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BACKGROUND: Deoxygenated sickle hemoglobin (HbS) polymerization drives the pathophysiology of sickle cell disease. Therefore, direct inhibition of HbS polymerization has potential to favorably modify disease outcomes. Voxelotor is an HbS polymerization inhibitor. METHODS: In a multicenter, phase 3, double-blind, randomized, placebo-controlled trial, we compared the efficacy and safety of two dose levels of voxelotor (1500 mg and 900 mg, administered orally once daily) with placebo in persons with sickle cell disease. The primary end point was the percentage of participants who had a hemoglobin response, which was defined as an increase of more than 1.0 g per deciliter from baseline at week 24 in the intention-to-treat analysis. RESULTS: A total of 274 participants were randomly assigned in a 1:1:1 ratio to receive a once-daily oral dose of 1500 mg of voxelotor, 900 mg of voxelotor, or placebo. Most participants had sickle cell anemia (homozygous hemoglobin S or hemoglobin Sß0-thalassemia), and approximately two thirds were receiving hydroxyurea at baseline. In the intention-to-treat analysis, a significantly higher percentage of participants had a hemoglobin response in the 1500-mg voxelotor group (51%; 95% confidence interval [CI], 41 to 61) than in the placebo group (7%; 95% CI, 1 to 12). Anemia worsened between baseline and week 24 in fewer participants in each voxelotor dose group than in those receiving placebo. At week 24, the 1500-mg voxelotor group had significantly greater reductions from baseline in the indirect bilirubin level and percentage of reticulocytes than the placebo group. The percentage of participants with an adverse event that occurred or worsened during the treatment period was similar across the trial groups. Adverse events of at least grade 3 occurred in 26% of the participants in the 1500-mg voxelotor group, 23% in the 900-mg voxelotor group, and 26% in the placebo group. Most adverse events were not related to the trial drug or placebo, as determined by the investigators. CONCLUSIONS: In this phase 3 randomized, placebo-controlled trial involving participants with sickle cell disease, voxelotor significantly increased hemoglobin levels and reduced markers of hemolysis. These findings are consistent with inhibition of HbS polymerization and indicate a disease-modifying potential. (Funded by Global Blood Therapeutics; HOPE ClinicalTrials.gov number, NCT03036813.).
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Anemia Falciforme/tratamento farmacológico , Antidrepanocíticos/administração & dosagem , Benzaldeídos/administração & dosagem , Hemoglobina Falciforme/efeitos dos fármacos , Hemoglobinas/metabolismo , Pirazinas/administração & dosagem , Pirazóis/administração & dosagem , Adolescente , Adulto , Anemia Falciforme/sangue , Antidrepanocíticos/efeitos adversos , Antidrepanocíticos/uso terapêutico , Benzaldeídos/efeitos adversos , Biomarcadores/sangue , Criança , Relação Dose-Resposta a Droga , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Hemoglobina Falciforme/metabolismo , Hemólise/efeitos dos fármacos , Humanos , Hidroxiureia/uso terapêutico , Análise de Intenção de Tratamento , Masculino , Pessoa de Meia-Idade , Polimerização/efeitos dos fármacos , Pirazinas/efeitos adversos , Pirazóis/efeitos adversos , Adulto JovemRESUMO
Management of immune thrombocytopenia (ITP) during pregnancy can be challenging because treatment choices are limited. Thrombopoietin receptor agonists (Tpo-RAs), which likely cross the placenta, are not recommended during pregnancy. To better assess the safety and efficacy of off-label use of Tpo-RAs during pregnancy, a multicenter observational and retrospective study was conducted. Results from 15 pregnant women with ITP (pregnancies, n = 17; neonates, n = 18) treated with either eltrombopag (n = 8) or romiplostim (n = 7) during pregnancy, including 2 patients with secondary ITP, were analyzed. Median time of Tpo-RA exposure during pregnancy was 4.4 weeks (range, 1-39 weeks); the indication for starting Tpo-RAs was preparation for delivery in 10 (58%) of 17 pregnancies, whereas 4 had chronic refractory symptomatic ITP and 3 were receiving eltrombopag when pregnancy started. Regarding safety, neither thromboembolic events among mothers nor Tpo-RA-related fetal or neonatal complications were observed, except for 1 case of neonatal thrombocytosis. Response to Tpo-RAs was achieved in 77% of cases, mostly in combination with concomitant ITP therapy (70% of responders). On the basis of these preliminary findings, temporary off-label use of Tpo-RAs for severe and/or refractory ITP during pregnancy seems safe for both mother and neonate and is likely to be helpful, especially before delivery.
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Benzoatos/administração & dosagem , Hidrazinas/administração & dosagem , Complicações Hematológicas na Gravidez/tratamento farmacológico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirazóis/administração & dosagem , Receptores Fc/administração & dosagem , Receptores de Trombopoetina , Proteínas Recombinantes de Fusão/administração & dosagem , Trombopoetina/administração & dosagem , Adulto , Benzoatos/efeitos adversos , Feminino , Seguimentos , Humanos , Hidrazinas/efeitos adversos , Gravidez , Pirazóis/efeitos adversos , Proteínas Recombinantes de Fusão/efeitos adversos , Estudos Retrospectivos , Trombopoetina/efeitos adversosRESUMO
BACKGROUND: The management of pregnant women with anti-Jsb is challenging due to the paucity of antigen-negative blood for fetal and neonatal transfusion. CASE REPORT: A 29-year-old woman with anti-Jsb was referred for assessment of recurrent fetal losses. With the presence of the sister as a historically matched donor, she was planned for active surveillance for fetal anemia during pregnancy. STUDY DESIGN AND METHODS: The fetus remained well until 21 weeks of gestation when signs of fetal anemia and early hydrops fetalis were noted. Anti-Jsb titer was at 128. The sister's red blood cells (RBCs) were cross-match incompatible. Urgent intrauterine transfusion (IUT) was performed with washed irradiated maternal RBCs, donated after cessation of heparin. The mother was given intravenous iron (IV-Fe) and continued on weekly recombinant human erythropoietin (rHu-EPO). RESULTS: Repeated IUTs were needed every 1 to 3 weeks. Throughout a 7-week period, three maternal donations were performed with total donated whole blood volume of 1250 mL, supporting four IUTs. At 29 weeks of gestation, the procedure was complicated by umbilical cord hematoma necessitating urgent cesarean section. A male newborn was delivered, transfused at birth, and subsequently treated with phototherapy and five top-up transfusions. CONCLUSION: This case represents a successful example of managing hemolytic disease of the fetus due to a rare antibody using maternal blood. It also supports previous data on safety of maternal donations during pregnancy and the use of combination of rHu-EPO and IV-Fe as a supportive measure.
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Transfusão de Sangue Intrauterina/métodos , Eritroblastose Fetal/terapia , Isoanticorpos/efeitos adversos , Sistema do Grupo Sanguíneo de Kell/imunologia , Adulto , Doadores de Sangue , Eritroblastose Fetal/etiologia , Feminino , Humanos , Recém-Nascido , Isoanticorpos/sangue , Masculino , Mães , Gravidez , Índice de Gravidade de Doença , Resultado do TratamentoRESUMO
ß-Thalassemia is one of the most common monogenetic diseases worldwide, with a particularly high prevalence in the Middle East region. As such, we have developed long-standing experience with disease management and devising solutions to address challenges attributed to resource limitations. The region has also participated in the majority of clinical trials and development programs of iron chelators and more novel ineffective erythropoiesis-targeted therapy. In this review, we provide a practical overview of management for patients with transfusion-dependent ß-thalassemia, primarily driven by such experiences, with the aim of transferring knowledge to colleagues in other regions facing similar challenges.
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Sobrecarga de Ferro , Talassemia , Talassemia beta , Humanos , Talassemia beta/terapia , Talassemia beta/tratamento farmacológico , Talassemia/tratamento farmacológico , Transfusão de Sangue , Quelantes de Ferro/uso terapêutico , Prevalência , Sobrecarga de Ferro/tratamento farmacológicoRESUMO
Sickle cell disease (SCD) is a major public health burden worldwide with increasing morbidity and mortality. The study evaluates the risk factors associated with mortality in SCD patients, between the years 2006 and 2020 at three hospitals in Oman. The analysis includes clinical manifestations, haematological, biochemical, and radiological parameters, use of antibiotics, and blood and exchange transfusions. Our cohort included 123 patients (82 males, 41 females), with a median age of 27 (Interquartile Range 21-35 years). SCD related complications included acute chest syndrome (ACS) in 52.8%, splenic sequestration in 21.1%, right upper quadrant syndrome in 19.5%, more than > 6 VOC/year in 17.9%, and stroke in 13.8%. At the terminal admission, patients had cough, reduced O2 saturation, crepitation and fever in 24.4%, 49.6%, 53.6% and 68.3% respectively. Abnormal chest X-ray and chest CT scan were seen in 57.7%, and 76.4% respectively. Laboratory parameters showed a significant drop in hemoglobin (Hb) and platelet counts from baseline, with a significant rise in WBC, LDH and CRP from baseline (p < 0.05, Wilcoxon Signed Ranks test). All patients received antibiotics, whereas, 95.9% and 93.5% received simple blood transfusions, and exchange transfusions respectively, and 66.6% required non-invasive ventilation. Among the causes of death, ACS is seen in 32 (26%), sepsis in 49 (40%), and miscellaneous in 42 (34%). Sudden death was seen in 32 (26%) of patients. Male gender, with low HbF, rapid drop in Hb and platelet, and increased in WBC, LDH, ferritin, and CRP, correlated significantly with mortality in this cohort.
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Síndrome Torácica Aguda , Anemia Falciforme , Adulto , Feminino , Humanos , Masculino , Adulto Jovem , Síndrome Torácica Aguda/etiologia , Anemia Falciforme/complicações , Antibacterianos , Causalidade , Causas de Morte , Fatores de RiscoRESUMO
INTRODUCTION: Coinheritance of α-thalassemia influences the clinical and hematological phenotypes of ß-hemoglobinopathies (ß-thalassemia and sickle cell disease) and when present together in significant frequency within a population, a spectrum of clinical forms is observed. Precise molecular characterization of α-thalassemia is important in understanding their disease-modifying role in ß-hemoglobinopathies and for diagnostic purposes. PATIENTS AND METHODS: Because currently used approaches are labor/cost-intensive, time-consuming, error-prone in certain genotype combinations and not applicable for large epidemiological screening, we developed a systematic stepwise strategy to overcome these difficulties. We successfully applied this to characterize the α-globin gene status in 150 Omani cord blood samples with Hb Barts and 32 patients with HbH disease. RESULTS: We observed a good correlation between α-globin genotypes and level of Hb Bart's with the Hb Bart's levels significantly higher in both deletional and non-deletional α-globin genotypes. The most common α-globin genotype in HbH cases was α(TSaudi) α/α(TSaudi) α (n = 16; 50%) followed by -α(3.7) /-(MED) (n = 10; 31%). This approach detects also the α-globin gene triplication as exemplified by the study of a family where the ß-globin gene defect failed to explain the ß-thalassemia intermedia phenotype. CONCLUSION: Molecular characterization of α-thalassemia is complex due to high sequence homology between the duplicated α-globin genes and to the existence of a variety of gene rearrangements (small and large deletions of various sizes) and punctual substitutions (non-deletional alleles). The novelty of our strategy resides, not in the individual technical steps per se but in the reasoned sequential order of their use taking into consideration the hematological phenotype as well.
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Testes Genéticos , Talassemia alfa/diagnóstico , Índices de Eritrócitos , Ordem dos Genes , Testes Genéticos/métodos , Genótipo , Humanos , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Prevalência , alfa-Globinas/genética , Talassemia alfa/epidemiologia , Talassemia alfa/genética , Talassemia beta/diagnóstico , Talassemia beta/genéticaRESUMO
Background: Sickle cell disease is an inherited disorder characterized by the presence of sickle hemoglobin (HbS). The process of Hb molecule polymerization is a pivotal step in the sickling process. Voxelotor, a recently approved novel therapeutic agent, is known to interfere with polymerization. We aim to study the impact of Voxelotor on Hb variants analysis using high performance liquid chromatography (HPLC). Material and methods: We are reporting the impact of Voxelotor on Hb variants analysis using HPLC after an informed consent and medical research committee approval. Data was collected from eight patients who are enrolled in the GBT440-034OL study using electronic medical records, to evaluate the Hb levels, hemolytic markers and the clinical response. Results: Our patients were well-balanced for gender, with a mean age of 31.1 years (19-50). Six patients showed a significant improvement in the Hb level, with reduced reticulocytes, bilirubin, LDH and an improved clinical outcome. Interestingly, these patients showed the appearance of a split band of Hb S and D on HPLC impacting significantly on HbS level. Two patients did not show any improvement on laboratory parameters, and no changes on their HPLC analysis. Conclusions: We report here eight patients on Voxelotor therapy, six of which showed improved hemolytic markers and anemia and demonstrated the appearance of HbD peak on the HPLC chromatogram. Therefore, the absence of HbD on HPLC or other laboratory methods for estimating HbS in patients on Voxelotor therapy, gives the clinician a possible hint regarding the patient's compliance with the drug.
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Artificial intelligence (AI) is rapidly becoming an established arm in medical sciences and clinical practice in numerous medical fields. Its implications have been rising and are being widely used in research, diagnostics, and treatment options for many pathologies, including sickle cell disease (SCD). AI has started new ways to improve risk stratification and diagnosing SCD complications early, allowing rapid intervention and reallocation of resources to high-risk patients. We reviewed the literature for established and new AI applications that may enhance management of SCD through advancements in diagnosing SCD and its complications, risk stratification, and the effect of AI in establishing an individualized approach in managing SCD patients in the future. Aim: to review the benefits and drawbacks of resources utilizing AI in clinical practice for improving the management for SCD cases.
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The objective of our present study was to develop a warfarin dosing algorithm for the Omani patients, as performances of warfarin dosing algorithms vary across populations with impact on the daily maintenance dose. We studied the functional polymorphisms of CYP2C9, CYP4F2 and VKORC1 genes to evaluate their impact on the warfarin maintenance dose in an admixed Omani patient cohort with Caucasian, African and Asian ancestries. We observed a 64-fold inter-patient variability for warfarin to achieve stable international normalized ratio in these patients. Univariate analysis revealed that age, gender, weight, atrial fibrillation, deep vein thrombosis/pulmonary embolism and variant genotypes of CYP2C9 and VKORC1 loci were significantly associated with warfarin dose in the studied patient population. However, multiple regression model showed that only the atrial fibrillation, and homozygous CYP2C9 variant genotypes (*2/*3 and *3/*3) and VKORC1 GA and AA genotypes remained significant. A multivariate model, which included demographic, clinical and pharmacogenetic variables together explained 63% of the overall inter-patient variability in warfarin dose requirement in this microgeographically defined, ethnically admixed Omani patient cohort on warfarin. This locally developed model performed much better than the International Warfarin Pharmacogenetics Consortium (IWPC) model as the latter could only explain 34% of the inter-patient variability in Omani patients. VKORC1 3673G>A polymorphism emerged as the single most important predictor of warfarin dose variability, even in this admixed population (partial R(2)=0.45).
Assuntos
Algoritmos , Farmacogenética/métodos , Varfarina/administração & dosagem , Adulto , Idoso , Hidrocarboneto de Aril Hidroxilases/genética , Fibrilação Atrial/tratamento farmacológico , Citocromo P-450 CYP2C9 , Sistema Enzimático do Citocromo P-450/genética , Família 4 do Citocromo P450 , Cálculos da Dosagem de Medicamento , Etnicidade/genética , Feminino , Estudos de Associação Genética , Loci Gênicos , Genética Populacional/métodos , Genótipo , Humanos , Modelos Lineares , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Oxigenases de Função Mista/genética , Omã/etnologia , Polimorfismo Genético , Estudos Prospectivos , Trombose Venosa/tratamento farmacológico , Vitamina K Epóxido RedutasesRESUMO
Mutations in the anion exchanger 1 (AE1) gene encoding the erythroid and kidney anion (chloride-bicarbonate) exchanger 1 may result in familial distal renal tubular acidosis (dRTA) in association with membrane defect hemolytic anemia. Seven children presenting with hyperchloremic normal anion gap metabolic acidosis, failure to thrive, and compensated hemolytic anemia were studied. Analysis of red cell AE1/Band 3 surface expression by Eosin 5'-maleimide (E5M) was performed in patients and their family members using flow cytometry. Genetic studies showed that all patients carried a common SLC4A1 mutation, c.2573C>A; p.Ala858Asp in exon 19, found as homozygous (A858D/A858D) mutation in the patients and heterozygous (A858D/N) in the parents. Analysis by flowcytometry revealed a single uniform fluorescence peak, with the mean channel fluorescence (MCF) markedly reduced in cases with homozygous mutation, along with a left shift of fluorescence signal but was only mildly reduced in the heterozygous state. Red cell morphology showed striking acanthocytosis in the homozygous state [patients] and only a mild acanthocytosis in heterozygous state [parents]. In conclusion, this is the first description of a series of homozygous cases with the A858D mutation. The E5M flowcytometry test is specific for reduction in the Band 3 membrane protein and was useful in conjunction with a careful morphological examination of peripheral blood smears in our patient cohort.
Assuntos
Acidose Tubular Renal/genética , Anemia Hemolítica/genética , Proteína 1 de Troca de Ânion do Eritrócito/genética , Mutação , Pré-Escolar , Citoesqueleto/metabolismo , Análise Mutacional de DNA , Feminino , Homozigoto , Humanos , Lactente , Masculino , Neuroacantocitose/genética , Omã , Isoformas de ProteínasRESUMO
This is the first study to evaluate the spectrum and prevalence of dose-predictive genetic polymorphisms of the CYP2C9, CYP4F2 and VKORC1 loci together, in a geographically defined, ethnically admixed healthy adult Omani population sharing common lifestyle/environmental factors. Since the present-day Omani population is the result of an admixture of Caucasian, African and Asian ancestries, we compared the pharmacogenetic profile of these three loci in this population. Interestingly, the Omani pharmacogenetic profile, in terms of allele and genotype distribution, has values that are intermediate between Caucasians and African Americans, the African admixture further substantiated by the presence of the CYP2C9*8 allele. However, limitations and usefulness of such comparisons warrant caution, as the data from pharmacogenetic literature do not always represent bona fide population categories. Furthermore, definition of study population based on microgeographical scale would be more appropriate in pharmacogenetic research rather than the flawed racial, ethnic, or social categorizations since pharmacogenetic variation is clinal, and genetic influences will be further altered by lifestyle and environmental factors.
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Anticoagulantes/farmacologia , Hidrocarboneto de Aril Hidroxilases/genética , Sistema Enzimático do Citocromo P-450/genética , Oxigenases de Função Mista/genética , Varfarina/farmacologia , Adulto , Hidrocarboneto de Aril Hidroxilases/metabolismo , Distribuição de Qui-Quadrado , Citocromo P-450 CYP2C9 , Sistema Enzimático do Citocromo P-450/metabolismo , Família 4 do Citocromo P450 , Feminino , Frequência do Gene , Genótipo , Humanos , Masculino , Oxigenases de Função Mista/metabolismo , Omã , Polimorfismo Genético , Prevalência , Vitamina K Epóxido RedutasesRESUMO
Patients with sickle-cell disease who develop autoimmune connective tissue disorders can present with similar clinical manifestations and/or complications making them indistinguishable. We report here a single-institution study on a cohort of 24 patients, with the above combination. The results suggest that there is often a significant delay in making the second diagnosis because of the overlapping clinical profile. It is emphasized that the clinician should be aware of and vigilant about such cases and should diligently follow up such cases to make an early diagnosis and start the appropriate treatment.
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Anemia Falciforme/diagnóstico , Doenças Autoimunes/diagnóstico , Doenças do Tecido Conjuntivo/diagnóstico , Adolescente , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/complicações , Doenças Autoimunes/sangue , Doenças Autoimunes/etiologia , Estudos de Coortes , Doenças do Tecido Conjuntivo/sangue , Doenças do Tecido Conjuntivo/etiologia , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Omã , Estudos Retrospectivos , Adulto JovemRESUMO
Hematopoietic stem cell transplantation (HSCT) activity was surveyed in the 9 countries in the World Health Organization Eastern Mediterranean region that reported transplantation activity. Between the years of 1984 and 2007, 7933 transplantations were performed. The number of HSCTs per year has continued to increase, with a plateau in allogeneic HSCT (allo-HSCT) between 2005 and 2007. Overall, a greater proportion of transplantations were allo-HSCT (n = 5761, 77%) compared with autologous HSCT (ASCT) (n = 2172, 23%). Of 5761 allo-HSCT, acute leukemia constituted the main indication (n = 2124, 37%). There was a significant proportion of allo-HSCT for bone marrow failures (n = 1001, 17%) and hemoglobinopathies (n = 885, 15%). The rate of unrelated donor transplantations remained low, with only 2 matched unrelated donor allo-HSCTs reported. One hundred umbilical cord blood transplantations were reported (0.017% of allo-HSCT). Peripheral blood stem cells were the main source of graft in allo-HSCT, and peripheral blood stem cells increasingly constitute the main source of hematopoietic stem cells overall. Reduced-intensity conditioning was utilized in 5.7% of allografts over the surveyed period. ASCT numbers continue to increase. There has been a shift in the indication for ASCT from acute leukemia to lymphoproliferative disorders (45%), followed by myeloma (26%). The survey reflects transplantation activity according to the unique health settings of this region. Notable differences in transplantation practices as reported to the European Group for Blood and Marrow Transplantation over recent years are highlighted.
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Transplante de Células-Tronco Hematopoéticas/estatística & dados numéricos , Doenças da Medula Óssea/terapia , Coleta de Dados , Bases de Dados Factuais , Transplante de Células-Tronco Hematopoéticas/tendências , Humanos , Transtornos Linfoproliferativos/terapia , Região do Mediterrâneo , Fatores de Tempo , Condicionamento Pré-Transplante/métodos , Condicionamento Pré-Transplante/estatística & dados numéricos , Transplante Autólogo/estatística & dados numéricos , Transplante Homólogo/estatística & dados numéricosRESUMO
A novel ß-globin gene promoter (-71 C>T) nucleotide change was recently posted to the HbVar database (ID 2701) without precision on phenotype and ethnicity. We found the same change in compound heterozygosity with Hb S [ß6(A3)Glu>Val] in an Omani family with almost equal expression of Hb A and Hb S. This suggested that the -71 C to T mutation may be a mild ß-thalassemic allele. Subsequent search found three other independent cases with the same atypical Hb A:Hb S ratio, further confirming the mild thalassemic feature of this mutation. In addition, molecular screening of a set of subjects (with only Hb A) with borderline Hb A(2) or MCV values revealed the presence of -71 C>T change in heterozygous state, altogether assigning the mutation as a mild ß(+) thalassemic allele. In a region such as Oman, where several genetic conditions of the red blood cell coexist (α- and ß-thalassemia, Hb S, Hb D, Hb E) in significant frequencies, it is crucial to decipher the molecular basis of these atypical forms of ß(+) thalassemias, especially in a genetic counseling setting.
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Alelos , Mutação , Regiões Promotoras Genéticas , Globinas beta/genética , Talassemia beta/genética , Sequência de Bases , Primers do DNA , Humanos , Reação em Cadeia da PolimeraseRESUMO
In an Omani family, four different alpha thalassemic alleles, one single-gene deletional (-α(3.7) ) and three non-deletional forms (α(TSaudi) , α(Δ5nt) , and α(ΔG) ), interact in various combinations and result in two distinct hematological phenotypes, with and without HbH inclusions. After excluding the presence of potential genetic modifiers, viz associated ß-thalassemic alleles or functional alpha hemoglobin stabilizing protein (AHSP) polymorphisms, we observed that only the genetic combinations involving α(TSaudi) mutation are associated with HbH inclusions (a marker of degree of α/ß-chain imbalance) and high reticulocyte count (a marker of ongoing hemolysis). Overall, the α(TSaudi) mutation is associated with a more severe α-globin deficiency than the other two (α(Δ5nt) and α(ΔG) ) non-deletional α(0) thalassemic mutations. The likely molecular explanation is that the compensatory increase in the linked α1 globin gene expression is much more compromised in cases with α(TSaudi) mutation.
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Mutação , alfa-Globinas/genética , Talassemia alfa/genética , Adolescente , Adulto , Alelos , Sequência de Bases , Criança , Pré-Escolar , Códon sem Sentido , Análise Mutacional de DNA , Feminino , Mutação da Fase de Leitura , Deleção de Genes , Estudos de Associação Genética , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Omã , Linhagem , Mutação Puntual , Talassemia alfa/sangueRESUMO
A novel ß-globin structural variant, namely Hb Sheffield [ß58(E2)ProâHis], was recently found as a sporadic event in a British Subject and posted to the HbVar database (ID 2672). Here we describe the same variant in 11 Omani subjects in the heterozygous state and in one Omani woman in compound heterozygosity with Hb S [ß6(A3)GluâVal]. Hb Sheffield coelutes in the Hb A(2) window in the high performance liquid chromatography (HPLC) system as does Hb E [ß26(B8)GluâLys], and might be erroneously diagnosed as Hb E unless additional tests including DNA analyses are done. Indeed, correct diagnosis of Hb E is important because of its association with other ß-thalassemic and variant alleles can result in relevant clinical conditions, while Hb Sheffield will not. In a genetic (premarital) counseling setting, and in regions where both Hb E ad Hb Sheffield are present, failure to distinguish these variants will represent a serious pitfall.
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Aconselhamento Genético , Hemoglobinas Anormais/genética , Globinas beta/genética , Adulto , Substituição de Aminoácidos/genética , Sequência de Bases , Códon , Ordem dos Genes , Genótipo , Testes Hematológicos , Hemoglobina E/genética , Hemoglobina Falciforme/genética , Hemoglobinopatias/diagnóstico , Hemoglobinopatias/genética , Humanos , Omã , Mutação Puntual , Adulto JovemRESUMO
The treatment of sickle cell disease (SCD) is mainly supportive, except for a minority, who receive bone marrow transplantation (BMT). Serum ferritin (SF) is routinely available but is notoriously unreliable as a tool for iron-overload assessment since it is an acute-phase reactant. Although blood transfusion is one of the most effective ways to deal with specific acute and chronic complications of SCD, this strategy is often associated with alloimmunization, iron overload, and hemolytic reactions. This study, thus, aims to evaluate iron overload in patients with SCD on chronic blood transfusions and specifically, correlate SF with the current standard of care of iron-overload assessment using MRI-based imaging techniques. Amongst a historic cohort of 58 chronically transfused patients with SCD, we were able to evaluate 44 patients who are currently alive and had multiple follow-up testing. Their mean age (±SD) was 35 (9) years and comprised of 68.2% of women. The studied iron-overload parameters included cardiac T2* MRI, liver iron concentration (LIC) by Liver T2* MRI, and serial SF levels. Additionally, in a smaller cohort, we also studied LIC by FerriScan© R2-MRI. Chronic blood transfusions were necessary for severe vaso-occlusive crisis (VOC) (38.6%), severe symptomatic anemia (38.6%), past history of stroke (15.9%), and recurrent acute chest syndrome (6.9%). About 14 (24%) patients among the original cohort died following SCD-related complications. Among the patients currently receiving chelation, 26 (96%) are on Deferasirox (DFX) [Jadenu® (24) or Exjade® (2)], with good compliance and tolerance. However, one patient is still receiving IV deferoxamine (DFO), in view of the significantly high systemic iron burden. In this evaluable cohort of 44 patients, the mean SF (±SD) reduced marginally from 4,311 to 4,230 ng/ml, mean Liver T2* MRI dropped from 12 to 10.3 mg/gm dry weight, while the mean cardiac T2*MRI improved from 36.8 to 39.5 ms. There was a mild to moderate correlation between the baseline and final values of SF ng/ml, r = 0.33, p = 0.01; Cardiac T2* MRI ms, r = 0.3, p = 0.02 and Liver T2* MRI mg/kg dry weight, r = 0.6, p < 0.001. Overall, there was a positive correlation between SF and Liver T2* MRI (Pearson's r = 0.78, p < 0.001). Cardiac T2*MRI increased with the decreasing SF concentration, showing a negative correlation which was statistically significant (Pearson's r = -0.6, p < 0.001). Furthermore, there was an excellent correlation between SF ng/ml and LIC by FerriScan© R2-MRI mg/g or mmol/kg (Spearmen's rho = -0.723, p < 0.008) in a small subset of patients (n = 14) who underwent the procedure. In conclusion, our study demonstrated a good correlation between serial SF and LIC by either Liver MRI T2* or by FerriScan© R2-MRI, even though SF is an acute-phase reactant. It also confirms the cardiac sparing effect in patients with SCD, even with the significant transfusion-related iron burden. About 14 (24%) patients of the original cohort died over the past 15 years, indicative of a negative impact of iron overload on disease morbidity and mortality.
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The pivotal Endari trial in sickle cell disease showed a reduction in pain crises events. This reanalysis of the l-glutamine phase 3 trial using annual rates of pain crises, consistent with other SCD studies, supported the statistically significant outcomes of the original analysis. The observed 45% difference in the VOC rate is comparable to what was reported in other sickle cell therapeutics used to reduce the incidence of pain. The results presented in this communication are informative for clinicians evaluating treatment effects across available SCD therapeutic options based on studies that utilized VOC as the primary endpoint.
Assuntos
Anemia Falciforme , Glutamina , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Comunicação , Humanos , Dor/tratamento farmacológico , Dor/etiologiaRESUMO
OBJECTIVE: To assess the clinical and laboratory predictors of venous thromboembolism (VTE) in patients with sickle cell anaemia (SCA) and its relationship to morbidity and mortality. METHODS: This retrospective case-control study analysed data from patients with SCA that experienced VTE compared with matched control patients with SCA but no VTE (2:1 ratio). RESULTS: A total of 102 patients with SCA were enrolled (68 cases with VTE and 34 controls). Amongst the 68 cases (median age, 29.5 years), 26 (38.2%) presented with isolated pulmonary embolism (PE). A higher prevalence of splenectomy (73.5% versus 35.3%) was observed in the cases compared with the controls. A significantly higher prevalence of central venous catheter (CVC) insertion (42.6% versus 8.8%) was observed in the cases compared with the controls. High white blood cell counts, serum lactic dehydrogenase (LDH), bilirubin and C-reactive protein (CRP) and low haemoglobin (Hb) and HbF were significant risk factors for VTE. Forty-two cases (61.8%) developed acute chest syndrome, 10 (14.7%) had a stroke and seven (10.3%) died. CONCLUSIONS: VTE in patients with SCA has a high impact on morbidity and mortality. PE was the leading presentation of VTE, with CVC insertion, high LDH, bilirubin, CRP and white blood cell counts along with low Hb and HbF constituting other significant risk factors.
Assuntos
Anemia Falciforme , Tromboembolia Venosa , Adulto , Anemia Falciforme/complicações , Estudos de Casos e Controles , Humanos , Estudos Retrospectivos , Fatores de Risco , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controleRESUMO
OBJECTIVES: We sought to investigate the nutritional and hematological status of Sudanese women of childbearing age with sickle cell anemia (SCA). Anthropometry and hematology were used to assess nutritional status and health and disease conditions, respectively. METHODS: Women with steady-state (HbSS, n = 39; age = 19.0±2.7) and without (HbAA, n = 36; age, 19.8±2.7) SCA were recruited during a routine visit to the Hematology Clinic, Ibn-Auf Teaching Hospital, Khartoum, Sudan. RESULTS: The two groups of women lived in similar environmental conditions and ate similar diets three times a day. However, despite taking regular meals, the women with sickle anemia were thinner and lighter (p < 0.001) and shorter (p = 0.002) compared with those who do not have the disease. Also, they had higher levels of mean corpuscular hemoglobin (Hb) concentration and white cell count (p < 0.001), mean corpuscular volume (p = 0.003), and platelet (p = 0.002) and lower packed cell volume and Hb (p < 0.001). There was no difference in levels of anthropometric and hematological variables between the hydroxyurea treated and untreated SCA patients (p > 0.050). CONCLUSIONS: The low anthropometric (height, weight, and body mass index) and abnormal hematological values in the women with SCA in steady-state reflect sustained nutritional insults inflected by the disease and poverty. Tailored nutritional counseling/advice must be an integral part of managing patients with SCA. Such advice is particularly vital for women of childbearing age because of the adverse effects of prepregnancy nutritional deficiency on outcomes.