Non-viral DNA delivery and TALEN editing correct the sickle cell mutation in hematopoietic stem cells.

Sickle cell disease is a devastating blood disorder that originates from a single point mutation in the HBB gene coding for hemoglobin. Here, we develop a GMP-compatible TALEN-mediated gene editing process enabling efficient HBB correction via a DNA repair template while minimizing risks associated with HBB inactivation. Comparing viral versus non-viral DNA repair template delivery in hematopoietic stem and progenitor cells in vitro, both strategies achieve comparable HBB correction and result in over 50% expression of normal adult hemoglobin in red blood cells without inducing ß-thalassemic phenotype. In an immunodeficient female mouse model, transplanted cells edited with the non-viral strategy exhibit higher engraftment and gene correction levels compared to those edited with the viral strategy. Transcriptomic analysis reveals that non-viral DNA repair template delivery mitigates P53-mediated toxicity and preserves high levels of long-term hematopoietic stem cells. This work paves the way for TALEN-based autologous gene therapy for sickle cell disease.

ß-Thalassemia gene editing therapy: Advancements and difficulties.

ß-Thalassemia is the world's number 1 single-gene genetic disorder and is characterized by suppressed or impaired production of ß-pearl protein chains. This results in intramedullary destruction and premature lysis of red blood cells in peripheral blood. Among them, patients with transfusion-dependent ß-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 ß-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 ß-thalassemia diseases.

Differential effects of iron chelators on iron burden and long-term morbidity and mortality outcomes in a large cohort of transfusion-dependent ß-thalassemia patients who remained on the same monotherapy over 10 years.

We conducted a retrospective cohort study on 663 transfusion-dependent ß-thalassemia patients receiving the same iron chelation monotherapy with deferoxamine, deferiprone, or deferasirox for up to 10 years (median age 31.8 years, 49.9 % females). Patients on all three iron chelators had a steady and significant decline in serum ferritin over the 10 years (median deferoxamine: -170.7 ng/mL, P = 0.049, deferiprone: -236.7 ng/mL, P = 0.001; deferasirox: -323.7 ng/mL, P < 0.001) yet had no significant change in liver iron concentration or cardiac T2*; while noting that patients generally had low hepatic and cardiac iron levels at study start. Median absolute, relative, and normalized changes were generally comparable between the three iron chelators. Patients receiving deferasirox had the highest morbidity and mortality-free survival probability among the three chelators, although the difference was only statistically significant when compared with deferoxamine (P = 0.037). On multivariate Cox regression analysis, there was no significant association between iron chelator type and the composite outcome of morbidity or mortality. In a real-world setting, there is comparable long-term iron chelation effectiveness between the three available iron chelators for patients with mild-to-moderate iron overload.

Acute Graft versus Host Disease in Beta Thalassemia Patients Following Allogeneic Haematopoietic Stem Cell Transplantation.

OBJECTIVE: To analyse the frequency, risk factors, and clinical symptoms of acute graft-versus-host disease (aGvHD) in patients with beta-thalassemia major after allogeneic haematopoietic stem cell transplantation (HSCT). STUDY DESIGN: Descriptive study. Place and Duration of the Study: Department of Clinical Haematology, Armed Forces Bone Marrow Transplant Centre, Rawalpindi, Pakistan, from January 2017 to December 2021. METHODOLOGY: Data were obtained from patients diagnosed with bone and tissue malignancies (BTM) who had undergone haematopoietic stem cell transplantation (HSCT) and experienced aGVHD. Patients who experienced initial graft failure and individuals who underwent subsequent bone marrow transplantation were excluded. RESULTS: Total of 117 patients diagnosed with BTM underwent fully matched HSCT, including 76 (65%) males, and 41 (35%) females. The median age of the patients undergoing transplantation was 7.34±7.32 years and the donors' median age was 7.6±9.85 years. Among the donors, 53 (45.3%) were males and 64 (54.7%) were females. Gender disparity was observed in 46 (39.3%) instances as a female donor matched with a male recipient. A total of 106 individuals underwent bone marrow harvest (BMH); with 5 (4.3%) patients receiving peripheral blood stem cells (PBSC) and 6 (5.2%) patients receiving both BMH and PBSC. Acute GvHD was observed in 50 (42.7%) patients, including 30 (60%) males and 20 (40%) females. Grade I GvHD occurred in 32 (27.3%) individuals, Grade II GvHD in 16 (13.7%) patients, and Grade III GvHD in one (0.8%) patient. It had no statistically significant association with recipient/donor age, gender disparity, the source of the graft source, the dose of stem cells, or the presence of thymoglobulin (TG). CONCLUSION: Acute GvHD was observed in high frequency in Beta-thalassemia patients receiving morrow harvesting proportional to their gender distribution. Associated factors were GvHD prophylaxis measure, mucositis and, CMV reactivation. KEY WORDS: Beta thalassemia major patients, Acute graft versus host disease, Allogeneic haematopoietic stem cell.

[Advance of research on the role of BCL11A in the occurrence and treatment of ß-Thalassemia].

ß-Thalassemia is a single-gene disease caused by mutations in ß-globin and has a distinct geographical characteristics. Current treatment for patients with moderate to severe thalassemia has mainly relied on long-term blood transfusion and/or hematopoietic stem cell transplantation. B cell lymphoma/leukemia 11A (BCL11A) as a transcriptional repressor plays a vital role in monitoring γ/ß hemoglobin switching, maintaining the normal function of hematopoietic stem cells, and regulating erythrocyte differentiation and lymphocyte development. With the rapid progress in gene editing technology, the BCL11A as a therapeutic target for ß-thalassemia has shown promising results. This article has systematically summarized the regulatory mechanism and therapeutic potential of the BCL11A, with an aim to provide new ideas for the treatment of ß-thalassemia.

Growth and endocrinopathies among children with ß-Thalassemia major treated at Dubai Thalassemia centre.

BACKGROUND: ß-Thalassemia major (BTM) is one of the most common hereditary anemias worldwide. Patients suffer from iron overload that results from repeated blood transfusion This in turn leads to multiple organ damage and endocrinopathies. This study aims to assess the prevalence of growth retardation, hypothyroidism, and diabetes mellitus in children and adolescents with BTM treated at Dubai Thalassemia Centre. METHODS: A total of 105 children and adolescents were included in this retrospective observational study. RESULTS: 39 children and 66 adolescents' data were analyzed. Females composed 51.3% (n = 20) of children and 53.0% (n = 35) of adolescents. Pretransfusion hemoglobin below 9 gm/dl was observed in 10.8% (n = 4) and 10.6% (n = 7) in children and adolescents, respectively. The mean age of menarche was 13.5 years. Among all study participants, 22.6% (n = 14) had normal height velocity whereas 37.1% (n = 23) had reduced height velocity in one year and 40.3% (n = 25) had reduced height velocity in two consecutive years. The proportion of children and adolescents showing reduced height velocity was significantly higher in females compared to the males (90.6% versus 63.3%, respectively, Chi-square = 6.597, p-value = 0.010). Although none of the study participants had diabetes mellitus, 26.1% (n = 12/46) had pre-diabetes. Elevated TSH was observed in 14.7% (n = 5) children and 8.1% (n = 5) adolescents while low FT4 was reported in one child and one adolescent. CONCLUSION: Of all endocrinopathies seen among children and adolescents with BTM, growth delay remains the main concern for this group of patients. Effective treatment is key to further reducing endocrinopathies. Although the sample size is limited, we postulate that the low percentage of endocrinopathies among children with BTM treated at Dubai thalassemia center and the low level of pretransfusion anemia reflect the effective transfusion and chelation at the center.

Impact of SCOPE Program on Health-Related Quality of Life and Health Status of Children With Thalassemia: A Quasi-Experimental Study.

Background: Iron chelation, blood transfusions, and complication management are typical hospital requirements for children with beta-thalassemia major. This affects their health-related quality of life (HRQoL). The purpose of this study was to evaluate how the Supportive and Coping strategies, Ongoing Assessment, Prevention of Complications, and Empowerment (SCOPE) Program impacted the HRQoL and overall health of children with thalassemia. Method: The study employed a quasi-experimental pretest-posttest control group with a sequential follow-up design. A nonprobability purposive sampling technique was used to include 80 children with beta-thalassemia major in the sample, ranging in age from 6 to 18. Data were gathered using a Demographic Profile, PedsQLTM Version 4.0, and a Clinical Profile. The children in the intervention group received the SCOPE Program over the course of 6 months. The data collection included a pretest and a posttest with four follow-up evaluations. Results: During the pretest, children with thalassemia had a very low HRQoL. However, the final assessment after the intervention showed a significant difference in the mean scores between the two groups in the areas of physical functioning (p = .001), emotional functioning (p = .0001), social functioning (p = .001), and school functioning (p = .001). Growth indicators also demonstrated a notable improvement in the intervention group of children. Discussion: The SCOPE Program may be a thorough and efficient intervention for enhancing the general health of children with thalassemia. It can be used as a cooperative, well-organized, family-focused care strategy. Further study with a larger sample size is suggested.

Exagamglogene Autotemcel for Transfusion-Dependent ß-Thalassemia.

BACKGROUND: Exagamglogene 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). METHODS: We conducted an open-label, single-group, phase 3 study of exa-cel in patients 12 to 35 years of age with transfusion-dependent ß-thalassemia and a ß0/ß0, ß0/ß0-like, or non-ß0/ß0-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. RESULTS: A total of 52 patients with transfusion-dependent ß-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. CONCLUSIONS: Treatment with exa-cel, preceded by myeloablation, resulted in transfusion independence in 91% of patients with transfusion-dependent ß-thalassemia. (Supported by Vertex Pharmaceuticals and CRISPR Therapeutics; CLIMB THAL-111 ClinicalTrials.gov number, NCT03655678.).

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

Multiparametric cardiac magnetic resonance in patients with thalassemia intermedia: new insights from the E-MIOT network.

PURPOSE: In a relatively large cohort of thalassemia intermedia (TI) patients, we systematically investigated myocardial iron overload (MIO), function, and replacement fibrosis using cardiac magnetic resonance (CMR), we assessed the clinical determinants of global heart T2* values, and we explored the association between multiparametric CMR findings and cardiac complications. MATERIALS AND METHODS: We considered 254 beta-TI patients (43.14 ± 13.69 years, 138 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia project. MIO was quantified by T2* technique and biventricular function and atrial areas by cine images. Macroscopic myocardial fibrosis was detected by late gadolinium enhancement technique. RESULTS: Compared to never/sporadically transfused patients, regularly transfused (RT)-TI patients exhibited significantly lower global heart T2* values, biventricular end-diastolic volume indexes, left ventricular mass index, and cardiac index. In RT-TI patients, age and serum ferritin levels were the strongest predictors of global heart T2* values. Independently from the transfusional state, cardiac T2* values were not associated with biventricular function. Of the 103 (40.6%) patients in whom the contrast medium was administrated, 27 (26.2%) had replacement myocardial fibrosis. Age, sex distribution, cardiac iron, and biventricular function parameters were comparable between patients without and without replacement myocardial fibrosis. Twenty-five (9.8%) patients had a history of cardiac complications (heart failure and arrhythmias). Increased age and replacement myocardial fibrosis emerged as significant risk markers for cardiac complications. CONCLUSIONS: In TI, regular transfusions are associated with less pronounced cardiac remodeling but increase the risk of MIO. Replacement myocardial fibrosis is a frequent finding associated with cardiac complications.

Survival and causes of death in patients with alpha and beta-thalassemia in Northern Thailand.

BACKGROUND: Thalassemia is the most prevalent hereditary anaemia worldwide. Severe forms of thalassemia can lead to reduced life expectancy due to disease-related complications. OBJECTIVES: To investigate the survival of thalassemia patients across varying disease severity, causes of death and related clinical factors. PATIENTS AND METHODS: We conducted a retrospective review of thalassemia patients who received medical care at Chiang Mai University Hospital. The analysis focused on survival outcomes, and potential associations between clinical factors and patient survival. RESULTS: A total of 789 patients were included in our study cohort. Among them, 38.1% had Hb H disease, 35.4% had Hb E/beta-thalassemia and 26.5% had beta-thalassemia major. Half of the patients (50.1%) required regular transfusions. Sixty-five patients (8.2%) had deceased. The predominant causes of mortality were infection-related (36.9%) and cardiac complications (27.7%). Transfusion-dependent thalassemia (TDT) (adjusted HR 3.68, 95% CI 1.39-9.72, p = 0.008) and a mean serum ferritin level ≥3000 ng/mL (adjusted HR 4.18, 95% CI 2.20-7.92, p < 0.001) were independently associated with poorer survival. CONCLUSIONS: Our study highlights the primary contributors to mortality in patients with thalassemia as infection-related issues and cardiac complications. It also underscores the significant impact of TDT and elevated serum ferritin levels on the survival of thalassemia patients.

Proportion of Hypogonadism in Transfusion-Dependent Thalassemia Patients and Its Contributing Factors.

BACKGROUND: Beta thalassemia is a lifelong disease involving malformed red blood cells (RBC). One of the disease's complications is hypogonadism, in which adults tend to exhibit regression in sexual characteristics, experience sexual dysfunction, and therefore have a lower quality of life. Around 3-10% of the Indonesian population carries the beta-thalassemia gene. This study aimed to see the proportions of hypogonadism in transfusion-dependent thalassemia patients and its contributing factors. METHODS: This is a cross-sectional study involving 60 male patients admitted to three Indonesian general hospitals from July 2022 to July 2023. All patients were diagnosed with beta-thalassemia via chromatography hemoglobin analysis. We performed a single-time physical examination and laboratory examinations to determine FSH, LH, and free testosterone levels. The correlation between Hb and sexual hormone levels was analyzed using Spearman's rank correlation coefficient. ROC curve analysis was conducted afterward. All statistical analysis was done in SPSS version 29. RESULTS: 31 out of 60 thalassemia patients had hypogonadism. Pre-transfusion Hb count was found to be linearly correlated with FSH (r = 0.388, p = 0.049), LH (r = 0.338, p = 0.008), and free testosterone (r = 0.255, p = 0.049). ROC analysis indicated that pre-transfusion Hb was viable as a predictor for hypogonadism (AUC = 0.655, 65.5% sensitivity, 67.7% specificity). CONCLUSION: We confirmed the role of pre-transfusion Hb count as a potential predictor for hypogonadism due to the tissue hypoxia mechanism and transfusion-related iron overload in TDT patients. Decreased Hb is linearly correlated with FSH, LH, and testosterone levels. Decreased Hb also downregulates these factors.

[Health status and quality of life in ß-thalassemia adults in Marseille, France]. / État de santé et qualité de vie des patients ß-thalassémiques adultes à Marseille, France.

INTRODUCTION: The life expectancy of ß-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. METHODS: This is a single-center, descriptive study conducted between June and August 2019 in patients over 18 years of age with ß-thalassemia major or intermedia. Clinical and paraclinical data were collected retrospectively and the SF-36 health survey questionnaire was proposed to each patient. RESULTS: 43 of 64 selected patients were included and divided into 2 groups: 35 patients with transfusion-dependent ß-thalassemia and 8 patients with non-transfusion-dependent ß-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 ß-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). CONCLUSION: Despite an improvement in medical care, our patients with ß-thalassemia show an alteration in their quality of life that will need to be characterized in the entire French cohort.

Hearing loss in beta-thalassaemia: An Italian multicentre case-control study.

BACKGROUND: Despite numerous studies, the true scenario of hearing loss in beta-thalassaemia remains rather nebulous. MATERIALS AND METHODS: Pure tone audiometry, chelation therapy, demographics and laboratory data of 376 patients (mean age 38.5 ± 16.6 years, 204 females, 66 non-transfusion-dependent) and 139 healthy controls (mean age 37.6 ± 17.7 years, 81 females) were collected. RESULTS: Patient and control groups did not differ for age (p = 0.59) or sex (p = 0.44). Hypoacusis rate was higher in patients (26.6% vs. 7.2%; p < 0.00001), correlated with male sex (32.6% in males vs. 21.8% in females; p = 0.01) and it was sensorineural in 79/100. Hypoacusis rate correlated with increasing age (p = 0.0006) but not with phenotype (13/66 non-transfusion-dependent vs. 87/310 transfusion-dependent patients; p = 0.16). Sensorineural-notch prevalence rate did not differ between patients (11.4%) and controls (12.2%); it correlated with age (p = 0.01) but not with patients' sex or phenotype. Among adult patients without chelation therapy, the sensorineural hypoacusis rate was non-significantly lower compared to chelation-treated patients while it was significantly higher compared to controls (p = 0.003). CONCLUSIONS: Sensorineural hypoacusis rate is high in beta-thalassaemia (about 21%) and it increases with age and in males while disease severity or chelation treatment seems to be less relevant. The meaning of sensorineural-notch in beta-thalassaemia appears questionable.

Autologous gene therapy for hemoglobinopathies: From bench to patient's bedside.

In recent years, a growing number of clinical trials have been initiated to evaluate gene therapy approaches for the treatment of patients with transfusion-dependent ß-thalassemia and sickle cell disease (SCD). Therapeutic modalities being assessed in these trials utilize different molecular techniques, including lentiviral vectors to add functional copies of the gene encoding the hemoglobin ß subunit in defective cells and CRISPR-Cas9, transcription activator-like effector protein nuclease, and zinc finger nuclease gene editing strategies to either directly address the underlying genetic cause of disease or induce fetal hemoglobin production by gene disruption. Here, we review the mechanisms of action of these various gene addition and gene editing approaches and describe the status of clinical trials designed to evaluate the potentially for these approaches to provide one-time functional cures to patients with transfusion-dependent ß-thalassemia and SCD.

Droplet digital polymerase chain reaction-based quantitation of therapeutic lentiviral vector copies in transduced hematopoietic stem cells.

BACKGROUND AIMS: Gene therapy using lentiviral vectors (LVs) that harbor a functional ß-globin gene provides a curative treatment for hemoglobinopathies including beta-thalassemia and sickle cell disease. Accurate quantification of the vector copy number (VCN) and/or the proportion of transduced cells is critical to evaluate the efficacy of transduction and stability of the transgene during treatment. Moreover, commonly used techniques for LV quantification, including real-time quantitative polymerase chain reaction (PCR) or fluorescence-activated cell sorting, require either a standard curve or expression of a reporter protein for the detection of transduced cells. In the present study, we describe a digital droplet PCR (ddPCR) technique to measure the lentiviral VCN in transduced hematopoietic stem and progenitor cells (HSPCs). METHODS: After HSPCs were transduced with an LV encoding the therapeutic ß-globin (ßA-T87Q) gene, the integrated lentiviral sequence in the host genome was amplified with primers that targeted a sequence within the vector and the human RPP30 gene. The dynamic range of ddPCR was between 5 × 10-3 ng and 5 × 10-6 ng of target copy per reaction. RESULTS: We found that the ddPCR-based approach was able to estimate VCN with high sensitivity and a low standard deviation. Furthermore, ddPCR-mediated quantitation of lentiviral copy numbers in differentiated erythroblasts correlated with the level of ßA-T87Q protein detected by reverse-phase high-performance liquid chromatography. CONCLUSIONS: Taken together, the ddPCR technique has the potential to precisely detect LV copy numbers in the host genome, which can be used for VCN estimation, calculation of infectious titer and multiplicity of infection for HSPC transduction in a clinical setting.

Spanish registry of hemoglobinopathies and rare anemias (REHem-AR): demographics, complications, and management of patients with ß-thalassemia.

INTRODUCTION: The increase in the number of patients with hemoglobinopathies in Europe in recent decades highlights the need for more detailed epidemiological information in Spain. To fulfil this need, the Spanish Society of Pediatric Hematology and Oncology (SEHOP) sponsored the creation of a national registry of hemoglobinopathies known as REHem-AR (Spanish Registry of Hemoglobinopathies and Rare Anemias). Data from the transfusion-dependent (TDT) and non-transfusion-dependent (NTDT) ß-thalassemia cohorts are described and analyzed. METHODS: We performed an observational, multicenter, and ambispective study, which included patients of any age with TDT and NTDT, registered up to December 31, 2021. RESULTS: Among the 1741 patients included, 168 cases of thalassemia were identified (103 TDT and 65 NTDT-patients). Survival at 18 years was 93% for TDT and 100% for NTDT. Regarding management, 80 patients with TDT (77.7%) and 23 patients with NTDT (35.4%) started chelation treatment during follow-up, with deferasirox being the most widely used. A total of 76 patients within the TDT cohort presented at least 1 complication (73.8%), the most frequent being hemosiderosis and osteopenia-osteoporosis. Comparison of both cohorts revealed significant differences in the diagnosis of hepatic hemosiderosis (p = 0.00024), although these were not observed in the case of cardiac iron overload (p = 0.27). DISCUSSION: Our registry enabled us to describe the management of ß thalassemia in Spain and to analyze the morbidity and mortality of the cohorts of patients with TDT and NTDT. Complications related to iron overload in TDT and NTDT account for most of the morbidity and mortality of the disease, which is associated with a considerable social, psychological, and economic impact, although cardiac, osteopathy and endocrinological complications requiring more attention. The convenience and simplicity of online registries make it possible to homogenize variables and periodically update data, thus providing valuable information on these diseases.