Synergistic silencing of α-globin and induction of γ-globin by histone deacetylase inhibitor, vorinostat as a potential therapy for β-thalassaemia

Therapeutic Relevance of Inducing Autophagy in β-Thalassemia

The β-thalassemias are inherited genetic disorders affecting the hematopoietic system. In β-thalassemias, more than 350 mutations of the adult β-globin gene cause the low or absent production of adult hemoglobin (HbA). A clinical parameter affecting the physiology of erythroid cells is the excess of free α-globin. Possible experimental strategies for a reduction in excess free α-globin chains in β-thalassemia are CRISPR-Cas9-based genome editing of the β-globin gene, forcing "de novo" HbA production and fetal hemoglobin (HbF) induction. In addition, a reduction in excess free α-globin chains in β-thalassemia can be achieved by induction of the autophagic process. This process is regulated by the Unc-51-like kinase 1 (Ulk1) gene. The interplay with the PI3K/Akt/TOR pathway, with the activity of the α-globin stabilizing protein (AHSP) and the involvement of microRNAs in autophagy and Ulk1 gene expression, is presented and discussed in the context of identifying novel biomarkers and potential therapeutic targets for β-thalassemia.

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

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

Pharmacogenomics of Drugs Used in β-Thalassemia and Sickle-Cell Disease: From Basic Research to Clinical Applications

In this short review we have presented and discussed studies on pharmacogenomics (also termed pharmacogenetics) of the drugs employed in the treatment of β-thalassemia or Sickle-cell disease (SCD). This field of investigation is relevant, since it is expected to help clinicians select the appropriate drug and the correct dosage for each patient. We first discussed the search for DNA polymorphisms associated with a high expression of γ-globin genes and identified this using GWAS studies and CRISPR-based gene editing approaches. We then presented validated DNA polymorphisms associated with a high HbF production (including, but not limited to the HBG2 XmnI polymorphism and those related to the BCL11A, MYB, KLF-1, and LYAR genes). The expression of microRNAs involved in the regulation of γ-globin genes was also presented in the context of pharmacomiRNomics. Then, the pharmacogenomics of validated fetal hemoglobin inducers (hydroxyurea, butyrate and butyrate analogues, thalidomide, and sirolimus), of iron chelators, and of analgesics in the pain management of SCD patients were considered. Finally, we discuss current clinical trials, as well as international research networks focusing on clinical issues related to pharmacogenomics in hematological diseases.

Epigenetic drugs as new emerging therapeutics: What is the scale's orientation of application and challenges?

Epigenetics is the study of heritable changes in gene expression or function without altering the DNA sequence. Important factors are part of epigenetic events, such as methylation, DNA histone rearrangements, nucleosome transposition, and non-coding RNAs. Dysregulated epigenetic mechanics are associated with various cancers' initiation, development, and metastasis. It is known that the occurrence and development of cancer can be controlled by regulating unexpected epigenetic events. Epi-drugs are used singly or in combination with chemotherapy and enhance antitumor activity, reduce drug resistance, and stimulate the host immune response. Despite these benefits, epigenetic therapy as a single therapy or in combination with other drugs leads to adverse effects. This review article introduces and compares the advantages, disadvantages, and side effects of using these drugs for the first time since their introduction. Also, this article describes the mechanism of action of various epigenetic drugs. Recommendations for future use of epigenetic drugs as cancer therapeutics are suggested as an overall conclusion.

Combined approaches for increasing fetal hemoglobin (HbF) and de novo production of adult hemoglobin (HbA) in erythroid cells from β-thalassemia patients: treatment with HbF inducers and CRISPR-Cas9 based genome editing

Genome editing (GE) is one of the most efficient and useful molecular approaches to correct the effects of gene mutations in hereditary monogenetic diseases, including β-thalassemia. CRISPR-Cas9 gene editing has been proposed for effective correction of the β-thalassemia mutation, obtaining high-level "de novo" production of adult hemoglobin (HbA). In addition to the correction of the primary gene mutations causing β-thalassemia, several reports demonstrate that gene editing can be employed to increase fetal hemoglobin (HbF), obtaining important clinical benefits in treated β-thalassemia patients. This important objective can be achieved through CRISPR-Cas9 disruption of genes encoding transcriptional repressors of γ-globin gene expression (such as BCL11A, SOX6, KLF-1) or their binding sites in the HBG promoter, mimicking non-deletional and deletional HPFH mutations. These two approaches (β-globin gene correction and genome editing of the genes encoding repressors of γ-globin gene transcription) can be, at least in theory, combined. However, since multiplex CRISPR-Cas9 gene editing is associated with documented evidence concerning possible genotoxicity, this review is focused on the possibility to combine pharmacologically-mediated HbF induction protocols with the "de novo" production of HbA using CRISPR-Cas9 gene editing.

Fetal Hemoglobin Regulation in Beta-Thalassemia

β-thalassemia is caused by mutations that reduce β-globin production, causing globin chain imbalance, ineffective erythropoiesis, and consequent anemia. Increased fetal hemoglobin (HbF) levels can ameliorate the severity of β-thalassemia by compensating for the globin chain imbalance. Careful clinical observations paired with population studies and advances in human genetics have enabled the discovery of major regulators of HbF switching (i.e. BCL11A, ZBTB7A) and led to pharmacological and genetic therapies for treating β-thalassemia patients. Recent functional screens using genome editing and other emerging tools have identified many new HbF regulators, which may improve therapeutic HbF induction in the future.

Production and Characterization of K562 Cellular Clones Hyper-Expressing the Gene Encoding α-Globin: Preliminary Analysis of Biomarkers Associated with Autophagy

One of the most relevant pathophysiological hallmarks of β-thalassemia is the accumulation of toxic α-globin chains inside erythroid cells, which is responsible for their premature death (hemolysis). In this context, the availability of an experimental model system mimicking the excess in α-globin chain production is still lacking. The objective of the present study was to produce and characterize K562 cellular clones forced to produce high amounts of α-globin, in order to develop an experimental model system suitable for studies aimed at the reduction of the accumulation of toxic α-globin aggregates. In the present study, we produced and characterized K562 cellular clones that, unlike the original K562 cell line, stably produced high levels of α-globin protein. As expected, the obtained clones had a tendency to undergo apoptosis that was proportional to the accumulation of α-globin, confirming the pivotal role of α-globin accumulation in damaging erythroid cells. Interestingly, the obtained clones seemed to trigger autophagy spontaneously, probably to overcome the accumulation/toxicity of the α-globin. We propose this new model system for the screening of pharmacological agents able to activate the full program of autophagy to reduce α-globin accumulation, but the model may be also suitable for new therapeutical approaches targeted at the reduction of the expression of the α-globin gene.

Pharmacological Induction of Fetal Hemoglobin in β-Thalassemia and Sickle Cell Disease: An Updated Perspective

A significant amount of attention has recently been devoted to the mechanisms involved in hemoglobin (Hb) switching, as it has previously been established that the induction of fetal hemoglobin (HbF) production in significant amounts can reduce the severity of the clinical course in diseases such as β-thalassemia and sickle cell disease (SCD). While the induction of HbF using lentiviral and genome-editing strategies has been made possible, they present limitations. Meanwhile, progress in the use of pharmacologic agents for HbF induction and the identification of novel HbF-inducing strategies has been made possible as a result of a better understanding of γ-globin regulation. In this review, we will provide an update on all current pharmacological inducer agents of HbF in β-thalassemia and SCD in addition to the ongoing research into other novel, and potentially therapeutic, HbF-inducing agents.

Erythroid Cell Research: 3D Chromatin, Transcription Factors and Beyond

Studies of the regulatory networks and signals controlling erythropoiesis have brought important insights in several research fields of biology and have been a rich source of discoveries with far-reaching implications beyond erythroid cells biology. The aim of this review is to highlight key recent discoveries and show how studies of erythroid cells bring forward novel concepts and refine current models related to genome and 3D chromatin organization, signaling and disease, with broad interest in life sciences.

A randomised double-blind placebo-controlled clinical trial of oral hydroxyurea for transfusion-dependent β-thalassaemia

Hydroxyurea is an antimetabolite drug that induces fetal haemoglobin in sickle cell disease. However, its clinical usefulness in β-thalassaemia is unproven. We conducted a randomised, double-blind, placebo-controlled clinical trial to evaluate the efficacy and safety of hydroxyurea in transfusion-dependent β-thalassaemia. Sixty patients were assigned 1:1 to oral hydroxyurea 10–20 mg/kg/day or placebo for 6 months by stratified block randomisation. Hydroxyurea treatment did not alter the blood transfusion volume overall. However, a significantly higher proportion of patients on hydroxyurea showed increases in fetal haemoglobin percentage (89% vs. 59%; p < 0.05) and reductions in erythropoietic stress as measured by soluble transferrin receptor concentration (79% vs. 40%; p < 0.05). Based on fetal haemoglobin induction (> 1.5%), 44% of patients were identified as hydroxyurea-responders. Hydroxyurea-responders, required significantly lower blood volume (77 ± SD27ml/kg) compared to hydroxyurea-non-responders (108 ± SD24ml/kg; p < 0.01) and placebo-receivers (102 ± 28ml/kg; p < 0.05). Response to hydroxyurea was significantly higher in patients with HbE β-thalassaemia genotype (50% vs. 0%; p < 0.01) and Xmn1 polymorphism of the γ-globin gene (67% vs. 27%; p < 0.05). We conclude that oral hydroxyurea increased fetal haemoglobin percentage and reduced erythropoietic stress of ineffective erythropoiesis in patients with transfusion-dependent β-thalassaemia. Hydroxyurea reduced the transfusion burden in approximately 40% of patients. Response to hydroxyurea was higher in patients with HbE β-thalassaemia genotype and Xmn1 polymorphism of the γ-globin gene.

Revisiting fetal hemoglobin inducers in beta-hemoglobinopathies: a review of natural products, conventional and combinatorial therapies

Beta-hemoglobinopathies exhibit a heterogeneous clinical picture with varying degrees of clinical severity. Pertaining to the limited treatment options available, where blood transfusion still remains the commonest mode of treatment, pharmacological induction of fetal hemoglobin (HbF) has been a lucrative therapeutic intervention. Till now more than 70 different HbF inducers have been identified. The practical usage of many pharmacological drugs has been limited due to safety concerns. Natural compounds, like Resveratrol, Ripamycin and Bergaptene, with limited cytotoxicity and high efficacy have started capturing the attention of researchers. In this review, we have summarized pharmacological drugs and bioactive compounds isolated from natural sources that have been shown to increase HbF significantly. It primarily discusses recently identified synthetic and natural compounds, their mechanism of action, and their suitable screening platforms, including high throughput drug screening technology and biosensors. It also delves into the topic of combinatorial therapy and drug repurposing for HbF induction. Overall, we aim to provide insights into where we stand in HbF induction strategies for treating β-hemoglobinopathies.

Genetic and Epigenetic Therapies for β-Thalassaemia by Altering the Expression of α-Globin Gene

β-Thalassaemia is caused by over 300 mutations in and around the β-globin gene that lead to impaired synthesis of β-globin. The expression of α-globin continues normally, resulting in an excess of α-globin chains within red blood cells and their precursors. These unpaired α-globin chains form unstable α-hemichromes that trigger cascades of events to generate reactive oxygen species, leading to ineffective erythropoiesis and haemolysis in patients with β-thalassaemia. The clinical genetic data reported over several decades have demonstrated how the coinheritance of α-thalassaemia ameliorates the disease phenotype of β-thalassaemia. Thus, it is evident that down-regulation of the α-globin gene expression in patients with β-thalassaemia could ameliorate or even cure β-thalassaemia. Over the last few years, significant progress has been made in utilising this pathway to devise a cure for β-thalassaemia. Most research has been done to alter the epigenetic landscape of the α-globin locus or the well-characterised distant enhancers of α-globin. In vitro, pre-clinical studies on primary human erythroid cells have unveiled inhibition of histone lysine demethylation and histone deacetylation as potential targets to achieve selective downregulation of α-globin through epigenetic drug targeting. CRISPR based genome editing has been successfully used in vitro to mutate α-globin genes or enhancers of α-goblin to achieve clinically significant knockdowns of α-globin to the levels beneficial for patients with β-thalassaemia. This review summarises the current knowledge on the regulation of human α-globin genes and the clinical genetic data supporting the pathway of targeting α-globin as a treatment for β-thalassaemia. It also presents the progress of epigenetic drug and genome editing approaches currently in development to treat β-thalassaemia.

Luspatercept for β-thalassemia: beyond red blood cell transfusions

INTRODUCTION

Red blood cell transfusions and iron chelation therapy are the cornerstone of treatment for β-thalassemia, with allogeneic hematopoietic stem cell transplantation and gene therapy offering further disease-management options for eligible patients. With up to 90% of severe cases of β-thalassemia occurring in resource-constrained countries, and estimates indicating that 22,500 deaths occur annually as a direct consequence of undertransfusion, provision of adequate treatment remains a major issue.

AREAS COVERED

In this review, we provide an overview of luspatercept, a first-in-class erythroid maturation agent, and present the available clinical data related to the treatment of β-thalassemia.

EXPERT OPINION

The recent approval of luspatercept offers a new, long-term therapeutic option for adult patients with transfusion-dependent β-thalassemia to reduce red blood cell transfusion burden, anemia, and iron overload.

Therapy Development by Genome Editing of Hematopoietic Stem Cells

Accessibility of hematopoietic stem cells (HSCs) for the manipulation and repopulation of the blood and immune systems has placed them at the forefront of cell and gene therapy development. Recent advances in genome-editing tools, in particular for clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas) and CRISPR/Cas-derived editing systems, have transformed the gene therapy landscape. Their versatility and the ability to edit genomic sequences and facilitate gene disruption, correction or insertion, have broadened the spectrum of potential gene therapy targets and accelerated the development of potential curative therapies for many rare diseases treatable by transplantation or modification of HSCs. Ongoing developments seek to address efficiency and precision of HSC modification, tolerability of treatment and the distribution and affordability of corresponding therapies. Here, we give an overview of recent progress in the field of HSC genome editing as treatment for inherited disorders and summarize the most significant findings from corresponding preclinical and clinical studies. With emphasis on HSC-based therapies, we also discuss technical hurdles that need to be overcome en route to clinical translation of genome editing and indicate advances that may facilitate routine application beyond the most common disorders.

Correction of β-thalassemia by CRISPR/Cas9 editing of the α-globin locus in human hematopoietic stem cells

β-thalassemias (β-thal) are a group of blood disorders caused by mutations in the β-globin gene (HBB) cluster. β-globin associates with α-globin to form adult hemoglobin (HbA, α2β2), the main oxygen-carrier in erythrocytes. When β-globin chains are absent or limiting, free α-globins precipitate and damage cell membranes, causing hemolysis and ineffective erythropoiesis. Clinical data show that severity of β-thal correlates with the number of inherited α-globin genes (HBA1 and HBA2), with α-globin gene deletions having a beneficial effect for patients. Here, we describe a novel strategy to treat β-thal based on genome editing of the α-globin locus in human hematopoietic stem/progenitor cells (HSPCs). Using CRISPR/Cas9, we combined 2 therapeutic approaches: (1) α-globin downregulation, by deleting the HBA2 gene to recreate an α-thalassemia trait, and (2) β-globin expression, by targeted integration of a β-globin transgene downstream the HBA2 promoter. First, we optimized the CRISPR/Cas9 strategy and corrected the pathological phenotype in a cellular model of β-thalassemia (human erythroid progenitor cell [HUDEP-2] β0). Then, we edited healthy donor HSPCs and demonstrated that they maintained long-term repopulation capacity and multipotency in xenotransplanted mice. To assess the clinical potential of this approach, we next edited β-thal HSPCs and achieved correction of α/β globin imbalance in HSPC-derived erythroblasts. As a safer option for clinical translation, we performed editing in HSPCs using Cas9 nickase showing precise editing with no InDels. Overall, we described an innovative CRISPR/Cas9 approach to improve α/β globin imbalance in thalassemic HSPCs, paving the way for novel therapeutic strategies for β-thal.

Epigenetic Insights and Potential Modifiers as Therapeutic Targets in β-Thalassemia

Thalassemia, an inherited quantitative globin disorder, consists of two types, α- and β-thalassemia. β-thalassemia is a heterogeneous disease that can be asymptomatic, mild, or even severe. Considerable research has focused on investigating its underlying etiology. These studies found that DNA hypomethylation in the β-globin gene cluster is significantly related to fetal hemoglobin (HbF) elevation. Histone modification reactivates γ-globin gene expression in adults and increases β-globin expression. Down-regulation of γ-globin suppressor genes, i.e., BCL11A, KLF1, HBG-XMN1, HBS1L-MYB, and SOX6, elevates the HbF level. β-thalassemia severity is predictable through FLT1, ARG2, NOS2A, and MAP3K5 gene expression. NOS2A and MAP3K5 may predict the β-thalassemia patient's response to hydroxyurea, a HbF-inducing drug. The transcription factors NRF2 and BACH1 work with antioxidant enzymes, i.e., PRDX1, PRDX2, TRX1, and SOD1, to protect erythrocytes from oxidative damage, thus increasing their lifespan. A single β-thalassemia-causing mutation can result in different phenotypes, and these are predictable by IGSF4 and LARP2 methylation as well as long non-coding RNA expression levels. Finally, the coinheritance of β-thalassemia with α-thalassemia ameliorates the β-thalassemia clinical presentation. In conclusion, the management of β-thalassemia is currently limited to genetic and epigenetic approaches, and numerous factors should be further explored in the future.

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.

When basic science reaches into rational therapeutic design: from historical to novel leads for the treatment of β-globinopathies

PURPOSE OF REVIEW

β-hemoglobinopathies, such as β-Thalassemias (β-Thal) and sickle cell disease (SCD) are among the most common inherited genetic disorders in humans worldwide. These disorders are characterized by a quantitative (β-Thal) or qualitative (SCD) defects in adult hemoglobin production, leading to anemia, ineffective erythropoiesis and severe secondary complications. Reactivation of the fetal globin genes (γ-globin), making-up fetal hemoglobin (HbF), which are normally silenced in adults, represents a major strategy to ameliorate anemia and disease severity.

RECENT FINDINGS

Following the identification of the first 'switching factors' for the reactivation of fetal globin gene expression more than 10 years ago, a multitude of novel leads have recently been uncovered.

SUMMARY

Recent findings provided invaluable functional insights into the genetic and molecular networks controlling globin genes expression, revealing that complex repression systems evolved in erythroid cells to maintain HbF silencing in adults. This review summarizes these unique and exciting discoveries of the regulatory factors controlling the globin switch. New insights and novel leads for therapeutic strategies based on the pharmacological induction of HbF are discussed. This represents a major breakthrough for rational drug design in the treatment of β-Thal and SCD.

Functional abdominal pain disorders and asthma: two disorders, but similar pathophysiology?

INTRODUCTION

Functional abdominal pain disorders (FAPDs) and asthma are common ailments affecting both children and adults worldwide. Multiple studies have demonstrated an association between these two disorders. However, the exact reason for this observed association is not apparent.

AREAS COVERED

The current review has explored available literature and outlined multiple underlying pathophysiological mechanisms, common to both asthma and FAPDs, as possible reasons for this association.

EXPERT OPINION

Smooth muscle dysfunction, hypersensitivity and hyper-responsiveness, mucosal inflammation, and barrier dysfunction involving gastrointestinal and respiratory tracts are the main underlying pathophysiological mechanisms described for the generation of symptoms in FAPDs and asthma. In addition, alterations in neuroendocrine regulatory functions, immunological dysfunction, and microbial dysbiosis have been described in both disorders. We believe that the pathophysiological processes that were explored in this article would be able to expand the mechanisms of the association. The in-depth knowledge is needed to be converted to therapeutic and preventive strategies to improve the quality of care of children suffering from FAPDs and asthma.

Efficacy and safety of oral hydroxyurea in transfusion-dependent β-thalassaemia: a protocol for randomised double-blind controlled clinical trial

INTRODUCTION

Despite being one of the first diseases to be genetically characterised, β-thalassaemia remains a disorder without a cure in a majority of patients. Most patients with β-thalassaemia receive only supportive treatment and therefore have a poor quality of life and shorter life spans. Hydroxyurea, which has shown to induce fetal haemoglobin synthesis in human erythroid cells, is currently recommended for the treatment of sickle cell disease. However, its clinical usefulness in transfusion-dependent β-thalassaemia is unclear. Here, we present a protocol for a randomised double-blind controlled clinical trial to evaluate the efficacy and safety of oral hydroxyurea in transfusion-dependent β-thalassaemia.

METHODS AND ANALYSIS

This single-centre randomised double-blind placebo-controlled clinical trial is conducted at the Thalassaemia Centre of Colombo North Teaching Hospital, Ragama, Sri Lanka. Adult and adolescent patients with haematologically and genetically confirmed transfusion-dependent β-thalassaemia are enrolled and randomised into the intervention or control group. The intervention group receives oral hydroxyurea 10-20 mg/kg daily for 6 months, while the control group receives a placebo which is identical in size, shape and colour to hydroxyurea without its active ingredient. Transfused blood volume, pretransfusion haemoglobin level, fetal haemoglobin percentage and adverse effects of treatment are monitored during treatment and 6 months post-treatment. Cessation or reduction of blood transfusions during the treatment period will be the primary outcome measure. The statistical analysis will be based on intention to treat.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Ethics Committee of Faculty of Medicine, University of Kelaniya (P/116/05/2018) and the trial is approved by the National Medicinal Regulatory Authority of Sri Lanka. Results of the trial will be disseminated in scientific publications in reputed journals.

TRIAL REGISTRATION NUMBER

SLCTR/2018/024; Pre-results.

Microcytic anemia in children: parallel screening for iron deficiency and thalassemia provides a useful opportunity for thalassemia prevention in low- and middle-income countries

Microcytic anemia in children is commonly attributed to iron deficiency without attempting to find the cause. Inadequate investigations to exclude hemoglobinopathies lead to missed opportunities for identification of thalassemia carriers. Here we aim to describe the relative contribution of iron deficiency and thalassemia to microcytic anemia in children. This hospital-based prospective study was conducted at the Colombo North Teaching Hospital, Ragama, Sri Lanka. All newly diagnosed patients with microcytic anemia were recruited and data were collected using an interviewer-administered questionnaire. Full blood count, blood film, serum ferritin, c-reactive protein, quantification of hemoglobin sub-types and α-globin genotype were performed using 4 ml of venous blood. A total of 104 children (Male- 60.5%) were recruited. Iron deficiency was the cause for anemia in 49% whilst 16% and 10% had α- and β-thalassemia trait respectively. Seven (6.7%) children had co-existing iron deficiency and thalassemia trait while two coinherited α- and β-thalassemia trait. Children with β-thalassemia trait had significantly higher red cell count and lower mean corpuscular volume compared to children with iron deficiency. However, none of the red cell parameters were significantly different between children with α-thalassemia trait and iron deficiency. Iron deficiency contributes only to half of children with microcytic anemia; one-fourth had thalassemia trait. Co-existence of iron deficiency and thalassemia trait or co-inheritance of α- and β-thalassemia trait were found in 9%. Parallel investigation of children with microcytic anemia to diagnose iron deficiency and thalassemia provides an opportunity to identify thalassemia carriers which is beneficial for thalassemia prevention.

Psychological morbidity among children with transfusion dependent β-thalassaemia and their parents in Sri Lanka

Background

Thalassaemia is a chronic disease which requires lifelong treatment in a majority. Despite recent advances in the medical care, minimal attempts are made to improve psychological health in these patients. In this study, we aim to describe the psychological morbidity in patients with transfusion dependent β-thalassaemia and their mothers in Sri Lanka.

Methods

This case control study was conducted in the three largest thalassaemia centres of Sri Lanka. All patients with transfusion dependent β-thalassaemia aged 4–18 years were recruited as cases whilst a randomly selected group of children without chronic diseases were recruited as controls. Psychological morbidity of children was assessed using the Strengths and Difficulties Questionnaire and depressive symptoms of mothers was assessed by the Centre for Epidemiological Studies Depression Scale.

Results

288 transfusion dependent β-thalassaemia patients and equal number of controls were recruited. Abnormal emotional, conduct, hyperactivity and peer relationship symptom scores were reported by 18%, 17%, 9% and 14% of patients with thalassaemia respectively. Prevalences of abnormal psychological symptom scores in all domains were significantly higher among patients compared to controls. Abnormal conduct symptoms were significantly more prevalent among patients with HbE β-thalassaemia and those with suboptimal pretransfusion haemoglobin levels, lower transfusion volumes, hypothyroidism and undernutrition. Short stature was associated with abnormal emotional and hyperactivity scores. Depressive symptoms were significantly higher among mothers of patients with thalassaemia. Higher depressive symptom scores in mothers were significantly associated with abnormal emotional, conduct and peer relationship symptom scores in children.

Conclusions

A higher proportion of patients with transfusion dependent β-thalassaemia had abnormal psychological symptom scores. Abnormal conduct symptoms were more prevalent among patients with HbE β-thalassaemia, those who were inadequately transfused and having hypothyroidism and undernutrition. Mothers of the children with transfusion dependent β-thalassaemia had significantly higher depressive symptoms which were significantly associated with psychological symptoms among children.