Thalassaemia

Survival and causes of death in patients with alpha and beta-thalassemia in Northern Thailand

BACKGROUND

Thalassemia is the most prevalent hereditary anaemia worldwide. Severe forms of thalassemia can lead to reduced life expectancy due to disease-related complications.

OBJECTIVES

To investigate the survival of thalassemia patients across varying disease severity, causes of death and related clinical factors.

PATIENTS AND METHODS

We conducted a retrospective review of thalassemia patients who received medical care at Chiang Mai University Hospital. The analysis focused on survival outcomes, and potential associations between clinical factors and patient survival.

RESULTS

A total of 789 patients were included in our study cohort. Among them, 38.1% had Hb H disease, 35.4% had Hb E/beta-thalassemia and 26.5% had beta-thalassemia major. Half of the patients (50.1%) required regular transfusions. Sixty-five patients (8.2%) had deceased. The predominant causes of mortality were infection-related (36.9%) and cardiac complications (27.7%). Transfusion-dependent thalassemia (TDT) (adjusted HR 3.68, 95% CI 1.39-9.72, p = 0.008) and a mean serum ferritin level ≥3000 ng/mL (adjusted HR 4.18, 95% CI 2.20-7.92, p < 0.001) were independently associated with poorer survival.

CONCLUSIONS

Our study highlights the primary contributors to mortality in patients with thalassemia as infection-related issues and cardiac complications. It also underscores the significant impact of TDT and elevated serum ferritin levels on the survival of thalassemia patients.

Regulation of N6-methyladenosine modification in erythropoiesis and thalassemia

In eukaryotic RNA, N6-methyladenosine (m6A) is a prevalent form of methylation modification. The m6A modification process is reversible and dynamic, written by m6A methyltransferase complex, erased by m6A demethylase, and recognized by m6A binding proteins. Through mediating RNA stability, decay, alternative splicing, and translation processes, m6A modification regulates gene expression at the post-transcriptional level. Erythropoiesis is the process of hematopoietic stem cells undergoing proliferation, a series of differentiation and maturation to form red blood cells (RBCs). Thalassemia is a common monogenic disease characterized by excessive production of ineffective RBCs in the peripheral circulation, resulting in hemolytic anemia. Increasing evidence suggests that m6A modification plays a crucial role in erythropoiesis. In this review, we comprehensively summarize the function of m6A modification in erythropoiesis and further generalize the mechanism of m6A modification regulating ineffective erythropoiesis and fetal hemoglobin expression. The purpose is to improve the understanding of the pathogenesis of erythroid dysplasia and offer new perspectives for the diagnosis and treatment of thalassemia.

Iron overload: the Achilles heel of β- thalassemia

Systematic transfusions coupled with iron chelation therapy have substantially improved the life expectancy of thalassemia patients in developed nations. As the human organism does not have a protective mechanism to remove excess iron, iron overload is a significant concern in thalassemia, leading to organ damage, especially in the heart and liver. Thus, iron chelation therapy is crucial to prevent or reverse organ iron overload. There are three widely used iron chelators, either as monotherapy or in combination. The choice of iron chelator depends on several factors, including local guidelines, drug availability, and the individual clinical scenario. Despite treatment advancements, challenges persist, especially in resource-limited settings, highlighting the need for improved global healthcare access. This review discusses clinical management, current treatments, and future directions for thalassemia, focusing on iron overload and its complications. Furthermore, it underscores the progress in transforming thalassemia into a manageable chronic condition and the potential of novel therapies to further enhance patient outcomes.

Polypharmacy and medication regimen complexity in transfusion-dependent thalassaemia patients: a cross- sectional study

BACKGROUND

Medication burden and complexity have been longstanding problems in chronically ill patients. However, more data are needed on the extent and impact of medication burden and complexity in the transfusion-dependent thalassaemia population.

AIM

The aim of this study was to determine the characteristics of medication complexity and polypharmacy and determine their relationship with drug-related problems (DRP) and control of iron overload in transfusion-dependent thalassaemia patients.

METHOD

Data were derived from a cross-sectional observational study on characteristics of DRPs conducted at a Malaysian tertiary hospital. The medication regimen complexity index (MRCI) was determined using a validated tool, and polypharmacy was defined as the chronic use of five or more medications. The receiver operating characteristic curve analysis was used to determine the optimal cut-off value for MRCI, and logistic regression analysis was conducted.

RESULTS

The study enrolled 200 adult patients. The MRCI cut-off point was proposed to be 17.5 (Area Under Curve  =  0.722; sensitivity of 73.3% and specificity of 62.0%). Approximately 73% and 64.5% of the patients had polypharmacy and high MRCI, respectively. Findings indicated that DRP was a full mediator in the association between MRCI and iron overload.

CONCLUSION

Transfusion-dependent thalassaemia patients have high MRCI and suboptimal control of iron overload conditions in the presence of DRPs. Thus, future interventions should consider MRCI and DRP as factors in serum iron control.

Third-generation sequencing identified a novel complex variant in a patient with rare alpha-thalassemia

BACKGROUND

Thalassemias represent some of the most common monogenic diseases worldwide and are caused by variations in human hemoglobin genes which disrupt the balance of synthesis between the alpha and beta globin chains. Thalassemia gene detection technology is the gold standard to achieve accurate detection of thalassemia, but in clinical practice, most of the tests are only for common genotypes, which can easily lead to missing or misdiagnosis of rare thalassemia genotypes.

CASE PRESENTATION

We present the case of an 18-year-old Chinese female with abnormal values of routine hematological indices who was admitted for genetic screening for thalassemia. Genomic DNA was extracted and used for the genetic assays. Gap polymerase chain reaction and agarose gel electrophoresis were performed to detect HBA gene deletions, while PCR-reverse dot blot hybridization was used to detect point mutations in the HBA and HBB genes. Next-generation sequencing and third-generation sequencing (TGS) were used to identify known and potentially novel genotypes of thalassemia. We identified a novel complex variant αHb WestmeadαHb Westmeadαanti3.7/-α3.7 in a patient with rare alpha-thalassemia.

CONCLUSIONS

Our study identified a novel complex variant that expands the thalassemia gene variants spectrum. Meanwhile, the study suggests that TGS could effectively improve the specificity of thalassemia gene detection, and has promising potential for the discovery of novel thalassemia genotypes, which could also improve the accuracy of genetic counseling. Couples who are thalassemia carriers have the opportunity to reduce their risk of having a child with thalassemia.

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.

Circulating hematopoietic stem/progenitor cell subsets contribute to human hematopoietic homeostasis

ABSTRACT

In physiological conditions, few circulating hematopoietic stem/progenitor cells (cHSPCs) are present in the peripheral blood, but their contribution to human hematopoiesis remain unsolved. By integrating advanced immunophenotyping, single-cell transcriptional and functional profiling, and integration site (IS) clonal tracking, we unveiled the biological properties and the transcriptional features of human cHSPC subpopulations in relationship to their bone marrow (BM) counterpart. We found that cHSPCs reduced in cell count over aging and are enriched for primitive, lymphoid, and erythroid subpopulations, showing preactivated transcriptional and functional state. Moreover, cHSPCs have low expression of multiple BM-retention molecules but maintain their homing potential after xenotransplantation. By generating a comprehensive human organ-resident HSPC data set based on single-cell RNA sequencing data, we detected organ-specific seeding properties of the distinct trafficking HSPC subpopulations. Notably, circulating multi-lymphoid progenitors are primed for seeding the thymus and actively contribute to T-cell production. Human clonal tracking data from patients receiving gene therapy (GT) also showed that cHSPCs connect distant BM niches and participate in steady-state hematopoietic production, with primitive cHSPCs having the highest recirculation capability to travel in and out of the BM. Finally, in case of hematopoietic impairment, cHSPCs composition reflects the BM-HSPC content and might represent a biomarker of the BM state for clinical and research purposes. Overall, our comprehensive work unveiled fundamental insights into the in vivo dynamics of human HSPC trafficking and its role in sustaining hematopoietic homeostasis. GT patients' clinical trials were registered at ClinicalTrials.gov (NCT01515462 and NCT03837483) and EudraCT (2009-017346-32 and 2018-003842-18).

Understanding the role of red blood cells in venous thromboembolism: A comprehensive review

Traditionally, red blood cells (RBCs) have been perceived as passive entities within the fibrin network, without any significant role in the pathophysiology of venous thromboembolism (VTE). This review explores the involvement of RBCs in the VTE process, summarizing previous study findings and providing a comprehensive review of the latest theories. At first, it explores the influence of abnormal RBC counts (as seen in polycythemia vera and with erythropoietin use) and the exposure of RBCs to phosphatidylserine (Ptd-L-Ser) in the pathophysiology of VTE. The mechanisms of endothelial injury induced by RBCs and their adhesion to the endothelium under different disease models are then demonstrated. We explore the role of physical and chemical interactions between RBCs and platelets, as well as the interactions between RBCs and neutrophils - particularly the neutrophil extracellular traps (NETs) released by neutrophils - in the process of VTE. Additionally, we investigate the effect of RBCs on thrombin activation through two pathways, namely, the FXIIa-FXI-FIX pathway and the prekallikrein-dependent pathway. Lastly, we discuss the impact of RBCs on clot volume. In conclusion, we propose several potential methods aimed at unraveling the role of RBCs and their interaction with other components in the vascular system in the pathogenesis of VTE.

Iron chelators: as therapeutic agents in diseases

The concentration of iron is tightly regulated, making it an essential element. Various cellular processes in the body rely on iron, such as oxygen sensing, oxygen transport, electron transfer, and DNA synthesis. Iron excess can be toxic because it participates in redox reactions that catalyze the production of reactive oxygen species and elevate oxidative stress. Iron chelators are chemically diverse; they can coordinate six ligands in an octagonal sequence. Because of the ability of chelators to trap essential metals, including iron, they may be involved in diseases caused by oxidative stress, such as infectious diseases, cardiovascular diseases, neurodegenerative diseases, and cancer. Iron-chelating agents, by tightly binding to iron, prohibit it from functioning as a catalyst in redox reactions and transfer iron and excrete it from the body. Thus, the use of iron chelators as therapeutic agents has received increasing attention. This review investigates the function of various iron chelators in treating iron overload in different clinical conditions.

Can Cyprus Afford Luspatercept? A Budget Impact Analysis of the Reimbursement of Luspatercept for the Management of Thalassaemia in Cyprus

OBJECTIVE

This study aims to estimate the budget impact of luspatercept reimbursement as an adjuvant to the standard management of β-thalassaemia major in Cyprus, from a societal perspective, and assess the financial feasibility of its inclusion in the β-thalassaemia armamentarium.

METHODS

A 5-year horizon budget impact model was developed to determine the budget impact of reimbursing luspatercept for the management of β-thalassaemia major in Cyprus. Two treatment discontinuation scenarios were elaborated. In the first scenario, luspatercept is reimbursed complementary to best supportive care, and a dropout rate of 40% is assumed based on published real-world data, while for the second scenario a dropout rate of 25%, is assumed as per the clinical trial data. Input parameters were retrieved from the phase III clinical trial of luspatercept, literature, and expert opinion consensus. One-way sensitivity analyses were conducted for both scenarios.

RESULTS

The addition of luspatercept to the standard management of β-thalassaemia major in Cyprus imparted an incremental budget impact ranging from €21,300,643 to €25,834,368, depending on the drop-out rate scenario assumed. Results were sensitive to the number of eligible patients and dose per patient.

CONCLUSION

The potential reimbursement of luspatercept will wield a substantial impact on Cyprus total pharmaceutical expenditure and it is therefore imperative to affix a reimbursement framework that will allow the payer to mitigate uncertainty stemming out of the scarce clinical data and the inherently complex therapeutic landscape of β-thalassemia management.

A Novel 165 Kb Duplication Involving the α-Globin Gene Cluster Is Identified by Low-Pass Whole Genome Sequencing in a Chinese Thalassemia Intermedia Patient

Copy number variations (CNVs) involving the α-globin gene cluster can lead to an imbalance in the proportion of α- and β-globin chains and consequently cause clinical symptoms of β-thalassemia. In our case, a 6-year-old boy, clinically diagnosed with β thalassemia intermedia, was admitted for further genetic diagnosis with his family. Targeted sequencing and third generation sequencing (TGS) were used to detect the possible variants of the thalassemia genes. Low-pass whole genome sequencing (lpWGS) was conducted to specify the exact location of relevant CNVs across the genome, which was then validated by multiplex ligation-dependent probe amplification.The results revealed that the patient had a heterozygous β0 mutation of Codon17 (A > T) and a full duplication of the α-globin gene cluster, inherited from his mother and father, respectively. Besides, a novel point mutation within the 5' untranslated region of β-Globin (HBB: c. -175 (G > A) was only detected in the patient. This study suggests that lpWGS seems a powerful alternative to detect large CNVs related to thalassemia with second intention for more information of the breakpoints and a simultaneous genome-scale detection of other pathogenic CNVs.

Interplay between α-thalassemia and β-hemoglobinopathies: Translating genotype-phenotype relationships into therapies

α-Thalassemia represents one of the most important genetic modulators of β-hemoglobinopathies. During this last decade, the ongoing interest in characterizing genotype-phenotype relationships has yielded incredible insights into α-globin gene regulation and its impact on β-hemoglobinopathies. In this review, we provide a holistic update on α-globin gene expression stemming from DNA to RNA to protein, as well as epigenetic mechanisms that can impact gene expression and potentially influence phenotypic outcomes. Here, we highlight defined α-globin targeted strategies and rationalize the use of distinct molecular targets based on the restoration of balanced α/β-like globin chain synthesis. Considering the therapies that either increase β-globin synthesis or reactivate γ-globin gene expression, the modulation of α-globin chains as a disease modifier for β-hemoglobinopathies still remains largely uncharted in clinical studies.

Long-Term Follow-Up of Patients Undergoing Thalidomide Therapy for Transfusion-Dependent β-Thalassaemia: A Single-Center Experience

Objective

We evaluated the long-term safety and efficacy of thalidomide in the treatment of transfusion-dependent β-thalassemia (TDT).

Methods

Fifty patients with TDT were treated with thalidomide and followed-up for 5 years. Thalidomide at a 50 mg dose was administered once a day after dinner. The dose was increased to 150 mg/d after 3 d if well tolerated. After 1 year of treatment, the hemoglobin (Hb) level was stabilized at its maximum, and thalidomide was gradually reduced and maintained at the minimum dose. The hematological response, transfusion dependence, and haemolytic indicators were assessed.

Results

At 9 month of follow-up, 38 (76%) patients achieved an excellent response, 1 (2%) a good response, 4(8%) a minor response, and 7(14%) did not show a response. The overall response rate was 86%. At 9 months, the Hb level increased from 79.0 ± 13.2 g/L at baseline to 99.0 ± 13.7g/L (P<0.001). Patients who achieved excellent response continued to show an increase in Hb levels during follow-up. At 48 months, the mean Hb level was 98.99 ± 10.3g/L; 21 patients (84.0%) became transfusion independent. Thalidomide was reduced and maintained to 25 mg/d in three of these patients. Moreover, five patients completed 60 months of follow-up, and with a mean Hb level of 99.8 ± 6.7g/L. During follow-up, grade 1-2 adverse drug reactions were noted; however, no grade 3 or higher adverse event was reported. However, no decrease in hemolytic indicators was observed.

Conclusion

Thalidomide was well tolerated in the long term, while it significantly improved Hb levels and reduced the transfusion burden.

Liver steatosis in patients with transfusion-dependent thalassaemia

We evaluated the prevalence and the clinical associations of liver steatosis (LS) in patients with transfusion-dependent thalassaemia (TDT). We considered 301 TDT patients (177 females, median age = 40.61 years) enrolled in the Extension-Myocardial Iron Overload in Thalassaemia Network, and 25 healthy subjects. Magnetic resonance imaging was used to quantify iron overload and hepatic fat fraction (FF) by T2* technique and cardiac function by cine images. The glucose metabolism was assessed by the oral glucose tolerance test (OGTT). Hepatic FF was significantly higher in TDT patients than in healthy subjects (median value: 1.48% vs. 0.55%; p = 0.013). In TDT, hepatic FF was not associated with age, gender, serum ferritin levels or liver function parameters, but showed a weak inverse correlation with high-density lipoprotein cholesterol. The 36.4% of TDT patients showed LS (FF >3.7%). Active hepatitis C virus (HCV) infection, increased body mass index and hepatic iron were independent determinants of LS. A hepatic FF >3.53% predicted the presence of an abnormal OGTT. Hepatic FF was not correlated with cardiac iron, biventricular volumes or ejection fractions, but was correlated with left ventricular mass index. In TDT, LS is a frequent finding, associated with iron overload, increased weight and HCV, and conveying an increased risk for the alterations of glucose metabolism.

Base Editors-Mediated Gene Therapy in Hematopoietic Stem Cells for Hematologic Diseases

Base editors, developed from the CRISPR/Cas system, consist of components such as deaminase and Cas variants. Since their emergence in 2016, the precision, efficiency, and safety of base editors have been gradually optimized. The feasibility of using base editors in gene therapy has been demonstrated in several disease models. Compared with the CRISPR/Cas system, base editors have shown great potential in hematopoietic stem cells (HSCs) and HSC-based gene therapy, because they do not generate double-stranded breaks (DSBs) while achieving the precise realization of single-base substitutions. This precise editing mechanism allows for the permanent correction of genetic defects directly at their source within HSCs, thus promising a lasting therapeutic effect. Recent advances in base editors are expected to significantly increase the number of clinical trials for HSC-based gene therapies. In this review, we summarize the development and recent progress of DNA base editors, discuss their applications in HSC gene therapy, and highlight the prospects and challenges of future clinical stem cell therapies.

Screening for thalassemia carriers among the Han population of childbearing age in Southwestern of China

Purpose

Thalassemia is a severe hereditary blood disorder that poses a significant threat to human health and leads to mortality and disability. It is one of the most prevalent monogenic diseases worldwide. The aim of this study was to analyze the molecular epidemiological data of individuals of childbearing age from the Han ethnic group with thalassemia in Southwest China and to explore the application of next-generation sequencing (NGS) technology in screening thalassemia carriers.

Methods

The participants were Han males and females of childbearing age who sought medical advice at the West China Second University Hospital, Sichuan University from June 2022 to June 2023. We detected α- and β-thalassemia mutations using full-length capture of the thalassemia genes and NGS technology.

Results

In a cohort of 1,093 participants, 130 thalassemia carriers were identified, with an overall detection rate of 11.89% (130/1,093). Among these, 0.91% (10/1,093) had mutations that could not be detected using traditional PCR techniques. The proportions of carriers with α-, β-, and α-complexed β-thalassemia gene mutations were 7.68% (84/1,093), 3.93% (43/1,093), and 0.27% (3/1,093), respectively. We identified a novel HBA2 c.166del variant that has not been previously reported.

Conclusion

Using NGS technology, we found that the mutation-carrying rate of thalassemia genes was 11.89% in the Han population of childbearing age in Southwest China. Compared with the results of traditional PCR techniques, NGS detected an additional 0.91% (10/1,093) rare genetic variants. NGS technology should be utilized as the primary screening method for thalassemia carriers among Han nationality people of childbearing age in Southwest China.

Ginsenoside Rg1 promotes fetal hemoglobin production in vitro: A potential therapeutic avenue for β-thalassemia

β-thalassemia, a globally prevalent genetic disorder, urgently requires innovative treatment options. Fetal hemoglobin (HbF) induction stands as a key therapeutic approach. This investigation focused on Ginsenoside Rg1 from the Panax genus for HbF induction. Employing K562 cells and human erythroid precursor cells (ErPCs) derived from neonatal cord blood, the study tested Rg1 at different concentrations. We measured its effects on γ-globin mRNA levels and HbF expression, alongside assessments of cell proliferation and differentiation. In K562 cells, Rg1 at 400 μM significantly increased γ-globin mRNA expression by 4.24 ± 1.08-fold compared to the control. In ErPCs, the 800 μM concentration was most effective, leading to an over 80% increase in F-cells and a marked upregulation in HbF expression. Notably, Rg1 did not adversely affect cell proliferation or differentiation, with the 200 μM concentration showing an increase in γ-globin mRNA by 2.33 ± 0.58-fold, and the 800 μM concentration enhancing HbF expression by 2.59 ± 0.03-fold in K562 cells. Our results underscore Rg1's potential as an effective and safer alternative for β-thalassemia treatment. By significantly enhancing HbF levels without cytotoxicity, Rg1 offers a notable advantage over traditional treatments like Hydroxyurea. While promising, these in vitro findings warrant further in vivo exploration to confirm Rg1's therapeutic efficacy and to unravel its underlying mechanistic pathways.

[Health status and quality of life in β-thalassemia adults in Marseille, France]

INTRODUCTION

The life expectancy of β-thalassemia patients has increased over the last 20 years. In this study, we evaluated the current health status and quality of life of these patients managed in a reference center in Marseille.

METHODS

This is a single-center, descriptive study conducted between June and August 2019 in patients over 18 years of age with β-thalassemia major or intermedia. Clinical and paraclinical data were collected retrospectively and the SF-36 health survey questionnaire was proposed to each patient.

RESULTS

43 of 64 selected patients were included and divided into 2 groups: 35 patients with transfusion-dependent β-thalassemia and 8 patients with non-transfusion-dependent β-thalassemia. Liver iron overload is the most frequent complication, present in 80% of transfusion-dependent and 62.5% of non-transfusion-dependent patients. Cardiac iron overload is present only in the transfusion dependent β-thalassemia group (20%). Hypogonadotropic hypogonadism remains the most common endocrine disorder (41.9%) followed by osteoporosis (37.2%). Among the 31 patients who completed the SF-36 questionnaire, physical and mental quality of life scores were lowered in transfusion dependent (respectively 42.7 and 46.8) as in non-transfusion-dependent patients (respectively 43.8 and 28.9).

CONCLUSION

Despite an improvement in medical care, our patients with β-thalassemia show an alteration in their quality of life that will need to be characterized in the entire French cohort.

Effects on hearing after long-term use of iron chelators in beta-thalassemia: Over twenty years of longitudinal follow-up

OBJECTIVE

The role of iron chelation in causing hearing loss (HL) is still unclear. The present study assessed the prevalence of HL among transfusion-dependent thalassemia (TDT) patients who underwent audiological follow-up over a 20-year period.

METHODS

We retrospectively analyzed clinical records and audiological tests from January 1990 (T0) to December 2022 (T22) of a group of TDT patients who received iron chelation therapy with deferoxamine (DFO), deferiprone (DFP) or deferasirox (DFX), in monotherapy or as part of combination therapy.

RESULTS

A total of 42 adult TDT patients (18 male, 24 female; age range: 41-55 years; mean age: 49.2 ± 3.7 years) were included in the study. At the T22 assessment, the overall prevalence of sensorineural HL was 23.8 % (10/42). When patients were stratified into two groups, with and without ototoxicity, no differences were observed for sex, age, BMI, creatinine level, pre-transfusional hemoglobin, start of transfusions, cardiac or hepatic T2 MRI; only ferritin serum values and duration of chelation were significantly higher (p = 0.02 and p = 0.01, respectively) in patients with hearing impairment in comparison to those with normal hearing.

CONCLUSION

This study with long-term follow-up suggests that iron chelation therapy might induce ototoxicity; therefore, a long and accurate audiological follow-up should be performed in TDT patients.

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.

A cross-sectional study: caregiver burden and related determinants of adult patients with β-thalassemia major in mainland China

BACKGROUND

The informal caregivers of adult patients with β-thalassemia major (β-TM) bear not only physical but also emotional and economic pressures of providing care. This study is the first to evaluate the caregiver burden by Zarit Burden Interview (ZBI) of adult patients with β-TM in mainland China and to identify predictors of caregiver burden.

METHODS

In this cross-sectional study, we conducted an online survey with snowball sampling covering seven provinces between September 1, 2021, and January 31, 2022, of patients aged ≥ 18 years with β-TM and their informal caregivers. Caregiver burden was assessed using the ZBI. Data on patient demographics, disease and therapy characteristics, and informal caregivers' demographic characteristics were collected and analysed using independent t-tests, analysis of variance, Spearman's correlation and multiple linear regression.

RESULTS

Of 75 included patients, more than half (50.7%) were male. The mean patient age was 24.69 ± 5.59 years. The mean age of the informal caregivers was 50.60 ± 9.16 years, with women (74.7%) being predominant. The ZBI score was 38.00 ± 17.02. Multiple linear regression analysis showed that patients with interrupted blood transfusion therapy and informal caregivers required to care of others were positively associated with caregiver burden (p < 0.05). Age of informal caregivers were borderline significant positively associated with caregiver burden (p < 0.1). Married informal caregivers were negatively associated with caregiver burden (p < 0.05).

CONCLUSIONS

The informal caregivers of adult patients with β-TM in mainland China experienced a moderate-to-severe level of caregiving burden. The caregiver burden was higher in patients with a history of interrupted blood transfusion therapy or in informal caregivers who were older or needed to care for others. Additionally, married informal caregivers experienced lower burdens compared to non-married informal caregivers. These findings provide a reference to identify informal caregivers with higher burdens among patients with β-TM.

Bone Health Impairment in Patients with Hemoglobinopathies: From Biological Bases to New Possible Therapeutic Strategies

Hemoglobinopathies are monogenic disorders affecting hemoglobin synthesis. Thalassemia and sickle cell disease (SCD) are considered the two major hemoglobinopathies. Thalassemia is a genetic disorder and one of the major hemoglobinopathies determined by an impairment of globin chain production, which causes an alteration of erythropoiesis, an improvement in hemolysis, and an alteration of iron homoeostasis. In SCD, the mutations are on the β-globin chain of hemoglobin which results in a substitution of glutamic acid by valine with consequent formation of Hemoglobin S (HbS). Several factors are involved in bone metabolism alteration in patients with hemoglobinopathies, among them hormonal deficiency, bone marrow hyperplasia, iron overload, inflammation, and increased bone turnover. Bone metabolism is the result of balance maintenance between bone deposition and bone resorption, by osteoblasts (OBs) and osteoclasts (OCs). An impairment of this balance is responsible for the onset of bone diseases, such as osteoporosis (OP). Therefore, here we will discuss the alteration of bone metabolism in patients with hemoglobinopathies and the possible therapeutic strategies to contain and/or counteract bone health impairment in these patients, taking into consideration not only the pharmacological treatments already used in the clinical armamentarium, but also the new possible therapeutic strategies.

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.

Αlpha-thalassemia: A practical overview

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and β globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.

Comparison of Third-Generation Sequencing and Routine Polymerase Chain Reaction in Genetic Analysis of Thalassemia

CONTEXT.—

Thalassemia is the most widely distributed monogenic autosomal recessive disorder in the world. Accurate genetic analysis of thalassemia is crucial for thalassemia prevention.

OBJECTIVE.—

To compare the clinical utility of a third-generation sequencing-based approach termed comprehensive analysis of thalassemia alleles with routine polymerase chain reaction (PCR) in genetic analysis of thalassemia and explore the molecular spectrum of thalassemia in Hunan Province.

DESIGN.—

Subjects in Hunan Province were recruited, and hematologic testing was performed. Five hundred four subjects positive on hemoglobin testing were then used as the cohort, and third-generation sequencing and routine PCR were used for genetic analysis.

RESULTS.—

Of the 504 subjects, 462 (91.67%) had the same results, whereas 42 (8.33%) exhibited discordant results between the 2 methods. Sanger sequencing and PCR testing confirmed the results of third-generation sequencing. In total, third-generation sequencing correctly detected 247 subjects with variants, whereas PCR identified 205, which showed an increase in detection of 20.49%. Moreover, α triplications were identified in 1.98% (10 of 504) hemoglobin testing-positive subjects in Hunan Province. Seven hemoglobin variants with potential pathogenicity were detected in 9 hemoglobin testing-positive subjects.

CONCLUSIONS.—

Third-generation sequencing is a more comprehensive, reliable, and efficient approach for genetic analysis of thalassemia than PCR, and allowed for a characterization of the thalassemia spectrum in Hunan Province.

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.

Neuroimaging features of primary central nervous system post-transplantation lymphoproliferative disorder following hematopoietic stem cell transplant in patients with β-thalassemia: a case series and review of literature

PURPOSE

Primary central nervous system post-transplantation lymphoproliferative disorder (PCNS-PTLD) is a rare but serious complication of hematopoietic stem cell transplantation (HSCT) in patients with severe β-thalassemia. This study aimed to assess the clinical presentation, pathological characteristics, neuroimaging findings, and treatment strategies in patients with β-thalassemia who developed PCNS-PTLD and to compare a case series from our transplant center to reported cases from literature.

METHODS

We retrospectively reviewed our hospital database and identified four cases of pathologically confirmed PCNS-PTLD without a history of systemic PTLD in patients with severe β-thalassemia after HSCT. We also performed a relevant literature review on PCNS-PTLD.

RESULTS

The median time from transplantation to diagnosis of PCNS-PTLD was 5.5 months. Intracerebral lesions were usually multiple involving both supratentorial and infratentorial regions with homogeneous or rim enhancement. All patients had pathologically confirmed PCNS-PTLD with three patients having diffuse large B-cell lymphoma and the fourth patient having plasmacytic hyperplasia. There was low response to treatment with a median survival of 83 days.

CONCLUSION

PCNS-PTLD should be considered in the differential diagnosis of patients with β-thalassemia who had an intracranial lesion on neuroimaging after HSCT.

CRITICAL RELEVANCE STATEMENT

This case series with a comprehensive review of neuroimaging and clinical characteristics of children with primary central nervous system post-transplantation lymphoproliferative disorder should advance our understanding and improve management of this rare yet severe complication following transplant for β-thalassemia.

KEY POINTS

• We assessed clinical presentation, treatment strategies, and neuroimaging characteristics of PCNS-PTLD in patients with β-thalassemia after transplantation. • Patients with β-thalassemia may have post-transplantation lymphoproliferative disorder presenting as brain lesions on neuroimaging. • Neuroimaging findings of the brain lesions are helpful for prompt diagnosis and proper management.

Unmet needs in β-thalassemia and the evolving treatment landscape

β-thalassemias are genetic disorders causing an imbalance in hemoglobin production, leading to varying degrees of anemia, with two clinical phenotypes: transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT). Red blood cell transfusions and iron chelation therapy are the conventional treatment options for the management of β-thalassemia. Currently available conventional therapies in thalassemia have many challenges and limitations. Accordingly, multiple novel therapeutic approaches are currently being developed for the treatment of β-thalassemias. These strategies can be classified into three categories based on their efforts to address different aspects of the underlying pathophysiology of β-thalassemia: correction of the α/β globin chain imbalance, addressing ineffective erythropoiesis, and targeting iron dysregulation. Managing β- thalassemia presents challenges due to the many complications that can manifest, limited access and availability of blood products, and lack of compliance/adherence to treatment. Novel therapies targeting ineffective erythropoiesis and thus improving anemia and reducing the need for chronic blood transfusions seem promising. However, the complex nature of the disease itself requires personalized treatment plans for each patient. Collaborations and partnerships between thalassemia centers can also help share knowledge and resources, particularly in regions with higher prevalence and limited resources. This review will explore the different conventional treatment modalities available today for the management of β-thalassemia, discuss the unmet needs and challenges associated with them in addition to exploring the role of some novel therapeutic agents in the field.

An Update on the Application of CRISPR Technology in Clinical Practice

The CRISPR/Cas system, an innovative gene-editing tool, is emerging as a promising technique for genome modifications. This straightforward technique was created based on the prokaryotic adaptive immune defense mechanism and employed in the studies on human diseases that proved enormous therapeutic potential. A genetically unique patient mutation in the process of gene therapy can be corrected by the CRISPR method to treat diseases that traditional methods were unable to cure. However, introduction of CRISPR/Cas9 into the clinic will be challenging because we still need to improve the technology's effectiveness, precision, and applications. In this review, we first describe the function and applications of the CRISPR-Cas9 system. We next delineate how this technology could be utilized for gene therapy of various human disorders, including cancer and infectious diseases and highlight the promising examples in the field. Finally, we document current challenges and the potential solutions to overcome these obstacles for the effective use of CRISPR-Cas9 in clinical practice.

A randomized placebo-controlled clinical trial of oral green tea epigallocatechin 3-gallate on erythropoiesis and oxidative stress in transfusion-dependent β-thalassemia patients

β-Thalassemia patients suffer from ineffective erythropoiesis and increased red blood cell (RBC) hemolysis. Blood transfusion, erythropoietic enhancement, and antioxidant supplementation can ameliorate chronic anemia. Green tea extract (GTE) is comprised of catechin derivatives, of which epigallocatechin-3-gallate (EGCG) is the most abundant, presenting free-radical scavenging, iron-chelating, and erythropoiesis-protective effects. The present study aimed to evaluate the effects of GTE tablets on the primary outcome of erythropoiesis and oxidative stress parameters in transfusion-dependent β-thalassemia (TDT) patients. Twenty-seven TDT patients were randomly divided into placebo and GTE tablet (50 and 100 mg EGCG equivalent) groups and assigned to consume the product once daily for 60 days. Blood was collected for analysis of hematological, biochemical, and oxidative stress parameters. Accordingly, consumption of GTE tablets improved blood hemoglobin levels when compared with the placebo; however, there were more responders to the GTE tablets. Interestingly, amounts of nonheme iron in RBC membranes tended to decrease in both GTE tablet groups when compared with the placebo. Importantly, consumption of GTE tablets lowered plasma levels of erythroferrone (p < 0.05) and reduced bilirubin non-significantly and dose-independently. Thus, GTE tablets could improve RBC hemolysis and modulate erythropoiesis regulators in transfusion-dependent thalassemia patients.

Mutation spectrum of thalassemia among pre-pregnant adults in the Jiangsu Province by capillary electrophoresis-based multiplex PCR assay

BACKGROUND

Thalassemia is a common genetic disorder in southwestern China, and an increasing number of cases from eastern China have been recently reported. Here, we developed a rapid, convenient, and accurate assay to evaluate the mutation spectrum of thalassemia in eastern China.

METHODS

A carrier screening assay for 61 hotspot variants among HBA1/HBA2 and HBB (OMIM: 141800, 141850, and 141900) genes was developed by SNaPshot/high-throughput ligation-dependent probe amplification (HLPA) technology. We used this assay to detect the mutation spectrum of thalassemia in individuals from eastern China and compared with the data collected from literatures focused on southern and northern China for variant distribution.

RESULTS

Among 4276 tested individuals, 2.62% (112/4276) were α-thalassemia carriers, with 90 carrying one deletion or mutation and 22 carrying two deletions. 0.40% (17/4276) were β-thalassemia carriers, and the most common variant of β-thalassemia was c.126_129delCTTT (29.41%) followed by c.316-197C>T (23.53%). The genotype distribution in our study was similar to those from southern China populations.

CONCLUSION

The Chinese population from different regions presented comparable mutation spectrum of thalassemia, and the SNaPshot/HLPA technique may serve as a capable assay for a routine genetic test in clinical practice with its accurate, rapid, and inexpensive advantage.

Diagnosis and screening of abnormal hemoglobins

Hemoglobin (Hb) abnormalities, such as thalassemia and structural Hb variants, are among the most prevalent inherited diseases and are associated with significant mortality and morbidity worldwide. However, there were not comprehensive reviews focusing on different clinical analytical techniques, research methods and artificial intelligence (AI) used in clinical screening and research on hemoglobinopathies. Hence the review offers a comprehensive summary of recent advancements and breakthroughs in the detection of aberrant Hbs, research methods and AI uses as well as the present restrictions anddifficulties in hemoglobinopathies. Recent advances in cation exchange high performance liquid chromatography (HPLC), capillary zone electrophoresis (CZE), isoelectric focusing (IEF), flow cytometry, mass spectrometry (MS) and polymerase chain reaction (PCR) etc have allowed for the definitive detection by using advanced AIand portable point of care tests (POCT) integrating with smartphone microscopic classification, machine learning (ML) model, complete blood counts (CBC), imaging-based method, speedy immunoassay, and electrochemical-, microfluidic- and sensing-related platforms. In addition, to confirm and validate unidentified and novel Hbs, highly specialized genetic based techniques like PCR, reverse transcribed (RT)-PCR, DNA microarray, sequencing of genomic DNA, and sequencing of RT-PCR amplified globin cDNA of the gene of interest have been used. Hence, adequate utilization and improvement of available diagnostic and screening technologies are important for the control and management of hemoglobinopathies.

First Report of Filipino β0-Thalassemia/β-Thalassemia in a Chinese Family

A pregnant woman living in Fujian Province, southeastern China, presented due to a risk of having a baby with β-thalassemia major, during her second pregnancy, since she and her husband were suspected as β-thalassemia carriers and their affected daughter was a transfusion-dependent patient. Using the common α-thalassemia and β-thalassemia genotypes test, the pregnant woman was diagnosed as a β-thalassemia carrier with βIVS-2 - 654 (C→T)/βN genotype and her daughter had a homozygosity for IVS - 2 - 654 (C→T) mutation, however, no abnormalities were detected in her husband. SMRT identified a Filipino β0-deletion in her husband, and MLPA also revealed an unknown deletion in the HBB gene. Electrophoresis showed approximately 350 bp of the PCR product, and the β-Filipino genotype presented novel fracture fragments ranging from 5,112,884 to 5,231,358 bp, and lacked a 118,475 bp fragment relative to the wild-type sequence. The daughter was therefore diagnosed with the βIVS-2 - 654 (C→T)/βFilipino genotype. Prenatal diagnosis with umbilical cord blood at 27th week of gestation showed heteroztgosity for IVS - 2 - 654 (C→T) mutation in the fetus and continued pregnancy was recommended. In conclusion, we identified the Filipino β0-deletion in a Chinese family, from Fujian area, for the first time, during prenatal screening.

The Danish national haemoglobinopathy screening programme: Report from 16 years of screening in a low-prevalence, non-endemic region

The Danish national haemoglobinopathy screening programme seeks to determine parental haemoglobinopathy carrier state antenatally. In this retrospective register-based study, we evaluated the 16-year trajectory of this programme, utilising the Danish Red Blood Cell Centre's laboratory database, covering approximately 77% of the Danish population. During the study period, we observed a substantial increase in annual diagnostic examinations performed, from 389 in 2007 to 3030 in 2022. Women constituted 88% of these cases, aligning with the emphasis of the screening programme. Of these, 54% of women of reproductive age (15-40 years) and 10% of women >40 years were specified as pregnant. During our study period, 61 children were born with a severe haemoglobinopathy, out of which 23 children were born from mothers not residing in Denmark during their first trimester thus not included in the screening programme. Prenatal invasive testing was performed for 60 fetuses, identifying 12 with homozygous or compound heterozygous haemoglobinopathy. The Danish haemoglobinopathy screening programme has provided screening, information and reproductive choices for numerous families. During the study period, screening for haemoglobinopathies has been steadily increasing and is expected to continue to increase. Awareness of and adherence to the screening programme is subject of further investigation and optimisation.

Thurston syndrome with thalassaemia: a rare case devising a novel molecular and phenotypic variation

A male infant presented with progressive paleness of the body since 3 months of age. On examination, the child had pallor, microcephaly with dysmorphic facies (depressed nasal bridge, low set ears, retrognathia, high arched palate and tongue hamartoma). Postaxial polydactyly in bilateral hands and feet, broad great toes, with syndactyly of left fourth and fifth toes were present. The haemogram showed severe anaemia with a microcytic hypochromic picture. High-performance liquid chromatography (HPLC) was normal. However, the parents' HPLC was suggestive of beta thalassaemia trait. Whole-exome sequencing revealed Thurston syndrome with beta-thalassaemia in homozygous pattern with a novel mutation. It is a rare genetic syndrome exclusively found in the South Asian population. Due to the rarity, identification of this syndrome is often difficult and requires awareness among clinicians. However, it is important to diagnose the disorder accurately in order to provide appropriate genetic counselling and prognostication to the parents.

miR-365-3p mediates BCL11A and SOX6 erythroid-specific coregulation: A new player in HbF activation

Hemoglobin switching is a complex biological process not yet fully elucidated. The mechanism regulating the suppression of fetal hemoglobin (HbF) expression is of particular interest because of the positive impact of HbF on the course of diseases such as β-thalassemia and sickle cell disease, hereditary hemoglobin disorders that affect the health of countless individuals worldwide. Several transcription factors have been implicated in the control of HbF, of which BCL11A has emerged as a major player in HbF silencing. SOX6 has also been implicated in silencing HbF and is critical to the silencing of the mouse embryonic hemoglobins. BCL11A and SOX6 are co-expressed and physically interact in the erythroid compartment during differentiation. In this study, we observe that BCL11A knockout leads to post-transcriptional downregulation of SOX6 through activation of microRNA (miR)-365-3p. Downregulating SOX6 by transient ectopic expression of miR-365-3p or gene editing activates embryonic and fetal β-like globin gene expression in erythroid cells. The synchronized expression of BCL11A and SOX6 is crucial for hemoglobin switching. In this study, we identified a BCL11A/miR-365-3p/SOX6 evolutionarily conserved pathway, providing insights into the regulation of the embryonic and fetal globin genes suggesting new targets for treating β-hemoglobinopathies.

Identification of double heterozygous -α4.2Ⅰ/-α4.2Ⅱ using third-generation sequencing

OBJECTIVE

The 4.2 kb deletion (-α4.2/) is a common a+-thalassemia with a carrier rate, followed by the South-East Asian deletion (-SEA) and the 3.7 kb deletion (-α3.7/). There are few reports about 4.2 kb deletion sub-types. Herein, we present a patient with double heterozygous -α4.2Ⅰ/-α4.2Ⅱwho was identified using third-generation sequencing (TGS).

METHODS

Hematology and hemoglobin fraction analysis were carried out by complete blood count (CBC) and capillary electrophoresis (CE). Gap-PCR was used to detect the common deletional α-thalassemia, and multiple ligation-dependent probe amplification (MLPA) was performed to screen the large deletion. Sanger sequencing identified the variant. The different deletions were confirmed by TGS.

RESULTS

CBC showed the patient with microcytic hypochromic anemia, and CE indicated the presence of a Hb variant. Gap-PCR and MLPA detected 4.2 kb deletion homozygotes (-α4.2/-α4.2). The Hb variant was confirmed as Hb Q-Thailand by Sanger sequencing. The patient was identified as compound heterozygous of 4.2 kb deletion and Hb Q-Thailand (-α4.2/-α4.2-Q-Thailand, -α4.2Ⅰ/-α4.2Ⅱ) using TGS.

CONCLUSIONS

Hb Q-Thailand (-α4.2-Q-Thailand/) complex 4.2 kb deletion heterozygote (-α4.2/) is easily misdiagnosed as 4.2 kb homozygous using Gap-PCR and MLPA. The TGS enables the identification of the two different 4.2 kb deletion sub-types.

Perturbations in lipid metabolism and gut microbiota composition precede cardiac dysfunction in a mouse model of thalassemia

Cardiomyopathy is a major complication of thalassemia, yet the precise underlying molecular mechanisms remain unclear. We examined whether altered lipid metabolism is an early driving factor in the development of cardiomyopathy using the Th3/+ mouse model of thalassemia. At age 20 weeks, male and female Th3/+ mice manifested anemia and iron overload; however, only males displayed metabolic defects and altered cardiac function. Untargeted lipidomics indicated that the circulating levels of 35 lipid species were significantly altered in Th3/+ mice compared to wild-type controls: triglycerides (TGs) with saturated fatty acids (FAs; TG42:0 and TG44:0) were elevated, while TGs with unsaturated FAs (TG(18:2_20:5_18:2 and TG54:8)) were reduced. Similarly, phosphatidylcholines (PCs) with long chain FAs (palmitic (16:0) or oleic (18:1)) were increased, while PCs with polyunsaturated FAs decreased. Circulating PC(16:0_14:0), GlcCer(d18:1/24:0) correlated significantly with iron overload and cardiac hypertrophy. 16S rRNA gene profiling revealed alterations in the intestinal microbiota of Th3/+ mice. Differentially abundant bacterial genera correlated with PC(39:6), PC(18:1_22:6), GlcCer(d18:1/24:1) and CE(14:0). These results provide new knowledge on perturbations in lipid metabolism and the gut microbiota of Th3/+ mice and identify specific factors which may represent early biomarkers or therapeutic targets to prevent development of cardiomyopathy in β-thalassemia.

CRISPR/Cas-based gene editing in therapeutic strategies for beta-thalassemia

Beta-thalassemia (β-thalassemia) is an autosomal recessive disorder caused by point mutations, insertions, and deletions in the HBB gene cluster, resulting in the underproduction of β-globin chains. The most severe type may demonstrate complications including massive hepatosplenomegaly, bone deformities, and severe growth retardation in children. Treatments for β-thalassemia include blood transfusion, splenectomy, and allogeneic hematopoietic stem cell transplantation (HSCT). However, long-term blood transfusions require regular iron removal therapy. For allogeneic HSCT, human lymphocyte antigen (HLA)-matched donors are rarely available, and acute graft-versus-host disease (GVHD) may occur after the transplantation. Thus, these conventional treatments are facing significant challenges. In recent years, with the advent and advancement of CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 (CRISPR-associated protein 9) gene editing technology, precise genome editing has achieved encouraging successes in basic and clinical studies for treating various genetic disorders, including β-thalassemia. Target gene-edited autogeneic HSCT helps patients avoid graft rejection and GVHD, making it a promising curative therapy for transfusion-dependent β-thalassemia (TDT). In this review, we introduce the development and mechanisms of CRISPR/Cas9. Recent advances on feasible strategies of CRISPR/Cas9 targeting three globin genes (HBB, HBG, and HBA) and targeting cell selections for β-thalassemia therapy are highlighted. Current CRISPR-based clinical trials in the treatment of β-thalassemia are summarized, which are focused on γ-globin reactivation and fetal hemoglobin reproduction in hematopoietic stem cells. Lastly, the applications of other promising CRISPR-based technologies, such as base editing and prime editing, in treating β-thalassemia and the limitations of the CRISPR/Cas system in therapeutic applications are discussed.

Biology of Anemia: A Public Health Perspective

Our goal is to present recent progress in understanding the biological mechanisms underlying anemia from a public health perspective. We describe important advances in understanding common causes of anemia and their interactions, including iron deficiency (ID), lack of other micronutrients, infection, inflammation, and genetic conditions. ID develops if the iron circulating in the blood cannot provide the amounts required for red blood cell production and tissue needs. ID anemia develops as iron-limited red blood cell production fails to maintain the hemoglobin concentration above the threshold used to define anemia. Globally, absolute ID (absent or reduced body iron stores that do not meet the need for iron of an individual but may respond to iron supplementation) contributes to only a limited proportion of anemia. Functional ID (adequate or increased iron stores that cannot meet the need for iron because of the effects of infection or inflammation and does not respond to iron supplementation) is frequently responsible for anemia in low- and middle-income countries. Absolute and functional ID may coexist. We highlight continued improvement in understanding the roles of infections and inflammation in causing a large proportion of anemia. Deficiencies of nutrients other than iron are less common but important in some settings. The importance of genetic conditions as causes of anemia depends upon the specific inherited red blood cell abnormalities and their prevalence in the settings examined. From a public health perspective, each setting has a distinctive composition of components underlying the common causes of anemia. We emphasize the coincidence between regions with a high prevalence of anemia attributed to ID (both absolute and functional), those with endemic infections, and those with widespread genetic conditions affecting red blood cells, especially in sub-Saharan Africa and regions in Asia and Oceania.

Case report: Identification of a novel triplication of alpha-globin gene by the third-generation sequencing: pedigree analysis and genetic diagnosis

BACKGROUND

Thalassemia, a common autosomal hereditary blood disorder worldwide, mainly contains α- and β-thalassemia. The α-globin gene triplicates allele is harmless for carriers, but aggravates the phenotype of β-thalassemia. Therefore, it is particularly crucial to accurately detect the structural variants of α-globin gene clusters.

CASE REPORT

We reported a 28-year-old man, the proband, with microcytic hypochromic anemia. From pedigree analysis, his mother and sister had hypochromic microcytosis, and his father was normal. Genetic testing of thalassemia identified a novel α-globin gene triplicate named αααanti4.2del726bp (NC_000016.10:g.170769_174300dupinsAAAAAA) by third-generation sequencing (TGS) in the proband and his father, which was further validated by multiplex ligation-dependent probe amplification (MLPA) and Sanger sequencing. The genotypes of the proband's mother and sister were both -α3.7/αα compounded with heterozygous HBB:c.126_129delCTTT. They were categorized as silent α-thalassemia with co-inheritance of β-thalassemia trait. The proband's genotype additionally had the α-globin gene triplicates compared with his mother and sister, which increased the imbalance between α/β-globin, so the proband had more severe hematological parameters. The proband's wife was diagnosed as HBA2:c.427T > C heterozygosis, and his daughter had the novel α-globin gene triplicates compounded with HBA2:c.427T > C, therefore the girl might be asymptomatic.

CONCLUSION

The identification of the novel α-globin gene triplicates provides more insight for the research of thalassemia variants and indicates that TGS has significant advantages on genetic testing of thalassemia for the reliability, accuracy and comprehensiveness.

Approaches to Address the Anemia Challenge

Anemia is a multifactorial condition; approaches to address it must recognize that the causal factors represent an ecology consisting of internal (biology, genetics, and health) and external (social/behavioral/demographic and physical) environments. In this paper, we present an approach for selecting interventions, followed by a description of key issues related to the multiple available interventions for prevention and reduction of anemia. We address interventions for anemia using the following 2 main categories: 1) those that address nutrients alone, and, 2) those that address nonnutritional causes of anemia. The emphasis will be on interventions of public health relevance, but we also consider the clinical context. We also focus on interventions at different stages of the life course, with a particular focus on women of reproductive age and preschool-age children, and present evidence on various factors to consider when selecting an intervention-inflammation, genetic mutations, nutrient delivery, bioavailability, and safety. Each section on an intervention domain concludes with a brief discussion of key research areas.

Causal links of α-thalassemia indices and cardiometabolic traits and diabetes: MR study

Our study aimed to investigate if genetic variants around 16p13.3's HBA1 locus, associated with erythrocyte indices and HbA1c levels, predict α-thalassemia-related erythrocyte indices, cardiometabolic traits, and diabetes risk in Taiwanese individuals. We analyzed Taiwan Biobank data, including whole-genome sequencing from 1,493 participants and genotyping arrays from 129,542 individuals. First, we performed regional association analysis using whole-genome sequencing data to identify genetic variants significantly associated with erythrocyte indices, confirming their linkage disequilibrium with the α0 thalassemia --SEA deletion mutation, a common cause of α-thalassemia in Southeast Asian populations. Deletion mutation sequencing further validated these variants' association with α-thalassemia. Subsequently, we analyzed genotyping array data, revealing associations between specific genetic variants and cardiometabolic traits, including lipid profiles, HbA1c levels, bilirubin levels, and diabetes risk. Using Mendelian randomization, we established causal relationships between α-thalassemia-related erythrocyte indices and cardiometabolic traits, elucidating their role in diabetes susceptibility. Our findings highlight genetic variants around the α-globin genes as surrogate markers for common α-thalassemia mutations in Taiwan, emphasizing the causal links between α-thalassemia-related erythrocyte indices, cardiometabolic traits, and heightened diabetes risk.

Beta-thalassemia: is cure still a dream?

β-thalassemia is a monogenic disorder characterized by decreased hemoglobin production, resulting in chronic anemia. There are several factors affecting the clinical presentation of patients with β-thalassemia, and several complications such as iron overload or ineffective erythropoiesis have been linked to this disease. Until nowadays, several conservative therapies namely blood transfusions, iron chelation, and the FDA-approved drug Luspatercept have been adopted alongside other debatable permanent cures. Other clinical trials are being conducted to develop better and safer management techniques for these patients. This review will discuss the different treatment strategies of β-thalassemia including novel therapies, besides all possible curative therapies that are being developed for this disease.

Predicting Thalassemia Using Feature Selection Techniques: A Comparative Analysis

Thalassemia represents one of the most common genetic disorders worldwide, characterized by defects in hemoglobin synthesis. The affected individuals suffer from malfunctioning of one or more of the four globin genes, leading to chronic hemolytic anemia, an imbalance in the hemoglobin chain ratio, iron overload, and ineffective erythropoiesis. Despite the challenges posed by this condition, recent years have witnessed significant advancements in diagnosis, therapy, and transfusion support, significantly improving the prognosis for thalassemia patients. This research empirically evaluates the efficacy of models constructed using classification methods and explores the effectiveness of relevant features that are derived using various machine-learning techniques. Five feature selection approaches, namely Chi-Square (χ2), Exploratory Factor Score (EFS), tree-based Recursive Feature Elimination (RFE), gradient-based RFE, and Linear Regression Coefficient, were employed to determine the optimal feature set. Nine classifiers, namely K-Nearest Neighbors (KNN), Decision Trees (DT), Gradient Boosting Classifier (GBC), Linear Regression (LR), AdaBoost, Extreme Gradient Boosting (XGB), Random Forest (RF), Light Gradient Boosting Machine (LGBM), and Support Vector Machine (SVM), were utilized to evaluate the performance. The χ2 method achieved accuracy, registering 91.56% precision, 91.04% recall, and 92.65% f-score when aligned with the LR classifier. Moreover, the results underscore that amalgamating over-sampling with Synthetic Minority Over-sampling Technique (SMOTE), RFE, and 10-fold cross-validation markedly elevates the detection accuracy for αT patients. Notably, the Gradient Boosting Classifier (GBC) achieves 93.46% accuracy, 93.89% recall, and 92.72% F1 score.

Current trends of clinical trials involving CRISPR/Cas systems

The CRISPR/Cas9 system is a powerful genome editing tool that has made enormous impacts on next-generation molecular diagnostics and therapeutics, especially for genetic disorders that traditional therapies cannot cure. Currently, CRISPR-based gene editing is widely applied in basic, preclinical, and clinical studies. In this review, we attempt to identify trends in clinical studies involving CRISPR techniques to gain insights into the improvement and contribution of CRISPR/Cas technologies compared to traditional modified modalities. The review of clinical trials is focused on the applications of the CRISPR/Cas systems in the treatment of cancer, hematological, endocrine, and immune system diseases, as well as in diagnostics. The scientific basis underlined is analyzed. In addition, the challenges of CRISPR application in disease therapies and recent advances that expand and improve CRISPR applications in precision medicine are discussed.

Flexible Self-Powered Sensing System Based on Novel DNA Circuit Strategy and Graphdiyne for Thalassemia Gene by Rapid Naked-Eye Tracking and Open-Circuit Voltage

Based on the controllable instantaneous self-assembly ability of long-chain branched DNA nanostructures and the synergistic effect between nucleic acid amplification without enzymes, a highly sensitive and highly specific self-powered biosensing platform is developed. Two-dimensional graphdiyne is prepared, modified on flexible carbon cloth, and then functionalized with gold nanoparticles. When DNA mi-tubes are applied on it, target thalassemia gene CD122 triggers a dual-catalytic hairpin assembly reaction. The generated nanoscale DNA is precisely captured by the DNA mi-tube, exposing binding sites and activating the hybridization chain reaction to form long-chain branched DNA. Double-stranded DNA, along with dendritic DNA carrying a large number of guanine bases, precisely captures the signal molecule methylene blue (MB), generating a significant electrochemical signal. The redox reaction of MB also causes a proportional change in the system's color, achieving a colorimetric detection functionality. An efficient dual-mode self-powered sensing platform, therefore, is established for detecting the thalassemia gene CD122. The linear response range of target concentration to open-circuit voltage and RGB Blue value is 0.0001-10,000 pM. The detection limit under electrochemical mode is 36.3 aM (S/N = 3), and under colorimetric mode, it is as low as 12.1 aM (S/N = 3). The new method exhibits high sensitivity, excellent selectivity, and high accuracy, providing a universal strategy for designing novel biosensing platforms that can be extended to the detection of other biomolecules.