Non-Transfusion-Dependent Thalassemia: An Update on Complications and Management

Impact of genotype on multi-organ iron and complications in patients with non-transfusion-dependent β-thalassemia intermedia

We evaluated the impact of the genotype on clinical and hematochemical features, hepatic and cardiac iron levels, and endocrine, hepatic, and cardiovascular complications in non-transfusion-dependent (NTD) β-thalassemia intermedia (TI) patients. Sixty patients (39.09 ± 11.11 years, 29 females) consecutively enrolled in the Myocardial Iron Overload in Thalassemia project underwent Magnetic Resonance Imaging to quantify iron overload, biventricular function parameters, and atrial areas and to detect replacement myocardial fibrosis. Three groups of patients were identified: homozygous β+ (N = 18), heterozygous β0β+ (N = 22), and homozygous β0 (N = 20). The groups were homogeneous for sex, age, splenectomy, hematochemical parameters, chelation therapy, and iron levels. The homozygous β° genotype was associated with significantly higher biventricular end-diastolic and end-systolic volume indexes and bi-atrial area indexes. No difference was detected in biventricular ejection fractions or myocardial fibrosis. Extramedullary hematopoiesis and leg ulcers were significantly more frequent in the homozygous β° group compared to the homozygous β+ group. No association was detected between genotype and liver cirrhosis, hypogonadism, hypothyroidism, osteoporosis, heart failure, arrhythmias, and pulmonary hypertension. Heart remodelling related to a high cardiac output state cardiomyopathy, extramedullary hematopoiesis, and leg ulcers were more pronounced in patients with the homozygous β° genotype compared to the other genotypes analyzed. The knowledge of the genotype can assist in the clinical management of NTD β-TI patients.

β-Thalassemia and Diabetes Mellitus: Current State and Future Directions

β-Thalassemia major is a congenital hemoglobin disorder that requires regular blood transfusion. The disease is often associated with iron overload and diabetes mellitus, among other complications. Pancreatic iron overload in β-thalassemia patients disrupts β-cell function and insulin secretion and induces insulin resistance. Several risk factors, including family history of diabetes, sedentary lifestyle, obesity, gender, and advanced age increase the risk of diabetes in β-thalassemia patients. Precautionary measures such as blood glucose monitoring, anti-diabetic medications, and healthy living in β-thalassemia patients notwithstanding, the prevalence of diabetes in β-thalassemia patients continues to rise. This review aims to address the relationship between β-thalassemia and diabetes in an attempt to understand how the pathology and management of β-thalassemia precipitate diabetes mellitus. The possible employment of surrogate biomarkers for early prediction and intervention is discussed. More work is still needed to better understand the molecular mechanism(s) underlying the link between β-thalassemia and diabetes and to identify novel prognostic and therapeutic targets.

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.

Spectrum of Adrenal Dysfunction in Hemoglobin E/Beta Thalassemia

BACKGROUND

Adrenal insufficiency (AI) in hemoglobin E (HbE)/beta thalassemia, including evaluation of mineralocorticoid axis, had not been studied.

AIMS AND OBJECTIVES

In this study, we attempted to evaluate the prevalence of AI in HbE/beta thalassemia and wanted to determine if the prevalence of AI varied according to severity of HbE/beta thalassemia and transfusion requirements.

METHODS

In this observational, cross-sectional study, 104 patients with HbE/beta thalassemia were evaluated. Among them, 57 and 47 were transfusion dependent and non-transfusion dependent. According to Mahidol criteria, patients were classified into mild (n = 39), moderate (n = 39), and severe (n = 26) disease. Early morning (8 Am) serum cortisol, plasma ACTH, and plasma aldosterone, renin were measured. Patients with baseline cortisol of 5 to 18 μg/dL underwent both 1 μg and 250 μg short Synacthen test. According to these results, patients were classified as having either normal, subclinical, or overt (primary/secondary) adrenal dysfunction.

RESULTS

Adrenal insufficiency was found in 41% (n = 43). Among them 83.7% (n = 34) had primary AI and 16.3% (n = 9) had secondary AI. Thirty-three patients (31%) with normal or elevated ACTH and with low or normal aldosterone with high renin were diagnosed as having subclinical AI. There was no difference in prevalence of AI between transfusion dependent and non-transfusion dependent (P = .56) nor was there was any difference in prevalence of AI according to disease severity (P = .52).

CONCLUSION

Adrenal insufficiency is common in HbE/beta thalassemia and is independent of transfusion dependency and disease severity.

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.

How I treat non-transfusion-dependent β-thalassemia

The intricate interplay of anemia and iron overload under the pathophysiological umbrella of ineffective erythropoiesis in non-transfusion-dependent β-thalassemia (NTDT) results in a complex variety of clinical phenotypes that are challenging to diagnose and manage. In this article, we use a clinical framework rooted in pathophysiology to present 4 common scenarios of patients with NTDT. Starting from practical considerations in the diagnosis of NTDT, we delineate our strategy for the longitudinal care of patients who exhibit different constellations of symptoms and complications. We highlight the use of transfusion therapy and novel agents, such as luspatercept, in the patient with anemia-related complications. We also describe our approach to chelation therapy in the patient with iron overload. Although tackling every specific complication of NTDT is beyond the scope of this article, we touch on the management of the various morbidities and multisystem manifestations of the disease.

Cardiovascular Complications in β-Thalassemia: Getting to the Heart of It

Beta thalassemia is an inherited disorder resulting in abnormal or decreased production of hemoglobin, leading to hemolysis and chronic anemia. The long-term complications can affect multiple organ systems, namely the liver, heart, and endocrine. Myocardial iron overload is a common finding in β-thalassemia. As a result, different cardiovascular complications in the form of cardiomyopathy, pulmonary hypertension, arrhythmias, and vasculopathies can occur, and in extreme cases, sudden cardiac death. Each of these complications pertains to underlying etiologies and risk factors, which highlights the importance of early diagnosis and prevention. In this review, we will discuss different types of cardiovascular complications that can manifest in patients with β-thalassemia, in addition to the current diagnostic modalities, preventive and treatment modalities for these complications.

Non-Transfusion-Dependent Thalassemia: A Panoramic Review

Non-transfusion-dependent thalassemia (NTDT) has been considered less severe than its transfusion-dependent variants. The most common forms of NTDT include β-thalassemia intermedia, hemoglobin E/beta thalassemia, and hemoglobin H disease. Patients with NTDT develop several clinical complications, despite their regular transfusion independence. Ineffective erythropoiesis, iron overload, and hypercoagulability are pathophysiological factors that lead to morbidities in these patients. Therefore, an early and accurate diagnosis of NTDT is essential to ascertaining early interventions. Currently, several conventional management options are available, with guidelines suggested by the Thalassemia International Federation, and novel therapies are being developed in light of the advancement of the understanding of this disease. This review aimed to increase clinicians’ awareness of NTDT, from its basic medical definition and genetics to its pathophysiology. Specific complications to NTDT were reviewed, along with the risk factors for its development. The indications of different therapeutic options were outlined, and recent advancements were reviewed.

Luspatercept for the treatment of anaemia in non-transfusion-dependent β-thalassaemia (BEYOND): a phase 2, randomised, double-blind, multicentre, placebo-controlled trial

BACKGROUND

In patients with non-transfusion-dependent β-thalassaemia, haemoglobin concentrations lower than 10 g/dL are associated with a higher risk of morbidity, mortality, and impaired quality of life. No drugs are specifically approved for anaemia management in patients with non-transfusion-dependent β-thalassaemia, other than transfusion therapy administered infrequently in accordance with patients' needs. We assessed the efficacy and safety of luspatercept versus placebo in patients with non-transfusion-dependent β-thalassaemia.

METHODS

We did a phase 2, randomised, double-blind, multicentre, placebo-controlled trial in 12 centres in six countries (Thailand [n=1], Lebanon [n=1], Greece [n=2], Italy [n=5], the UK [n=1], and the USA [n=2]). Eligible patients were aged 18 years or older, had confirmed diagnosis of β-thalassaemia or haemoglobin E/β-thalassaemia (concomitant α-globin deletion, mutation, or duplication were allowed), and a baseline haemoglobin concentration of 10·0 g/dL or lower. All patients were non-transfusion-dependent. Patients were randomly assigned (2:1) to luspatercept or placebo using an interactive response technology system and stratified by baseline haemoglobin concentration (≥8·5 g/dL vs <8·5 g/dL) and baseline Non-Transfusion-Dependent β-thalassaemia-Patient-Reported Outcome Tiredness/Weakness domain score (≥3 vs <3). All patients, study site staff, and sponsor representatives (who reviewed the data), except for designated individuals, were masked to drug assignment until the time the study was unblinded. Luspatercept or placebo was given once subcutaneously every 3 weeks for 48 weeks in the double-blind treatment period. Luspatercept was started at 1·0 mg/kg with titration up to 1·25 mg/kg, or reduction in the event of toxicity or excessive haemoglobin concentration increase. The primary endpoint was achievement of an increase from baseline of 1·0 g/dL or higher in mean haemoglobin concentration over a continuous 12-week interval during weeks 13-24, in the absence of transfusions. The primary efficacy and safety analyses were done in the intention-to-treat population. This trial is registered at ClinicalTrials.gov, NCT03342404, and is ongoing.

FINDINGS

Between Feb 5, 2018, and Oct 14, 2019, 160 patients were screened for eligiblity, of whom 145 were randomly assigned to luspatercept (n=96) or placebo (n=49). 82 (57%) patients were female and 63 (43%) were male. 44 (30%) patients were Asian, 87 (60%) were White, and 14 (10%) identified as another race. The study met its primary endpoint: 74 (77%) of 96 patients in the luspatercept group and none in the placebo group had an increase of at least 1·0 g/dL in haemoglobin concentration (common risk difference 77·1 [95% CI 68·7-85·5]; p<0·0001). The proportion of patients with serious adverse events was lower in the luspatercept group than in the placebo group (11 [12%] vs 12 [25%]). Treatment-emergent adverse events most commonly reported with luspatercept were bone pain (35 [37%]), headache (29 [30%]), and arthralgia (28 [29%]). No thromboembolic events or deaths were reported during the study.

INTERPRETATION

Luspatercept represents a potential treatment for adult patients with non-transfusion-dependent β-thalassaemia, for whom effective approved treatment options are scarce.

FUNDING

Celgene and Acceleron Pharma.

Luspatercept, a two-edged sword in beta-thalassemia-associated paravertebral extramedullary hematopoietic masses (EHMs)

Paravertebral extramedullary hematopoietic masses (EHMs) account for up to 15% of extramedullary pseudotumors in beta-thalassemia (BT) and are most likely related to compensatory hematopoiesis. In most cases, pseudotumors are incidentally detected, as the majority of patients are asymptomatic. Since June 2020, luspatercept is approved for the treatment of patients with BT who require regular red blood cell transfusions. Data addressing the safety and efficacy of luspatercept in patients with BT-associated EHMs are pending. To date (May 2022), paravertebral EHMs were observed in two asymptomatic patients out of currently 43 adult patients with BT registered at the Adult Hemoglobinopathy Outpatient Unit of the University Hospital Essen, Germany. In one of them, a paravertebral EHM was diagnosed for more than 10 years prior to referral. Throughout observation time, treatment with luspatercept was associated with a clinically significant reduction in transfusion burden while allowing to maintain a baseline hemoglobin concentration of ≥10 g/dl aiming to suppress endogenous (ineffective) erythropoiesis associated with BT. Considering the rarity of paravertebral EHMs in BT, luspatercept might potentially represent a novel therapeutic option for these often-serious disease-associated complications. However, appropriate follow-up investigations are recommended to detect (early) treatment failures secondary to an undesired luspatercept-associated erythroid expansion.

Safety and efficacy of mitapivat, an oral pyruvate kinase activator, in adults with non-transfusion dependent α-thalassaemia or β-thalassaemia: an open-label, multicentre, phase 2 study

BACKGROUND

Patients with non-transfusion-dependent thalassaemia (NTDT), although they do not require regular blood transfusions for survival, can still accrue a heavy burden of comorbidities. No approved disease-modifying therapies exist for these patients. We aimed to investigate the safety and efficacy of mitapivat (Agios Pharmaceuticals, Cambridge, MA, USA), a pyruvate kinase activator, in adults with non-transfusion-dependent (NTD) α-thalassaemia or NTD β-thalassaemia.

METHODS

In this open-label, multicentre, phase 2 study, patients were recruited from four academic clinical study sites in Oakland, CA, and Boston, MA, USA; Toronto, ON, Canada; and London, UK. Patients were eligible if they were aged 18 years or older, with NTDT (including β-thalassaemia with or without α-globin gene mutations, haemoglobin E β-thalassaemia, or α-thalassaemia), and a baseline haemoglobin concentration of 10·0 g/dL or lower. During a 24-week core period, mitapivat was administered orally at 50 mg twice daily for the first 6 weeks followed by an escalation to 100 mg twice daily for 18 weeks thereafter. The primary endpoint was haemoglobin response (a ≥1·0 g/dL increase in haemoglobin concentration from baseline at one or more assessments between weeks 4 and 12). Efficacy and safety were assessed in the full analysis set (ie, all patients who received at least one dose of study drug). This study is registered with ClinicalTrials.gov, NCT03692052, and is closed to accrual.

FINDINGS

Between Dec 28, 2018, and Feb 6, 2020, 27 patients were screened, of whom 20 were enrolled (15 [75%] with β-thalassaemia and five [25%] with α-thalassaemia) and received mitapivat. The median age of patients was 44 years (IQR 35-56), 15 (75%) of 20 patients were female, five (25%) were male, and ten (50%) identified as Asian. 16 (80% [90% CI 60-93]) of 20 patients had a haemoglobin response (p<0·0001), five (100%) of five with α-thalassaemia and 11 (73%) of 15 with β-thalassaemia. 17 (85%) patients had a treatment-emergent adverse event, and 13 had a treatment-emergent event that was considered to be treatment related. One serious treatment-emergent adverse event occurred (grade 3 renal impairment), which was considered unrelated to study drug, resulting in discontinuation of treatment. The most commonly reported treatment-emergent adverse events were initial insomnia (ten [50%] patients), dizziness (six [30%]), and headache (five [25%]). No patients died during the 24-week core period.

INTERPRETATION

These efficacy and safety results support the continued investigation of mitapivat for the treatment of both α-thalassaemia and β-thalassaemia.

FUNDING

Agios Pharmaceuticals.

Good Clinical Practice of the Italian Society of Thalassemia and Haemoglobinopathies (SITE) for the Management of Endocrine Complications in Patients with Haemoglobinopathies

Background: The treatment of endocrinopathies in haemoglobinopathies is a continually expanding research area; therefore, recommendations supporting the appropriateness of treatments are a pressing need for the medical community. Methods: The Management Committee of SITE selected and gathered a multidisciplinary and multi-professional team, including experts in haemoglobinopathies and experts in endocrinopathies, who have been flanked by experts with methodological and organizational expertise, in order to formulate recommendations based on the available scientific evidence integrated by personal clinical experience. The project followed the systematic approach for the production of clinical practice guidelines according to the methodology suggested by the National Center for Clinical Excellence, Quality and Safety of Care (CNEC). Results: Out of 14 topics, 100 clinical questions were addressed, and 206 recommendations were elaborated on. The strength of recommendations, panel agreement, a short general description of the topic, and the interpretation of evidence were reported. Conclusions: Good Practice Recommendations are the final outcome of translational research and allow one to transfer to the daily clinical practice of endocrine complications in haemoglobinopathies.

Vascular Brain Damage in Thalassemia Syndrome: An Emerging Challenge

Thalassemia syndromes are the most prevalent monogenic hemoglobinopathy in the world. In Iran, thalassemia is a public health problem because this country has been located on the thalassemia belt. In recent decades, considering that the life expectancy of patients with thalassemia has dramatically improved, some unrecognized complications have emerged in these individuals. One of these complications is a hypercoagulable state that may lead to thromboembolic events (TEE). The TEE may involve any organ in the body, including the central nervous system. Ischemic cerebrovascular events in thalassemic patients have been divided into two categories, namely overt stroke and silent cerebral infarcts (SCI). Overt stroke often develops in patients with beta-thalassemia major; however, patients with thalassemia intermedia usually suffer from SCI. This review article discusses brain vascular involvement.

Analysis of Common Beta-Thalassemia (β-Thalassemia) Mutations in East Java, Indonesia

BACKGROUND

The frequency of the beta-thalassemia (β-thalassemia) gene in Indonesia ranges from 3 to 10%. However, in the East Java province, there is still limited information on the prevalence of β-thalassemia mutations in clinically diagnosed beta-thalassemia patients of East Java. Therefore, this study aimed to characterize β-thalassemia mutations in selected patients in the East Java province of Indonesia.

METHODS

This is an analytical observational study. Diagnosis of β-thalassemia was based on clinical presentation, complete blood count (CBC), and hemoglobin (Hb) electrophoresis. Blood specimens taken from each patient in three ethylenediaminetetraacetic acid (EDTA) tubes were analyzed for CBC and Hb electrophoresis and processed for DNA extraction and subsequent polymerase chain reaction (PCR). Detection of mutations in Hemoglobin Subunit Beta (HBB) gene exons 1-3 of the β-thalassemia gene as the common mutation in Indonesia was done using PCR followed by Sanger sequencing.

RESULTS

In total, 33 (n = 33) participants were involved in this study with ages ranging from 5 to 17 years comprising 19 women and 14 men. Their ethnic origins were Javanese (n = 30) and Chinese (n = 3). CBC results showed that mean ± standard deviation (SD) for Hb, red blood cell (RBC), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), and red cell distribution width (RDW)-CV were 81.2 ± 7.0 g/L; 3.40 ± 0.39 × 10⁹/L; 71.05 ± 5.72 fL; 24.12 ± 2.45 pg; 33.91 ± 1.47 g/dl; 24.38 ± 6.02%, respectively. Hb electrophoresis revealed that 5 out of 33 participants had beta-thalassemia and 28 out of 33 participants had hemoglobinopathy (Hb) E/beta-thalassemia. Results of Sanger sequencing showed the following genotype variations in the samples: 12 (36.4%) with β ^CD26 /β ^IVS-I-5; 6 (18.2%) with β ^CD26 /β ^CD35; 3 (9.1%) with β ^CD26 /β ^IVS-I-2; 2 (6.1%) with β ^CD27/28 /β ^CD40; 2 (6.1%) with β ^IVS-I-1 /β ^CAP+1; and β ^CD26 /β ^IVS-I-1; β ^IVS-I-5 /β ^CAP+1; β ^IVS-I-5 /β ^CD35; β ^CD26 /β ^CD37; β ^CD26 /β ^CD15; β ^CD26 /β ^CD40; and β ^IVS-I-5 /β ^CD19 in 1 (3%) sample, respectively, and 1 (3%) had no abnormality detected in sequencing even though electrophoresis showed abnormality in the migration pattern. The β ^CD26 /β ^IVS-I-5 mutation was found in samples that were noted to have Hb E/beta-thalassemia on Hb electrophoresis.

CONCLUSION

The underlying genetic variations are heterogeneous in thalassemia patients in East Java, where 12 variants were found. The most common variant was β ^CD26 /β ^IVS-I-5, which all accounted for Hb E/beta-thalassemia on Hb electrophoresis. Furthermore, 28 out of 33 participants had hemoglobinopathy (Hb) E/beta-thalassemia.

Impact of HFE-2 and HAMP Gene Variations on Iron Overload in Pediatric Patients with Non-Transfusion Dependent Thalassemia: A Pilot Study

Patients with non-transfusion dependent thalassemia (NTDT) develop variable degrees of iron overload. Possible genes which may be implicated in causing iron overload are hepcidin (HAMP) and hemojuvelin (HFE). There is variable data assessing the role of c.-582Y A > G HAMP gene and H63D hotspot in HFE-1 gene in causing iron overload, while role of HFE-2 gene is undetermined. Twenty-five patients with NTDT (≥ 10 years) were assessed for iron overload. Genetic analysis for β-globin, α-globin, HAMP, HFE-2 and C282Y and H63D hotspots in HFE-1 genes was performed. T2*MRI demonstrated elevated LIC in 48% patients. No mutations were detected in HAMP gene or HFE-1 hotspots. Four single nucleotide variations (SNV) were detected in HFE-2 gene in 4 (20%) patients, including a novel SNV, p.Gln315Arg in 2 patients in heterozygous state. This is a likely pathogenic mutation; however, in heterozygous state, it did not lead to iron overload. HAMP and HFE-2 gene variations were infrequently seen in this pilot study, with no significant impact on iron overload. Presence of SNV p.Gln315Argin HFE-2 gene needs to be evaluated in larger sample sizes in our population to determine the incidence in homozygous state and its association with iron overload.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s12288-021-01442-9.

An update on the US adult thalassaemia population: a report from the CDC thalassaemia treatment centres

Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.

Fracture prevalence in thalassemia: a systematic review and meta-analysis

BACKGROUND

Multiple observational studies have reported high prevalence of fracture in patients with thalassemia. However, most of these studies have included limited number of patients, and only few of them have reported prevalence of fracture among patients with different types and severity of thalassemia.

OBJECTIVE

This systematic review and meta-analysis was conducted to summarize all available data of fracture prevalence among patients with thalassemia.

METHODS

A systematic review was conducted using EMBASE and MEDLINE databases from inception to June 2021 to determine studies that reported prevalence of fracture in thalassemia patients. The pooled prevalence with 95% confidence interval (95%CI) of fracture across studies was determined using a random-effect, generic inverse variance method.

RESULTS

After two rounds of systematic review, a total of 25 studies with 4934 patients were included in the meta-analysis. The pooled prevalence of fracture among patients with thalassemia was 16% (95%CI, 15-17%, I² = 94.3%). The subgroup analyses showed that the pooled prevalence of fracture was 4% (95%CI, 2-6%; I² = 70.4%) among patients with alpha thalassemia, 17% (95%CI, 16-19%; I² = 93.2%) among patients with beta thalassemia, 18% (95%CI, 16-19%; I² = 89.0%) among patients with transfusion-dependent thalassemia, and 7% (95%CI, 4-10%; I² = 94.2%) among patients with non-transfusion-dependent thalassemia.

CONCLUSION

Fracture is common in patients with thalassemia, and may be more prevalent in beta thalassemia and transfusion-dependent thalassemia than in alpha thalassemia and non-transfusion-dependent thalassemia.

Thalassemias: From gene to therapy

Thalassemias (α, β, γ, δ, δβ, and εγδβ) are the most common genetic disorders worldwide and constitute a heterogeneous group of hereditary diseases characterized by the deficient synthesis of one or more hemoglobin (Hb) chain(s). This leads to the accumulation of unstable non-thalassemic Hb chains, which precipitate and cause intramedullary destruction of erythroid precursors and premature lysis of red blood cells (RBC) in the peripheral blood. Non-thalassemic Hbs display high oxygen affinity and no cooperativity. Thalassemias result from many different genetic and molecular defects leading to either severe or clinically silent hematologic phenotypes. Thalassemias α and β are particularly diffused in the regions spanning from the Mediterranean basin through the Middle East, Indian subcontinent, Burma, Southeast Asia, Melanesia, and the Pacific Islands, whereas δβ-thalassemia is prevalent in some Mediterranean regions including Italy, Greece, and Turkey. Although in the world thalassemia and malaria areas overlap apparently, the RBC protection against malaria parasites is openly debated. Here, we provide an overview of the historical, geographic, genetic, structural, and molecular pathophysiological aspects of thalassemias. Moreover, attention has been paid to molecular and epigenetic pathways regulating globin gene expression and globin switching. Challenges of conventional standard treatments, including RBC transfusions and iron chelation therapy, splenectomy and hematopoietic stem cell transplantation from normal donors are reported. Finally, the progress made by rapidly evolving fields of gene therapy and gene editing strategies, already in pre-clinical and clinical evaluation, and future challenges as novel curative treatments for thalassemia are discussed.

Cerebrovascular Complications of Anemia

PURPOSE OF THE REVIEW

Anemia has been called the fifth cardiovascular risk factor. It is one of the most prevalent pathologies worldwide. In this article, we aimed to perform a narrative review of the main cerebrovascular complications of anemia and its influence on stroke prognosis.

RECENT FINDINGS

Both hypoproliferative anemia (thalassemia, iron deficiency anemia, etc.) and hyperproliferative anemia (sickle cell disease, paroxysmal nocturnal hemoglobinuria, hereditary spherocytosis, etc.) are associated to cerebrovascular disease ranging from transient ischemic attack to ischemic stroke and hemorrhagic stroke with both intraparenchymal hemorrhage and subarachnoid hemorrhage or cerebral venous thrombosis. Anemia is associated to a worse prognosis in patients with cerebrovascular disease In some cases, like sickle cell disease, pathophysiological mechanisms and therapeutic guidelines are well established, while in others, due to their rarity, there are still lack of robust data. More studies are needed to clarify how the prognosis of stroke patients with anemia could be improved.

Digital thermography and vascular involvement in β-thalassemia intermedia

Beta-thalassemia intermedia (β-TI) is associated with vascular dysfunction. We used digital thermal monitoring (DTM), a non-invasive tool that evaluates vascular function based on changes in fingertip temperature during and after cuff occlusion on β-TI patients. Thirty-three patients (18 years and older) were recruited in this study and divided into 3 groups: thalassemia, anemic controls, and healthy controls. Exclusion criteria included factors that are known to be associated with vascular damage. Patients underwent DTM and results were extracted as vascular reactivity index (VRI), a measure of how well the circulatory system responds to stimuli that require adjustments of blood flow. One-way analysis of variance (ANOVA) was used to test the mean difference in VRI between the 3 groups. A multiple linear regression was also carried out with VRI as the outcome of interest and a function of covariates that were thought to be of clinical relevance to VRI. The frequency, mean VRI ± standard error (SE) for the thalassemic group were (N = 16), mean = 2.243 ± 0.111; for anemic controls (N = 9), mean = 2.374 ± 0.162; and for the controls (N = 8), mean = 2.338 ± 0.092. ANOVA test indicated a non-significant difference in mean VRI between the three groups (P value = 0.731). Multiple linear regression couldn't detect any significant association between VRI and any of the predictors including the groups. Our study did not show a significant difference in VRI between the 3 study groups. Prospective studies of larger sample size are warranted to establish DTM as a possible non-invasive tool used to evaluate vascular function in β-TI patients.

SARS-CoV-2 infection in patients with β-thalassemia: The French experience

INTRODUCTION

Because of iron overload complications, thrombosis and infectious predisposition, patients with severe forms of thalassemia are likely to be at increased risk of COVID-19 complications.

RESULTS

A national survey conducted during the year 2020 across the French reference centers for hemoglobinopathies identified 16 cases of COVID-19 confirmed by RT-PCR in beta-thalassemia patients. Their age ranged from 11 months to 60 years. 15 patients were transfusion-dependent and 6 were splenectomized. Concerning iron overload related complications, none had diabetes or cirrhosis and only one had experienced heart failure. All 4 pediatric patients were pauci-symptomatic during the viral episode. Three patients (41, 49 and 57 years old) developed COVID-19 pneumonia requiring oxygen therapy without the need for mechanical ventilation. Neutropenia (absolute neutrophils count <0.5 10 ⁹/L) was observed in 2 patients receiving long-term treatment with hydroxycarbamide and deferiprone. No thrombosis event, organ failure or death occurred. All patients recovered.

CONCLUSION

Severity of COVID-19 in this population of young and middle-aged patients appeared increased compared to the general population but remained mild to moderate as already described in the few series reported in the literature. Occurrence of adverse events related to chronic treatment administered in thalassemia disease may be favored by the infectious episode.

Drug safety in thalassemia: lessons from the present and directions for the future

Introduction: Beta-thalassemia is an autosomal recessive hereditary anemia characterized by reduced or absent β-globin chain synthesis, affecting about 60,000 people peryear. Management for β-thalassemia major includes regular blood transfusions followed by iron chelating therapy and drug targeting ineffective erythropoiesis.Areas covered: The safety of licensed drugs for the management of β-thalassemia is reviewed, using evidence from clinical trials and observational research. Such drugs include the iron chelators and the erythrocyte maturation agent luspatercept. The safety of emerging treatment, such as hydroxyurea and thalidomide is also reviewed.Expert opinion: Beta-thalassemia is arare disease, and is not surprising that there are limited studies investigating the safety of drugs used in this disease. Indeed, although observational studies are the main source of drug safety information in areal-world setting, only eleven studies were identified for iron-chelators and none of these estimated the risk of agiven safety outcome. Future work should aim to better leverage existing sources of real-world datato investigate drug safety in thalassemia.

Correcting β-thalassemia by combined therapies that restrict iron and modulate erythropoietin activity

β-Thalassemia intermedia is a disorder characterized by ineffective erythropoiesis (IE), anemia, splenomegaly, and systemic iron overload. Novel approaches are being explored based on the modulation of pathways that reduce iron absorption (ie, using hepcidin activators like Tmprss6-antisense oligonucleotides [ASOs]) or increase erythropoiesis (by erythropoietin [EPO] administration or modulating the ability of transferrin receptor 2 [Tfr2] to control red blood cell [RBC] synthesis). Targeting Tmprss6 messenger RNA by Tmprss6-ASO was proven to be effective in improving IE and splenomegaly by inducing iron restriction. However, we postulated that combinatorial strategies might be superior to single therapies. Here, we combined Tmprss6-ASO with EPO administration or removal of a single Tfr2 allele in the bone marrow of animals affected by β-thalassemia intermedia (Hbbth3/+). EPO administration alone or removal of a single Tfr2 allele increased hemoglobin levels and RBCs. However, EPO or Tfr2 single-allele deletion alone, respectively, exacerbated or did not improve splenomegaly in β-thalassemic mice. To overcome this issue, we postulated that some level of iron restriction (by targeting Tmprss6) would improve splenomegaly while preserving the beneficial effects on RBC production mediated by EPO or Tfr2 deletion. While administration of Tmprss6-ASO alone improved the anemia, the combination of Tmprss6-ASO + EPO or Tmprss6-ASO + Tfr2 single-allele deletion produced significantly higher hemoglobin levels and reduced splenomegaly. In conclusion, our results clearly indicate that these combinatorial approaches are superior to single treatments in ameliorating IE and anemia in β-thalassemia and could provide guidance to translate some of these approaches into viable therapies.

A comprehensive review of hydroxyurea for β-haemoglobinopathies: the role revisited during COVID-19 pandemic

Background

Hydroxyurea is one of the earliest drugs that showed promise in the management of haemoglobinopathies that include β-thalassaemia and sickle cell disease. Despite this, many aspects of hydroxyurea are either unknown or understudied; specifically, its usefulness in β-thalassaemia major and haemoglobin E β-thalassaemia is unclear. However, during COVID-19 pandemic, it has become a valuable adjunct to transfusion therapy in patients with β-haemoglobinopathies. In this review, we aim to explore the available in vitro and in vivo mechanistic data and the clinical utility of hydroxyurea in β-haemoglobinopathies with a special emphasis on its usefulness during the COVID-19 pandemic.

Main body

Hydroxyurea is an S-phase-specific drug that reversibly inhibits ribonucleoside diphosphate reductase enzyme which catalyses an essential step in the DNA biosynthesis. In human erythroid cells, it induces the expression of γ-globin, a fetal globin gene that is suppressed after birth. Through several molecular pathways described in this review, hydroxyurea exerts many favourable effects on the haemoglobin content, red blood cell indices, ineffective erythropoiesis, and blood rheology in patients with β-haemoglobinopathies. Currently, it is recommended for sickle cell disease and non-transfusion dependent β-thalassaemia. A number of clinical trials are ongoing to evaluate its usefulness in transfusion dependent β-thalassaemia. During the COVID-19 pandemic, it was widely used as an adjunct to transfusion therapy due to limitations in the availability of blood and logistical disturbances. Thus, it has become clear that hydroxyurea could play a remarkable role in reducing transfusion requirements of patients with haemoglobinopathies, especially when donor blood is a limited resource.

Conclusion

Hydroxyurea is a well-tolerated oral drug which has been in use for many decades. Through its actions of reversible inhibition of ribonucleoside diphosphate reductase enzyme and fetal haemoglobin induction, it exerts many favourable effects on patients with β-haemoglobinopathies. It is currently approved for the treatment of sickle cell disease and non-transfusion dependent β-thalassaemia. Also, there are various observations to suggest that hydroxyurea is an important adjunct in the treatment of transfusion dependent β-thalassaemia which should be confirmed by randomised clinical trials.

Curcuminoids supplementation ameliorates iron overload, oxidative stress, hypercoagulability, and inflammation in non-transfusion-dependent β-thalassemia/Hb E patients

Curcuminoids, polyphenol compounds in turmeric, possess several pharmacological properties including antioxidant, iron-chelating, and anti-inflammatory activities. Effects of curcuminoids in thalassemia patients have been explored in a limited number of studies using different doses of curcuminoids. The present study aims to evaluate the effects of 24-week curcuminoids supplementation at the dosage of 500 and 1000 mg/day on iron overload, oxidative stress, hypercoagulability, and inflammation in non-transfused β-thalassemia/Hb E patients. In general, both curcuminoids dosages significantly lowered the levels of oxidative stress, hypercoagulability, and inflammatory markers in the patients. In contrast, reductions in iron parameter levels were more remarkable in the 1000 mg/day group. Subgroup analysis revealed that a marker of hypercoagulability was significantly decreased only in patients with baseline ferritin ≤ 1000 ng/ml independently of curcuminoids dosage. Moreover, the alleviation of iron loading parameters was more remarkable in patients with baseline ferritin > 1000 ng/ml who receive 1000 mg/day curcuminoids. On the other hand, the responses of oxidative stress markers were higher with 500 mg/day curcuminoids regardless of baseline ferritin levels. Our study suggests that baseline ferritin levels should be considered in the supplementation of curcuminoids and the appropriate curcuminoids dosage might differ according to the required therapeutic effect. Thai Clinical Trials Registry (TCTR): TCTR20200731003; July 31, 2020 "retrospectively registered".

Molecular Characterization and Disease-Related Morbidities of β-Thalassemia Patients from the Northeastern Part of Iraq

BACKGROUND

β-thalassemia is a significant problem in the northeastern part of Iraq, and has imposed a huge burden on the health authorities.

OBJECTIVE

To identify the molecular characterization and morbidity prevalence in transfusion-dependent thalassemia (TDT) and non-transfusion dependent thalassemia (NTDT) phenotypes in northeastern Iraq.

PATIENTS AND METHODS

This is a cross-sectional study conducted on 242 β-thalassemia patients from 162 families. Reverse hybridization technique and direct gene sequencing were used to characterize β-thalassemia mutations, and medical records of the patients were reviewed with a well-designed questionnaire.

RESULTS

A total of 22 β-globin mutations arranged in 53 different genotypes were identified: IVS-II-1 (G> A) (35.7%), followed by IVS-I-6 (T> C) (18.0%), and codon 8/9 (+G) (8.5%) were the most frequent. Among disease-related morbidities, bone disease amounted to (66.9%), followed by endocrinopathies (32.2%), hepatobiliary complications (28.9%), and pulmonary hypertension (9.9%), whereas thrombosis, extramedullary hemopoiesis, and leg ulcers were less frequent.

CONCLUSION

The overall complications rate was 78.9%, with a growing probability of complications with advanced age, with evidently higher rates in patients with β0β0 and β0β+ genotypes that explain the role of underlying genetic defects in the pathophysiology of disease complications.

Recent Progress in Gene Therapy and Other Targeted Therapeutic Approaches for Beta Thalassemia

Beta-thalassemia is a genetic disorder characterized by the impaired synthesis of the betaglobin chain of adult hemoglobin. The disorder has a complex pathophysiology that affects multiple organ systems. The main complications of beta thalassemia are ineffective erythropoiesis, chronic hemolytic anemia and hemosiderosis-induced organ dysfunction. Regular blood transfusions are the main therapy for beta thalassemia major; however, this treatment can cause cardiac and hepatic hemosiderosis - the most common cause of death in these patients. This review focuses on unique future therapeutic interventions for thalassemia that reverse splenomegaly, reduce transfusion frequency, decrease iron toxicity in organs, and correct chronic anemia. The targeted effective protocols include hemoglobin fetal inducers, ineffective erythropoiesis correctors, antioxidants, vitamins, and natural products. Resveratrol is a new herbal therapeutic approach which serves as fetal Hb inducer in beta thalassemia. Hematopoietic stem cell transplantation (HSCT) is the only curative therapy for beta thalassemia major and is preferred over iron chelation and blood transfusion for ensuring long life in these patients. Meanwhile, several molecular therapies, such as ActRIIB/IgG1 Fc recombinant protein, have emerged to address complications of beta thalassemia or the adverse effects of current drugs. Regarding gene correction strategies, a phase III trial called HGB-207 (Northstar-2; NCT02906202) is evaluating the efficacy and safety of autologous cell transplantation with LentiGlobin. Advanced gene-editing approaches aim to cut DNA at a targeted site and convert HbF to HbA during infancy, such as the suppression of BCL11A (B cell lymphoma 11A), HPFH (hereditary persistence of fetal hemoglobin) and zinc-finger nucleases. Gene therapy is progressing rapidly, with multiple clinical trials being conducted in many countries and the promise of commercial products to be available in the near future.

Recommendations for Pregnancy in Rare Inherited Anemias

Rare inherited anemias are a subset of anemias caused by a genetic defect along one of the several stages of erythropoiesis or in different cellular components that affect red blood cell integrity, and thus its lifespan. Due to their low prevalence, several complications on growth and development, and multi-organ system damage are not yet well defined. Moreover, during the last decade there has been a lack of proper understanding of the impact of rare anemias on maternal and fetal outcomes. In addition, there are no clear-cut guidelines outlining the pathophysiological trends and management options unique to this special population. Here, we present on behalf of the European Hematology Association, evidence- and consensus-based guidelines, established by an international group of experts in different fields, including hematologists, gynecologists, general practitioners, medical geneticists, and experts in rare inherited anemias from various European countries for standardized and appropriate choice of therapeutic interventions for the management of pregnancy in rare inherited anemias, including Diamond-Blackfan Anemia, Congenital Dyserythropoietic Anemias, Thalassemia, Sickle Cell Disease, Enzyme deficiency and Red cell membrane disorders.

The changing epidemiology of the ageing thalassaemia populations: A position statement of the Thalassaemia International Federation

Therapeutic advances in β-thalassaemia have gradually lead to a significant improvement in prognosis over the past few decades. As a result, patients living in areas where disease-specific programmes offering access to modern therapy are in place experience a new era of prolonged survival that tends to reach that of the normal population. This ageing thalassaemia population, however, faces a new spectrum of comorbidities resulting from increasing age that may jeopardise the advances in prognosis provided by current therapy and thus poses new challenges in diagnosis, monitoring and treatment. In this position paper of the Thalassaemia International Federation, we review the changing epidemiology and clinical spectrum of patients with β-thalassaemia and propose actions to be undertaken in order to address the emerging spectrum of comorbidities resulting from ageing.

Beta-Thalassemia Intermedia: A Single Thalassemia Center Experience from Northeastern Iraq

OBJECTIVE

To determine the molecular characterization and disease-associated complications of beta-thalassemia intermedia (β-TI) patients in Sulaymaniyah province, northeastern Iraq.

METHODS

A total of 159 β-TI) patients in Sulaymaniyah province, northeastern Iraq. β-TI) patients in Sulaymaniyah province, northeastern Iraq.

RESULTS

Nineteen different β-globin gene mutations arranged in 37 various genotypes were determined. The most frequent were IVS-II-I (G>A) (47.2%), followed by IVS-I-6 (T>C) (23.3%) and IVS-I-110 (G>A) (5%). Among disease-related morbidities documented, bone disease amounted to 53% (facial deformity and osteoporosis), followed by endocrinopathies 17.6% (growth retardation and subclinical hypothyroidism), cholelithiasis 13.8%, pulmonary hypertension 11.3%, and abnormal liver function test 7.5%, whereas venous thrombosis, extramedullary hemopoiesis, and leg ulcer were less frequently observed. Age ≥ 35 and female sex were risk factors for cholelithiasis, while age was an independent risk for hypothyroidism and female sex was associated with increased risk for osteoporosis. Mean serum ferritin of ≥1000 μg/L was associated with an increased risk of osteoporosis, whereas chelation therapy was protective for a multitude of other complications. Transfusion, on the other hand, increased the risk of osteoporosis, yet it was protective for cholelithiasis and hypothyroidism. Moreover, splenectomy was protective for cholelithiasis, although it was an independent risk for hypothyroidism. Finally, hydroxyurea was associated with an increased risk of osteoporosis, while it was protective for cholelithiasis. Discussion and Conclusion. β +-thalassemia mutation had contributed to 41.25 of families with a less severe β-thalassemia phenotype in the northeastern part of Iraq, justifying the need to investigate the contribution of genetic modifiers in ameliorating disease severity. In addition, the substantial number of β-TI patients developed disease-related morbidities, which necessitates the need for more appropriate clinical management with earlier intervention.β-TI) patients in Sulaymaniyah province, northeastern Iraq. μg/L was associated with an increased risk of osteoporosis, whereas chelation therapy was protective for a multitude of other complications. Transfusion, on the other hand, increased the risk of osteoporosis, yet it was protective for cholelithiasis and hypothyroidism. Moreover, splenectomy was protective for cholelithiasis, although it was an independent risk for hypothyroidism. Finally, hydroxyurea was associated with an increased risk of osteoporosis, while it was protective for cholelithiasis. Discussion and Conclusion. β +-thalassemia mutation had contributed to 41.25 of families with a less severe β-thalassemia phenotype in the northeastern part of Iraq, justifying the need to investigate the contribution of genetic modifiers in ameliorating disease severity. In addition, the substantial number of β-TI patients developed disease-related morbidities, which necessitates the need for more appropriate clinical management with earlier intervention.Discussion and Conclusion. β +-thalassemia mutation had contributed to 41.25 of families with a less severe β-thalassemia phenotype in the northeastern part of Iraq, justifying the need to investigate the contribution of genetic modifiers in ameliorating disease severity. In addition, the substantial number of β-TI patients developed disease-related morbidities, which necessitates the need for more appropriate clinical management with earlier intervention.β-TI) patients in Sulaymaniyah province, northeastern Iraq. β-TI) patients in Sulaymaniyah province, northeastern Iraq.

Nationwide carrier detection and molecular characterization of β-thalassemia and hemoglobin E variants in Bangladeshi population

Background

ß-thalassemia is one of the most common inherited blood disorders in the world and a major deterrent to the public health of Bangladesh. The management of thalassemia patients requires lifelong frequent blood transfusion and the available treatment options are unsatisfactory. A national policy on thalassemia prevention is mandatory in Bangladesh. However, precise and up-to-date information on the frequency of ß-thalassemia carriers are missing due to lack of accurate diagnostic approaches, limited access to information and absence of national screening program. This study aims to determine the nationwide carrier frequency of hemoglobin E (HbE) and β- thalassemia and mutation spectrum among the carriers using molecular, hematological and biochemical methods.

Methods

The study enrolled a total of 1877 individuals (60.1% male and 39.9% female) aged between 18 and 35 years. Total sample size and its division-wise breakdown were calculated in proportion to national and division-wise population. Venous blood was collected and subjected to CBC analysis and Hb-electrophoresis for each participant. Serum ferritin was measured to detect coexistence of iron deficiency anemia with thalassemia carrier. DNA-based High Resolution Melting (HRM) curve analysis was performed for confirmation of carrier status by mutation detection.

Results

Of 11.89% (95% CI, 10.43–13.35) carriers of β-globin gene mutations, 8.68% (95% CI, 7.41–9.95) had HbE trait (ETT) and 2.24% (95% CI, 1.57–2.91) had beta-thalassemia trait (BTT). Among eight divisions, Rangpur had the highest carrier frequency of 27.1% (ETT-25%, BTT-2.1%), whereas Khulna had the lowest frequency of 4.2% (ETT-4.2% only). Moreover, α- thalassemia, HbD trait, HbE disease, hereditary persistence of HbF were detected in 0.11, 0.16, 0.43 and 0.16% participants, respectively. HRM could identify two individuals with reported pathogenic mutations in both alleles who were erroneously interpreted as carriers by hematological indices. Finally, a total of nine different mutations including a novel mutation (c.151A > G) were detected in the β-globin gene.

Conclusions

Since carrier frequency for both HbE and β-thalassemia is alarmingly high in Bangladesh, a nationwide awareness and prevention program should be made mandatory to halt the current deteriorating situations. Mutation-based confirmation is highly recommended for the inconclusive cases with conventional carrier screening methods to avoid any faulty detection of thalassemia carriers.

A Concise Review on the Frequency, Major Risk Factors and Surveillance of Hepatocellular Carcinoma (HCC) in β-Thalassemias: Past, Present and Future Perspectives and the ICET-A Experience

Due to the recent alarming increase in the incidence of hepatocellular carcinoma (HCC) in thalassemias, the present report reviews briefly the frequency, the major risk factors, and the surveillance of HCC in β-thalassemias. Over the past 33 years, 153 cases of HCC were reported in patients with thalassemia, mainly in Italy and Greece. Among HCV-infected patients, additional factors promoting the development of HCC included: advanced age, male sex, chronic hepatitis B (CHB) co-infection, and iron overload. For early diagnosis of HCC, sequential ultrasound screening is recommended especially for thalassemia patients with chronic hepatitis C (CHC), which coincides with (one or more) additional risk factors for HCC. Here we report also the preliminary data from thalassemic patients, above the age of 30 years, followed in 13 ICET-A centers. The total number of enrolled patients was 1,327 (males: 624 and 703 females). The prevalence of HCC in thalassemia major patients [characterized by transfusion-dependency (TDT)] and thalassemia intermedia [characterized by nontransfusion dependency (NTDT)] was 1.66 % and 1.96 %, respectively. The lowest age at diagnosis of HCC was 36 years for TDT and 47 years for NTDT patients. We hope that this review can be used to develop more refined and prospective analyses of HCC magnitude and risk in patients with thalassemia and to define specific international guidelines to support clinicians for early diagnosis and treatment of HCC in thalassemic patients.

Kinetics and localisation of haemin-induced lipoprotein oxidation

Haemin (iron (III)-protoporphyrin IX) is a degradation product of haemoglobin in circulating erythrocytes. Haemin may play a key oxidising agent for lipoprotein oxidation in patients with haemolytic anaemia. In this study, kinetic changes in chemical composition and target sites of haemin-induced LDL and HDL oxidation were investigated. Haemin initially induced the loss of α-tocopherol, followed by accumulation of lipid hydroperoxide (LP) and alteration of core lipid fluidity. The absence of LP in HDL was explained by the antioxidant activity of PON in addition to α-tocopherol. The target site of haemin was evaluated by ESR spin labelling with 5- and 16-doxyl steric acids. In the presence of t-BuOOH and haemin, ESR signal decay of the doxyl moiety demonstrated the initiation phase and the propagation phase of lipid peroxidation. The results of the lag time and the rate of signal decay indicated that haemin is located near the 16th carbon atom of the fatty acid chain in the phospholipid layer. The analyses of motion parameters, order parameter (S) of 5-DS and rotational correlation time (τ) of 16-DS, supported the observation that the lipid properties changed near the hydrophobic region rather than at the surface region of lipoproteins. Moreover, ESR spin labelling demonstrated that haemin molecules but not iron ions caused lipoprotein oxidation. In conclusion, haemin is a potent inducer of lipoprotein oxidation, and the target site for this oxidation is near the hydrophobic core of the lipoprotein leading to the loss of antioxidant activities and changes in lipid composition and physical properties.

Health related quality of life among children with transfusion dependent β-thalassaemia major and haemoglobin E β-thalassaemia in Sri Lanka: a case control study

Background

Thalassaemia is a chronic disease without an effective cure in a majority. The clinical management has improved considerably during recent years; however, minimal attempts are made to up lift the quality of life among patients, especially in developing countries. Here we aim to describe and compare and to determine factors associated with health related quality of life among patients with transfusion dependent β-thalassaemia major and haemoglobin E β-thalassemia in Sri Lanka.

Methods

A case control study was conducted in the three largest thalassaemia centres of Sri Lanka. All patients with transfusion dependent β-thalassaemia (β-thalassaemia major and haemoglobin E β-thalassaemia) aged 5–18 years were recruited as cases whilst a randomly selected group of children without chronic diseases were recruited as controls. Socio-demographic and clinical data were collected using an interviewer-administered questionnaire and health related quality of life was measured using the validated Paediatric Quality of Life Inventory Version 4.0.

Results

Two hundred and seventy one patients with transfusion dependent β-thalassaemia (male-49.1%; mean age- 10.9 ± 3.6 years) and 254 controls (male-47.2%; mean age- 10.4 ± 3.5 years) were recruited. Mean health-related quality of life scores were significantly lower in patients compared to controls (72.9 vs. 91.5, p < 0.001). Of the patients, 224 (84%) had β-thalassaemia major and 43 (16%) had haemoglobin E β-thalassaemia. Quality of life scores in psychological health (p < 0.05), emotional functioning (p < 0.05) and social functioning (p < 0.05) were significantly lower in patients with haemoglobin E β-thalassaemia compared to β-thalassaemia major. Splenectomy (p < 0.05), short stature (p < 0.05), under nutrition (p < 0.05) and longer hospital stays (p < 0.05) were significantly associated with lower quality of life scores.

Conclusions

Despite improvements in management, the quality of life among patients with β-thalassaemia still remains low. This is more pronounced in the subset of patients with haemoglobin E β-thalassaemia. Splenectomy, short stature, undernutrition and longer hospital stays were significantly associated with poor quality of life. It is timely, even in developing countries, to direct emphasis and to take appropriate steps to improve standards of living and quality of life of patients with β-thalassaemia.

Molecular Analysis of Non-Transfusion Dependent Thalassemia Associated with Hemoglobin E-β-Thalassemia Disease without α-Thalassemia

Background

The finding of many Thai Hb E-β⁰-thalassemia patients with non-transfusion dependent thalassemia (NTDT) phenotype without co-inheritance of α-thalassemia has prompted us to investigate the existence of other genetic modifying factors.

Methods

Study was done on 122 adult Thai patients with NTDT Hb E-β-thalassemia patients without co-inheritance of α-thalassemia. Multiple single-nucleotide polymorphisms (SNPs) associated with γ-globin gene expression including the ^Gγ-XmnI of HBG2 gene, rs2297339, rs4895441, and rs9399137 of the HBS1L-MYB gene, rs4671393 in the BCL11A gene, and G176AfsX179, T334R, R238H and −154 (C-T) in the KLF1 gene were investigated using PCR and related techniques.

Results

Heterozygous and homozygous for ^Gγ-XmnI of HBG2 gene were detected at 70.5% and 7.4%, respectively. Further DNA analysis identified the rs2297339 (C-T), rs4895441 (A-G), and rs9399137 (T-C) of HBS1L-MYB gene in 86.9%, 25.4%, and 23.0%, respectively. The rs4671393 (G-A) of the BCL11A gene was found at 31.2%. For the KLF1 gene, only T334R was detected at 9.0%.

Conclusions

It was found that these SNPs, when analyzed in combination, could explain the mild phenotypic expression of all cases. These results underline the importance of these informative SNPs on phenotypic expression of Hb E-β-thalassemia patients.

Blood transfusion therapy for β-thalassemia major and hemoglobin E β-thalassemia: Adequacy, trends, and determinants in Sri Lanka

BACKGROUND

Regular blood transfusion therapy still remains the cornerstone in the management of β-thalassemia. Although recommendations are clear for patients with β-thalassemia major, uniform transfusion guidelines are lacking for patients with hemoglobin E β-thalassemia. In this study, we aim to describe the adequacy, trends, and determinants of blood transfusion therapy in a large cohort of pediatric patients with β-thalassemia major and hemoglobin E β-thalassemia.

METHODS/PROCEDURE

This cross-sectional study was performed among all regularly transfused patents with β-thalassemia aged 2 to 18 years attending three large thalassemia centers in Sri Lanka. Data were collected using an interviewer-administered questionnaire, perusal of clinical records, and physical examination of patients by trained doctors.

RESULTS

A total of 328 patients (male 47%) were recruited; 83% had β-thalassemia major, whereas 16% had hemoglobin E β-thalassemia. Sixty-one percent of patients had low pretransfusion hemoglobin levels (< 9.0 g/dL) despite receiving high transfusion volumes (> 200 mL/kg/year) by a majority (56%). Median pretransfusion hemoglobin was significantly lower in patients with hemoglobin E β-thalassemia compared with β-thalassemia major (P < 0.001); however, there was no difference in requirement for high transfusion volumes over 200 mL/kg/year in both groups (P = 0.14). Hepatomegaly and splenomegaly were more common in hemoglobin E β-thalassemia and were associated with lower pretransfusion hemoglobin. Transfusion requirements were higher among patients with hepatitis C and in those who are underweight.

CONCLUSIONS

Over 60% of regularly transfused patients with β-thalassemia have low pretransfusion hemoglobin levels despite receiving large transfusion volumes. Patients with hemoglobin E β-thalassemia are undertransfused and specific recommendations should be developed to guide transfusions in these patients.

Thalassemias: An Overview

Thalassemia syndromes are among the most serious and common genetic conditions. They are indigenous in a wide but specific geographical area. However, through migration they are spreading across regions not previously affected. Thalassemias are caused by mutations in the α (HBA1/HBA2) and β globin (HBB) genes and are usually inherited in an autosomal recessive manner. The corresponding proteins form the adult hemoglobin molecule (HbA) which is a heterotetramer of two α and two β globin chains. Thalassemia-causing mutations lead to an imbalanced globin chain production and consecutively to impaired erythropoiesis. The severity of the disease is largely determined by the degree of chain imbalance. In the worst case, survival is dependent on regular blood transfusions, which in turn cause transfusional iron overload and secondary multi-organ damage due to iron toxicity. A vigorous monitoring and treatment regime is required, even for the milder syndromes. Thalassemias are a major public health issue in many populations which many health authorities fail to address. Even though comprehensive care has resulted in long-term survival and good quality of life, poor access to essential components of management results in complications which increase the cost of treatment and lead to poor outcomes. These requirements are not recognized by measures such as the Global Burden of Disease project, which ranks thalassemia very low in terms of disability-adjusted life years (DALYs), and fails to consider that it ranks highly in the one to four-year-old age group, making it an important contributor to under-5 mortality. Thalassemia does not fulfil the criteria to be accepted as a target disease for neonatal screening. Nevertheless, depending on the screening methodology, severe cases of thalassemia will be detected in most neonatal screening programs for sickle cell disease. This is very valuable because: (1) it helps to prepare the affected families for having a sick child and (2) it is an important measure of secondary prevention.

Transferrin receptor 2 is a potential novel therapeutic target for β-thalassemia: evidence from a murine model

β-thalassemias are genetic disorders characterized by anemia, ineffective erythropoiesis, and iron overload. Current treatment of severe cases is based on blood transfusion and iron chelation or allogeneic bone marrow (BM) transplantation. Novel approaches are explored for nontransfusion-dependent patients (thalassemia intermedia) who develop anemia and iron overload. Here, we investigated the erythropoietin (EPO) receptor partner, transferrin receptor 2 (TFR2), as a novel potential therapeutic target. We generated a murine model of thalassemia intermedia specifically lacking BM Tfr2: because their erythroid cells are more susceptible to EPO stimulation, mice show improved erythropoiesis and red blood cell morphology as well as partial correction of anemia and iron overload. The beneficial effects become attenuated over time, possibly due to insufficient iron availability to sustain the enhanced erythropoiesis. Germ line deletion of Tfr2, including haploinsufficiency, had a similar effect in the thalassemic model. Because targeting TFR2 enhances EPO-mediated effects exclusively in cells expressing both receptors, this approach may have advantages over erythropoiesis-stimulating agents in the treatment of other anemias.

Renal complications in thalassemia

Thalassemia is a disease with an extensive morbidity profile affecting almost every organ system. Renal involvement, once considered rare, is an underestimated and poorly studied complication that has been on the rise ever since medical advances granted patients longer life spans. Several studies and reports have emerged recently to shed light on the seriousness of this complication, although data is still lacking in terms of pathophysiology, diagnosis, prevention and treatment. In this review, we evaluate and compare renal involvement in the transfusion-dependent and independent variants of β-Thalassemia, highlighting the pathophysiology of kidney damage that involves iron overload, chronic anemia, and iron chelation therapy. An in-depth and focused review of the types of injuries incurred is also presented along with the diagnostic biomarkers accompanying each type of injury. Most research so far has focused on the transfusion-dependent thalassemia population being the group with most renal involvement, however recent reports have shown evidence of comparable, if not worse, involvement of the non-transfusion dependent population, sometimes leading to end-stage renal disease. As such, we try to shed light on distinct renal involvements in NTDT whenever available.