β-Thalassemia

Upregulation of miR‑6747‑3p affects red blood cell lineage development and induces fetal hemoglobin expression by targeting BCL11A in β‑thalassemia

In β‑thalassemia, excessive α‑globin chain impedes the normal development of red blood cells resulting in anemia. Numerous miRNAs, including miR‑6747‑3p, are aberrantly expressed in β‑thalassemia major (β‑TM), but there are no reports on the mechanism of miR‑6747‑3p in regulating red blood cell lineage development and fetal hemoglobin (HbF) expression. In the present study, RT‑qPCR was utilized to confirm miR‑6747‑3p expression in patients with β‑TM and the healthy controls. Electrotransfection was employed to introduce the miR‑6747‑3p mimic and inhibitor in both HUDEP‑2 and K562 cells, and red blood cell lineage development was evaluated by CCK‑8 assay, flow cytometry, Wright‑Giemsa staining and Benzidine blue staining. B‑cell lymphoma/leukemia 11A (BCL11A) was selected as a candidate target gene of miR‑6747‑3p for further validation through FISH assay, dual luciferase assay and Western blotting. The results indicated that miR‑6747‑3p expression was notably higher in patients with β‑TM compared with healthy controls and was positively related to HbF levels. Functionally, miR‑6747‑3p overexpression resulted in the hindrance of cell proliferation, promotion of cell apoptosis, facilitation of cellular erythroid differentiation and γ‑globin expression in HUDEP‑2 and K562 cells. Mechanistically, miR‑6747‑3p could specifically bind to the 546‑552 loci of BCL11A 3'‑UTR and induce γ‑globin expression. These data indicate that upregulation of miR‑6747‑3p affects red blood cell lineage development and induces HbF expression by targeting BCL11A in β‑thalassemia, highlighting miR‑6747‑3p as a potential molecular target for β‑thalassemia therapy.

Clinical Burden and Healthcare Resource Utilization Associated With Managing Transfusion-dependent β-Thalassemia in England

PURPOSE

Patients with transfusion-dependent β-thalassemia (TDT) have reduced levels of β-globin, leading to ineffective erythropoiesis and iron overload. Patients with TDT depend on regular red blood cell transfusions (RBCTs) and iron chelation therapy for survival and management of disease- and treatment-related clinical complications. This study describes the clinical and economic burden in patients with TDT in England.

METHODS

This longitudinal, retrospective study linked the Clinical Practice Research Datalink (CPRD) database with secondary care data from the Hospital Episode Statistics database to identify patients with a diagnosis of β-thalassemia between July 1, 2008, and June 30, 2018. Included patients had a diagnosis of β-thalassemia prior to the index date, ≥8 RBCTs per year for ≥2 consecutive years, and ≥1 year of follow-up data available from the index date. Each eligible patient was exact matched with up to 5 controls in the CPRD. Proportions of deaths and rates of mortality, acute and chronic complications, and healthcare resource utilization (HCRU) were calculated during the follow-up period.

FINDINGS

Of 11,359 identified patients with β-thalassemia, 237 patients with TDT met the eligibility criteria and were matched with 1184 controls. The mean age at the index date was approximately 25 years in the patient and control groups. The proportion of deaths (7.17% vs 1.18%; P < 0.05) and mortality rate (1.19 deaths per 100 person-years vs 0.20 deaths per 100 person-years) were higher among patients with TDT compared to controls. Endocrine complications and bone disorders were the most prevalent complications among patients with TDT (58.23%) and included osteoporosis (29.11%), diabetes mellitus (28.27%), and hypopituitarism (28.27%). Patients with TDT had a mean of 13.62 RBCTs per patient per year (PPPY). HCRU was substantially higher among patients with TDT, wherein patients with TDT had higher rates of prescriptions recorded in primary care (24.09 vs 8.61 PPPY), outpatient visits (16.69 vs 1.31 PPPY), and inpatient hospitalizations (17.41 vs 0.24 PPPY) than controls. Inpatient hospitalizations were primarily <1 day, with 16.62 events PPPY lasting <1 day and 0.79 events PPPY lasting ≥1 day. Patients with TDT aged ≥18 years had increased rates of mortality, clinical complications, and HCRU than those aged <18 years.

IMPLICATIONS

Patients with TDT in England have higher mortality than matched controls, substantial disease-related clinical complications, and substantial HCRU. High mortality and clinical complications highlight the need for additional innovative therapies for TDT.

Relationship between hemoglobinopathies and male infertility: a scoping review

Infertility is a common issue that threatens couples worldwide. Infertility can result from the male or female partner alone, or both partners. It can be due to multiple factors related to the patient's overall health or lifestyle. Causes related to patient health can be systemic or related to gonadal dysfunction. One of the systematic causes can be hematological. The two most common hemoglobinopathies that are thought to cause infertility, especially male infertility, are sickle cell disease (SCD) and thalassemia major (TM). These two hemoglobinopathies cause male infertility through pathophysiological alterations. Specifically, they alter the oxygen carrying ability of red blood cells (RBCs), causing tissue hypoxia that affects the normal physiological process of spermatogenesis, eventually inducing infertility. Semen analyses and other systemic blood testing can be used to investigate male infertility. Both hemoglobinopathies can be helped by blood transfusions, which can then alleviate male infertility. This paper aims to explore the relationship between hemoglobinopathies (SCD and TM) and their role in contributing to male infertility, in addition to the role of blood transfusions in addressing male infertility by correcting the root cause.

Impact of met-haemoglobin and oxidative stress on endothelial function in patients with transfusion dependent β-thalassemia

Transfusion dependent β-thalassemia is a genetic blood disorder characterized by chronic anaemia. Blood transfusion is lifesaving but comes at a cost. Iron overload emerges as a prime culprit as a free radicals damage endothelial cells. Chronic anaemia further disrupts oxygen delivery, exacerbating the oxidative stress. Increased levels of met-haemoglobin and malondialdehyde compromise endothelial function. This research sheds light on the impact of met-haemoglobin and oxidative stress on endothelial function in 50 patients with transfusion dependent β-thalassemia major compared to 50 healthy individuals as control. Blood samples were collected & subjected to CBC, biochemical analysis including creatinine, ferritin, CRP, LDH, and HCV antibodies. Oxidative stress was assessed using met-haemoglobin & malondialdehyde. Endothelial dysfunction was evaluated by endothelial activation and stress index (EASIX). EASIX, met-haemoglobin and malondialdehyde were significantly increased in patients (1.44 ± 0.75, 2.07 ± 0.2, 4.8 ± 0.63; respectively) compared to the control (0.52 ± 0.24,0.88 ± 0.34,0.8 ± 0.34; respectively). Significant strong positive correlation was found between EASIX and met-haemoglobin, malondialdehyde, serum ferritin and CRP (P = 0.00, r = 0.904, P = 0.00, r = 0.948, P = 0.00, r = 0.772, P = 0.00, r = 0.971; respectively. Met-haemoglobin as well as EASIX should be routinely estimated to assess endothelial function especially before the decision of splenectomy. Antioxidant drugs should be supplemented.

Mandibular bone imaging assessment in thalassemia - a systematic review

OBJECTIVE

This systematic review aimed to verify if individuals with thalassemia present changes in radiomorphometric indices and fractal analysis that can be accessed using panoramic radiographs.

MATERIAL AND METHODS

Observational studies that evaluated cortical and trabecular bone patterns in dental routine radiographs were selected from six bibliographic databases. Risk of bias was analyzed using the Joanna Briggs Institute Critical Appraisal Checklists. Quality of evidence was verified using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

Two hundred three studies were initially retrieved from databases. Three cross-sectional studies, encompassing a total of 129 thalassemic patients, were deemed eligible after applying the inclusion criteria. Bone mineral density (BMD) evaluations were performed using panoramic radiographs and considered the following radiomorphometric indexes: mandibular cortical index (MCI), mandibular cortical width (MCW), panoramic mandibular index (PMI). Fractal dimension analysis (FDA) and simple visual estimation (SVE) were also employed. Overall, FDA and MCW from thalassemia individuals were lower than controls.

CONCLUSION

FDA and MCW are frequently altered in patients with thalassemia and may be employed as screening tools for reduced BMD. However, the certainty of evidence for this outcome was very low, mainly due to methodological flaws.

Prevalence and Molecular Characterization of β-Thalassemia in Kirkuk Province of Northern Iraq

To determine the prevalence and molecular basis of β-thalassemia in the Northeastern Iraqi province of Kirkuk, a total of 3954 individuals attending the provincial premarital screening center were recruited. The prevalence of β-thalassemia minor among the screened individuals was found to be 3.0%, while those of Hemoglobin E, and δβ-thalassemia carrier states were 0.05%, and 0.03% respectively. Molecular characterization of the β-thalassemia mutations was achieved by multiplex PCR and reverse hybridization, followed by next generation sequencing for those left uncharacterized by the former technique. Among 19 β-thalassemia mutations identified, seven were the most frequent, namely: IVS-II-1 (G > A), codon 8/9 (+G), IVS-I-6 (T > C), IVS-I-110 (G > A), IVS-I-I (G > A), IVS-I-5 (G > C) and codon 44 (-C) accounting for 78.5% of the mutations. This study further illustrates the heterogeneity of the spectrum of β-thalassemia in different parts of Iraq, and provides an essential step to facilitate prenatal diagnosis in the setting of a future national thalassemia prevention program.

In Utero Gene Therapy and its Application in Genetic Hearing Loss

For monogenic genetic diseases, in utero gene therapy (IUGT) shows the potential for early prevention against irreversible and lethal pathological changes. Moreover, animal models have also demonstrated the effectiveness of IUGT in the treatment of coagulation disorders, hemoglobinopathies, neurogenetic disorders, and metabolic and pulmonary diseases. For major alpha thalassemia and severe osteogenesis imperfecta, in utero stem cell transplantation has entered the phase I clinical trial stage. Within the realm of the inner ear, genetic hearing loss significantly hampers speech, cognitive, and intellectual development in children. Nowadays, gene therapies offer substantial promise for deafness, with the success of clinical trials in autosomal recessive deafness 9 using AAV-OTOF gene therapy. However, the majority of genetic mutations that cause deafness affect the development of cochlear structures before the birth of fetuses. Thus, gene therapy before alterations in cochlear structure leading to hearing loss has promising applications. In this review, addressing advances in various fields of IUGT, the progress, and application of IUGT in the treatment of genetic hearing loss are focused, in particular its implementation methods and unique advantages.

Technically feasible solutions to challenges in preimplantation genetic testing for thalassemia: experiences of multiple centers between 2019 and 2022

PURPOSE

In clinical practice, the success of preimplantation genetic testing for monogenic diseases (PGT-M) for thalassemia was hindered by the absence of probands, incomplete family members, or failure in detecting embryonic gene mutation sites. This study aimed to address these issues.

METHODS

This retrospective study included 342 couples undergoing PGT-M for α- or β-thalassemia at three reproductive medicine centers from 2019 to 2022. Various methods were used to construct parental haplotypes. A total of 1778 embryos were analyzed and selected for transfer based on chromosomal ploidy and PGT-M results. Follow-up involved amniocentesis results and clinical outcomes.

RESULTS

Haplotypes were established using DNA samples from probands or parents, as well as sibling blood samples, single sperm, and affected embryos, achieving an overall success rate was 99.4% (340/342). For α-thalassemia and β-thalassemia, the concordance between embryo single nucleotide polymorphism (SNP) haplotype analysis results and mutation loci detection results was 93.8% (1011/1078) and 98.2% (538/548), respectively. Multiple annealing and looping-based amplification cycles (MALBAC) showed a higher whole genome amplification success rate than multiple displacement amplification (MDA) (98.8% (1031/1044) vs. 96.2% (703/731), p < 0.001). Amniocentesis confirmed PGT-M outcomes in 100% of cases followed up (99/99).

CONCLUSION

This study summarizes feasible solutions to various challenging scenarios encountered in PGT-M for thalassemia, providing valuable insights to enhance success rate of PGT-M in clinical practice.

The predicting formula and scoring system for cardiac iron overload for thalassaemia children: Study from a middle-income country

Magnetic resonance imaging T2* screening is the gold standard for detecting cardiac iron overload in thalassemia, but its implementation in Indonesia is limited by the high costs. A predicting formula and scoring system based on low-cost investigations is needed. This cross-sectional study was conducted among thalassemia aged 6-18 years at Rumah Sakit Anak dan Bunda RSAB Harapan Kita Indonesia, during October 2017 to April 2019. All subjects were scheduled for clinical examination, laboratory tests, ECGs, echocardiography, tissue Doppler imaging, and MRIT2*. Multivariate logistic regression was used to identify the formula, simplifying to a scoring system, and risk classification for myocardial iron overload using odds ratio (OR) and 95% confidence interval (CI). Significance was set as p<0,05. We recruited 80 children, of those, 8 (10%) were classified as cardiac iron overload based on MRI T2* screening. Multivariate logistic regression showed determinant factors for cardiac iron overload were hemoglobin (95% CI:1.92-369.14), reticulocyte (95% CI:1.14-232.33), mitral deceleration time (DT) (95% CI:1.80-810.62,), and tricuspid regurgitation (TR Vmax) (95% CI:1.87-1942.56) with aOR of 26.65, 14.27, 38.22, and 60.27 respectively. The formula for cardiac iron overload was decided as 9.32 + 3.28 (Hb) + 2.9 (reticulocyte) + 3.64 (DT) + 4.1 (TR Vmax). A scoring system was defined by simplifying the formula of Hb ≤ 8.2 g/L, reticulocyte ≤0.33%, DT ≤ 114.5 cm/s, and TR Vmax ≥ 2.37 m/s were given a score of 1, while others were assigned 0. Total scores of 0 or 1, 2 and 3 or 4 were categorized as low, moderate, and high risk for iron cardiac overload. The cardiac iron overload formula was 9.32 + 3.28 (Hb) + 2.9 (reticulocyte) + 3.64 (DT) + 4.1 (TR Vmax). Variables of Hb ≤ 8.2 g/L, reticulocyte ≤0.33%, DT ≤ 114.5 cm/s, and TR Vmax ≥ 2.37 m/s were given a score of 1, while others were assigned 0. Total scores of 0 or 1, 2, and 3 or 4 were categorized as low, moderate, and high risk for iron cardiac overload.

Potential Use of MicroRNA Technology in Thalassemia Therapy

Thalassemia encompasses a group of inherited hemoglobin disorders characterized by reduced or absent production of the α- or β-globin chains, leading to anemia and other complications. Current management relies on lifelong blood transfusions and iron chelation, which is burdensome for patients. This review summarizes the emerging therapeutic potential of modulating microRNAs (miRNAs) to treat thalassemia. MiRNAs are small non-coding RNAs that regulate gene expression through sequence-specific binding to messenger RNAs (mRNAs). While they commonly repress gene expression by binding to the 3' untranslated regions (UTRs) of target mRNAs, miRNAs can also interact with 5'UTRs and gene promoters to activate gene expression. Many miRNAs are now recognized as critical regulators of erythropoiesis and are abnormally expressed in β-thalassemia. Therapeutically restoring levels of deficient miRNAs or inhibiting overexpression through miRNA mimics or inhibitors (antagomir), respectively, has shown preclinical efficacy in ameliorating thalassemic phenotypes. The miR-144/451 cluster is especially compelling for targeted upregulation to reactivate fetal hemoglobin synthesis. Advances in delivery systems are addressing previous challenges in stability and targeting of miRNA-based drugs. While still early, gene therapy studies suggest combinatorial approaches with miRNA modulation may provide synergistic benefits. Several key considerations remain including enhancing delivery, minimizing off-target effects, and demonstrating long-term safety and efficacy. While no miRNA therapies have yet progressed to clinical testing for thalassemia specifically, important lessons are being learned through clinical trials for other diseases and conditions, such as cancer, cardiovascular diseases, and viral. If limitations can be overcome through multi-disciplinary collaboration, miRNAs hold great promise to expand and transform treatment options for thalassemia in the future by precisely targeting pathogenic molecular networks. Ongoing innovations, such as advancements in miRNA delivery systems, improved targeting mechanisms, and enhanced understanding of miRNA biology, continue to drive progress in this emerging field towards realizing the clinical potential of miRNA-based medicines for thalassemia patients.

Skin complications during iron chelation therapy for beta-thalassemia: overview and treatment approach

Thalassemia is an inherited genetic disorder of hemoglobin that affects a large population worldwide, and it is estimated that between 50,000 and 60,000 infants with thalassemia are born each year. The most common treatment for thalassemia is blood transfusion, which leads to iron overload. This in itself is a serious clinical condition, and is commonly managed with iron chelation therapy. However, iron chelators can cause various skin complications, including hyperpigmentation, skin rash, itching, and photosensitivity. These skin side effects can impact patients' quality of life. Therefore, this article provides a comprehensive overview of skin complications caused by iron chelators, along with a proposed comprehensive approach to their management in patients with beta-thalassemia. Key strategies include patient education, regular skin assessment, sun protection measures, symptomatic relief with topical corticosteroids and antihistamines, and consideration of treatment modification if severe complications occur. Collaboration between hematologists and dermatologists, along with psychological support and regular follow-up, is an essential component of this multidisciplinary approach. By implementing these strategies, healthcare providers can optimize skin care for patients with beta-thalassemia treated with iron chelators and improve their quality of life.

Impact of Empagliflozin on the Outcomes of β-Thalassemia Major in Patients With Type 2 Diabetes Mellitus: The THALEMPA Observational Study

OBJECTIVE

Beta-thalassemia major (β-TM) is a genetic disorder characterized by ineffective erythropoiesis and chronic hemolytic anemia, necessitating lifelong blood transfusions and leading to severe complications. This study, termed THALEMPA by the authors, investigated the effect of empagliflozin (EMPA) on β-TM outcomes in patients with type 2 diabetes mellitus (T2DM), focusing on disease severity and associated complications of iron overload and hyperuricemia.

METHODOLOGY

This study conducted a single-center prospective observational investigation involving adults diagnosed with β-TM and T2DM. A total of 20 carefully selected patients were stratified into two groups based on their medical condition: the EMPA group, receiving 10 mg of empagliflozin, and a control group, receiving standard care. This focused cohort size was chosen to ensure a detailed, in-depth analysis of the treatment effects within this specific patient population. Over three months, both groups were closely monitored for β-TM outcomes. The study assessed β-TM severity parameters such as hemoglobin levels, blood transfusion frequency, aspartate aminotransferase (AST), alanine aminotransferase (ALT), left ventricular ejection fraction percentage, and spleen size. Additionally, β-TM complications were evaluated through serum ferritin and uric acid levels.

RESULTS

Our analysis revealed that EMPA increased hemoglobin levels by up to 0.56 g/dL compared to baseline (P < 0.05). Liver enzyme levels significantly improved with EMPA by the third month. AST and ALT decreased by 36.22% and 33.36%, respectively, from baseline levels (P < 0.05), highlighting EMPA's potential benefits for β-TM severity. Serum ferritin and uric acid levels decreased by 27.93% and 21.29%, respectively, over three months on EMPA (P < 0.05). However, other parameters did not show significant changes post-EMPA.

CONCLUSIONS

This study demonstrates the significant impact of EMPA treatment over three months on β-TM patients with T2DM, evidenced by notable improvements in hemoglobin levels and reductions in liver enzymes, as well as in complications related to iron overload and hyperuricemia. Future research should confirm these benefits over longer durations and assess broader patient outcomes such as quality of life.

Active spread of β-thalassemia beyond the thalassemia belt: A study on a Russian population

β-Thalassemia is a disease traditionally associated with thalassemia belt countries. Nonetheless, as global migration intensifies, β-thalassemia-causing variants spread far from their origin. We investigated this process to detect some patterns underlying its course. We analyzed β-thalassemia-causing variants and the origin of 676 unrelated participants in Moscow, the largest city of Russia, far away from the thalassemia belt. Our analyses revealed that modern Russia has one of the broadest spectra of thalassemia-causing variants: 46 different variants, including two novel β0 variants. Only a small proportion of the reported pathogenic variants likely originated in the resident subpopulation. Almost half of the variants that supposedly had emerged outside the Russian borders have already been assimilated by (were found in) the resident subpopulation. The primary modern source of immigration transferring thalassemia to a nonthalassemic part of Russia is the Caucasus region. We also found traces of ancient migration flows from non-Caucasus countries. Our data indicate that β-thalassemia-causing variants are actively spilling over into resident populations of countries outside thalassemia belt regions. Therefore, viewing thalassemia as a disease exclusive to specific ethnic groups creates a mind trap that can complicate the diagnosis.

Differential detection of megakaryocytic and erythroid DNA in plasma in hematological disorders

The tissues of origin of plasma DNA can be revealed by methylation patterns. However, the relative DNA contributions from megakaryocytes and erythroblasts into plasma appeared inconsistent among studies. To shed light into this phenomenon, we developed droplet digital PCR (ddPCR) assays for the differential detection of contributions from these cell types in plasma based on megakaryocyte-specific and erythroblast-specific methylation markers. Megakaryocytic DNA and erythroid DNA contributed a median of 44.2% and 6.2% in healthy individuals, respectively. Patients with idiopathic thrombocytopenic purpura had a significantly higher proportion of megakaryocytic DNA in plasma compared to healthy controls (median: 59.9% versus 44.2%; P = 0.03). Similarly, patients with β-thalassemia were shown to have higher proportions of plasma erythroid DNA compared to healthy controls (median: 50.9% versus 6.2%) (P < 0.0001). Hence, the concurrent analysis of megakaryocytic and erythroid lineage-specific markers could facilitate the dissection of their relative contributions and provide information on patients with hematological disorders.

Assessment of Serum Vitamin D and Parathyroid Hormone in Children With Beta Thalassemia Major: A Case-Control Study

BACKGROUND

A defective synthesis of vitamin D contributes to alterations in calcium homeostasis due to chronic endocrinopathies, leading to metabolic bone diseases. This study aimed to ascertain the levels of calcium, vitamin D, and parathyroid hormone (PTH) in children with β-thalassemia.

METHODS

In this case-control study, 36 children with major β-thalassemia receiving iron chelation therapy were included. For the control group, 36 cases matched for age and sex were selected. The packed cell volume (PCV) requirements varied among the thalassemic children, with an average PCV requirement of 78.57±49.07. The study was conducted for six months in the Department of Pediatrics at the Government Medical College, Nagpur, India. Serum PTH levels were determined by immunoassay, and serum vitamin D levels were assessed using electrochemiluminescence technique. Additional tests looked at liver function, serum ferritin, calcium, phosphorus, and complete blood count. The student's t-test, Mann-Whitney, and chi-square tests were used for statistical analysis.

RESULT

In comparison to the control group (10.4±1.21 g/dL), the case group's mean hemoglobin level was considerably lower (5.62±1.9 g/dL) (p<0.001). The mean serum ferritin level in the cases was notably higher (3073±1262.24 ng/mL) compared to the control group's level (58.37±29.67 ng/mL) (p<0.001). A total of 80.6% of cases compared to 5.6% of controls had vitamin D deficiency, and 72.2% of cases compared to 2.8% of controls had PTH deficit, both of which showed statistically significant differences (p<0.001). Significant differences were observed between the case and control groups for the mean levels of total serum calcium (8.51±0.84 mg/dL), vitamin D (15.23±10.07 ng/mL), and PTH (14.66±19.86 pg/mL) (9.13±0.6 mg/dL, p=0.05; 34.94±9.57 ng/mL, p<0.001; 32.08±12.42 pg/mL, p<0.001; respectively).

CONCLUSION

Growth failure may result from the markedly reduced serum calcium, vitamin D, and PTH levels in children with β-thalassemia. The relevance of treatment approaches is highlighted by the possibility that these anomalies are caused by excessive iron and inadequate nutritional support.

CRISPR-Cpf1 system and its applications in animal genome editing

The clustered regularly interspaced short palindromic repeats (CRISPR) and their associated protein (Cas) system is a gene editing technology guided by RNA endonuclease. The CRISPR-Cas12a (also known as CRISPR-Cpf1) system is extensively utilized in genome editing research due to its accuracy and high efficiency. In this paper, we primarily focus on the application of CRISPR-Cpf1 technology in the construction of disease models and gene therapy. Firstly, the structure and mechanism of the CRISPR-Cas system are introduced. Secondly, the similarities and differences between CRISPR-Cpf1 and CRISPR-Cas9 technologies are compared. Thirdly, the main focus is on the application of the CRISPR-Cpf1 system in cell and animal genome editing. Finally, the challenges faced by CRISPR-Cpf1 technology and corresponding strategies are analyzed. Although CRISPR-Cpf1 technology has certain off-target effects, it can effectively and accurately edit cell and animal genomes, and has significant advantages in the preclinical research.

A Compact Differential Dynamic Microscopy-based Device (cDDM): An Approach Tool for Early Detection of Hypercoagulable State in Transfusion-Dependent-β-Thalassemia Patients

β-Thalassemia especially transfusion-dependent thalassemia (TDT) associates with a hypercoagulable state, which is the main cause of thromboembolic events (TEE). Plasma viscosity and rheological parameters could be essential markers for determining hypercoagulable state in β-thalassemia patients. The traditional methods for measuring viscosity are often limited by large sample volumes and are impractical for routine clinical monitoring. The compact differential dynamic microscopy-based device (cDDM), an optical microscopy for quantitative rheological assessment, was developed and applied for prognosis of the hypercoagulable state in β-TDT with and without splenectomy. The device was performed plasma viscosity measurement using low plasma volume (8 μL) and revealed a value as modulus of complex viscosity |η(ω)| in 7 min. We also parallelly demonstrated the correlation of the viscosity and related-coagulable parameters: complete blood count, prothrombin time (PT), activated partial thromboplastin time (APTT), protein C (PC), protein S (PS), CD62P and CD63 expression, and platelet aggregation test. The thalassemia plasma exhibited a higher value of |η(ω)| than healthy plasma, which can represent a different viscoelastic property among the groups. Even all related-coagulable parameters indicated hypercoagulable state in both nonsplenectomies and splenectomies β-TDT patients when compared to control, only high platelet numbers significantly correlated to high plasma viscosity in the splenectomy group. However, the other coagulable parameters have shown a trend of positive relationship with high plasma viscosity in all β-1thalassemia TDT patients. The relative results suggested that our device would be an approach tool for early detection of hypercoagulable state in transfusion-dependent-β-thalassemia patients, which can help to prevent TEE and the critical consequent-complications.

Manuka combinations with nigella sativa and hydroxyurea in treating iron overload of pediatric β-thalassemia major, randomized clinical trial

Background

β-thalassemia major is microcytic hypochromic anemia disorder inherited from parents, resulting from a mutation in the β-globin locus. As a result, a quantitative defective hemoglobin synthesis and relative excess in α-globin is occurred. As such, frequent blood transfusion is required, that leads to iron overload. Iron overload results in several pathological complications, including cell death, tissue injury, organ dysfunction, and liver fibrosis. The present study examined the effectiveness of nigella Sativa and manuka honey combination or manuka honey alone to the conventional therapy (Deferasirox + blood transfusion) used for preventing and managing iron overload in pediatric β-thalassemia major patients.

Methods

One hundred sixty-five patients participated in this randomized, double-blind, standard therapy-controlled, parallel-design multisite trial. The patients were randomly allocated into three groups, receiving either 500 mg nigella sativa oil combined with manuka honey lozenge (344 mg) daily or manuka honey alone plus the conventional therapy for ten treatment months. Ferritin level, serum iron, transferrin saturation, total iron binding capacity, alanine transaminase, and aspartate transaminase were determined at baseline and month 10.

Results

Eventually, serum ferritin and iron were decreased significantly in the nigella sativa + manuka honey group as compared with the control group. Other clinical parameters were significantly impacted. The level of alanine transaminase and aspartate transaminase were significantly decreased in the nigella sativa plus manuka honey group compared with the control group.

Conclusion

Results showed that nigella sativa plus manuka honey was more effective than manuka alone or the conventional treatment alone in managing iron overload of β-thalassemia major patients.

Assessing Psychological Disorders in Turkish Adolescents with Transfusion-Dependent Thalassemia

We investigated depression and anxiety levels and related psychological disorders in adolescents with transfusion-dependent thalassemia (TDT) in this study. The study was conducted in two pediatric hematology outpatient clinics and included adolescents with TDT (14.8 ± 2.4 years, n = 40) in the study and compared them with the healthy age-matched control group (14.3 ± 2.3 years, n = 62). The Turkish version of the Revised Child Anxiety and Depression Scale (RCADS) was used to determine depression, anxiety, and related psychologic disorders (obsession, panic disorder, social phobia). Depression, anxiety, obsession, panic disorder, and social phobia scores were significantly higher in the patient group compared with the control (all p < 0.05). Ferritin levels were positively correlated with total depression, general anxiety, separation anxiety, and social phobia scores, but transfusion frequency and young age were the confounding factors. Patients in early adolescence and those who require more frequent blood transfusions are at higher risk of developing psychological disorders; routine screening for mood disorders should be warranted. Serum ferritin level may be a good warning indicator for early recognition of psychologic disorders in TDT patients.

Modified lentiviral globin gene therapy for pediatric β0/β0 transfusion-dependent β-thalassemia: A single-center, single-arm pilot trial

β0/β0 thalassemia is the most severe type of transfusion-dependent β-thalassemia (TDT) and is still a challenge facing lentiviral gene therapy. Here, we report the interim analysis of a single-center, single-arm pilot trial (NCT05015920) evaluating the safety and efficacy of a β-globin expression-optimized and insulator-engineered lentivirus-modified cell product (BD211) in β0/β0 TDT. Two female children were enrolled, infused with BD211, and followed up for an average of 25.5 months. Engraftment of genetically modified hematopoietic stem and progenitor cells was successful and sustained in both patients. No unexpected safety issues occurred during conditioning or after infusion. Both patients achieved transfusion independence for over 22 months. The treatment extended the lifespan of red blood cells by over 42 days. Single-cell DNA/RNA-sequencing analysis of the dynamic changes of gene-modified cells, transgene expression, and oncogene activation showed no notable adverse effects. Optimized lentiviral gene therapy may safely and effectively treat all β-thalassemia.

Gene therapy in pediatrics - Clinical studies and approved drugs (as of 2023)

Gene therapy in pediatrics represents a cutting-edge therapeutic strategy for treating a range of genetic disorders that manifest in childhood. Gene therapy involves the modification or correction of a mutated gene or the introduction of a functional gene into a patient's cells. In general, it is implemented through two main modalities namely ex vivo gene therapy and in vivo gene therapy. Currently, a noteworthy array of gene therapy products has received valid market authorization, with several others in various stages of the approval process. Additionally, a multitude of clinical trials are actively underway, underscoring the dynamic progress within this field. Pediatric genetic disorders in the fields of hematology, oncology, vision and hearing loss, immunodeficiencies, neurological, and metabolic disorders are areas for gene therapy interventions. This review provides a comprehensive overview of the evolution and current progress of gene therapy-based treatments in the clinic for pediatric patients. It navigates the historical milestones of gene therapies, currently approved gene therapy products by the U.S. Food and Drug Administration (FDA) and/or European Medicines Agency (EMA) for children, and the promising future for genetic disorders. By providing a thorough compilation of approved gene therapy drugs and published results of completed or ongoing clinical trials, this review serves as a guide for pediatric clinicians to get a quick overview of the situation of clinical studies and approved gene therapy products as of 2023.

Dominant Beta Thalassemia: A Very Rare Cause of Thalassemia in a Mediterranean Country

Beta thalassemia is one of the monogenic disorders characterized by decreased production of β-globin chains and various types of mutations have been reported to cause thalassemia phenotype. On the other hand, rare mutations also affect and diversify the disease spectrum. Herein, we present an anemic patient from Turkey diagnosed with dominant β thalassemia due to a heterozygous mutation in exon 3 of the HBB gene.

Health-Related Quality-of-Life Impacts Associated with Transfusion-Dependent β-Thalassemia in the USA and UK: A Qualitative Assessment

BACKGROUND

Individuals living with transfusion-dependent β-thalassemia (TDT) experience reduced health-related quality of life due to fatigue and chronic pain, which cause disruptions to daily life. Currently, limited qualitative data exist that describe these impacts.

OBJECTIVE

This study aimed to examine the ways in which symptoms and current treatments of TDT impact health-related quality of life, to holistically describe the humanistic burden of TDT, and to identify the unmet needs of individuals living with TDT.

METHODS

Adults (aged ≥ 18 years) with TDT and caregivers of adolescents (aged 12‒17 years) with TDT participated in semi-structured one-on-one virtual interviews and focus group discussions. Interviews were conducted in the USA and UK and lasted approximately 60 minutes. After transcription, the interviews were analyzed thematically using a framework approach.

RESULTS

A total of ten interviews/focus group discussions (six interviews and four focus group discussions) were conducted with 14 adults with TDT and two caregivers of adolescents with TDT. A framework analysis revealed five themes describing health-related quality of life (negative impacts on daily activities, social life, family life, work and education, and psychological well-being) and three themes describing the lived experience of TDT (impact of red blood cell transfusions and iron chelation therapy, treatment, and stigma). Physical, psychological, and treatment-related factors contributed to negative impacts on daily activities, social and family life, and work and education. Concerns about reduced lifespan, relationships and family planning, and financial independence were detrimental to participants' mental well-being. Participants reported having high resilience to the many physical and psychological challenges of living with TDT. A lack of TDT-specific knowledge among healthcare professionals, particularly regarding chronic pain associated with the disease, left some participants feeling ignored or undermined. Additionally, many participants experienced stigma and were reluctant to disclose their disease to others.

CONCLUSIONS

Individuals living with TDT experience substantial negative impacts on health-related quality of life that disrupt their daily lives, disruptions that are intensified by inadequate healthcare interactions, demanding treatment schedules, and stigma. Our study highlights the unmet needs of individuals living with TDT, especially for alternative treatments that reduce or eliminate the need for red blood cell transfusions and iron chelation therapy.

Context base editing for splice correction of IVSI-110 β-thalassemia

β-Thalassemia is brought about by defective β-globin (HBB [hemoglobin subunit β]) formation and, in severe cases, requires regular blood transfusion and iron chelation for survival. Genome editing of hematopoietic stem cells allows correction of underlying mutations as curative therapy. As potentially safer alternatives to double-strand-break-based editors, base editors (BEs) catalyze base transitions for precision editing of DNA target sites, prompting us to reclone and evaluate two recently published adenine BEs (ABEs; SpRY and SpG) with relaxed protospacer adjacent motif requirements for their ability to correct the common HBBIVSI-110(G>A) splice mutation. Nucleofection of ABE components as RNA into patient-derived CD34+ cells achieved up to 90% editing of upstream sequence elements critical for aberrant splicing, allowing full characterization of the on-target base-editing profile of each ABE and the detection of differences in on-target insertions and deletions. In addition, this study identifies opposing effects on splice correction for two neighboring context bases, establishes the frequency distribution of multiple BE editing events in the editing window, and shows high-efficiency functional correction of HBBIVSI-110(G>A) for our ABEs, including at the levels of RNA, protein, and erythroid differentiation.

Guideline for the management of conception and pregnancy in thalassaemia syndromes: A British Society for Haematology Guideline

This comprehensive guideline, developed by a representative group of UK-based medical experts specialising in haemoglobinopathies, addresses the management of conception and pregnancy in patients with thalassaemia. A systematic search of PubMed and EMBASE using specific keywords, formed the basis of the literature review. Key terms included "thalassaemia," "pregnancy," "Cooley's anaemia," "Mediterranean anaemia," and others, covering aspects such as fertility, iron burden and ultrasonography. The guideline underwent rigorous review by prominent organisations, including the Endocrine Society, the Royal College of Obstetricians and Gynaecologists (RCOG), the United Kingdom Thalassaemia Society and the British Society of Haematology (BSH) guideline writing group. Additional feedback was solicited from a sounding board of UK haematologists, ensuring a thorough and collaborative approach. The objective of the guideline is to equip healthcare professionals with precise recommendations for managing conception and pregnancy in patients with thalassaemia.

Catalase, Glutathione Peroxidase, and Peroxiredoxin 2 in Erythrocyte Cytosol and Membrane in Hereditary Spherocytosis, Sickle Cell Disease, and β-Thalassemia

Catalase (CAT), glutathione peroxidase (GPx), and peroxiredoxin 2 (Prx2) can counteract the deleterious effects of oxidative stress (OS). Their binding to the red blood cell (RBC) membrane has been reported in non-immune hemolytic anemias (NIHAs). Our aim was to evaluate the relationships between CAT, GPx, and Prx2, focusing on their role at the RBC membrane, in hereditary spherocytosis (HS), sickle cell disease (SCD), β-thalassemia (β-thal), and healthy individuals. The studies were performed in plasma and in the RBC cytosol and membrane, evaluating OS biomarkers and the enzymatic activities and/or the amounts of CAT, GPx, and Prx2. The binding of the enzymes to the membrane appears to be the primary protective mechanism against oxidative membrane injuries in healthy RBCs. In HS (unsplenectomized) and β-thal, translocation from the cytosol to the membrane of CAT and Prx2, respectively, was observed, probably to counteract lipid peroxidation. RBCs from splenectomized HS patients showed the highest membrane-bound hemoglobin, CAT, and GPx amounts in the membrane. SCD patients presented the lowest amount of enzyme linkage, possibly due to structural changes induced by sickle hemoglobin. The OS-induced changes and antioxidant response were different between the studied NIHAs and may contribute to the different clinical patterns in these patients.

Exagamglogene Autotemcel for Transfusion-Dependent β-Thalassemia

BACKGROUND

Exagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs).

METHODS

We conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent β-thalassemia and a β0/β0, β0/β0-like, or non-β0/β0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed.

RESULTS

A total of 52 patients with transfusion-dependent β-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred.

CONCLUSIONS

Treatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent β-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.).

Beta-Thalassemia in Adulthood Previously Suspected as Treatment-Resistant Iron Deficiency Anemia: A Case Report

Beta-thalassemia (β-thalassemia) is a hematologic genetic condition that causes microcytic anemia due to defective synthesis of the hemoglobin beta chain. As a hypochromic microcytic anemia that is commonly associated with symptoms such as fatigue and pallor when identified in adulthood, β-thalassemia may be commonly underdiagnosed or misdiagnosed as iron deficiency anemia. This study presents a case of a patient with β-thalassemia who was initially misdiagnosed with treatment-resistant iron deficiency anemia. Here, we present the case of a 66-year-old male of Mediterranean descent with a history of military service who presented with persistent fatigue. He had a past medical history of hypertension, diabetes mellitus type 2, sleep apnea, and iron deficiency anemia. Despite undergoing unnecessarily prolonged iron supplementation for suspected iron deficiency anemia, the patient's complete blood count and peripheral blood smear continued to identify hypochromic microcytic anemia. Ultimately, hemoglobin electrophoresis was performed, and mutations were identified in the hemoglobin beta chain consistent with β-thalassemia minor. Due to its rarity and wide variation in presentation, β-thalassemia may be frequently misdiagnosed. β-thalassemia is a spectrum of disorders ranging from β-thalassemia minor, which may be asymptomatic and incidentally discovered in adulthood, to β-thalassemia major, which may include bone marrow deformities from extramedullary hematopoiesis and require frequent blood transfusions to sustain life. Therefore, patients who present with symptoms of β-thalassemia minor may not be identified until later in life after undergoing decades of ineffective treatment. β-thalassemia is a multifactorial disease with a variety of clinical presentations that can easily be misdiagnosed as other types of anemia. This case highlights the importance of performing thorough laboratory testing and casting a wide net of differential diagnoses when evaluating patients with treatment-resistant anemia. This case calls for further research on the genetic contributions to β-thalassemia as well as improved ways to identify this disorder, particularly in patients who may not have a severe form that is easily diagnosed in early childhood.

Growth and endocrinopathies among children with β-Thalassemia major treated at Dubai Thalassemia centre

BACKGROUND

β-Thalassemia major (BTM) is one of the most common hereditary anemias worldwide. Patients suffer from iron overload that results from repeated blood transfusion This in turn leads to multiple organ damage and endocrinopathies. This study aims to assess the prevalence of growth retardation, hypothyroidism, and diabetes mellitus in children and adolescents with BTM treated at Dubai Thalassemia Centre.

METHODS

A total of 105 children and adolescents were included in this retrospective observational study.

RESULTS

39 children and 66 adolescents' data were analyzed. Females composed 51.3% (n = 20) of children and 53.0% (n = 35) of adolescents. Pretransfusion hemoglobin below 9 gm/dl was observed in 10.8% (n = 4) and 10.6% (n = 7) in children and adolescents, respectively. The mean age of menarche was 13.5 years. Among all study participants, 22.6% (n = 14) had normal height velocity whereas 37.1% (n = 23) had reduced height velocity in one year and 40.3% (n = 25) had reduced height velocity in two consecutive years. The proportion of children and adolescents showing reduced height velocity was significantly higher in females compared to the males (90.6% versus 63.3%, respectively, Chi-square = 6.597, p-value = 0.010). Although none of the study participants had diabetes mellitus, 26.1% (n = 12/46) had pre-diabetes. Elevated TSH was observed in 14.7% (n = 5) children and 8.1% (n = 5) adolescents while low FT4 was reported in one child and one adolescent.

CONCLUSION

Of all endocrinopathies seen among children and adolescents with BTM, growth delay remains the main concern for this group of patients. Effective treatment is key to further reducing endocrinopathies. Although the sample size is limited, we postulate that the low percentage of endocrinopathies among children with BTM treated at Dubai thalassemia center and the low level of pretransfusion anemia reflect the effective transfusion and chelation at the center.

Transcript-specific induction of stop codon readthrough using a CRISPR-dCas13 system

Stop codon readthrough (SCR) is the process where translation continues beyond a stop codon on an mRNA. Here, we describe a strategy to enhance or induce SCR in a transcript-selective manner using a CRISPR-dCas13 system. Using specific guide RNAs, we target dCas13 to the region downstream of canonical stop codons of mammalian AGO1 and VEGFA mRNAs, known to exhibit natural SCR. Readthrough assays reveal enhanced SCR of these mRNAs (both exogenous and endogenous) caused by the dCas13-gRNA complexes. This effect is associated with ribosomal pausing, which has been reported for several SCR events. Our data show that CRISPR-dCas13 can also induce SCR across premature termination codons (PTCs) in the mRNAs of green fluorescent protein and TP53. We demonstrate the utility of this strategy in the induction of readthrough across the thalassemia-causing PTC in HBB mRNA and hereditary spherocytosis-causing PTC in SPTA1 mRNA. Thus, CRISPR-dCas13 can be programmed to enhance or induce SCR in a transcript-selective and stop codon-specific manner.

Natural Anticoagulant Protein Levels in Patients With Beta-Thalassemia Major: A Case-Control Study

Background

β-thalassemia is a group of inherited blood disorders that affect the production of β-globin chains, leading to the reduction or absence of these chains. One of the complications observed in patients with β-thalassemia major (β-TM) is thrombosis, especially in those who receive frequent blood transfusions. This may be due to a decrease in the levels of the natural anticoagulants: protein C (PC), total protein S (PS), and antithrombin (AT).

Methods

In this case-control study, patients with β-TM, who had received at least 20 packed cell transfusions during their lifetime, were included. Patients with other underlying diseases like bleeding or thrombotic disorders were excluded. Totally, 118 patients with β-TM and 120 healthy individuals were included.

Results

The mean level of PC and AT was significantly lower in patients with β-TM (48.2 ± 65.4 and 57.42 ± 13.6, respectively) compared to the control group (97.1 ± 21.46 and 81.79 ± 14.3, respectively), with P value of 0.001 and 0.01, respectively. Although the difference was not statistically significant (P = 0.1), a similar trend was observed for total PS (61.12 ± 21.12 for patients versus 72.2 ± 35.2 for the control group). Of note, the decrease in PC, AT, and total PS levels compared to the control group was 50.36%, 27.5%, and 15.34%, respectively.

Conclusions

It seems that β-TM patients who receive prolonged blood transfusions frequently are at an increased risk of decreased in natural anticoagulants levels and therefore potentially are at risk of thrombosis.

The crucial role of NRF2 in erythropoiesis and anemia: Mechanisms and therapeutic opportunities

The nuclear factor erythroid 2-related factor 2 (NRF2) is a transcription factor crucial in cellular defense against oxidative and electrophilic stresses. Recent research has highlighted the significance of NRF2 in normal erythropoiesis and anemia. NRF2 regulates genes involved in vital aspects of erythroid development, including hemoglobin catabolism, inflammation, and iron homeostasis in erythrocytes. Disrupted NRF2 activity has been implicated in various pathologies involving abnormal erythropoiesis. In this review, we summarize the progress made in understanding the mechanisms of NRF2 activation in erythropoiesis and explore the roles of NRF2 in various types of anemia. This review also discusses the potential of targeting NRF2 as a new therapeutic approach to treat anemia.

Coinheritance of HbO Arab/β0-thalassemia with Severe Manifestation in Newborn

OBJECTIVE

In this study, we report a Tunisian newborn boy referred for neonatal hemolytic anemia with yellowish skin and enlarged spleen due to coinheritance of hemoglobin O (HbO) Arab and β-thalassemia.

STUDY DESIGN

Hematological parameters were collected using an automated blood cell counter. The amounts of Hb fractions were measured by capillary electrophoresis of Hb. Amplification and sequencing of the HBB gene were performed by Sanger's method.

RESULTS

Family study and genetic analysis revealed that the proband was a carrier of two hemoglobinopathies: HbO Arab and β0-thalassemia.

CONCLUSION

The coexistence of these two pathologies complicated the general state of the newborn boy and led to a severe anemia at birth.

KEY POINTS

· Severe neonatal anemia can be caused by hemoglobinopathy.. · Coinheritance of HbO Arab/β0-thalassemia complicated the general state of the newborn.. · Diagnosing hemoglobinopathy at an early age improves patient care..

Genetics of Gallstone Disease and Their Clinical Significance: A Narrative Review

Gallstone (GS) disease is common and arises from a combination of genetic and environmental factors. Although genetic abnormalities specifically leading to cholesterol GSs are rare, there are clinically significant gene variants associated with cholesterol GSs. In contrast, most bilirubin GSs can be attributed to genetic defects. The pathogenesis of cholesterol and bilirubin GSs differs greatly. Cholesterol GSs are notably influenced by genetic variants within the ABC protein superfamily, including ABCG8, ABCG5, ABCB4, and ABCB11, as well as genes from the apolipoprotein family such as ApoB100 and ApoE (especially the E3/E3 and E3/E4 variants), and members of the MUC family. Conversely, bilirubin GSs are associated with genetic variants in highly expressed hepatic genes, notably UGT1A1, ABCC2 (MRP2), ABCC3 (MRP3), CFTR, and MUC, alongside genetic defects linked to hemolytic anemias and conditions impacting erythropoiesis. While genetic cases constitute a small portion of GS disease, recognizing genetic predisposition is essential for proper diagnosis, treatment, and genetic counseling.

Defining curative endpoints for transfusion-dependent β-thalassemia in the era of gene therapy and gene editing

β-thalassemia is a monogenic disease that results in varying degrees of anemia. In the most severe form, known as transfusion-dependent β-thalassemia (TDT), the clinical hallmarks are ineffective erythropoiesis and a requirement of regular, life-long red blood cell transfusions, with the development of secondary clinical complications such as iron overload, end-organ damage, and a risk of early mortality. With the exception of allogeneic hematopoietic cell transplantation, current treatments for TDT address disease symptoms and not the underlying cause of disease. Recently, a growing number of gene addition and gene editing-based treatments for patients with TDT with the potential to provide a one-time functional cure have entered clinical trials. A key challenge in the design and evaluation of these trials is selecting endpoints to evaluate if these novel genetic therapies have a curative versus an ameliorative effect. Here, we present an overview of the pathophysiology of TDT, review emerging gene addition or gene editing therapeutic approaches for TDT currently in clinical trials, and identify a series of endpoints that can quantify therapeutic effects, including a curative outcome.

Molecular Characterization of α- and β-Thalassemia Among Children Less Than 18 Years Old in Guizhou, China

BACKGROUND

Thalassemia is an inherited hemolytic disease, the complications and sequelae of which have posed a huge impact on both patients and society. But limited studies have investigated the molecular characterization of α- and β-thalassemia in children from Guizhou, China.

METHODS

Between January 2019 and December 2022, a total of 3301 children, aged 6 months to 18 years, suspected of having thalassemia underwent molecular analysis.

RESULTS

Out of the total sample, 824 (25%) children were found to carry thalassemia mutations. The carrier rates of α-thalassemia, β-thalassemia, and α + β-thalassemia were determined as 8.1%, 15.6%, and 1.3%, respectively. Approximately 96.5% of the α-thalassemia gene mutations were --SEA (51%), ααCS (20.9%), -α3.7 (19.6%), and -α4.2 (5.0%). The most prevalent mutations of β-thalassemia were βCD17(A>T) (41.5%), βCD41-42(-TTCT) (37.7%), and βIVS-II-654(C>T) (11.3%). Additionally, we identified rare cases, including one case with ααHb Nunobiki/αα, two cases with triplicated α-thalassemia (one case with ααα/ααα and βCD41-42/βN and the other with ααα-3.7/αα and βE CD26/βN), and also one case with α Q-Thailandα/-α4.2 and βCD41-42/βN.

CONCLUSIONS

Our study findings provide important insights into the heterogeneity of thalassemia carrier rates and molecular profiles among children in the Guizhou region. The findings support the development of prevention strategies to reduce the incidence of severe thalassemia in the future.

Past, present, and future of CRISPR genome editing technologies

Genome editing has been a transformative force in the life sciences and human medicine, offering unprecedented opportunities to dissect complex biological processes and treat the underlying causes of many genetic diseases. CRISPR-based technologies, with their remarkable efficiency and easy programmability, stand at the forefront of this revolution. In this Review, we discuss the current state of CRISPR gene editing technologies in both research and therapy, highlighting limitations that constrain them and the technological innovations that have been developed in recent years to address them. Additionally, we examine and summarize the current landscape of gene editing applications in the context of human health and therapeutics. Finally, we outline potential future developments that could shape gene editing technologies and their applications in the coming years.

The interactions between ineffective erythropoiesis and ferroptosis in β-thalassemia

In Guangxi, Hainan, and Fujian Province in southern China, β-thalassemia is a frequent monogenic hereditary disorder that is primarily defined by hemolytic anemia brought on by inefficient erythropoiesis. It has been found that ineffective erythropoiesis in β-thalassemia is closely associated with a high accumulation of Reactive oxygen species, a product of oxidative stress, in erythroid cells. During recent years, ferroptosis is an iron-dependent lipid peroxidation that involves abnormalities in lipid and iron metabolism as well as reactive oxygen species homeostasis. It is a recently identified kind of programmed cell death. β-thalassemia patients experience increased iron release from reticuloendothelial cells and intestinal absorption of iron, ultimately resulting in iron overload. Additionally, the secretion of Hepcidin is inhibited in these patients. What counts is both ineffective erythropoiesis and ferroptosis in β-thalassemia are intricately linked to the iron metabolism and Reactive oxygen species homeostasis. Consequently, to shed further light on the pathophysiology of β-thalassemia and propose fresh ideas for its therapy, this paper reviews ferroptosis, ineffective erythropoiesis, and the way they interact.

Algorithm of differential diagnosis of anemia involving laboratory medicine specialists to advance diagnostic excellence

OBJECTIVES

Anemia is a severe global public health issue. Testing practices for anemia suggest overuse of screening laboratory tests and misinterpretation of studies even in "easy-to-diagnose" underlying causes, leading to late diagnoses and missed treatment opportunities. We aimed to develop a complete and efficient algorithm for clinical pathologists and laboratory medicine physicians for the differential diagnosis of anemia.

METHODS

Comprehensive literature search encompassing original articles, studies, reviews, gold standard books, and other evidence.

RESULTS

We created a complex algorithm, primarily for clinical pathology/laboratory use, that explores all major and several rare causes of anemia in an efficient and evidence-based manner. The algorithm includes gold-standard diagnostic laboratory tests available in most clinical laboratories and indices that can be easily calculated to provide an evidence-based differential diagnosis of anemia.

CONCLUSIONS

The diagnostic strategy combines previously available diagnostic tests and protocols in an efficient order. Clinical pathologists following the algorithm can independently provide valuable diagnostic support for healthcare providers. Clinical pathologists providing complete differential diagnostic services with the proposed algorithm may create an opportunity for an advanced diagnostic service that supports diagnostic excellence and helps patients receive a timely diagnosis and early treatment opportunities.

Pregnancy outcomes and iron status in β-thalassemia major and intermedia: a systematic review and meta-analysis

ABSTRACT

Advancements in orally bioavailable iron chelators and MRI methods have improved life expectancy and reproductive potential in thalassemia major (TM) and thalassemia intermedia (TI). Pregnancy is associated with adverse maternal and neonatal outcomes, frequency of which has not been well delineated. This systematic review aims to provide risk estimates of maternal and fetal outcomes in TM and TI and explore pregnancy's impact on iron homeostasis. Fifteen studies (429 participants, 684 pregnancies) were included. Meta-analysis revealed a higher thrombosis risk in TI (3.7%) compared to TM (0.92%), unchanged from prepregnancy. Heart failure risks in the earlier years appeared similar (TM 1.6% vs TI 1.1%), and maternal mortality in TM was 3.7%, but with current management, these risks are rare. Gestational diabetes and pre-eclampsia occurred in 3.9% and 11.3% of TM pregnancies, respectively. Caesarean section rates were 83.9% in TM and 67% in TI. No significant difference in stillbirth, small for gestational age neonates, or preterm birth incidence between TM and TI was observed. In TM pregnancies, red cell requirements significantly increased (from 102 to 139 ml/kg/year, P = 0.001), and 70% of TI pregnancies required blood transfusions. As expected, increased transfusion alongside chelation cessation led to a significant increase in serum ferritin during pregnancy (TM by 1005 ng/mL; TI by 332 ng/mL, P < 0.0001). Deterioration in iron status was further reflected by an increase in liver iron concentration (from 4.6 to 11.9 mg/g dry weight, P < 0.0001), and myocardial T2-star (T2∗) magnetic resonance imaging decreased (from 36.2 ± 2.5 ms to 31.1 ms) during pregnancy. These findings emphasize the elevated maternal risk of iron-related cardiomyopathy during pregnancy and labor, stressing the importance of cardiac monitoring and postpartum chelation therapy resumption.

Reticulocyte Antioxidant Enzymes mRNA Levels versus Reticulocyte Maturity Indices in Hereditary Spherocytosis, β-Thalassemia and Sickle Cell Disease

The antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and peroxiredoxin 2 (Prx2) are particularly important in erythroid cells. Reticulocytes and other erythroid precursors may adapt their biosynthetic mechanisms to cell defects or to changes in the bone marrow environment. Our aim was to perform a comparative study of the mRNA levels of CAT, GPX1, PRDX2 and SOD1 in reticulocytes from healthy individuals and from patients with hereditary spherocytosis (HS), sickle cell disease (SCD) and β-thalassemia (β-thal), and to study the association between their transcript levels and the reticulocyte maturity indices. In controls, the enzyme mRNA levels were significantly correlated with reticulocyte maturity indices for all genes except for SOD1. HS, SCD and β-thal patients showed younger reticulocytes, with higher transcript levels of all enzymes, although with different patterns. β-thal and HS showed similar reticulocyte maturity, with different enzyme mRNA levels; SCD and HS, with different reticulocyte maturity, presented similar enzyme mRNA levels. Our data suggest that the transcript profile for these antioxidant enzymes is not entirely related to reticulocyte maturity; it appears to also reflect adaptive mechanisms to abnormal erythropoiesis and/or to altered erythropoietic environments, leading to reticulocytes with distinct antioxidant potential according to each anemia.

Point-of-Care Diagnostic Test for Beta-Thalassemia

Hemoglobin (Hb) disorders are among the most common monogenic diseases affecting nearly 7% of the world population. Among various Hb disorders, approximately 1.5% of the world population carries β-thalassemia (β-Thal), affecting 40,000 newborns every year. Early screening and a timely diagnosis are essential for β-thalassemia patients for the prevention and management of later clinical complications. However, in Africa, Southern Europe, the Middle East, and Southeast Asia, where β-thalassemia is most prevalent, the diagnosis and screening for β-thalassemia are still challenging due to the cost and logistical burden of laboratory diagnostic tests. Here, we present Gazelle, which is a paper-based microchip electrophoresis platform that enables the first point-of-care diagnostic test for β-thalassemia. We evaluated the accuracy of Gazelle for the β-Thal screening across 372 subjects in the age range of 4-63 years at Apple Diagnostics lab in Mumbai, India. Additionally, 30 blood samples were prepared to mimic β-Thal intermediate and β-Thal major samples. Gazelle-detected levels of Hb A, Hb F, and Hb A2 demonstrated high levels of correlation with the results reported through laboratory gold standard high-performance liquid chromatography (HPLC), yielding a Pearson correlation coefficient = 0.99. This ability to obtain rapid and accurate results suggests that Gazelle may be suitable for the large-scale screening and diagnosis of β-Thal.

An update on recent studies of extracellular vesicles and their role in hypercoagulability in thalassemia (Review)

Thromboembolic events are a significant clinical concern in thalassemia and hemoglobinopathies, highlighting the need for new strategies to treat and detect these specific hematologic complications. In recent years, extracellular vesicles (EVs) have garnered interest due to their role in cell-to-cell communication, including angiogenesis, immune responses and coagulation activation. Their multifaceted role depends on the cellular origin and cargo, making them potential diagnostic biomarkers and therapeutic agents. The present review highlights recent advances in understanding the involvement of EVs in hypercoagulability in thalassemia, the characterization of circulating EVs and the potential for using EVs as predictive biomarkers. β-Thalassemia intermedia exhibits a high incidence of thromboembolic events, contributing to significant morbidity and mortality. Advanced technologies have enabled the profiling and characterization of circulating EVs in patients with β-thalassemia through various techniques, including flow cytometry, proteomic studies, reverse transcription-quantitative PCR, transmission electron microscopy, nanoparticle tracking analysis and western blot analysis. Microparticles from splenectomized β-thalassemia/hemoglobin E patients induce platelet activation and aggregation, potentially contributing to thrombus formation. The abundance of these microparticles, primarily released from platelets and damaged red cells, may have a role in thromboembolic events and other clinical complications in thalassemia. This suggests a promising future for EVs as diagnostic and predictive biomarkers in thalassemia management.

In situ correction of various β-thalassemia mutations in human hematopoietic stem cells

β-thalassemia (β-thal) is the most common monogenic disorder caused by various mutations in the human hemoglobin β (HBB) gene and affecting millions of people worldwide. Electroporation of Cas9 and single-guide RNA (sgRNA)-ribonucleoprotein (RNP) complex-mediated gene targeting in patient-derived hematopoietic stem cells (HSCs), followed by autologous transplantation, holds the promise to cure patients lacking a compatible bone marrow donor. In this study, a universal gene correction method was devised to achieve in situ correction of most types of HBB mutations by using validated CRISPR/sgRNA-RNP complexes and recombinant adeno-associated viral 6 (rAAV6) donor-mediated homology-directed repair (HDR) in HSCs. The gene-edited HSCs exhibited multi-lineage formation abilities, and the expression of β-globin transcripts was restored in differentiated erythroid cells. The method was applied to efficiently correct different mutations in β-thal patient-derived HSCs, and the edited HSCs retained the ability to engraft into the bone marrow of immunodeficient NOD-scid-IL2Rg-/- (NSI) mice. This study provides an efficient and safe approach for targeting HSCs by HDR at the HBB locus, which provides a potential therapeutic approach for treating other types of monogenic diseases in patient-specific HSCs.

RNA therapeutics for β-thalassemia

β-thalassemia is an autosomal recessive disease, caused by one or more mutations in the β-globin gene that reduces or abolishes β-globin chain synthesis causing an imbalance in the ratio of α- and β-globin chain. Therefore, the ability to target mutations will provide a good result in the treatment of β-thalassemia. RNA therapeutics represents a promising class of drugs inclusive antisense oligonucleotides (ASO), small interfering RNA (siRNA), microRNA (miRNA) and APTAMER have investigated in clinical trials for treatment of human diseases as β-thalassemia; Especially, ASO therapeutics can completely treat β-thalassemia patients by the way of making ASO infiltrating through erythrocyte progenitor cells, migrating to the nucleus and hybridizing with abnormal splicing sites to suppress an abnormal splicing pattern of β-globin pre-mRNA. As a result, the exactly splicing process is restored to increase the expression of β-globin which increases the amount of mature hemoglobin of red blood cells of β-thalassemia patients. Furthermore, current study demonstrates that RNA-based therapeutics get lots of good results for β-thalassemia patients. Then, this chapter focuses on current advances of RNA-based therapeutics and addresses current challenges with their development and application for treatment of β-thalassemia patients.

New Synthetic Isoxazole Derivatives Acting as Potent Inducers of Fetal Hemoglobin in Erythroid Precursor Cells Isolated from β-Thalassemic Patients

Induction of fetal hemoglobin (HbF) is highly beneficial for patients carrying β-thalassemia, and novel HbF inducers are highly needed. Here, we describe a new class of promising HbF inducers characterized by an isoxazole chemical skeleton and obtained through modification of two natural molecules, geldanamycin and radicicol. After preliminary biological assays based on benzidine staining and RT-qPCR conducted on human erythroleukemic K562 cells, we employed erythroid precursors cells (ErPCs) isolated from β-thalassemic patients. ErPCs weretreated with appropriate concentrations of isoxazole derivatives. The accumulation of globin mRNAs was studied by RT-qPCR, and hemoglobin production by HPLC. We demonstrated the high efficacy of isozaxoles in inducing HbF. Most of these derivatives displayed an activity similar to that observed using known HbF inducers, such as hydroxyurea (HU) or rapamycin; some of the analyzed compounds were able to induce HbF with more efficiency than HU. All the compounds were active in reducing the excess of free α-globin in treated ErPCs. All the compounds displayed a lack of genotoxicity. These novel isoxazoles deserve further pre-clinical study aimed at verifying whether they are suitable for the development of therapeutic protocols for β-thalassemia.

Low Vitamin D Levels Are Associated with Increased Cardiac Iron Uptake in Beta-Thalassemia Major

We evaluated the association of vitamin D and parathormone (PTH) levels with cardiac iron and function in beta-thalassemia major (β-TM) patients. Two-hundred and seventy-eight TM patients (39.04 ± 8.58 years, 56.8% females) underwent magnetic resonance imaging for the assessment of iron overload (T2* technique), biventricular function parameters (cine images), and replacement myocardial fibrosis (late gadolinium enhancement technique). Vitamin D levels were deficient (<20 ng/dL) in 107 (38.5%) patients, insufficient (20-30 ng/dL) in 96 (34.5%) patients, and sufficient (≥30 ng/dL) in 75 (27.0%) patients. Deficient vitamin D patients had a significantly higher frequency of myocardial iron overload (MIO; global heart T2* < 20 ms) than patients with sufficient and insufficient vitamin D levels and a significantly higher left ventricular end-diastolic volume index and mass index than patients with sufficient vitamin D levels. PTH was not associated with cardiac iron, function, or fibrosis. In the multivariate regression analysis, vitamin D, serum ferritin, and pancreatic iron levels were the strongest predictors of global heart T2* values. In receiver operating characteristic curve analysis, a vitamin D level ≤ 17.3 ng/dL predicted MIO with a sensitivity of 81.5% and a specificity of 75.3% (p < 0.0001). In TM, the periodic and regular assessment of vitamin D levels can be beneficial for the prevention of cardiac iron accumulation and subsequent overt dysfunction.