Initiation of regular transfusion in transfusion-dependent thalassemia (TDT) is based on the assessment of clinical phenotype. Pathogenic HBB variants causing β-thalassemia are important determinants ...of phenotype and could be used to aid decision making. We investigated the association of HBB genotype with survival in a cohort study in the four thalassemia centres in Cyprus. HBB genotype was classified as severe (β0/β0 or β+/β0), moderate (β+/β+), or mild (β0/β++ or β+/β++). Risk factors for mortality were evaluated using multivariate Cox proportional-hazards regression. 537 subjects were followed for a total of 20,963 person years. 80.4% (95% CI 76.4-84.7) of individuals survived to 50 years of age with increasing rates of liver, infection and malignancy-related deaths observed during recent follow-up. We evaluated non-modifiable risk factors and found worse outcomes associated with male sex (Hazard ratio 1.9, 95% CI 1.1-3.0, p=0.01) and milder genotype (Hazard ratio 1.6, 95% CI 1.1-2.3, p=0.02). The effect of genotype was confirmed in a second model, which included treatment effects. Patients with a milder genotype initiated transfusion significantly later and had reduced blood requirements compared to those with moderate or severe genotypes, although pre-transfusion hemoglobin levels did not differ between genotypes. Our results suggest that early treatment decisions to delay transfusion and different long-term treatment strategies in milder genotypes have led to adverse long-term effects of under-treated thalassemia and worse survival. We propose that HBB genotype determination and use of this information to aid in decision making can improve long-term outcomes of thalassaemia patients.
Haemoglobinopathies, including thalassaemias and sickle-cell syndromes, are demanding, lifelong conditions that pose a significant burden to patients, families, and healthcare systems. Despite the ...therapeutic advances and the resulting improvements in prognosis accomplished in past decades, these patients still face important challenges, including suboptimal access to quality care in areas with developing economies, changing epidemiology due to massive migration flows, an evolving clinical spectrum due to ageing in well-treated patients, and limited access to novel high-cost therapies. We herein describe the organization of healthcare services for haemoglobinopathies in Cyprus—with particular focus on beta-thalassaemia, the most prevalent condition in this region—along with selected patient outcomes. This report aims at underscoring the fact that nationally funded and well-coordinated prevention and care programmes for chronic and complex conditions, such as haemoglobinopathies, with active involvement from patient organizations lead to effective disease control and excellent outcomes in survival, quality of life, social adaptation, and public health savings, and allow timely and effective responses to emerging crises, such as the COVID-19 pandemic. The Cyprus paradigm could therefore serve as a blueprint for the organization or adaptation of haemoglobinopathy programs in other countries since these disorders are still widely occurring.
The +33 C>G variant NM_000518.5(HBB):c.-18C>G in the 5' untranslated region (UTR) of the β-globin gene is described in the literature as both mild and silent, while it causes a phenotype of ...thalassemia intermedia in the presence of a severe β-thalassemia allele. Despite its potential clinical significance, the determination of its pathogenicity according to established standards requires a greater number of published cases and co-segregation evidence than what is currently available. The present study provides an extensive phenotypic characterization of +33 C>G using 26 heterozygous and 11 compound heterozygous novel cases detected in Cyprus and employs computational predictors (CADD, RegulomeDB) to better understand its impact on clinical severity. Genotype identification of globin gene variants, including α- and δ-thalassemia determinants, and rs7482144 (XmnI) was carried out using Sanger sequencing, gap-PCR, and restriction enzyme digestion methods. The heterozygous state of +33 C>G had a silent phenotype without apparent microcytosis or hypochromia, while compound heterozygosity with a β+ or β0 allele had a spectrum of clinical phenotypes. Awareness of the +33 C>G is required across Mediterranean populations where β-thalassemia is frequent, particularly in Cyprus, with significant relevance in population screening and fetal diagnostic applications.
Background
Data on the prevalence and type of endocrine disorders in β-thalassemia intermedia (β-TI) patients are scarce. This multicenter study was designed to determine the prevalence of endocrine ...complications and the associated risk factors in a large group of β-TI patients.
Methods
In this cross-sectional multicenter study, 726 β-TI patients, aged 2.5–80 years, registered at 12 thalassemic centers, from nine countries, were enrolled during 2017. In a subgroup of 522 patients (mean age 30.8 ± 12.1; range: 2.5–80 years) from Qatar, Iran, Oman, Cyprus, and Jordan detailed data were available.
Results
Overall, the most prevalent complications were osteopenia/osteoporosis (22.3%), hypogonadism (10.1%), and primary hypothyroidism (5.3%). In the subgroup multivariate analysis, older age was a risk factor for osteoporosis (Odds ratio: 7.870, 95% CI: 4.729–13.099,
P
< 0.001), hypogonadism (Odds ratio: 6.310, 95% CI: 2.944–13.521,
P
< 0.001), and non-insulin-dependent diabetes mellitus (NIDDM; Odds ratio: 17.67, 95% CI: 2.217–140.968,
P
= 0.007). Splenectomy was a risk factor for osteoporosis (Odds ratio: 1.736, 95% CI: 1.012–2.977,
P
= 0.045). Hydroxyurea was identified as a “protective factor” for NIDDM (Odds ratio: 0.259, 95% CI: 0.074–0.902,
P
= 0.034).
Conclusions
To the best of our knowledge, this is the largest cohort of β-TI patients with endocrine disorders evaluated in extremely heterogenic thalassemic populations for age, clinical, hematological, and molecular composition. The study demonstrates that endocrine complications are less common in patients with β-TI compared with β-TM patients. However, regular monitoring with timely diagnosis and proper management is crucial to prevent endocrine complications in β-TI patients.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Therapy via the gene addition of the anti-sickling βAS3-globin transgene is potentially curative for all β-hemoglobinopathies and therefore of particular clinical and commercial interest. This study ...investigates GLOBE-based lentiviral vectors (LVs) for βAS3-globin addition and evaluates strategies for an increased β-like globin expression without vector dose escalation. First, we report the development of a GLOBE-derived LV, GLV2-βAS3, which, compared to its parental vector, adds anti-sickling action and a transcription-enhancing 848-bp transcription terminator element, retains high vector titers and allows for superior β-like globin expression in primary patient-derived hematopoietic stem and progenitor cells (HSPCs). Second, prompted by our previous correction of HBBIVSI−110(G>A) thalassemia based on RNApol(III)-driven shRNAs in mono- and combination therapy, we analyzed a series of novel LVs for the RNApol(II)-driven constitutive or late-erythroid expression of HBBIVSI−110(G>A)-specific miRNA30-embedded shRNAs (shRNAmiR). This included bifunctional LVs, allowing for concurrent βAS3-globin expression. LVs were initially compared for their ability to achieve high β-like globin expression in HBBIVSI−110(G>A)-transgenic cells, before the evaluation of shortlisted candidate LVs in HBBIVSI−110(G>A)-homozygous HSPCs. The latter revealed that β-globin promoter-driven designs for monotherapy with HBBIVSI−110(G>A)-specific shRNAmiRs only marginally increased β-globin levels compared to untransduced cells, whereas bifunctional LVs combining miR30-shRNA with βAS3-globin expression showed disease correction similar to that achieved by the parental GLV2-βAS3 vector. Our results establish the feasibility of high titers for LVs containing the full HBB transcription terminator, emphasize the importance of the HBB terminator for the high-level expression of HBB-like transgenes, qualify the therapeutic utility of late-erythroid HBBIVSI−110(G>A)-specific miR30-shRNA expression and highlight the exceptional potential of GLV2-βAS3 for the treatment of severe β-hemoglobinopathies.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Genome editing tools, such as CRISPR/Cas, TALE nucleases and, more recently, double-strand-break-independent editors, have been successfully used for gene therapy and reverse genetics. Among various ...challenges in the field, tolerable and efficient delivery of editors to target cells and sites, as well as independence from commercially available tools for flexibility and fast adoption of new editing technology are the most pressing. For many hematopoietic research applications, primary CD34
cells and the human umbilical cord-derived progenitor erythroid 2 (HUDEP-2) cell line are highly informative substrates and readily accessible for
manipulation. Moreover,
editing of CD34
cells has immediate therapeutic relevance. Both cell types are sensitive to standard transfection procedures and reagents, such as lipofection with plasmid DNA, calling for more suitable methodology in order to achieve high efficiency and tolerability of editing with editors of choice. These challenges can be addressed by RNA delivery, either as a mixture of guide RNA and mRNA for CRISRP/Cas-based systems or as a mixture of mRNAs for TALENs. Compared to ribonucleoproteins or proteins, RNA as vector creates flexibility by removing dependence on commercial availability or laborious in-house preparations of novel editor proteins. Compared to DNA, RNA is less toxic and by obviating nuclear transcription and export of mRNA offers faster kinetics and higher editing efficiencies.
Here, we detail an
transcription protocol based on plasmid DNA templates with the addition of Anti-Reverse Cap Analog (ARCA) using T7 RNA polymerase, and poly (A) tailing using poly (A) polymerase, combined with nucleofection of HUDEP-2 and patient-derived CD34
cells. Our protocol for RNA-based delivery employs widely available reagents and equipment and can easily be adopted for universal
delivery of genome editing tools.
Drawing on a common use case, we employ the protocol to target a β-globin mutation and to reactivate γ-globin expression as two potential therapies for β-hemoglobinopathies, followed by erythroid differentiation and functional analyses. Our protocol allows high editing efficiencies and unimpaired cell viability and differentiation, with scalability, suitability for functional assessment of editing outcomes and high flexibility in the application to different editors.
IntroductionTo evaluate the effect of early chelation therapy (≤ 3 years) with a variety of chelating agents on age at menarche and menstrual characteristics in patients with transfusion-dependent ...thalassemia (TDT).DesignA retrospective multicenter study promoted by the International Network of Clinicians for Endocrinopathies in Thalassemia and Adolescent Medicine (ICET-A).SettingEight of 13 International Thalassemia Centers (61.5%) in the ICET-A Network participated.PatientsFifty-seven female TDT patients, aged 11 to 26 years, and with early iron chelation therapy, were eligible for the present study. They were enrolled from one center from Iran (33 patients), 3 centers from Bulgaria (9), 1 from Greece (8), one from Oman (4), 1 from Cyprus (2), and 1 from Italy (1). Seven patients were excluded, four still prepubertal (age 12-14 years) and 3 with primary amenorrhea. Therefore 50 patients were finally enrolled.ResultsAll fifty TDT patients developed spontaneous menarche at a mean age of 14.2 ± 2.24 years (range 9 - 20). A significant positive correlation was observed between age at menarche and serum ferritin levels (r: 0. 41, p=0.005). Regular menstrual cycles were reported from 32 (64%) patients, of whom 28 (83.3%) get menarche at age ≤ 14 years. Complications were more frequent in patients older than 14 years at menarche and in those with secondary amenorrhea.ConclusionsAge at menarche greater than 14 years was a forerunner of menstrual irregularities and associated complications in 36% of patients despite precocious chelation therapy. The poor adherence to treatment, to be demonstrated in future studies, could explain the finding.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
β-thalassemia is a disorder caused by altered hemoglobin protein synthesis and affects individuals worldwide. Severe forms of the disease, left untreated, can result in death before the age of 3 ...years (1). The standard of care consists of chronic and costly palliative treatment by blood transfusion combined with iron chelation. This dual approach suppresses anemia and reduces iron-related toxicities in patients. Allogeneic bone marrow transplant is an option, but limited by the availability of a highly compatible HSC donor. While gene therapy is been explored in several trials, its use is highly limited to developed regions with centers of excellence and well-established healthcare systems (2). Hence, there remains a tremendous unmet medical need to develop alternative treatment strategies for β-thalassemia (3). Occurrence of aberrant splicing is one of the processes that affects β-globin synthesis in β-thalassemia. The (C>G) IVS-2-745 is a splicing mutation within intron 2 of the β-globin gene. It leads to an aberrantly spliced mRNA that incorporates an intron fragment. This results in an in-frame premature termination codon that inhibits β-globin production. Here, we propose the use of uniform 2'-O-methoxyethyl (2'-MOE) splice switching oligos (SSOs) to reverse this aberrant splicing in the pre-mRNA. With these lead SSOs we show aberrant to wild type splice switching. This switching leads to an increase of adult hemoglobin (HbA) up to 80% in erythroid cells from patients with the IVS-2-745 mutation. Furthermore, we demonstrate a restoration of the balance between β-like- and α-globin chains, and up to an 87% reduction in toxic α-heme aggregates. While examining the potential benefit of 2'-MOE-SSOs in a mixed sickle-thalassemic phenotypic setting, we found reduced HbS synthesis and sickle cell formation due to HbA induction. In summary, 2'-MOE-SSOs are a promising therapy for forms of β-thalassemia caused by mutations leading to aberrant splicing.
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