A systematic review of adherence to iron chelation therapy among children and adolescents with thalassemia

Factors Related to the Quality of Life in Children with Transfusion-Dependent Thalassemia

Objective: Increased survival rate of patients with Transfusion-dependent Thalassemia (TDT) should be in line with their good quality of life (QoL). The study aimed to analyze the relationship between sociodemographic factors and clinical characteristics with the QoL of children with TDT. Methods: A cross-sectional study was conducted at Hasan Sadikin General Hospital from December 2022 to February 2023. A total of 158 eligible subjects aged 5-18 years with TDT were included in the analysis. QoL assessment was performed using child self-report and parent-proxy report questionnaires, along with physical examination findings. Bivariate and multivariate analyses were conducted to analyze the data. Results: A total of 158 subjects who met the research criteria were included in the analysis. Of 58.9% of children with TDT had a low adherence rate to iron chelating therapy (ICT). School function had the lowest score in QoL based on child-self report and parent proxy. Gender (p<0,05) and adherence to ICT (p<0,05) were significantly associated with lower quality of life. Conclusion: Female and adherence to ICT were predictors of children with TDT's QoL.

The impact of chelation compliance in health outcome and health related quality of life in thalassaemia patients: a systematic review

Understanding consequences of poor chelation compliance is crucial given the enormous burden of post-transfusional iron overload complications. We systematically reviewed iron-chelation therapy (ICT) compliance, and the relationship between compliance with health outcome and health-related quality of life (HRQoL) in thalassaemia patients. Several reviewers performed systematic search strategy of literature through PubMed, Scopus, and EBSCOhost. The preferred reporting items of systematic reviews and meta-analyses (PRISMA) guidelines were followed. Of 4917 studies, 20 publications were included. The ICT compliance rate ranges from 20.93 to 75.3%. It also varied per agent, ranging from 48.84 to 85.1% for desferioxamine, 87.2-92.2% for deferiprone and 90-100% for deferasirox. Majority of studies (N = 10/11, 90.91%) demonstrated significantly negative correlation between compliance and serum ferritin, while numerous studies revealed poor ICT compliance linked with increased risk of liver disease (N = 4/7, 57.14%) and cardiac disease (N = 6/8, 75%), endocrinologic morbidity (N = 4/5, 90%), and lower HRQoL (N = 4/6, 66.67%). Inadequate compliance to ICT therapy is common. Higher compliance is correlated with lower serum ferritin, lower risk of complications, and higher HRQoL. These findings should be interpreted with caution given the few numbers of evidence.

Beta thalassemia: Looking to the future, addressing unmet needs and challenges

Thalassemia management has reached new milestones, with new therapies promising the dawning of a new era. However, conventional and new approaches require accessibility, affordability, acceptability/adherence by patients, and medical expertise from healthcare providers. Current treatments still do not offer the expected duration and quality of life, and inequalities in patient care are almost a universal phenomenon. To understand the requirements to achieve improved care, including the adoption of new therapies, for the maximum number of the global patient population, it is necessary to recognize the weaknesses that are experienced in the present so that future corrective action can be taken. Deficits in service provision are due to poor political and financial support, lack of prioritization during resource rationing, and absence of epidemiological information for policy making. These system weaknesses require improved resource management and would benefit from patient support organizations, improved psychosocial support and patient welfare, and an increase in professional expertise through educational programs. Medical products and technology must also be made affordable and widely available, and the curative treatments and cheaper approaches to technology must be recognized as resource saving. Improvements in the access to innovative and quality care, and even a cure, require concerted actions by all stakeholders, including physicians and the patient community.

Unmet needs in β-thalassemia and the evolving treatment landscape

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

Health-related quality of life with standard and curative therapies in thalassemia: A narrative literature review

Health-related quality of life (HRQOL) is a patient-reported outcome that assesses the impact of a disease or illness on different domains of a patient's life. Different general and disease-specific measures can be used to evaluate HRQOL. This article aimed to summarize the evidence for HRQOL among patients with transfusion-dependent (TDT) and non-transfusion-dependent thalassemia (NTDT). We included HRQOL data related to standard therapy with blood transfusions, iron chelation, and/or luspatercept in TDT and NTDT, as well as curative therapies for TDT, including hematopoietic stem cell transplant (HSCT) and gene therapy. Patients with thalassemia had worse HRQOL scores compared to the general population, and chronic pain was seen to increase in frequency and severity over time with age. NTDT patients reported worse physical health and functioning, mental health, general health, and vitality than TDT patients. However, TDT patients reported worse pain, change in health, and social support than NTDT. Most therapies improved overall HRQOL among thalassemia patients. Deferasirox, an oral iron chelator, was associated with more HRQOL benefits compared to deferoxamine, an intravenous iron chelator. Luspatercept showed clinically meaningful improvement in physical functioning among TDT and NTDT. Furthermore, HSCT and gene therapy were associated with better physical, emotional, and mental domains scores.

A Water-Soluble Chitosan Derivative for the Release of Bioactive Deferoxamine

Deferoxamine (DFO) is a water-soluble iron chelator used pharmacologically for the management of patients with transfusional iron overload. However, DFO is not cell-permeable and has a short plasma half-life, which necessitates lengthy parenteral administration with an infusion pump. We previously reported the synthesis of chitosan (CS) nanoparticles for sustained slow release of DFO. In the present study, we developed solid dispersions and nanoparticles of a carboxymethyl water-soluble chitosan derivative (CMCS) for improved DFO encapsulation and release. CS dispersions and nanoparticles with DFO have been prepared by ironical gelation using sodium triphosphate (TPP) and were examined for comparison purposes. The successful presence of DFO in CMCS polymeric dispersions and nanoparticles was confirmed through FTIR measurements. Furthermore, the formation of CMCS nanoparticles led to inclusion of DFO in an amorphous state, while dispersion of DFO in the polymeric matrix led to a decrease in its crystallinity according to X-ray diffraction (XRD) and differential scanning calorimetry (DSC) results. An in vitro release assay indicated sustained release of DFO from CS and CMCS nanoparticles over 48 h and 24 h, respectively. Application of CMCS-DFO dispersions to murine RAW 264.7 macrophages or human HeLa cervical carcinoma cells triggered cellular responses to iron deficiency. These were exemplified in the induction of the mRNA encoding transferrin receptor 1, the major iron uptake protein, and the suppression of ferritin, the iron storage protein. Our data indicate that CMCS-DFO nanoparticles release bioactive DFO that causes effective iron chelation in cultured cells.

Adherence to Iron Chelation Therapy Among Children with Beta Thalassemia Major: A Multicenter Cross-Sectional Study

BACKGROUND

Adherence to iron chelation therapy (ICT) remains an issue among thalassemia patients. This study aimed to determine the prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia and the factors associated with it.

METHODS

This was a cross-sectional study conducted between November 2019 and November 2021 at seven tertiary hospitals in Malaysia. Participants registered with Malaysian Thalassemia Registry were recruited by convenience sampling. Adherence was measured via pill count and self-reported adherence. Knowledge about thalassemia and ICT was measured using a questionnaire from Modul Thalassemia by Ministry of Health of Malaysia. A decision tree was used to identify predictors of non-adherence.

RESULTS

A total of 135 patients were recruited. The prevalence of non-adherence to ICT in those who took subcutaneous ± oral medications was 47.5% (95% CI: 31.5%, 63.9%) and the prevalence of non-adherence to ICT in those who took oral medications only was 21.1% (95% CI: 13.4%, 30.6%). The median knowledge score was 67.5% (IQR 15%). A decision tree has identified two factors associated with non-adherence. They were ICT's route of administration and knowledge score. Out of 100 patients who were on oral medications only, 79 were expected to adhere. Out of 100 patients who were on subcutaneous ± oral medications and scored less than 56.25% in knowledge questionnaire, 86 were expected to non-adhere. Based on the logistic regression, the odds of non-adherence in patients who took oral medications only was 71% lower than the odds of non-adherence in patients who took subcutaneous ± oral medications (OR = 0.29; 95% CI = 0.13, 0.65; p = .002).

CONCLUSION

The prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia was 20/95 (21.1%) in those who took oral medications only and the prevalence of non-adherence was 19/40 (47.5%) in those who took subcutaneous ± oral medications. The factors associated with non-adherence were ICT's route of administration and knowledge score.

Prevalence and Management of Transfusional Iron Overload in Syrian Beta Thalassemia Major Patients Pre and during the Syrian Conflict

Objectives

The primary aim of this study was to evaluate the prevalence of iron overload and the real-world clinical effectiveness of the iron chelation therapies (ICTs) in Syrian patients with transfusion-dependent beta thalassemia major (BTM) prior to and during the ongoing Syrian conflict.

Methods

This single-center, two-stage observational study was conducted at Homs National Thalassemia Center (HNTC) prior to (2009) and during (2019) the armed conflict. The prevalence and the severity of iron overload, as well as the effectiveness of four iron chelation regimens, were assessed using serum ferritin (SF) concentrations as a means of monitoring in two cohorts of BTM patients receiving deferoxamine (DFO), deferiprone (DFP), deferasirox (DFX), or a combination of DFO and DFP therapy in both years. Statistical analyses encompassed one-way ANOVA, Kruskal-Wallis, Mann-Whitney U, and chi-square (χ2) tests for the comparisons of the variables and the frequencies between the two cohorts and subgroups.

Results

We included all eligible BTM patients at HNTC in 2009 (n = 205) and 2019 (n = 172). Only 84 patients from the 2009 cohort were accessible in 2019. Our findings revealed that 98% and 89% of the patients had iron overload (SF ≥ 1500 ng/mL) and comparable elevated median SF concentrations (3868 and 3757 ng/mL) in 2009 and 2019, respectively (P = 0.275). Furthermore, patients on DFO demonstrated the poorest control of iron overload and the highest SF concentrations (4319 and 5586 ng/mL), whereas those on DFX achieved superior outcomes and the lowest SF concentrations (3355 and 2152 ng/mL) in both years. Twenty-six patients from the 2019 cohort received no ICT for six years (from 2012 to 2018) and experienced extremely severe iron overload with SF levels ranging between 4481 and 16,000 ng/mL.

Conclusions

Our findings prove a high prevalence of iron overload and suboptimal chelation outcomes in Syrian BTM patients, both prior to and during the ongoing armed conflict, despite the provision of free ICTs at HNTC. Poor adherence and older age of patients may explain the unfavorable outcomes of DFO and (DFO+DFP) regimens, whereas younger age and higher socioeconomic status may have contributed to the lowest SF and superior outcomes in patients on DFX. This study also demonstrates the crucial role of the National Thalassemia Centers, namely HNTC, in providing health services to BTM patients in times of peace and conflict.

Polyneuropathy Associated with Age of Starting the Transfusion and Serum Ferritin Level in Iranian Patients with Thalassemia Major and Intermedia

Considering the importance of managing patients with β-thalassemia and the importance of early detection of disease complications, we examined the rate of sensorimotor neuropathy in patients with β-thalassemia and the risk factors related to it. This cross-sectional study included 44 blood transfusion-dependent β-thalassemia patients aged 5 years and older. Nerve conduction studies (NCSs) were performed via standard procedures for both motor and sensory nerves. Neuropathy was observed in 14 patients (31.8%). NCS results for sensorimotor nerves in patients were within normal range. In motor NCS results, increased ulnar nerve amplitude was observed in patients with increasing age, and peroneal nerve delay in patients with an increase in serum ferritin level (p < 0.05). In sensory NCS results, delayed ulnar and sural nerves latencies were found in patients with an increase in serum ferritin level (p < 0.05). We provide data that sensorimotor neuropathy exists in thalassemia patients. It seems that with the increase of serum ferritin level and the age of patients, neuropathy becomes more obvious, while other factors such as gender, body mass index, and the number of transfusions may not be associated with neuropathy.

Mitochondria hormesis delays aging and associated diseases in Caenorhabditis elegans impacting on key ferroptosis players

Excessive iron accumulation or deficiency leads to a variety of pathologies in humans and developmental arrest in the nematode Caenorhabditis elegans. Instead, sub-lethal iron depletion extends C. elegans lifespan. Hypoxia preconditioning protects against severe hypoxia-induced neuromuscular damage across species but it has low feasible application. In this study, we assessed the potential beneficial effects of genetic and chemical interventions acting via mild iron instead of oxygen depletion. We show that limiting iron availability in C. elegans through frataxin silencing or the iron chelator bipyridine, similar to hypoxia preconditioning, protects against hypoxia-, age-, and proteotoxicity-induced neuromuscular deficits. Mechanistically, our data suggest that the beneficial effects elicited by frataxin silencing are in part mediated by counteracting ferroptosis, a form of non-apoptotic cell death mediated by iron-induced lipid peroxidation. This is achieved by impacting on different key ferroptosis players and likely via gpx-independent redox systems. We thus point to ferroptosis inhibition as a novel potential strategy to promote healthy aging.

An evaluation of deferiprone as twice-a-day tablets or in combination therapy for the treatment of transfusional iron overload in thalassemia syndromes

INTRODUCTION

Regular blood transfusions in patients with thalassemia syndromes can cause iron overload resulting in complications including cirrhosis, heart problems, or endocrine abnormalities. To prevent iron overload toxicity in these patients, three iron chelators are currently FDA-approved for use: deferoxamine, deferasirox, and deferiprone. In the United States, deferiprone has been approved for three times daily dosing since 2011 and has recently gained approval for twice-daily administration.

AREAS COVERED

A PubMed literature search was performed with the keywords 'deferiprone' and 'thalassemia.' Relevant original research studying deferiprone's effects on transfusional iron overload in patients with thalassemia syndromes was included. Exclusion criteria included case reports and review papers. Deferiprone is effective at reducing serum ferritin levels in patients with iron overload. Twice-daily administration provides a similar level of iron chelation as three times daily dosing with a comparable side effect profile and increased patient acceptability.

EXPERT OPINION

New studies are highlighting deferiprone's potential for combination therapy with either deferoxamine or deferasirox to improve iron chelation. Deferiprone's ability to significantly decrease cardiac and liver iron content can be utilized in other transfusion-dependent hematologic conditions, as evidenced by its recent approval for use in the United States for sickle cell disease or other anemias.

Glucose Homeostasis and Assessment of β-Cell Function by 3-hour Oral Glucose Tolerance (OGTT) in Patients with β-Thalassemia Major with Serum Ferritin below 1,000 ng/dL: Results from a Single ICET-A Centre

Aims

The primary aim of this study was to evaluate retrospectively the glucose homeostasis and surrogate indices of insulin sensitivity and resistance, during a 3-hour oral glucose tolerance test (OGTT), in β-thalassemia major patients (β-TM) with serum ferritin (SF) below 1,000 ng/mL.

Patients and methods

The retrospective cohort study evaluated the medical records of 24 β-TM patients from 2010 to 2022. At the year of study the mean age of patients was 31.0 ± 4.1 (20-37.11) years; 13 (54.1%) were females. The most commonly used iron chelator was deferoxamine (DFO: 75%), followed by deferiprone (DFP:12.5%) and deferasirox (DFX: 12.5%). Insulin sensitivity and resistance indices were derived from OGTT. A liver iron concentration (LIC) < 3 mg/g d.w. and a global heart T2* value > 20 ms were considered as conservative cut-off values for insignificant iron overload (IOL).

Results

The mean SF levels in the whole study cohort population at the age of evaluation was 549.6 ± 232.3 ng/mL. Based on the SF levels, two groups were identified: Group A (N = 14) < 500 ng/mL and Group B (N=10) 500-1,000 ng/mL. Normal glucose tolerance (NGT) during OGTT was observed in 4 patients of Group A (28.5 %) and in 5 patients of Group B (50%) (P: 0.29). The remaining 15/24 patients (62.5%) had glucose dysregulation (GD). The mean age at starting iron chelation therapy (ICT) and the mean SF peak in Group A versus Group B were significantly higher in group A. The GD was associated with significantly attenuated IGI (first phase of insulin response) and impaired oral disposition index (oDI). Hypogonadotropic hypogonadism (HH) was the most common associated endocrine complication in both groups of patients.

Conclusions

This study showed that efficient iron chelation monotherapy in patients with β-TM and SF < 1,000 ng/ml did not entirely prevent glucose metabolism disorders, abnormalities of insulin secretion and sensitivity, and development of acquired hypogonadism.

Cobalt chloride has beneficial effects across species through a hormetic mechanism

Severe oxygen and iron deficiencies have evolutionarily conserved detrimental effects, leading to pathologies in mammals and developmental arrest as well as neuromuscular degeneration in the nematode Caenorhabditis elegans. Yet, similar to the beneficial effects of mild hypoxia, non-toxic levels of iron depletion, achieved with the iron chelator bipyridine or through frataxin silencing, extend C. elegans lifespan through hypoxia-like induction of mitophagy. While the positive health outcomes of hypoxia preconditioning are evident, its practical application is rather challenging. Here, we thus test the potential beneficial effects of non-toxic, preconditioning interventions acting on iron instead of oxygen availability. We find that limiting iron availability through the iron competing agent cobalt chloride has evolutionarily conserved dose-dependent beneficial effects: while high doses of cobalt chloride have toxic effects in mammalian cells, iPS-derived neurospheres, and in C. elegans, sub-lethal doses protect against hypoxia- or cobalt chloride-induced death in mammalian cells and extend lifespan and delay age-associated neuromuscular alterations in C. elegans. The beneficial effects of cobalt chloride are accompanied by the activation of protective mitochondrial stress response pathways.