Transfusion-dependent Β-thalassemia Research Articles

Liver disease in patients with transfusion-dependent β-thalassemia: The emerging role of metabolism dysfunction-associated steatotic liver disease

In this Editorial, we highlight the possible role that metabolism dysfunction-associated steatotic liver disease (MASLD) may play in the future, regarding liver disease in patients with transfusion-dependent β-thalassemia (TDBT). MASLD is characterized by excessive accumulation of fat in the liver (hepatic steatosis), in the presence of cardiometabolic factors. There is a strong correlation between the occurrence of MASLD and insulin resistance, while its increased prevalence parallels the global epidemic of diabetes mellitus (DM) and obesity. Patients with TDBT need regular transfusions for life to ensure their survival. Through these transfusions, a large amount of iron is accumulated, which causes saturation of transferrin and leads to the circulation of free iron molecules, which cause damage to vital organs (primarily the liver and myocardium). Over the past, the main mechanisms for the development of liver disease in these patients have been the toxic effect of iron on the liver and chronic hepatitis C, for which modern and effective treatments have been found, resulting in successful treatment. Additional advances in the treatment and monitoring of these patients have led to a reduction in deaths, and an increase in their life expectancy. This increased survival makes them vulnerable to the onset of diseases, which until recently were mainly related to the non-thalassemic general population, such as obesity and DM. There is insufficient data in the literature regarding the prevalence of MASLD in this population or on the risk factors for its occurrence. However, it was recently shown by a study of 45 heavily transfused patients with beta-thalassemia (Padeniya et al , BJH), that the presence of steatosis is a factor influencing the value of liver elastography and thus liver fibrosis. These findings suggest that future research in the field of liver disease in patients with TDBT should be focused on the occurrence, the risk factors, and the effect of MASLD on these patients.

Iron chelation therapy for children with transfusion-dependent β-thalassemia: How young is too young?

In this review, we provide a summary of evidence on iron overload in young children with transfusion-dependent β-thalassemia (TDT) and explore the ideal timing for intervention. Key data from clinical trials and observational studies of the three available iron chelators deferoxamine, deferiprone, and deferasirox are also evaluated for inclusion of subsets of young children, especially those less than 6years of age. Evidence on the efficacy and safety of iron chelation therapy for children ≥2years of age with transfusional iron overload is widely available. New data exploring the risks and benefits of early-start iron chelation in younger patients with minimal iron overload are also emerging.

Modified lentiviral globin gene therapy for pediatric β0/β0 transfusion-dependent β-thalassemia: A single-center, single-arm pilot trial.

β0/β0 thalassemia is the most severe type of transfusion-dependent β-thalassemia (TDT) and is still a challenge facing lentiviral gene therapy. Here, we report the interim analysis of a single-center, single-arm pilot trial (NCT05015920) evaluating the safety and efficacy of a β-globin expression-optimized and insulator-engineered lentivirus-modified cell product (BD211) in β0/β0 TDT. Two female children were enrolled, infused with BD211, and followed up for an average of 25.5months. Engraftment of genetically modified hematopoietic stem and progenitor cells was successful and sustained in both patients. No unexpected safety issues occurred during conditioning or after infusion. Both patients achieved transfusion independence for over 22months. The treatment extended the lifespan of red blood cells by over 42days. Single-cell DNA/RNA-sequencing analysis of the dynamic changes of gene-modified cells, transgene expression, and oncogene activation showed no notable adverse effects. Optimized lentiviral gene therapy may safely and effectively treat all β-thalassemia.

CRISPR-Based Gene Therapies: From Preclinical to Clinical Treatments.

In recent years, clustered regularly interspaced short palindromic repeats (CRISPRs) and CRISPR-associated (Cas) protein have emerged as a revolutionary gene editing tool to treat inherited disorders affecting different organ systems, such as blood and muscles. Both hematological and neuromuscular genetic disorders benefit from genome editing approaches but face different challenges in their clinical translation. The ability of CRISPR/Cas9 technologies to modify hematopoietic stem cells ex vivo has greatly accelerated the development of genetic therapies for blood disorders. In the last decade, many clinical trials were initiated and are now delivering encouraging results. The recent FDA approval of Casgevy, the first CRISPR/Cas9-based drug for severe sickle cell disease and transfusion-dependent β-thalassemia, represents a significant milestone in the field and highlights the great potential of this technology. Similar preclinical efforts are currently expanding CRISPR therapies to other hematologic disorders such as primary immunodeficiencies. In the neuromuscular field, the versatility of CRISPR/Cas9 has been instrumental for the generation of new cellular and animal models of Duchenne muscular dystrophy (DMD), offering innovative platforms to speed up preclinical development of therapeutic solutions. Several corrective interventions have been proposed to genetically restore dystrophin production using the CRISPR toolbox and have demonstrated promising results in different DMD animal models. Although these advances represent a significant step forward to the clinical translation of CRISPR/Cas9 therapies to DMD, there are still many hurdles to overcome, such as in vivo delivery methods associated with high viral vector doses, together with safety and immunological concerns. Collectively, the results obtained in the hematological and neuromuscular fields emphasize the transformative impact of CRISPR/Cas9 for patients affected by these debilitating conditions. As each field suffers from different and specific challenges, the clinical translation of CRISPR therapies may progress differentially depending on the genetic disorder. Ongoing investigations and clinical trials will address risks and limitations of these therapies, including long-term efficacy, potential genotoxicity, and adverse immune reactions. This review provides insights into the diverse applications of CRISPR-based technologies in both preclinical and clinical settings for monogenic blood disorders and muscular dystrophy and compare advances in both fields while highlighting current trends, difficulties, and challenges to overcome.

β-Thalassemia gene editing therapy: Advancements and difficulties.

β-Thalassemia is the world's number 1 single-gene genetic disorder and is characterized by suppressed or impaired production of β-pearl protein chains. This results in intramedullary destruction and premature lysis of red blood cells in peripheral blood. Among them, patients with transfusion-dependent β-thalassemia face the problem of long-term transfusion and iron chelation therapy, which leads to clinical complications and great economic stress. As gene editing technology improves, we are seeing the dawn of a cure for the disease, with its reduction of ineffective erythropoiesis and effective prolongation of survival in critically ill patients. Here, we provide an overview of β-thalassemia distribution and pathophysiology. In addition, we focus on gene therapy and gene editing advances. Nucleic acid endonuclease tools currently available for gene editing fall into 3 categories: zinc finger nucleases, transcription activator-like effector nucleases, and regularly interspaced short palindromic repeats (CRISPR-Cas9) nucleases. This paper reviews the exploratory applications and exploration of emerging therapeutic tools based on 3 classes of nucleic acid endonucleases in the treatment of β-thalassemia diseases.

Combination of a TGF-β ligand trap (RAP-GRL) and TMPRSS6-ASO is superior for correcting β-thalassemia.

A recently approved drug that induces erythroid cell maturation (luspatercept) has been shown to improve anemia and reduce the need for blood transfusion in non-transfusion-dependent as well as transfusion-dependent β-thalassemia (BT) patients. Although these results were predominantly positive, not all the patients showed the expected increase in hemoglobin (Hb) levels or transfusion burden reduction. Additional studies indicated that administration of luspatercept in transfusion-dependent BT was associated with increased erythropoietic markers, decreased hepcidin levels, and increased liver iron content. Altogether, these studies suggest that luspatercept may necessitate additional drugs for improved erythroid and iron management. As luspatercept does not appear to directly affect iron metabolism, we hypothesized that TMPRSS6-ASO could improve iron parameters and iron overload when co-administered with luspatercept. We used an agent analogous to murine luspatercept (RAP-GRL) and another novel therapeutic, IONIS TMPRSS6-LRx (TMPRSS6-ASO), a hepcidin inducer, to treat non-transfusion-dependent BT-intermedia mice. Our study shows that RAP-GRL alone improved red blood cell (RBC) production, with no or limited effect on splenomegaly and iron parameters. In contrast, TMPRSS6-ASO improved RBC measurements, ameliorated splenomegaly, and improved iron overload most effectively. Our results provide pre-clinical support for combining TMPRSS6-ASO and luspatercept in treating BT, as these drugs together show potential for simultaneously improving both erythroid and iron parameters in BT patients.

Exagamglogene Autotemcel for Transfusion-Dependent β-Thalassemia

BackgroundExagamglogene autotemcel (exa-cel) is a nonviral cell therapy designed to reactivate fetal hemoglobin synthesis through ex vivo clustered regularly interspaced short palindromic repeats (CRISPR)–Cas9 gene editing of the erythroid-specific enhancer region of BCL11A in autologous CD34+ hematopoietic stem and progenitor cells (HSPCs).MethodsWe conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent β-thalassemia and a β0/β0, β0/β0-like, or non–β0/β0-like genotype. CD34+ HSPCs were edited by means of CRISPR-Cas9 with a guide mRNA. Before the exa-cel infusion, patients underwent myeloablative conditioning with pharmacokinetically dose-adjusted busulfan. The primary end point was transfusion independence, defined as a weighted average hemoglobin level of 9 g per deciliter or higher without red-cell transfusion for at least 12 consecutive months. Total and fetal hemoglobin concentrations and safety were also assessed.ResultsA total of 52 patients with transfusion-dependent β-thalassemia received exa-cel and were included in this prespecified interim analysis; the median follow-up was 20.4 months (range, 2.1 to 48.1). Neutrophils and platelets engrafted in each patient. Among the 35 patients with sufficient follow-up data for evaluation, transfusion independence occurred in 32 (91%; 95% confidence interval, 77 to 98; P<0.001 against the null hypothesis of a 50% response). During transfusion independence, the mean total hemoglobin level was 13.1 g per deciliter and the mean fetal hemoglobin level was 11.9 g per deciliter, and fetal hemoglobin had a pancellular distribution (≥94% of red cells). The safety profile of exa-cel was generally consistent with that of myeloablative busulfan conditioning and autologous HSPC transplantation. No deaths or cancers occurred.ConclusionsTreatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent β-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.)

Unveiling Extramedullary Hematopoiesis: A Case Report Highlighting the Causes, Symptoms, and Management Strategies

Extramedullary hematopoiesis (EMH) serves as a compensatory mechanism in chronic hemolytic anemias, such as thalassemia, and can result in spinal cord compression. This case report highlights a 36-year-old woman with transfusion-dependent β-thalassemia (TDT) who presented with lower extremity motor deficiency, pelvic paresthesia, and bladder dysfunction. The patient had a history of lower back pain, bilateral lower limb weakness, and demonstrated poor compliance with iron chelation therapy. MRI findings indicated spinal cord compression attributable to extramedullary hematopoiesis. Due to the infeasibility of surgical intervention, the patient underwent hypertransfusion and iron chelation therapy. While neurological symptoms improved, urinary retention persisted. The patient continues to receive iron chelation treatment and undergo transfusions. Managing extramedullary hematopoiesis in thalassemia necessitates an individualized treatment approach.

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

We evaluated the long-term safety and efficacy of thalidomide in the treatment of transfusion-dependent β-thalassemia (TDT). Fifty patients with TDT were treated with thalidomide and followed-up for 5 years. Thalidomide at a 50 mg dose was administered once a day after dinner. The dose was increased to 150 mg/d after 3 d if well tolerated. After 1 year of treatment, the hemoglobin (Hb) level was stabilized at its maximum, and thalidomide was gradually reduced and maintained at the minimum dose. The hematological response, transfusion dependence, and haemolytic indicators were assessed. At 9 month of follow-up, 38 (76%) patients achieved an excellent response, 1 (2%) a good response, 4(8%) a minor response, and 7(14%) did not show a response. The overall response rate was 86%. At 9 months, the Hb level increased from 79.0 ± 13.2 g/L at baseline to 99.0 ± 13.7g/L (P<0.001). Patients who achieved excellent response continued to show an increase in Hb levels during follow-up. At 48 months, the mean Hb level was 98.99 ± 10.3g/L; 21 patients (84.0%) became transfusion independent. Thalidomide was reduced and maintained to 25 mg/d in three of these patients. Moreover, five patients completed 60 months of follow-up, and with a mean Hb level of 99.8 ± 6.7g/L. During follow-up, grade 1-2 adverse drug reactions were noted; however, no grade 3 or higher adverse event was reported. However, no decrease in hemolytic indicators was observed. Thalidomide was well tolerated in the long term, while it significantly improved Hb levels and reduced the transfusion burden.

Health-Related Quality-of-Life Impacts Associated with Transfusion-Dependent β-Thalassemia in the USA and UK: A Qualitative Assessment.

Individuals living with transfusion-dependent β-thalassemia (TDT) experience reduced health-related quality of life due to fatigue and chronic pain, which cause disruptions to daily life. Currently, limited qualitative data exist that describe these impacts. This study aimed to examine the ways in which symptoms and current treatments of TDT impact health-related quality of life, to holistically describe the humanistic burden of TDT, and to identify the unmet needs of individuals living with TDT. Adults (aged ≥18 years) with TDT and caregivers of adolescents (aged 12‒17 years) with TDT participated in semi-structured one-on-one virtual interviews and focus group discussions. Interviews were conducted in the USA and UK and lasted approximately 60 minutes. After transcription, the interviews were analyzed thematically using a framework approach. A total of ten interviews/focus group discussions (six interviews and four focus group discussions) were conducted with 14 adults with TDT and two caregivers of adolescents with TDT. A framework analysis revealed five themes describing health-related quality of life (negative impacts on daily activities, social life, family life, work and education, and psychological well-being) and three themes describing the lived experience of TDT (impact of red blood cell transfusions and iron chelation therapy, treatment, and stigma). Physical, psychological, and treatment-related factors contributed to negative impacts on daily activities, social and family life, and work and education. Concerns about reduced lifespan, relationships and family planning, and financial independence were detrimental to participants' mental well-being. Participants reported having high resilience to the many physical and psychological challenges of living with TDT. A lack of TDT-specific knowledge among healthcare professionals, particularly regarding chronic pain associated with the disease, left some participants feeling ignored or undermined. Additionally, many participants experienced stigma and were reluctant to disclose their disease to others. Individuals living with TDT experience substantial negative impacts on health-related quality of life that disrupt their daily lives, disruptions that are intensified by inadequate healthcare interactions, demanding treatment schedules, and stigma. Our study highlights the unmet needs of individuals living with TDT, especially for alternative treatments that reduce or eliminate the need for red blood cell transfusions and iron chelation therapy.

Frequency and potential risk factors of polyneuropathy in transfusion-dependent Β-thalassemia major patients: a cross-sectional study

BackgroundNeurological complications, including peripheral polyneuropathy, have been reported in β-thalassemia patients that negatively impact their quality of life. Chronic hypoxia, iron overload, average age, and iron chelators-induced neurotoxicity might contribute to the development of neuropathy. However, the leading offender of this complication remains not clear. We aimed to study the frequency and potential risk factors of polyneuropathy in β-thalassemia patients. We performed a cross-section study on 150 transfusion-dependent β-thalassemia major patients with a mean age of 16.44 ± 3.32 years. We performed electrophysiological studies for motor and sensory nerves.ResultsWe found that 31.3% of cases had neurological manifestations with significant relation to age, duration of the disease, and frequent transfusion. Out of 47 patients with neurological manifestations, 12 (25.5%) had abnormal nerve conduction velocity (NCV). Abnormal median, peroneal, and tibial nerve motor amplitudes were detected in 10.6%, 10.6%, and 14.9% of patients respectively. Abnormal median, peroneal, and sural nerve sensory amplitudes were detected in 4.3%, 2.2%, and 10.6% of patients respectively. Apart from a significant relation between abnormal NCV and older ages, no significant relation was detected with other studied clinical and laboratory parameters.ConclusionWe detected a high frequency of motor and sensory polyneuropathy in B-thalassemia patients. Polyneuropathy was predominately detected in older ages highlighting that neuropathy in thalassemia patients is probably age-dependent. Other factors including disease duration, transfusion frequency, and iron overload might have a contributing effect, however, that could not be confirmed in this study. Further studies are needed to verify the frequency and predictors of polyneuropathy in B-thalassemia patients.

État de santé et qualité de vie des patients β-thalassémiques adultes à Marseille, France

IntroductionThe life expectancy of β-thalassemia patients has increased over the last 20 years. In this study, we evaluated the current health status and quality of life of these patients managed in a reference center in Marseille. MethodsThis is a single-center, descriptive study conducted between June and August 2019 in patients over 18 years of age with β-thalassemia major or intermedia. Clinical and paraclinical data were collected retrospectively and the SF-36 health survey questionnaire was proposed to each patient. Results43 of 64 selected patients were included and divided into 2 groups: 35 patients with transfusion-dependent β-thalassemia and 8 patients with non-transfusion-dependent β-thalassemia. Liver iron overload is the most frequent complication, present in 80% of transfusion-dependent and 62.5% of non-transfusion-dependent patients. Cardiac iron overload is present only in the transfusion dependent β-thalassemia group (20%). Hypogonadotropic hypogonadism remains the most common endocrine disorder (41.9%) followed by osteoporosis (37.2%). Among the 31 patients who completed the SF-36 questionnaire, physical and mental quality of life scores were lowered in transfusion dependent (respectively 42.7 and 46.8) as in non-transfusion-dependent patients (respectively 43.8 and 28.9). ConclusionDespite an improvement in medical care, our patients with β-thalassemia show an alteration in their quality of life that will need to be characterized in the entire French cohort.

Revisiting iron overload status and change thresholds as predictors of mortality in transfusion-dependent β-thalassemia: a 10-year cohort study.

Data on iron overload status and change thresholds that can predict mortality in patients with transfusion-dependent β-thalassemia (TDT) are limited. This was a retrospective cohort study of 912 TDT patients followed for up to 10years at treatment centers in Italy (median age 32years, 51.6% female). The crude mortality rate was 2.9%. Following best-predictive threshold identification through receiver operating characteristic curve analyses, data from multivariate Cox-regression models showed that patients with Period Average Serum Ferritin (SF) > 2145 vs ≤ 2145ng/mL were 7.1-fold (P < 0.001) or with Absolute Change SF > 1330 vs ≤ 1330ng/mL increase were 21.5-fold (P < 0.001) more likely to die from any cause. Patients with Period Average Liver Iron Concentration (LIC) > 8 vs ≤ 8mg/g were 20.2-fold (P < 0.001) or with Absolute Change LIC > 1.4 vs ≤ 1.4mg/g increase were 27.6-fold (P < 0.001) more likely to die from any cause. Patients with Index (first) cardiac T2* (cT2*) < 27 vs ≥ 27ms were 8.6-fold (P < 0.001) more likely to die from any cause. Similarly, results at varying thresholds were identified for death from cardiovascular disease. These findings should support decisions on iron chelation therapy by establishing treatment targets, including safe iron levels and clinically meaningful changes over time.

Transfusion Independence after Exagamglogene Autotemcel in Patients with Transfusion-Dependent β-Thalassemia

Transfusion Independence after Exagamglogene Autotemcel in Patients with Transfusion-Dependent β-Thalassemia

Sustained Efficacy and Safety in Adult and Pediatric Patients with Transfusion-Dependent β-Thalassemia up to 9 Years Post Treatment with Betibeglogene Autotemcel (Beti-cel)

Sustained Efficacy and Safety in Adult and Pediatric Patients with Transfusion-Dependent β-Thalassemia up to 9 Years Post Treatment with Betibeglogene Autotemcel (Beti-cel)

Mobilization and Apheresis Experience in Patients Receiving One-Time Gene Therapy with Beti-Cel for Patients with Transfusion-Dependent β-Thalassemia: A Pooled Analysis

Mobilization and Apheresis Experience in Patients Receiving One-Time Gene Therapy with Beti-Cel for Patients with Transfusion-Dependent β-Thalassemia: A Pooled Analysis

Audiologic and vestibular assessment in children and adolescents with transfusion dependent beta thalassemia major: The era of deferasirox film coated tablet

BackgroundHearing impairment has frequently been described in β-thalassemia patients with a significant impact on the patients’ quality of life. Most studies provided evidence of deferoxamine (DFO) dose-related ototoxicity, however, the data is scarce regarding deferasirox (DFX) as a sole iron chelator. AimWe aimed to assess the prevalence and risk factors of sensorineural hearing loss (SNHL) and vestibular dysfunction in regularly transfused β-thalassemia patients who had been treated with DFX film coated tablets. MethodsWe conducted a case control study on 57 transfusion dependent β-thalassemia patients with a mean age of 15.3 years who received DFX FCT as monotherapy for at least one consecutive year, and 57 healthy age and sex-matching controls. Comprehensive audiological evaluations using pure tone audiometry (PTA) and transient evoked otoacoustic emission (TEOAE) as well as vestibular evaluation using Video-nystagmography (VNG) were done. ResultsSNHL was identified in 12 patients (21.1 %) using PTA and a statistically significant difference was detected between controls and patients at 6 KHz and 12 KHz frequencies. A higher incidence of SNHL was detected using TEOAE, 22 patients (43.1 %) failed to pass TEOAE, with a statistically significant decrease in the signal at frequencies 1, 4 KHz bilaterally and at frequencies 1.5, 2 KHz in the right ear compared to controls. Canal paresis was detected in 21 (36.8 %) of thalassemic children using bithermal caloric test with significantly more unilateral weakness than control children (P = 0.008). We found no significant correlation between audio-vestibular dysfunction and age, sex, serum ferritin, frequency of blood transfusion and dose of DFX FCT in thalassemic children. ConclusionWe conclude that the incidence of SNHL and vestibular dysfunction was high among transfusion dependent β-thalassemia patients. Therefore, we recommend performing pre-treatment baseline audio-vestibular assessment and yearly audio-vestibular monitoring to early detect high risk patients and initiate timely management to prevent permanent damage.

Exagamglogene Autotemcel: First Approval.

Exagamglogene autotemcel (Casgevy™) is a genetically modified autologous CD34+ cell enriched population. It contains human haematopoietic stem and progenitor cells edited ex vivo by CRISPR/Cas9 (a DNA double strand break-inducing nuclease system) to differentiate into erythroid cells that produce high levels of foetal hemoglobin. Developed by Vertex Pharmaceuticals and CRISPR Therapeutics, exagamglogene autotemcel received its first approval on 16 November 2023 in the UK for the treatment of transfusion-dependent β-thalassemia (TDT) in patients aged ≥ 12years for whom haematopoietic stem cell (HSC) transplantation is appropriate and a human leukocyte antigen matched related HSC donor is not available. On the same day, it was also approved in the UK for the treatment of sickle cell disease (SCD) in patients aged ≥ 12years with recurrent vasoocclusive crises (VOCs) who have the βS/βS, βS/β+ or βS/β0 genotype for whom HSC transplantation is appropriate and a human leukocyte antigen matched related HSC donor is not available. Subsequently, exagamglogene autotemcel was approved in the USA on 8 December 2023 for the treatment of SCD in patients aged ≥ 12years with recurrent VOCs and received a positive opinion in the EU on 14 December 2023 for the treatment of TDT and SCD. A regulatory assessment of exagamglogene autotemcel is currently underway for the treatment of TDT in the USA. This article summarizes the milestones in the development of exagamglogene autotemcel leading to these first approvals.

Effects of Thalidomide on Erythropoiesis and Iron Homeostasis in Transfusion-Dependent β-Thalassemia.

Thalidomide is a therapeutic option for patients with β-thalassemia by increasing fetal hemoglobin and thereby reducing the requirement for blood transfusions. However, information on changes in erythropoiesis and iron homeostasis during thalidomide treatment is lacking. This study investigated the effects of thalidomide treatment on hematologic, erythropoietic, and ironstatus parameters in 22 patients with transfusion-dependent β-thalassemia (TDT). Thalidomide significantly improved anemia endpoints, including increases in hemoglobin (p<0.001), red blood cells (p<0.001), and hematocrit (p<0.001), as well as reducing erythropoietin levels (p=0.033) and ameliorating erythropoiesis. Thalidomide treatment significantly reduced serum iron levels (p=0.018) and transferrin saturation (p=0.039) and increased serum transferrin levels (p=0.030). Thalidomide had no observed effect on serum ferritin or hepcidin, but changes in hepcidin (r=0.439, p=0.041) and serum iron (r=-0.536, p=0.010) were significantly correlated with hemoglobin increment. This comprehensive study indicates that thalidomide treatment can ameliorate erythropoiesis and iron homeostasis in patients with TDT, thus supporting the effectiveness of this drug.

Can we Predict Incipient Diabetes Mellitus in Patients with Transfusion Dependent β-Thalassemia (β-TDT) Referred with a History of Prediabetes?

Prediabetes and diabetes mellitus (DM) are complications in adult patients with transfusion-dependent β-thalassemia (β-TDT), with their incidence increasing with age. This retrospective observational study describes the glycemic trajectories and evaluates predictive indices of β-cell function and insulin sensitivity/resistance in β-TDT patients with prediabetes, both in a steady state and during 3-h oral glucose tolerance test (OGTT), in order to identify patients at high risk for incipient diabetes. The study was mainly conducted at the Pediatric and Adolescent Outpatient Clinic, Quisisana Hospital, Ferrara (Italy), in collaboration with thalassemia referring centers across Italy. The study included 11 β-TDT (aged 15.11-31.10 years) with prediabetes. Methods: The ADA criteria for the diagnosis of glucose dysregulation were adopted. Investigations included evaluating plasma glucose levels and insulin secretion, analyzing glycemic trajectories and indices of β-cell function, and insulin sensitivity/resistance assessed in steady state and during OGTT. The duration of progression from prediabetes to DM, expressed in years, showed a positive direct correlation with corrected insulin response (CIR-30 = r: 0.7606, P: 0.0065), insulinogenic index (IGI 0-120 = r: 0.6121, P:0.045), oral disposition index (oDI = r: 0.7119, P:0.013), insulin growth factor-1 (IGF-1= r: 0.6246, P: 0.039) and an inverse linear correlation with serum ferritin (SF = r: -0.7197, P: 0.012). The number of patients with 1-hour post-load PG value ≥ 155 mg/dL ( ≥ 8.6 mmol/L) was at -4 years: 4/9 (44.4%); -3 years: 8/9 (88.8%); - 2 years: 7/10 (70 %) and at -1 year: 11/11 (100%) (PG range:162-217 mg/dL). A progressive increase in 1-hour PG in response to OGTT is associated with progressive β-cell failure, peripheral resistance to insulin action, and reduced oDI and may be considered a relevant marker for incipient DM in β-TDT patients with prediabetes.