Identification and key management of non-transfusion-dependent thalassaemia patients: not a rare but potentially under-recognised condition

Disease burden, management strategies, and unmet needs in α-thalassemia due to hemoglobin H disease

Alpha-thalassemia is an inherited blood disorder caused by impaired α-globin chain production, leading to anemia and other complications. Hemoglobin H (HbH) disease is caused by a combination of mutations generally affecting the expression of three of four α-globin alleles; disease severity is highly heterogeneous, largely driven by genotype. Notably, non-deletional mutations cause a greater degree of ineffective erythropoiesis and hemolysis, higher transfusion burden, and increased complication risks versus deletional mutations. There are limited treatment options for HbH disease, and effective therapies are needed. This review discusses the pathophysiology of HbH disease, current management strategies, unmet needs, and emerging treatment options.

Management of transfusion-dependent β-thalassemia (TDT): Expert insights and practical overview from the Middle East

β-Thalassemia is one of the most common monogenetic diseases worldwide, with a particularly high prevalence in the Middle East region. As such, we have developed long-standing experience with disease management and devising solutions to address challenges attributed to resource limitations. The region has also participated in the majority of clinical trials and development programs of iron chelators and more novel ineffective erythropoiesis-targeted therapy. In this review, we provide a practical overview of management for patients with transfusion-dependent β-thalassemia, primarily driven by such experiences, with the aim of transferring knowledge to colleagues in other regions facing similar challenges.

A highly sensitive self-powered sensing method designed on DNA circuit strategy and MoS2 hollow nanorods for detection of thalassemia

Thalassemia is one of the most common monogenic diseases, which seriously affects human growth and development, cardiovascular system, liver, etc. There is currently no effective cure for this disease, making screening for thalassemia particularly important. Herein, a self-powered portable device with high sensitivity and specificity for efficiently screening of low-level thalassemia is developed which is enabled with AuNPs/MoS2@C hollow nanorods and triple nucleic acid amplification technologies. It is noteworthy that AuNPs/MoS2@C electrode shows the advantages of high electrocatalytic activity, fast carrier migration rate and large specific surface area, which can significantly improve the stability and output signal of the platform. Using high-efficiency tetrahedral DNA as the probe, the target CD122 gene associated with thalassemia triggers a catalytic hairpin assembly reaction to achieve CD122 recycling while providing binding sites for subsequent hybridization chain reaction, greatly improving the detection accuracy and sensitivity of the device. A reliable electrochemical/colorimetric dual-mode assay for CD122 is then established, with a linear response range of 0.0001-100 pM for target concentration and open circuit voltage, and the detection limit is 78.7 aM (S/N = 3); a linear range of 0.0001-10000 pM for CD122 level and RGB Blue value, with a detection limit as low as 58.5 aM (S/N = 3). This method achieves ultra-sensitive and accurate detection of CD122, providing a new method for the rapid and accurate screening of thalassemia.

An Expert Overview on Therapies in Non-Transfusion-Dependent Thalassemia: Classical to Cutting Edge in Treatment

The thalassemia issue is a growing worldwide health concern that anticipates the number of patients suffering from the disease will soon increase significantly. Patients with β-thalassemia intermedia (β-TI) manifest mild to intermediate levels of anemia, which is a reason for it to be clinically located between thalassemia minor and β-thalassemia major (β-TM). Notably, the determination of the actual rate of β-TI is more complicated than β-TM. The leading cause of this illness could be partial repression of β-globin protein production; accordingly, the rate of β-globin gene repression is different in patients, and the gene repression intensity creates a different clinical status. This review article provides an overview of functional mechanisms, advantages, and disadvantages of the classic to latest new treatments for this group of patients, depending on the disease severity divided into the typical management strategies for patients with β-TI such as fetal hemoglobin (Hb) induction, splenectomy, bone marrow transplantation (BMT), transfusion therapy, and herbal and chemical iron chelators. Recently, novel erythropoiesis-stimulating agents have been added. Novel strategies are subclassified into molecular and cellular interventions. Genome editing is one of the efficient molecular therapies for improving hemoglobinopathies, especially β-TI. It encompasses high-fidelity DNA repair (HDR), base and prime editing, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 procedure, nuclease-free strategies, and epigenetic modulation. In cellular interventions, we mentioned the approach pattern to improve erythropoiesis impairments in translational models and patients with β-TI that involve activin II receptor traps, Janus-associated kinase 2 (JAK2) inhibitors, and iron metabolism regulation.

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.

Bone mineral density in primarily preadolescent children with hemoglobin E/β-thalassemia with different severities and transfusion requirements

BACKGROUND

Children with β-thalassemia major and β-thalassemia intermedia frequently have low bone mass. However, studies of bone mineral density (BMD) in children with transfusion-dependent (TD) or non-transfusion-dependent (NTD) hemoglobin (Hb) E/β-thalassemia are scarce.

OBJECTIVES

To determine the prevalence of low bone mass among mostly preadolescent children with NTD and TD Hb E/β thalassemia and the related factors.

METHODS

We investigated the BMD of the lumbar spine (LSBMD) and total body (TBBMD), measured by dual-energy X-ray absorptiometry, of 59 children with NTD Hb E/β-thalassemia and 50 with TD Hb E/β-thalassemia.

RESULTS

The median age of the patients was 10.4 (6.2-13.5) years in the NTD group and 10.3 (5.9-14.1) years in the TD group. These children had a relatively low prevalence of low bone mass (NTD: 1.7%-10.2%; TD: 4%-14%). The values varied with the bone site measured and the BMD size-adjustment method used (height age vs. bone age). The NTD group had significantly lower TBBMD Z-scores (adjusted for height age) than the TD group. The proportion of patients with low lumbar spine bone mass (adjusted for bone age) was significantly higher for the TD group than for the NTD group.

CONCLUSIONS

Our study demonstrates that most children with either disease had normal BMD. Patients with the NTD form had a lower TBBMD than those with the TD form. Low bone mass affected the lumbar spine of patients with TD Hb E/β-thalassemia more than those with the NTD form.

Random Forest Clustering Identifies Three Subgroups of β-Thalassemia with Distinct Clinical Severity

In this work, we aimed to establish subgroups of clinical severity in a global cohort of β-thalassemia through unsupervised random forest (RF) clustering. We used a large global dataset of 7910 β-thalassemia patients and evaluated 19 indicators of phenotype severity (IPhS) to determine their contribution and relatedness in grouping β-thalassemia patients into clusters using RF analysis. RF clustering suggested that three clusters with minimal overlapping exist (classification error rate: 4.3%), and six important IPhS were identified: the current age of the patient, the mean serum ferritin level, the age at diagnosis, the age at first transfusion, the age at first iron chelation, and the number of complications. Cluster 3 represented patients with early initiation of transfusion and iron chelation, considerable iron overload, and early mortality from heart failure. Patients in Cluster 2 had lower serum ferritin levels, although they had a higher number of complications manifesting overtime. Patients in Cluster 1 represented a subgroup with delayed or absent transfusion and iron chelation, but with a high morbidity rate. Hepatic disease and cancer were dominant causes of death in patients in Cluster 1 and 2. Our findings established that patients with β-thalassemia can be clustered into three groups based on six parameters of phenotype severity.

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.

Correlation of Serum Ferritin and Liver Iron Concentration with Transient Liver Elastography in Adult Thalassemia Intermedia Patients with Blood Transfusion

INTRODUCTION

Iron overload is a common feature of thalassemia intermedia due to regular blood transfusion and increased gastrointestinal iron absorption. Early detection and adequate iron chelator can decrease morbidity and mortality from iron overload. Liver iron concentration (LIC) by MRI T2* is the best non-invasive way to measure body iron stores. However, this method is expensive and not available nationwide in Indonesia. The aim of this study was to identify liver iron overload and correlation of transferrin saturation, serum ferritin, liver MRI T2* and LIC with transient liver elastography in adult thalassemia intermedia patients.

METHODS

This is a cross-sectional study of 45 patients with thalassemia intermedia with blood transfusion and with and without iron chelator therapy. The study was conducted at Cipto Mangunkusumo Hospital from August through October 2016. We performed measurements of transferrin saturation, serum ferritin level, transient liver elastography and liver MRI T2*. Pearson and Spearman correlation tests were used to evaluate the correlation between transient liver elastography with transferrin saturation, serum ferritin, liver MRI T2*and LIC.

RESULTS AND DISCUSSION

This study showed that 64.4% of study subjects are β-Hb E thalassemia intermedia. Furthermore, 84.4% of study subjects have regular transfusion. Based on liver MRI T2*all subjects suffered from liver iron overload, 48.9% had severe degree. Median value of liver MRI T2* was 1.6 ms. Mean serum ferritin was 2831 ng/mL, with median transferrin saturation of 66%. Mean of LIC corresponding to liver MRI T2* and mean liver stiffness measurement was 15.36±7.37 mg Fe/gr dry weight and 7.7±3.8 kPa, respectively. Liver stiffness correlated with serum ferritin (r=0.651; p=0.000), liver MRI T2* (r=-0.357; p=0.016), and LIC (r=0.433; p=0.003). No correlation was found between liver elastography and transferrin saturation (r=0.204; p=0.178).

CONCLUSION

Serum ferritin, liver MRI T2*and LIC correlated with liver elastography. No correlation was found between transferrin saturation and liver elastography.

A complication risk score to evaluate clinical severity of thalassaemia syndromes

The thalassaemia syndromes (TS) show different phenotype severity. Developing a reliable, practical and global tool to determine disease severity and tailor treatment would be of great value. Overall, 7910 patients were analysed with the aim of constructing a complication risk score (CoRS) to evaluate the probability of developing one or more complications. Nine independent variables were included in the investigation as predictors. Logistic regression models were used for Group A [transfusion-dependent thalassaemia (TDT)], Group B [transfused non-TDT (NTDT)] and Group C (non-transfused NTDT). Statistically significant predictors included age (years), haemoglobin levels, hepatic transaminases [alanine aminotransferase (ALT) and aspartate aminotransferase] and left-ventricular ejection fraction (LVEF) for Group A; age (years), age at first chelation (months), ALT and LVEF for Group B; and age (years), mean serum ferritin (SF) levels and LVEF for Group C. The area under the receiver operating characteristic curve was 84·5%, 82·1% and 80·0% for Groups A, Group B and Group C respectively, suggesting the models had good discrimination. Finally, the CoRS for each group was categorised into four risk classes (low, intermediate, high, and very high) using the centiles of its distribution. In conclusion, we have developed a CoRS for TS that can assist physicians in prospectively tailoring patients' treatment.

EF Bart's Disease with Coinheritance of Gγ-XmnI and Aγ-Globin Polymorphisms: A Case of Nontransfusion-Dependant Thalassemia

EF Bart's disease is a rare form of nontransfusion-dependant thalassemia (NTDT) due to the coinheritance of homozygous hemoglobin E (β^E/β^E) genotype with hemoglobin H disease. These individuals are routinely found to have thalassemia intermedia with moderate anemia, increased hemoglobin Bart's and hemoglobin F on electrophoresis. The contribution of hemoglobin F-inducing polymorphisms in this disease has not been described previously. Here, we describe the hematological profile in a young child with coinheritance of Gγ-XmnI and Aγ-globin gene polymorphisms in EF Bart's disease. Interestingly, in this rare form of NTDT, normal HbF and elevated HbA2 were noted.

Liver complications of haemoglobin H disease in adults

Haemoglobin H (HbH) disease is a type of non-transfusion-dependent thalassaemia. This cross-sectional study aimed at determining the prevalence and severity of liver iron overload and liver fibrosis in patients with HbH disease. Risk factors for advanced liver fibrosis were also identified. A total of 80 patients were evaluated [median (range) age 53 (24-79) years, male 34%, non-deletional HbH disease 24%]. Patients underwent 'observed' T2-weighted magnetic resonance imaging examination for liver iron concentration (LIC) quantification, and transient elastography for liver stiffness measurement (LSM) and fibrosis staging. In all, 25 patients (31%) had moderate-to-severe liver iron overload (LIC ≥7 mg/g dry weight). The median LIC was higher in non-deletional than in deletional HbH disease (7·8 vs. 2.9 mg/g dry weight, P = 0·002). In all, 16 patients (20%) had advanced liver fibrosis (LSM >7.9 kPa) and seven (9%) out of them had probable cirrhosis (LSM >11.9 kPa). LSM positively correlated with age (R = 0·24, P = 0·03), serum ferritin (R = 0·36, P = 0·001) and LIC (R = 0·28, P = 0·01). In multivariable regression, age ≥65 years [odds ratio (OR) 4·97, 95% confidence interval (CI) 1·52-17·50; P = 0·047] and moderate-to-severe liver iron overload (OR 3·47, 95% CI 1·01-12·14; P = 0·01) were independently associated with advanced liver fibrosis. The findings suggest that regular screening for liver complications should be considered in the management of HbH disease.

Genotype-Phenotype Correlation of β-Thalassemia in Malaysian Population: Toward Effective Genetic Counseling

Effective prevention of β-thalassemia (β-thal) requires strategies to detect at-risk couples. This is the first study attempting to assess the prevalence of silent β-thal carriers in the Malaysian population. Hematological and clinical parameters were evaluated in healthy blood donors and patients with β-thal trait, Hb E (HBB: c.79G>A)/β-thal and β-thal major (β-TM). β-Globin gene sequencing was carried out for 52 healthy blood donors, 48 patients with Hb E/β-thal, 34 patients with β-TM and 38 patients with β-thal trait. The prevalence of silent β-thal carrier phenotypes found in 25.0% of healthy Malaysian blood donors indicates the need for clinician's awareness of this type in evaluating β-thal in Malaysia. Patients with β-TM present at a significantly younger age at initial diagnosis and require more blood transfusions compared to those with Hb E/β-thal. The time at which genomic DNA was extracted after blood collection, particularly from patients with β-TM and Hb E/β-thal, was found to be an important determinant of the quality of the results of the β-globin sequencing. Public education and communication campaigns are recommended as apparently healthy individuals have few or no symptoms and normal or borderline hematological parameters. β-Globin gene mutation characterization and screening for silent β-thal carriers in regions prevalent with β-thal are recommended to develop more effective genetic counseling and management of β-thal.

Early development of decreased β-cell insulin secretion in children and adolescents with hemoglobin H disease and its relationship with levels of anemia

BACKGROUND

Diabetes mellitus (DM) associated with iron overload has been reported among adults with transfusion-dependent thalassemia and those with non-transfusion-dependent thalassemia (NTDT), especially in β-thalassemia disease. However, little is known about glucose metabolism and how early its dysregulation can develop in α-thalassemia hemoglobin H (Hb H) disease, which is one of the most common types of NTDT worldwide.

PROCEDURE

We prospectively calculated glucose metabolism index in 40 patients (aged 10-25 years) with Hb H disease. Glucose metabolism data were compared between patients with deletional versus nondeletional Hb H, and between patients with normal versus abnormal insulin secretion/sensitivity.

RESULTS

Despite normal glucose tolerance in all patients, 52.5% had abnormal insulinogenic index indicating decreased β-cell insulin secretion. Patients with functional hemoglobin < 8 g/dL had significantly higher percentages of abnormal insulinogenic index. There was no significant difference in abnormal insulinogenic index between deletional and nondeletional Hb H.

CONCLUSION

Decreased β-cell insulin secretion is highly prevalent among children and adolescents with Hb H disease, and it is associated with levels of functional anemia at baseline, but not with the type of Hb H disease. This result warrants heightened awareness among hematologists due to potentially increased risk of DM later in life.

Cardiac and hepatic siderosis in myelodysplastic syndrome, thalassemia and diverse causes of transfusion-dependent anemia: the TIMES study

Supplemental Digital Content is available in the text

The significant morbidity and mortality associated with iron overload can be reduced by effective iron chelation. Magnetic resonance imaging (MRI) provides accurate and reproducible iron load assessment. The aim of this epidemiological study was to assess the prevalence and severity of cardiac and hepatic siderosis by MRI and to evaluate the impact of MRI on clinical management in patients with transfusion-dependent anemia and non-transfusion-dependent thalassemia (NTDT). We enrolled 243 patients with myelodysplastic syndromes (MDS), thalassemia major (TM), NTDT or other chronic anemia. Overall, 10% and 48% had cardiac and hepatic siderosis, respectively. Mean liver iron concentration (LIC) was above target range in all groups; mean myocardial T2^∗ was normal. Hepatic siderosis was more prevalent than myocardial siderosis in patients with MDS, occurring in 54.4% and 4.4% of patients, respectively. As also observed in patients with NTDT or other anemia, hepatic siderosis was present in a large proportion of MDS patients who were chelation naïve (57.7%), as well as in patients receiving iron chelation therapy (ICT) (52.4%), despite a lower transfusion load compared with TM. Correlation between LIC and serum ferritin was observed across diseases; however, not all patients requiring ICT could be identified with serum ferritin alone, as serum ferritin underestimated LIC in 4.4% and overestimated LIC in 7.5% of patients. Exploratory analyses showed serum ferritin thresholds for liver siderosis detected by MRI at approximately 300 ng/mL higher in MDS than in TM. Most patients reported low–medium adherence to ICT; MRI assessment led to change in ICT in 46% of evaluable patients, including 52% of MDS patients. Accurate organ iron monitoring by MRI facilitated appropriate initiation of chelation, dose optimization and clinical decision making.

Trial registration: ClinicalTrials.gov: NCT01736540.

Increased risk of arterial thromboembolic events in transfusion-naïve thalassemia: a nationwide population-based study

Transfusion-naïve thalassemia minor/trait is often associated with decreased risk of coronary artery diseases. The present study aimed to evaluate the effect of transfusion-naïve thalassemia on the incidence of arterial thromboembolic events using the National Health Insurance Research Database, Taiwan (2001-2010). Data from patients with transfusion-naïve thalassemia (n=2356) frequency matched with non-thalassemia subjects (n=9424) according to sex, age, and index year at a ratio of 1:4 were included. The risk of arterial thromboembolic events, cerebrovascular ischemic events, arterial embolism/thrombosis, peripheral embolism, myocardial infarction, myocardial ischemia, and angina pectoris in transfusion-naïve thalassemia were analyzed using Cox proportional hazard regression models. The transfusion-naïve thalassemia group had significantly higher risk of arterial thromboembolic events (aHR=1.28, 95% CI 1.07 to 1.52) and myocardial ischemia (aHR=1.41, 95% CI 1.13 to 1.76) as compared with the non-thalassemia group. In addition, they also had a significantly higher cumulative incidence of arterial thromboembolic event and myocardial ischemia. Interestingly, a higher risk of arterial thromboembolic events (aHR=1.58, 95% CI 1.22 to 2.04) and myocardial ischemia (aHR=1.73, 95% CI 1.25 to 2.41) was observed in men with thalassemia as compared with those without. Furthermore, patients with comorbidities had an increased risk of arterial thromboembolic events than did those without comorbidities. The effect of thalassemia on arterial thromboembolic events may be mainly attributed to the influence of thalassemia on myocardial ischemia, as no significant differences were observed in other outcomes evaluated in the present study. In conclusion, the present study confirms the increased risk of arterial thromboembolic events, mainly attributed to the dramatic increase in myocardial ischemia, inminor patients with transfusion-naïve thalassemia.

Clinical Classification, Screening and Diagnosis for Thalassemia

At present, thalassemia diseases are classified into transfusion-dependent thalassemia and non-transfusion-dependent thalassemia. This classification is based on the clinical severity of patients determining whether they do require regular blood transfusions to survive (transfusion-dependent thalassemia) or not (non-transfusion-dependent thalassemia). In addition to the previous terminology of "thalassemia major" or "thalassemia intermedia," this classification has embraced all other forms of thalassemia syndromes such as α-thalassemia, hemoglobin E/β-thalassemia and combined α- and β-thalassemias. Definitive diagnosis of thalassemia and hemoglobinopathies requires a comprehensive workup from complete blood count, hemoglobin analysis, and molecular studies to identify mutations of globin genes.

Epidemiologic and clinical characteristics of nontransfusion-dependent thalassemia in the United States

BACKGROUND

Nontransfusion-dependent thalassemia (NTDT) refers to a diverse group of thalassemia mutations and clinical phenotypes that do not require chronic transfusions. It is increasingly prevalent in the United States.

PROCEDURE

This study reviews the epidemiology and clinical characteristics of 138 patients with NTDT treated at four US thalassemia centers from 1997 to 2014. Data on laboratory results, transfusions, and clinical complications were collected from patient charts.

RESULTS

Overall, 84 patients with α-thalassemia (62 deletional hemoglobin H; 22 nondeletional hemoglobin H), 39 with β-thalassemia (26 with homozygous or double heterozygous β mutations; 13 with single β mutations with or without α triplication), and 15 with E/β-thalassemia (12 E/β⁰ ; three E/β⁺ ) were identified. At study entry, the median age for patients with α-thalassemia was 2.3 years; 9.2 years for patients with β-thalassemia and 2.2 years for patients with E/β-thalassemia. Most patients with α-thalassemia were Asian. Patients with β-thalassemia were predominantly Caucasian (46%) or of African descent (36%). Twenty percent of patients were born outside the United States and 5% were transfused before immigration. Complications varied by genotype and age. Individuals with nondeletional hemoglobin H were severely affected and, despite their young age, had many complications. Iron overload increased with age and was more common in patients who received transfusions.

CONCLUSIONS

NTDT in the United States is a multi-ethnic disease with different genotypic mutations and phenotypic manifestations. A higher than expected proportion of patients was Black/African American. NTDT-related complications are common and increase with age, supporting a need for early diagnosis.

Management of Children With β-Thalassemia Intermedia: Overview, Recent Advances, and Treatment Challenges

Our knowledge of the various clinical morbidities that thalassemia intermedia (TI) patients endure has substantially increased over the past decade. It is mandatory to grasp a solid understanding of disease-specific complications in order to tailor management. The optimal course of management for TI patients has been hard to identify, and several controversies remain with regard to the best treatment plan. Although advances in TI are moving at a fast pace, many complications remain with no treatment guidelines. Studies that expand our understanding of the mechanisms and risk factors, as well as clinical trials evaluating the roles of available treatments, will help establish management guidelines that improve patient care. Novel therapeutic modalities are now emerging. This article focuses on the management of children with β-TI. We present various clinical morbidities and their association with the underlying disease pathophysiology and risk factors. All therapeutic options, recent advances, and treatment challenges were reviewed.

Clinical and molecular genetic features of Hb H and AE Bart's diseases in central Thai children

Background

α-Thalassemia, one of the major thalassemia types in Thailand, is caused by either deletion or non-deletional mutation of one or both α-globin genes. Inactivation of three α-globin genes causes hemoglobin H (Hb H) disease, and the combination of Hb H disease with heterozygous hemoglobin E (Hb E) results in AE Bart’s disease.

Objective

This study aimed to characterize the clinical and hematological manifestations of 76 pediatric patients with Hb H and AE Bart’s diseases treated at Phramongkutklao Hospital, a tertiary care center for thalassemia patients in central Thailand.

Patients and methods

Seventy-six unrelated pediatric patients, 58 patients with Hb H disease and 18 patients with AE Bart’s disease, were enrolled in this study. Their clinical presentations, transfusion requirement, laboratory findings, and mutation analysis were retrospectively reviewed and analyzed.

Results

A total of 76 pediatric patients with Hb H and AE Bart’s diseases who mainly lived in central Thailand were included in this study. The clinical severities of patients with non-deletional mutations were more severe than those with deletional mutations. Eighty-six percent of patients with non-deletional AE Bart’s disease required more blood transfusion compared to 12.5% of patients with deletional AE Bart’s disease. Non-deletional AE Bart’s disease also had a history of urgent blood transfusion with the average of 6±0.9 times compared to 1±0.3 times in patients with deletional Hb H disease. The difference was statistically significant.

Conclusion

This study revealed the differences in clinical spectrum between patients with Hb H disease and those with AE Bart’s disease in central Thailand. The differentiation of α-thalassemia is essential for appropriate management of patients. The molecular diagnosis is useful for diagnostic confirmation and genotype–phenotype correlation.

Thalassaemia

Inherited haemoglobin disorders, including thalassaemia and sickle-cell disease, are the most common monogenic diseases worldwide. Several clinical forms of α-thalassaemia and β-thalassaemia, including the co-inheritance of β-thalassaemia with haemoglobin E resulting in haemoglobin E/β-thalassaemia, have been described. The disease hallmarks include imbalance in the α/β-globin chain ratio, ineffective erythropoiesis, chronic haemolytic anaemia, compensatory haemopoietic expansion, hypercoagulability, and increased intestinal iron absorption. The complications of iron overload, arising from transfusions that represent the basis of disease management in most patients with severe thalassaemia, might further complicate the clinical phenotype. These pathophysiological mechanisms lead to an array of clinical manifestations involving numerous organ systems. Conventional management primarily relies on transfusion and iron-chelation therapy, as well as splenectomy in specific cases. An increased understanding of the molecular and pathogenic factors that govern the disease process have suggested routes for the development of new therapeutic approaches that address the underlying chain imbalance, ineffective erythropoiesis, and iron dysregulation, with several agents being evaluated in preclinical models and clinical trials.

Prevalence of low bone mass among adolescents with nontransfusion-dependent hemoglobin E/β-thalassemia and its relationship with anemia severity

BACKGROUND

Low bone mass is common among adolescents with transfusion-dependent β-thalassemia despite adequate transfusion and iron chelation. However, there are few reports regarding bone mineral density (BMD) among adolescents with nontransfusion-dependent thalassemia (NTDT). Indeed, only BMD data in patients with nontransfusion-dependent (NTD) β-thalassemia intermedia have been reported. No previous study has investigated BMD among adolescents with NTD hemoglobin (Hb) E/β-thalassemia.

OBJECTIVE

To determine the prevalence of low bone mass among adolescents with NTD Hb E/β-thalassemia and factors relating to low bone mass.

METHODS

We investigated BMD of lumbar spine (L2-L4; BMDLS) and total body (BMDTB), as measured by dual-energy X-ray absorptiometry, in 22 adolescents (aged 13.2-20 years) with NTD Hb E/β-thalassemia.

RESULTS

Low bone mass was found to be 18.2% and 22.7% at the lumbar spine (BMDLS Z-score adjusted for bone age and height age) and 13.6% and 9.1% at the total body (BMDTB Z-score adjusted for bone age and height age). Patients with mean Hb level <8 g/dl were more likely to have low bone mass (BMDLS and BMDTB Z-scores adjusted for bone age) compared to those with Hb level ≥ 8 g/dl. Mean Hb level correlated with BMDLS and BMDTB Z-scores adjusted for bone age.

CONCLUSION

We demonstrated that a low Hb level was associated with low bone mass among adolescents with NTD Hb E/β-thalassemia. A significant proportion of low bone mass among these patients highlights the importance of appropriate management, including red cell transfusion, vitamin D and calcium supplementation for improved long-term bone health.

Insights into the diagnosis and management of iron deficiency in inflammatory bowel disease

INTRODUCTION

Iron deficiency is a frequent comorbidity of chronic diseases such as inflammatory bowel disease that can severely impact the health and quality of life of affected individuals. It can exist as a silent condition and manifest in non-specific symptoms even in the absence of anemia. Even though iron deficiency anemia is the most common complication and extra-intestinal manifestation of inflammatory bowel disease, the majority of inflammatory bowel disease patients who are diagnosed with iron deficiency anemia are not treated. Areas covered: In this review, we discuss iron deficiency and iron deficiency anemia in patients with inflammatory bowel disease, and review diagnostic and therapeutic options. Expert commentary: We invite international gastroenterological societies and associations to refine the practice guidelines and include iron deficiency as a potential morbidity associated with IBD in analogy to arthritis, uveitis or any other extra intestinal manifestations. There should a more unanimous agreement among different societies on the specific diagnostic cutoff values for C-reactive protein levels, serum ferritin, and transferrin saturation in order to differentiate iron deficiency anemia from anemia of chronic disease.

Thalassemias in South Asia: clinical lessons learnt from Bangladesh

Thalassemias are emerging as a global public health concern. Due to remarkable success in the reduction of childhood mortality by controlling infectious diseases in developing countries, thalassemias are likely to be a major public health concern in the coming decades in South Asia. Despite the fact that Bangladesh lies in the world’s thalassemia belt, the information on different aspects (epidemiology, clinical course, mortality, complications and treatment outcomes) of thalassemias is lacking. In this comprehensive review, the aim is to to depict the epidemiological aspects of thalassemias, mutation profile and current treatment and management practices in the country by sharing the experience of dealing with 1178 cases over 2009–2014 time periods in a specialized thalassemia treatment centre. We have also discussed the preventative strategies of thalassemias from the context of Bangladesh which could be effective for other developing countries.

Non-transfusion-dependent thalassemia and thalassemia intermedia: epidemiology, complications, and management

OBJECTIVE

The non-transfusion-dependent thalassemias (NTDTs), including thalassemia intermedia (TI), hemoglobin E beta thalassemia, and hemoglobin H disease, have sometimes been regarded as less severe than their transfusion-dependent variants; however, these disorders carry a substantial disease burden (e.g., splenomegaly, iron overload, skeletal effects, and cardiopulmonary disease). The aim of this review is to increase clinician awareness of the growing global problem of NTDT and TI, and discuss the current management strategies for these conditions.

METHODS

Recent peer-reviewed articles (publication years 2000 through 2015) addressing the epidemiology, complications, management, and monitoring of NTDT were identified in the PubMed database and reviewed.

RESULTS

The changing epidemiology of thalassemia constitutes a growing health problem. Increased clinician awareness is necessary for the appropriate diagnosis and management of patients with NTDT.

CONCLUSIONS

Management of NTDT requires a comprehensive approach, beginning with screening and prenatal diagnosis, monitoring for iron overload and associated complications, and iron chelation therapy. Several novel strategies are in the early stages of investigation and may help increase treatment options in patients with NTDT. Importantly, ethnic or cultural barriers may exist within the affected populations and need to be considered in the management approach.