Dataset Information

Transfusion independence and HMGA2 activation after gene therapy of human ?-thalassaemia.

ABSTRACT: The ?-haemoglobinopathies are the most prevalent inherited disorders worldwide. Gene therapy of ?-thalassaemia is particularly challenging given the requirement for massive haemoglobin production in a lineage-specific manner and the lack of selective advantage for corrected haematopoietic stem cells. Compound ?(E)/?(0)-thalassaemia is the most common form of severe thalassaemia in southeast Asian countries and their diasporas. The ?(E)-globin allele bears a point mutation that causes alternative splicing. The abnormally spliced form is non-coding, whereas the correctly spliced messenger RNA expresses a mutated ?(E)-globin with partial instability. When this is compounded with a non-functional ?(0) allele, a profound decrease in ?-globin synthesis results, and approximately half of ?(E)/?(0)-thalassaemia patients are transfusion-dependent. The only available curative therapy is allogeneic haematopoietic stem cell transplantation, although most patients do not have a human-leukocyte-antigen-matched, geno-identical donor, and those who do still risk rejection or graft-versus-host disease. Here we show that, 33 months after lentiviral ?-globin gene transfer, an adult patient with severe ?(E)/?(0)-thalassaemia dependent on monthly transfusions since early childhood has become transfusion independent for the past 21?months. Blood haemoglobin is maintained between 9 and 10?g?dl(-1), of which one-third contains vector-encoded ?-globin. Most of the therapeutic benefit results from a dominant, myeloid-biased cell clone, in which the integrated vector causes transcriptional activation of HMGA2 in erythroid cells with further increased expression of a truncated HMGA2 mRNA insensitive to degradation by let-7 microRNAs. The clonal dominance that accompanies therapeutic efficacy may be coincidental and stochastic or result from a hitherto benign cell expansion caused by dysregulation of the HMGA2 gene in stem/progenitor cells.

SUBMITTER: Cavazzana-Calvo M

PROVIDER: S-EPMC3355472 | biostudies-literature | 2010 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Transfusion independence and HMGA2 activation after gene therapy of human β-thalassaemia.

Cavazzana-Calvo Marina M Payen Emmanuel E Negre Olivier O Wang Gary G Hehir Kathleen K Fusil Floriane F Down Julian J Denaro Maria M Brady Troy T Westerman Karen K Cavallesco Resy R Gillet-Legrand Beatrix B Caccavelli Laure L Sgarra Riccardo R Maouche-Chrétien Leila L Bernaudin Françoise F Girot Robert R Dorazio Ronald R Mulder Geert-Jan GJ Polack Axel A Bank Arthur A Soulier Jean J Larghero Jérôme J Kabbara Nabil N Dalle Bruno B Gourmel Bernard B Socie Gérard G Chrétien Stany S Cartier Nathalie N Aubourg Patrick P Fischer Alain A Cornetta Kenneth K Galacteros Frédéric F Beuzard Yves Y Gluckman Eliane E Bushman Frederick F Hacein-Bey-Abina Salima S Leboulch Philippe P

Nature 20100901 7313

The β-haemoglobinopathies are the most prevalent inherited disorders worldwide. Gene therapy of β-thalassaemia is particularly challenging given the requirement for massive haemoglobin production in a lineage-specific manner and the lack of selective advantage for corrected haematopoietic stem cells. Compound β(E)/β(0)-thalassaemia is the most common form of severe thalassaemia in southeast Asian countries and their diasporas. The β(E)-globin allele bears a point mutation that causes alternative ...[more]

PMID: 20844535

Similar Datasets

Project description:BackgroundHydroxyurea (hydroxycarbamide) promotes the production of foetal haemoglobin (HbF) by reactivating gamma-genes. Evidence has shown clinical benefits of hydroxyurea in people with sickle cell anemia; however, only a few studies have assessed this treatment in people with beta (β)-thalassaemia.ObjectivesThe primary objective is to review the efficacy of hydroxyurea in reducing or ameliorating the requirement of blood transfusions in people with transfusion-dependent β-thalassaemia. The second objective is to review the safety of hydroxyurea with regards to severe adverse effects in this population.Search methodsWe searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register, compiled from electronic database searches and hand searching of journals and conference abstract books. We also searched electronic databases and trial registries, including ClinicalTrials.gov, the WHO ICTRP and PubMed (09 October 2018).Date of last search of the Group's haemoglobinopathies trials register: 04 March 2019.Selection criteriaRandomised controlled trials of hydroxyurea in people with transfusion-dependent β-thalassaemia, compared with placebo or standard treatment or comparing different doses of hydroxyurea.Data collection and analysisTwo authors independently assessed trials for inclusion in the review, which was verified by a third author.Main resultsNo trials were eligible for inclusion in this review.Authors' conclusionsCurrently, there is no high-quality evidence to support or challenge the continued use of hydroxyurea for managing people with transfusion-dependent β-thalassaemia. Multicentre, randomised controlled trials (compared to placebo or other available treatment, i.e. blood transfusion and iron chelation) are needed in order to assess the efficacy and safety of hydroxyurea for reducing the need for blood transfusion, for maintaining or improving mean haemoglobin levels, as well as for determining its cost-effectiveness.

Project description:IntroductionAround 5% of the world's population is expected to have some degree and type of thalassaemia. Beta thalassaemia (BT) occurs due to a deficient production of the beta-globin chain of haemoglobin. Extramedullary haematopoiesis (EMH) is one of the complications of BT, mainly observed in minor/intermedia subtypes. EMH is the production of blood cells outside the marrow as a compensatory response to longstanding hypoxia. Due to chronic transfusions, it is not expected in patients with beta-thalassaemia major (BTM). However, there are increasingly reported cases of EMH in BTM. The incidence of EMH in BTM is thought to be <1%. We aim to pool the available data and provide cumulative evidence on the occurrence of EMH in BTM patients.MethodsThis is a systematic review of case reports, series, and retrospective studies that presented data on the occurrence of EMH in BTM patients. Data were recorded and analyzed in Microsoft Excel 2016 and SPSS 26. The protocol has been registered in PROSPERO: CRD42021242943.ResultsData from 253 cases of EMH in BTM patients were extracted with a mean age of 35.3 years. Mean haemoglobin at presentation with EMH was 8.2 mg/dL. Lower limb weakness was the most common presenting feature (N = 23) (paraspinal EMH). Magnetic resonance imaging (MRI) was the most widely used diagnostic modality (226). Overall, blood transfusion was the commonest reported treatment (30), followed by radiotherapy (20), surgery (15), hydroxyurea (12), steroids (6), and exchange transfusion (2). An outcome was reported in 20% of patients, all recovered, except one who died as a result of nosocomial infection.ConclusionEMH is rare in BTM and can occur in any organ system with varied clinical features. MRI can effectively diagnose EMH, and conservative management has similar results compared to invasive treatments. Larger studies, focussing on outcomes may enhance guidelines on preventive and therapeutic strategies for managing EMH in BTM.KEY MESSAGESExtramedullary haematopoiesis is a rare complication in beta thalassaemia. Although it is more common in non-transfusion dependent thalassaemia, increasingly reported cases suggest a higher prevalence of EMH in TDT than what is known before.There are no clear guidelines on the management of EMH in TDT, with reported patients showing similar outcomes with conservative invasive treatment modalities.More extensive and preferably prospectively designed studies are required focussing on the management of EMH and its outcomes in patients with TDT to formulate evidence-based guidelines.

Project description:BACKGROUND:Thalassaemia is a chronic disease which requires lifelong treatment in a majority. Despite recent advances in the medical care, minimal attempts are made to improve psychological health in these patients. In this study, we aim to describe the psychological morbidity in patients with transfusion dependent ?-thalassaemia and their mothers in Sri Lanka. METHODS:This case control study was conducted in the three largest thalassaemia centres of Sri Lanka. All patients with transfusion dependent ?-thalassaemia aged 4-18 years were recruited as cases whilst a randomly selected group of children without chronic diseases were recruited as controls. Psychological morbidity of children was assessed using the Strengths and Difficulties Questionnaire and depressive symptoms of mothers was assessed by the Centre for Epidemiological Studies Depression Scale. RESULTS:288 transfusion dependent ?-thalassaemia patients and equal number of controls were recruited. Abnormal emotional, conduct, hyperactivity and peer relationship symptom scores were reported by 18%, 17%, 9% and 14% of patients with thalassaemia respectively. Prevalences of abnormal psychological symptom scores in all domains were significantly higher among patients compared to controls. Abnormal conduct symptoms were significantly more prevalent among patients with HbE ?-thalassaemia and those with suboptimal pretransfusion haemoglobin levels, lower transfusion volumes, hypothyroidism and undernutrition. Short stature was associated with abnormal emotional and hyperactivity scores. Depressive symptoms were significantly higher among mothers of patients with thalassaemia. Higher depressive symptom scores in mothers were significantly associated with abnormal emotional, conduct and peer relationship symptom scores in children. CONCLUSIONS:A higher proportion of patients with transfusion dependent ?-thalassaemia had abnormal psychological symptom scores. Abnormal conduct symptoms were more prevalent among patients with HbE ?-thalassaemia, those who were inadequately transfused and having hypothyroidism and undernutrition. Mothers of the children with transfusion dependent ?-thalassaemia had significantly higher depressive symptoms which were significantly associated with psychological symptoms among children.

Project description:BackgroundHematopoietic stem cell transplantation (HSCT) is a treatment option with curative intent for patients with transfusion dependent thalassemia (TDT) but its application is limited by the lack of suitable donors and acceptability due to the related morbidity/mortality. Transplantation of autologous genetically modified hematopoietic cells, gene therapy (GT) is emerging as a promising treatment option for TDT as it eliminates graft versus host disease (GVHD) and need for immunosuppression. Early results of GT suggest that many, but not all patients achieve transfusion independence after the procedure. There is little information about the acceptability of GT in patients with TDT. We sought to examine patient/family knowledge about GT in TDT and to examine factors that influence decision-making about this therapy.MethodsParents of children with TDT and adults with TDT were who provided informed consent underwent semi-structured interviews to understand patient/family knowledge and decision-making regarding GT in TDT. Transcribed interviews were coded and the data was examined for emerging themes using a combination of thematic and content analysis.ResultsTwenty-five study participants with mean age of 38Y (17-52Y) including eight adults living with TDT, and 17 parents of children with TDT underwent semi-structured qualitative interviews. Participant responses coalesced around broad themes related to knowledge of GT, motivating/deterring factors and outcomes. Study participants expressed a desire for 'cure' from thalassemia including transfusion independence, chelation reduction and improved quality of life as motivators for considering GT. Insufficient knowledge about the process, long-term outcomes, safety, and side effects as well as the potential for death/failure of the procedure were deterrents for the consideration GT. Reduction in frequency of transfusions, even without elimination of transfusions was an acceptable outcome of GT for most participants. Participant choice for preferred treatment modality was split between indefinitely continuing transfusions which was familiar to them versus GT which was unfamiliar, and with an uncertain outcome. None of the participants had a matched sibling donor; alternate donor HSCT was the least preferred option in this group.ConclusionThere is tempered excitement about GT in patients/families with TDT with a general willingness to accept transfusions reduction as the outcome.

Project description:BackgroundTransfusion-dependent thalassaemia (TDT) is a hereditary blood disorder in which blood transfusion is the mainstay treatment to prolong survival and improve quality of life. Patients with this disease require blood transfusion at more than 100 ml/kg annually and iron-chelating therapy (ICT) to prevent iron overload (IOL) complications. There are substantial numbers of TDT patients in Malaysia, but limited data are available regarding the economic burden associated with this disease. The purpose of this study was to determine the lifetime cost of TDT from a societal perspective and identify potential factors increasing patient and family expenditures among thalassaemia populations.MethodsThe total lifetime cost per TDT patient (TC1) is the sum of lifetime healthcare cost (TC2) and lifetime patient and family healthcare expenditure (TC3). TC2 was simulated using the Markov model, taking into account all costs subsidized by the government, and TC3 was estimated through a cross-sectional health survey approach. A survey was performed using a two-stage sampling method in 13 thalassaemia centres covering all regions in Malaysia.ResultsA TDT patient is expected to incur TC2 of USD 561,208. ICT was the main driver of cost and accounted for 56.9% of the total cost followed by blood transfusion cost at 13.1%. TC3 was estimated to be USD 45,458. Therefore, the estimated TC1 of a TDT patient was USD 606,665. Sensitivity analyses showed that if all patients were prescribed oral ICT deferasirox for their lifetime, the total healthcare cost would increase by approximately 65%. Frequency of visits to health facilities for blood transfusion/routine monitoring and patients who were prescribed desferrioxamine were observed to be factors affecting patient and family monthly expenses.ConclusionThe lifetime cost per TDT patient was USD 606,665, and this result may be useful for national health allocation planning. An estimation of the economic burden will provide additional information to decision makers on implementing prevention interventions to reduce the number of new births and medical service reimbursement.

Dataset Information

Transfusion independence and HMGA2 activation after gene therapy of human ?-thalassaemia.

Publications

Transfusion independence and HMGA2 activation after gene therapy of human β-thalassaemia.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets