transtornos Cognitivos/fisiopatologia , Feminino , Humanos , Imageamento por Ressonância Magnética/instrumentação , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Córtex Pré-Frontal/patologia , Córtex Pré-Frontal/fisiopatologia , Método Simples-Cego , Tálamo/patologia , Tálamo/fisiopatologiaRESUMO
OBJECTIVE: Chronic blood transfusion therapy reduces clinical events in children with sickle cell anemia but increases risk for an iron-related liver injury. Liver biopsy is the gold standard technique for quantifying liver iron content (LIC) and evaluating liver pathology. Ferritin, liver enzymes, and R2* magnetic resonance imaging of the liver are obtained as surrogate markers. In this study we compared surrogate markers with the gold standard, liver biopsy, in assessing liver histology. METHODS: We conducted a retrospective review of 259 liver biopsies in 109 children with sickle cell anemia on chronic transfusion therapy and chelation therapy during a 9-year period at a single center. Liver pathology was compared with LIC, ferritin, and alanine aminotransferase. RESULTS: Ferritin correlates with LIC (râ=â0.74, Pâ<â0.001), although there is a broad range of ferritin values for a given LIC. Furthermore, patients with a high LIC (≥7 mg Fe/g dry weight) demonstrated significantly higher ferritin as compared to the patients with lower LIC <7 (Pâ<â0.001). Periportal/portal inflammation also showed a significant relation. There was no significance when comparing ferritin and lobular inflammation or ferritin and alanine aminotransferase. When evaluating LIC in relation to fibrosis, the present study revealed that there was only a significant correlation with severe fibrosis (Fâ=â36, Pâ<â0.001). CONCLUSIONS: The results suggest that although correlations exist among ferritin and LIC and severe fibrosis and LIC, caution should be taken when they are used in isolation. Liver biopsy provides important pathologic information that cannot be obtained through surrogate markers.
Assuntos
Anemia Falciforme/terapia , Ferritinas/metabolismo , Ferro/metabolismo , Cirrose Hepática/etiologia , Fígado/patologia , Reação Transfusional , Adolescente , Adulto , Alanina Transaminase/sangue , Anemia Falciforme/sangue , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Biomarcadores/sangue , Biomarcadores/metabolismo , Biópsia , Terapia por Quelação , Criança , Pré-Escolar , Humanos , Inflamação/metabolismo , Fígado/metabolismo , Cirrose Hepática/sangue , Cirrose Hepática/metabolismo , Estudos Retrospectivos , Índice de Gravidade de Doença , Adulto JovemRESUMO
We investigated whether or not Omega-3 long-chain polyunsaturated fatty acid (omega-3 LCPUFA) supplementation exacerbates oxidative stress in homozygous sickle cell patients aged 2 to 14 years. Depending on their age, they received between one and three omega-3 (277.8mg DHA and 39.0mg EPA/capsule) or placebo (high oleic acid sunflower seed oil) capsules for one year. Supplementation increased significantly the levels of the two fatty acids in red cell phosphatidylcholine and phosphatidylethanolamine (p<0.001). The patients who received omega-3 LCPUFA compared with their placebo-taking counterparts had a higher concentration of plasma vitamin E at one year (14.3±2.8 versus 12.3±2.8µmol/l; p<0.001). The two groups had comparable concentrations of the vitamin at six month intervention (10.8±2.2 versus 10.7±2.9µmol/l; p>0.05) and baseline (10.7±3.1 versus 10.7±2.8µmol/l; p>0.05). After six month of intervention, the patients on omega 3 fatty acids had lower GPx-1 (33.5±13.4 versus 46.6 ±17.6, p<0.01) and Cu/Zn-SOD (1070±600 versus 1470±690 p<0.05) activities than at baseline. GPx-1 (33.5±17.6IU/g Hb versus 43.7±13.2IU/g Hb; p<0.01) and Cu/Zn-SOD (1070±600IU/g Hb versus 1360±920IU/g Hb; p>0.05) activities were reduced in the omega 3 compared with the placebo at six month intervention. There was no difference in the activity of either of the enzymes between baseline and six month intervention in the placebo group (p>0.05). This study demonstrates; DHA and EPA supplementation, rather than exacerbating the inherent oxidative stress associated with the disease, seems to provide an antioxidant protection. Hence, it will be safe to provide omega-3 LCPUFA to sickle cell patients to help ameliorate vaso-occlusive and haemolytic crises and membrane fatty acid abnormality.
Assuntos
Anemia Falciforme/dietoterapia , Vasos Sanguíneos/efeitos dos fármacos , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/administração & dosagem , Ácido Eicosapentaenoico/administração & dosagem , Eritrócitos/efeitos dos fármacos , Adolescente , Anemia Falciforme/metabolismo , Anemia Falciforme/patologia , Vasos Sanguíneos/patologia , Estudos de Casos e Controles , Criança , Pré-Escolar , Eritrócitos/química , Eritrócitos/patologia , Feminino , Hemólise/efeitos dos fármacos , Homozigoto , Humanos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Superóxido Dismutase/sangue , Vitamina E/sangueRESUMO
PURPOSE OF REVIEW: To summarize the findings of the recent publications on sickle cell bone disease (SBD). RECENT FINDINGS: Individuals with sickle cell disease (SCD) are living longer and develop progressive organ damage including SBD with age. Recent studies suggest alternative radiological diagnostics such as ultrasound and scintigraphy can detect and differentiate between different forms of SBD. MRI with or without diffusion-weighted sequences remains the gold standard. Case reports of cranio-orofacial SBD highlight the rarity of this presentation. Vitamin D deficiency is highly prevalent at all ages, but may not be an independent risk factor for avascular necrosis (AVN). Gene polymorphisms of the Annexin A gene may predict AVN in SCD. A recent study demonstrated reduced days with pain and improved physical activity quality of life following high-dose vitamin D therapy. The high rates of osteopenia and osteoporosis in SCD support the need for research addressing this rising public health problem. Lastly, results of total hip arthroplasty for AVN in SCD has improved significantly over time with the use of cementless prosthetic material and improved supportive care. SUMMARY: SBD remains poorly studied. Prospective randomized studies targeting predictors, diagnostics, prevention, and treatment options for SBD are sorely needed.