Risk factors for pulmonary hypertension in patients with β thalassemia intermedia

Prognostic Role of Multiparametric Cardiac Magnetic Resonance in Neo Transfusion-Dependent Thalassemia

BACKGROUND

We prospectively evaluated the predictive value of multiparametric cardiac magnetic resonance (CMR) for cardiovascular complications in non-transfusion-dependent β-thalassemia (β-NTDT) patients who started regular transfusions in late childhood/adulthood (neo β-TDT).

METHODS

We considered 180 patients (38.25 ± 11.24 years; 106 females). CMR was used to quantify cardiac iron overload, biventricular function, and atrial dimensions, and to detect left ventricular (LV) replacement fibrosis.

RESULTS

During a mean follow-up of 76.87 ± 41.60 months, 18 (10.0%) cardiovascular events were recorded: 2 heart failures, 13 arrhythmias (10 supraventricular), and 3 cases of pulmonary hypertension. Right ventricular (RV) end-diastolic volume index (EDVI), RV mass index (MI), LV replacement fibrosis, and right atrial (RA) area index emerged as significant univariate prognosticators of cardiovascular complications. The low number of events prevented us from performing a multivariable analysis including all univariable predictors simultaneously. Firstly, a multivariable analysis including the two RV size parameters (mass and volume) was carried out, and only the RV MI was proven to independently predict cardiovascular diseases. Then, a multivariable analysis, including RV MI, RA atrial area, and LV replacement fibrosis, was conducted. In this model, RV MI and LV replacement fibrosis emerged as independent predictors of cardiovascular outcomes (RV MI: hazard ratio (HR) = 1.18; LV replacement fibrosis: HR = 6.26).

CONCLUSIONS

Our results highlight the importance of CMR in cardiovascular risk stratification.

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

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

Cardiac complications in thalassemia throughout the lifespan: Victories and challenges

Thalassemias are among the most common hereditary diseases in the world because heterozygosity offers protection against malarial infection. Affected individuals have variable expression of alpha or beta chains that lead to their unbalanced utilization during hemoglobin formation, oxidative stress, and apoptosis of red cell precursors prior to maturation. Some individuals produce sufficient hemoglobin to survive but suffer the vascular stress imposed by chronic anemia and ineffective erythropoiesis. In other patients, mature red cell formation is insufficient, and chronic transfusions are required-suppressing anemia and ineffective erythropoiesis but at the expense of iron overload. The cardiovascular consequences of thalassemia have changed dramatically over the previous five decades because of evolving treatment practices. This review summarizes this evolution, focusing on complications and management pertinent to modern patient cohorts.

How I treat non-transfusion-dependent β-thalassemia

The intricate interplay of anemia and iron overload under the pathophysiological umbrella of ineffective erythropoiesis in non-transfusion-dependent β-thalassemia (NTDT) results in a complex variety of clinical phenotypes that are challenging to diagnose and manage. In this article, we use a clinical framework rooted in pathophysiology to present 4 common scenarios of patients with NTDT. Starting from practical considerations in the diagnosis of NTDT, we delineate our strategy for the longitudinal care of patients who exhibit different constellations of symptoms and complications. We highlight the use of transfusion therapy and novel agents, such as luspatercept, in the patient with anemia-related complications. We also describe our approach to chelation therapy in the patient with iron overload. Although tackling every specific complication of NTDT is beyond the scope of this article, we touch on the management of the various morbidities and multisystem manifestations of the disease.

Non-Transfusion-Dependent Thalassemia: A Panoramic Review

Non-transfusion-dependent thalassemia (NTDT) has been considered less severe than its transfusion-dependent variants. The most common forms of NTDT include β-thalassemia intermedia, hemoglobin E/beta thalassemia, and hemoglobin H disease. Patients with NTDT develop several clinical complications, despite their regular transfusion independence. Ineffective erythropoiesis, iron overload, and hypercoagulability are pathophysiological factors that lead to morbidities in these patients. Therefore, an early and accurate diagnosis of NTDT is essential to ascertaining early interventions. Currently, several conventional management options are available, with guidelines suggested by the Thalassemia International Federation, and novel therapies are being developed in light of the advancement of the understanding of this disease. This review aimed to increase clinicians’ awareness of NTDT, from its basic medical definition and genetics to its pathophysiology. Specific complications to NTDT were reviewed, along with the risk factors for its development. The indications of different therapeutic options were outlined, and recent advancements were reviewed.

Thalassemia Intermedia: Chelator or Not?

Thalassemia is the most common genetic disorder worldwide. Thalassemia intermedia (TI) is non-transfusion-dependent thalassemia (NTDT), which includes β-TI hemoglobin, E/β-thalassemia and hemoglobin H (HbH) disease. Due to the availability of iron chelation therapy, the life expectancy of thalassemia major (TM) patients is now close to that of TI patients. Iron overload is noted in TI due to the increasing iron absorption from the intestine. Questions are raised regarding the relationship between iron chelation therapy and decreased patient morbidity/mortality, as well as the starting threshold for chelation therapy. Searching all the available articles up to 12 August 2022, iron-chelation-related TI was reviewed. In addition to splenectomized patients, osteoporosis was the most common morbidity among TI cases. Most study designs related to ferritin level and morbidities were cross-sectional and most were from the same Italian study groups. Intervention studies of iron chelation therapy included a subgroup of TI that required regular transfusion. Liver iron concentration (LIC) ≥ 5 mg/g/dw measured by MRI and ferritin level > 300 ng/mL were suggested as indicators to start iron chelation therapy, and iron chelation therapy was suggested to be stopped at a ferritin level ≤ 300 ng/mL. No studies showed improved overall survival rates by iron chelation therapy. TI morbidities and mortalities cannot be explained by iron overload alone. Hypoxemia and hemolysis may play a role. Head-to-head studies comparing different treatment methods, including hydroxyurea, fetal hemoglobin-inducing agents, hypertransfusion as well as iron chelation therapy are needed for TI, hopefully separating β-TI and HbH disease. In addition, the target hemoglobin level should be determined for β-TI and HbH disease.

Eligibility criteria for pediatric patients who may benefit from anti SARS-CoV-2 monoclonal antibody therapy administration: an Italian inter-society consensus statement

The fast diffusion of the SARS-CoV-2 pandemic have called for an equally rapid evolution of the therapeutic options.The Human recombinant monoclonal antibodies (mAbs) have recently been approved by the Food and Drug Administration (FDA) and by the Italian Medicines Agency (AIFA) in subjects aged ≥12 with SARS-CoV-2 infection and specific risk factors.Currently the indications are specific for the use of two different mAbs combination: Bamlanivimab+Etesevimab (produced by Eli Lilly) and Casirivimab+Imdevimab (produced by Regeneron).These drugs have shown favorable effects in adult patients in the initial phase of infection, whereas to date few data are available on their use in children.AIFA criteria derived from the existing literature which reports an increased risk of severe COVID-19 in children with comorbidities. However, the studies analyzing the determinants for progression to severe disease are mainly monocentric, with limited numbers and reporting mostly generic risk categories.Thus, the Italian Society of Pediatrics invited its affiliated Scientific Societies to produce a Consensus document based on the revision of the criteria proposed by AIFA in light of the most recent literature and experts' agreement.This Consensus tries to detail which patients actually have the risk to develop severe disease, analyzing the most common comorbidities in children, in order to detail the indications for mAbs administration and to guide the clinicians in identifying eligible patients.

Doppler-defined pulmonary hypertension in β-thalassemia major in Kurdistan, Iraq

Cardiopulmonary complications are among the most important complications of thalassemia major. Pulmonary hypertension is among these complications and studies addressing its frequency and associations in the latter disorder are sparse from Iraq. For this purpose a total 100 thalassemia major patients (≥ 8 years old) were enrolled from a main thalassemia center in Kurdistan, Northern Iraq. All patients had a full history and clinical examination. Full blood count, biochemical tests and viral screen including hepatitis B surface antigen and hepatitis C virus antibody, in addition to transthoracic Doppler echocardiography for tricuspid regurgitation jet velocity (TRV). The enrolled patients had a mean (SD) age of 17.6 (5.5) years, and included 52 males and 48 females. Pulmonary hypertension as defined by TRV> 2.8 m/s coupled with both exertional dyspnea and an absence of left sided heart failure, was identified in nine patients (9%). The latter subgroup of patients had significantly higher reticulocyte counts, S. LDH, S. ferritin, and hepatitis C sero-positivity compared to those without this complication by univariate analysis. While by multivariate logistic regression only reticulocytes and hepatitis C sero-positivity remained significant. Furthermore, TRV as a continuous variable was positively correlated with reticulocytes, S. bilirubin and LDH (p<0.001, p = 0.002 and p<0.001 respectively), but not with age or S. ferritin (p = 0.77, and p = 0.93 respectively). In conclusion, pulmonary hypertension is not uncommon in Iraqi patients with thalassemia major, and it appears to be linked to chronic hemolysis rather than iron overload.

The improvement of pulmonary artery pressure after bosentan therapy in patients with β-thalassemia and Doppler-defined pulmonary arterial hypertension

Introduction

Pulmonary arterial hypertension (PAH) is relatively prevalent in patients with thalassemia. PAH treatment is necessary as the prevalence of Doppler-estimated PAH and the resultant mortality is high in such patients.

Materials and methods

This study aimed at evaluating the effect of bosentan therapy on patients with thalassemia suspected of PAH. Based on pulsed Doppler echocardiography, all the cases were suspected of severe PAH. Consequently, bosentan was initiated at a dose of 62.5 mg twice a day for 4 weeks, which was increased to 62.5–125 mg twice a day, if no adverse side effects were observed.

Results

The results of this study showed that pulmonary artery pressure (PAP) decreased after the administration of bosentan in three cases, from 160 to 120, 110 to 65, and 60 to 25 mmHg; in other words, the PAP reduced in the mentioned cases by 25%, 36.4%, and 58.4%, respectively.

Conclusion

In this study, PAP improved after bosentan therapy in patients with β-thalassemia suspected of PAH; however, further studies are required to confirm the findings.

How I manage medical complications of β-thalassemia in adults

The complex pathophysiology in β-thalassemia can translate to multiple morbidities that affect every organ system. Improved survival due to advances in management means that patients are exposed to the harmful effects of ineffective erythropoiesis, anemia, and iron overload for a longer duration, and we started seeing new or more frequent complications in adult compared with younger patients. In this article, we highlight particular aspects of managing adult patients with β-thalassemia, using our own experience in treating such patients. We cover both transfusion-dependent and nontransfusion-dependent forms of the disease and tackle specific morbidities of highest interest.

A prospective analysis for prevalence of complications in Thai nontransfusion-dependent Hb E/β-thalassemia and α-thalassemia (Hb H disease)

Recently, complications in patients with nontransfusion-dependent thalassemia (NTDT), in particular those with β-thalassemia intermedia (β-TI), were found to be significantly different from those in patients with transfusion dependent thalassemia (TDT), mainly β-thalassemia major (β-TM). However, this information is rather limited in other forms of NTDT. In this prospective study, adult Thai NTDT patients were interviewed and clinically evaluated for thalassemia related complications. Fifty-seven NTDT patients (age 18-74 years), 59.6% Hb E/β-thalassemia and 40.4% Hb H disease, were recruited; 26.4% were splenectomized. The most common complications were gallstones (68.4%), osteoporosis (26.3%), and pulmonary hypertension (15.8%). Splenectomy was associated with higher rate of gallstones and serious infection (P = .001 and .052, respectively), consistent with a multivariate analysis (RR = 9.5, P = .044, and RR = 15.1, P = .043, respectively). In addition, a higher hemoglobin level was inversely associated with gallstones in both univariate and multivariate analyses (P = .01 and .022, respectively). Serum ferritin was associated with abnormal liver function (P = .002). In contrast to the previous study, the prevalence of thrombosis was less common in our population (1.7%), probably due to differences in transfusion therapy, ethnicity, and underlying genotypes. For the first time, this prospective study provided the current prevalence of NTDT related complications in a Southeast Asian population with a different underlying genetic basis compared with previous studies. Although individual prevalence of each complication might differ from other studies, several important clinical factors such as splenectomy, degree of anemia, and iron overload seem to be determining risks of developing these complications consistently across different ethnicities.

Non-Transfusion-Dependent Thalassemia: An Update on Complications and Management

Patients with non-transfusion-dependent thalassemia (NTDT) experience many clinical complications despite their independence from frequent transfusions. Morbidities in NTDT stem from the interaction of multiple pathophysiological factors: ineffective erythropoiesis, iron overload (IOL), and hypercoagulability. Ineffective erythropoiesis and hemolysis are associated with chronic hypoxia and a hypercoagulable state. The latter are linked to a high prevalence of thromboembolic and cerebrovascular events, as well as leg ulcers and pulmonary hypertension. IOL in NTDT patients is a cumulative process that can lead to several iron-related morbidities in the liver (liver fibrosis), kidneys, endocrine glands (endocrinopathies), and vascular system (vascular disease). This review sheds light on the pathophysiology underlying morbidities associated with NTDT and summarizes the mainstays of treatment and some of the possible future therapeutic interventions.

Whole-exome sequencing identifies an α-globin cluster triplication resulting in increased clinical severity of β-thalassemia

Whole-exome sequencing (WES) has been increasingly useful for the diagnosis of patients with rare causes of anemia, particularly when there is an atypical clinical presentation or targeted genotyping approaches are inconclusive. Here, we describe a 20-yr-old man with a lifelong moderate-to-severe anemia with accompanying splenomegaly who lacked a definitive diagnosis. After a thorough clinical workup and targeted genetic sequencing, we identified a paternally inherited β-globin mutation (HBB:c.93-21G>A, IVS-I-110:G>A), a known cause of β-thalassemia minor. As this mutation alone was inconsistent with the severity of the anemia, we performed WES. Although we could not identify any relevant pathogenic single-nucleotide variants (SNVs) or small indels, copy-number variant (CNV) analyses revealed a likely triplication of the entire α-globin cluster, which was subsequently confirmed by multiplex ligation-dependent probe amplification. Treatment and follow-up was redefined according to the diagnosis of β-thalassemia intermedia resulting from a single β-thalassemia mutation in combination with an α-globin cluster triplication. Thus, we describe a case where the typical WES-based analysis of SNVs and small indels was unrevealing, but WES-based CNV analysis resulted in a definitive diagnosis that informed clinical decision-making. More generally, this case illustrates the value of performing CNV analysis when WES is otherwise unable to elucidate a clear genetic diagnosis.

Revisiting beta thalassemia intermedia: past, present, and future prospects

BACKGROUND

The spectrum of thalassemias is wide ranging from thalassemia minor, which consists of mild hypochromic microcytic anemia without obvious clinical manifestations, to thalassemia major (TM), which is characterized by severe anemia since the first years of life and is transfusion dependent. Thalassemia intermedia (TI) describes those patients with mild or moderate anemia.

OBJECTIVE

To describe the genetic features and major clinical complications of TI, and the therapeutic approaches available in the management of this disease.

METHODS

Publications from potentially relevant journals were searched on Medline.

RESULTS AND DISCUSSION

Over the past decade, the understanding of TI has increased with regard to pathophysiology and molecular studies. It is now clear that clinical presentation and specific complications make TI different from TM. It is associated with greater morbidity, a wider spectrum of organ dysfunction and more complications than previously thought.

CONCLUSION

TI is not a mild disease. The interplay of three hallmark pathophysiologic factors (ineffective erythropoiesis, chronic anemia, and iron overload) leads to the clinical presentations seen in TI. New treatment modalities are currently being investigated to broaden the options available for TI management.

Current Standards of Care and Long Term Outcomes for Thalassemia and Sickle Cell Disease

Thalassemia and sickle cell disease (SCD) are disorders of hemoglobin that affect millions of people worldwide. The carrier states for these diseases arose as common, balanced polymorphisms during human history because they afforded protection against severe forms of malaria. These complex, multisystem diseases are reviewed here with a focus on current standards of clinical management and recent research findings. The importance of a comprehensive, multidisciplinary and lifelong system of care is also emphasized.

Non-Transfusion-Dependent Thalassaemia: A Panoramic Survey from Pathophysiology to Treatment

Non-transfusion-dependent thalassaemia (NTDT) is a rather broad term that encompasses a group of thalassaemia syndromes, most commonly β-thalassaemia intermedia, haemoglobin E/β-thalassemia, and α-thalassaemia intermedia (haemoglobin H disease). Importantly, these entities do not require regular blood transfusions for survival, and therefore have transfusion independence. Clinical morbidities associated with the NTDTs are the end result of the culmination of three principal pathophysiological aberrancies: ineffective erythropoiesis, chronic anaemia (and associated haemolysis), and iron overload. Such complications involve multiple organs and organ systems; hence, the importance of prompt identification of at-risk individuals and holistic management of diagnosed subjects can never be overstated. Several management options, both medical and surgical, remain at the disposal of involved clinicians, with a significant body of data favouring the virtue of iron chelation therapy, fetal haemoglobin induction, and treatment with blood transfusions, the latter only when absolutely indicated, with reservation of splenectomy to a few select cases. Yet, a better understanding of the molecular phenomena at the origin of the disease process in the NTDT syndromes calls for a pressing need to explore novel therapeutic modalities, in light of the increasing incidence of NTDT in the developed world.

Comparing the Efficacy of Tadalafil Versus Placebo on Pulmonary Artery Systolic Pressure and Right Ventricular Function in Patients with Beta-Thalassaemia Intermedia

BACKGROUND

Conventional oral therapies in the management of pulmonary hypertension in people without haemoglobinopathies are of limited value in thalassaemia patients because of toxicity and poor effectiveness. This study was conducted to assess the effect of tadalafil on pulmonary artery pressure and right ventricular systolic function in patients with beta-thalassaemia intermedia.

METHODS

Forty-four patients with beta-thalassaemia intermedia with pulmonary hypertension based on transthoracic echocardiography (TTE) were entered in the study. Patients with hepatic or renal insufficiency and also patients who were treated with organic nitrates or alpha-blockers were excluded. The patients were randomly divided into two groups (n=22) and they were treated for six weeks with tadalafil (40mg daily) or placebo. The pulmonary artery systolic pressure (PASP), tricuspid regurgitation velocity (TRV) and parameters related to systolic function of the right ventricle were measured by the TTE before and after treatment.

RESULTS

Significant improvement in TRV (3.02±0.02 m/s-2.52±0.06 m/s), PASP (45.31±0.66 mmHg-34.26±1.15mmHg) and parameters related to systolic function of the right ventricle were observed in the group who received tadalafil compared to placebo (p< 0.05).

CONCLUSIONS

Tadalafil significantly decreased PASP and TRV in patients with beta-thalassaemia intermedia. Likewise, tadalafil improved right ventricular systolic function in the patients.

Platelet haemostatic properties in β-thalassaemia: the effect of blood transfusion

BACKGROUND

Patients with thalassaemia may have thromboembolic events and, even without thrombosis, they have a subclinical hypercoagulable state. In this setting, several coagulation laboratory abnormalities have been described, but thus far no studies have explored the contribution of platelet adhesive and procoagulant properties to blood clotting activation. In this study, we dissected the platelet procoagulant effect and influence of blood transfusions on haemostasis and platelet function in thalassaemic patients.

MATERIAL AND METHODS

Sixteen subjects with thalassaemia were studied (9 with transfusion-dependent β-thalassaemia, 7 "trait" carriers). Splenectomised and non-splenectomised patients undergoing blood transfusion were compared. All splenectomised patients were then compared to "trait" carriers and to healthy controls (n=9). The following parameters were measured in transfusion-dependent patients before and after monthly transfusions and compared to those of controls: levels of platelet surface activation markers (P-selectin, tissue factor, and fibrinogen), whole blood platelet aggregation, tissue factor or adenosine diphosphate (ADP)-induced platelet thrombin generation (TG) potential, and D-dimer.

RESULTS

Before transfusion, platelets from splenectomised patients showed significantly higher ADP-induced tissue factor expression, ADP- and collagen-induced platelet aggregation and TG potential than those from non-splenectomised patients and controls. Blood transfusion in splenectomised patients reduced platelet activation, aggregation and TG potential.

DISCUSSION

Splenectomised patients with β-thalassaemia had a prothrombotic state, characterised by enhanced platelet reactivity and function, and high platelet-induced TG potential. One hour after blood transfusions platelet and coagulation parameters improved, supporting the hypothesis that transfusion might have a protective role on platelet haemostatic status.

Exome sequencing results in successful diagnosis and treatment of a severe congenital anemia

Whole-exome sequencing is increasingly used for diagnosis and identification of appropriate therapies in patients. Here, we present the case of a 3-yr-old male with a lifelong and severe transfusion-dependent anemia of unclear etiology, despite an extensive clinical workup. Given the difficulty of making the diagnosis and the potential side effects from performing interventions in patients with a congenital anemia of unknown etiology, we opted to perform whole-exome sequencing on the patient and his parents. This resulted in the identification of homozygous loss-of-function mutations in the EPB41 gene, encoding erythrocyte protein band 4.1, which therefore causes a rare and severe form of hereditary elliptocytosis in the patient. Based on prior clinical experience in similar patients, a surgical splenectomy was performed that resulted in subsequent transfusion independence in the patient. This case illustrates how whole-exome sequencing can lead to accurate diagnoses (and exclusion of diagnoses where interventions, such as splenectomy, would be contraindicated), thereby resulting in appropriate and successful therapeutic intervention—a major goal of precision medicine.

Evaluation of the Relationship Between Hb F Levels and Nucleated Red Blood Cells with Morbidity in Non Transfusion-Dependent Thalassemia Patients

Recognition of risk factors of morbidities in patients with β-thalassemia intermedia (β-TI) is an important issue that must be evaluated. Non transfusion-dependent thalassemia patients referred to the outpatient clinic of Shiraz University of Medical Science, Shiraz, South Iran were enrolled in this study between 2013 and 2014. Two peripheral blood smears were prepared for evaluating developmental stage of normoblasts. One hundred and thirty-one patients with ages ranging from 3 to 42 years (mean: 23.35 ± 7.9) were selected. Sixty-seven patients had at least one morbidity (51.1%). Osteoporosis and gallstones were the most common morbidities (33.6 and 24.4%, respectively). In the univariate model, hemoglobin (Hb), ferritin, Hb F, developmental stage of normoblasts and hydroxyurea (HU) therapy did not differ between patients with and without morbidity (p > 0.05) but mean age of patients and mean number of normoblasts were higher in patients with morbidity (p = 0.026 and p = 0.012, respectively). In the regression model, sex and splenectomy status were different between patients with and without morbidity. It seems that females and splenectomy are risk factors for morbidity in non transfusion-dependent thalassemia patients. [Sex: odds ratio (OR) = 2.21, 95% confidence interval (95% CI): 1.04-4.72, p = 0.39. Splenectomy: OR = 3.10, 95% CI: 1.12-8.59, p = 0.029.] This study shows that Hb F level and developmental stage of normoblasts does not effect the incidence of morbidities in non transfusion-dependent thalassemia patients but sex and splenectomy were effective factors in development of morbidities. Thus, splenectomy should be avoided as much as possible in patients with non transfusion-dependent thalassemia.

Prevalence and Risk Factors for Complications in Patients with Nontransfusion Dependent Alpha- and Beta-Thalassemia

Background. Nontransfusion dependent thalassemia (NTDT) is a milder form of thalassemia that does not require regular transfusion. It is associated with many complications, which differ from that found in transfusion-dependent thalassemia (TDT). Currently available information is mostly derived from beta-NTDT; consequently, more data is needed to describe complications found in the alpha-NTDT form of this disease. Methods. We retrospectively reviewed the medical records of NTDT patients from January 2012 to December 2013. Complications related to thalassemia were reviewed and compared. Results. One hundred patients included 60 females with a median age of 38 years. The majority (54 patients) had alpha-thalassemia. Overall, 83 patients had one or more complications. The three most common complications were cholelithiasis (35%), abnormal liver function (29%), and extramedullary hematopoiesis (EMH) (25%). EMH, cardiomyopathy, cholelithiasis, and pulmonary hypertension were more commonly seen in beta-thalassemia. Osteoporosis was the only complication that was more common in alpha-thalassemia. The risk factors significantly related to EMH were beta-thalassemia type and hemoglobin < 8 g/dL. The risk factors related to osteoporosis were female gender and age > 40 years. Iron overload (ferritin > 800 ng/mL) was the only risk factor for abnormal liver function. Conclusion. The prevalence of alpha-NTDT complications was lower and different from beta-thalassemia.

Dysregulated arginine metabolism and cardiopulmonary dysfunction in patients with thalassaemia

Pulmonary hypertension (PH) commonly develops in thalassaemia syndromes, but is poorly characterized. The goal of this study was to provide a comprehensive description of the cardiopulmonary and biological profile of patients with thalassaemia at risk for PH. A case-control study of thalassaemia patients at high versus low PH-risk was performed. A single cross-sectional measurement for variables reflecting cardiopulmonary status and biological pathophysiology were obtained, including Doppler-echocardiography, 6-min-walk-test, Borg Dyspnoea Score, New York Heart Association functional class, cardiac magnetic resonance imaging (MRI), chest-computerized tomography, pulmonary function testing and laboratory analyses targeting mechanisms of coagulation, inflammation, haemolysis, adhesion and the arginine-nitric oxide pathway. Twenty-seven thalassaemia patients were evaluated, 14 with an elevated tricuspid-regurgitant-jet-velocity (TRV) ≥ 2·5 m/s. Patients with increased TRV had a higher frequency of splenectomy, and significantly larger right atrial size, left atrial volume and left septal-wall thickness on echocardiography and/or MRI, with elevated biomarkers of abnormal coagulation, lactate dehydrogenase (LDH) levels and arginase concentration, and lower arginine-bioavailability compared to low-risk patients. Arginase concentration correlated significantly to several echocardiography/MRI parameters of cardiovascular function in addition to global-arginine-bioavailability and biomarkers of haemolytic rate, including LDH, haemoglobin and bilirubin. Thalassaemia patients with a TRV ≥ 2·5 m/s have additional echocardiography and cardiac-MRI parameters suggestive of right and left-sided cardiac dysfunction. In addition, low arginine bioavailability may contribute to cardiopulmonary dysfunction in β-thalassaemia.

Pulmonary arterial hypertension in a patient with β-thalassemia intermedia and reversal with infusion epoprostenol then transition to oral calcium channel blocker therapy: review of literature

Pulmonary arterial hypertension (PAH) is a potentially life-threatening complication of thalassemia. A sexagenarian with β-thalassemia intermedia presented with new-onset dyspnea and syncope. Right heart catheterization confirmed severe PAH. Her functional class IV symptoms and severely elevated mean pulmonary artery pressure prompted the initiation of continuous epoprostenol therapy. Clinical follow-up documented significant improvement in functional class, 6-minute walk distance, and right ventricular size and function as well as pulmonary arterial pressure on echocardiogram. At the patient's request, epoprostenol was down-titrated and eventually discontinued. The patient was then safely transitioned to nifedipine therapy after verification of vasoresponsiveness.

Non-Transfusion Dependent Thalassemia: Translating Evidence to Guidelines

The thalassemias are a group of inherited disorders of hemoglobin synthesis characterized by various degrees of defective production of the α- or β-globin chains of adult hemoglobin A. Non-transfusion- dependent thalassemia (NTDT) includes a group of thalassemia patients who do not require regular RBC transfusions for survival, but may require occasional transfusions due to infection or pregnancy or may require more regular transfusions later in life due to splenomegaly or other complications. Due to the rising phenomenon of global migration, this previously well-localized entity is currently spreading more and more worldwide reaching Northern America and Northern Europe. The clinical picture of NTDT is governed by the severity of the ineffective erythropoiesis and the chronic hemolytic anemia, which, in turn, lead to iron overload, hypercoagulability, and an array of clinical complications involving almost every organ system. Patients with NTDT suffer from complications that are distinct from those encountered in patients with transfusion- dependent thalassemia (TDT) in addition to the complications shared by both TDT and NTDT. As a consequence, patients with NTDT deserve a care specifically tailored to their needs. In the care of patients with NTDT, aiming at a standardized yet personalized care is not an easy task especially that NTDT patients lie on a heterogeneous spectrum with a wide variability in their clinical presentation and response to therapy. Therefore, guidelines emerge as a necessity to answer the specific needs of NTDT patients and the clinicians caring for them. In this article, we summarize the complications most commonly associated with NTDT and the recommendations of the guidelines for the management of patients with NTDT, based on the best available evidence.

Guidelines for diagnosis and management of Beta-thalassemia intermedia

Beta-thalassemia intermedia (β-TI) is a genetic variant of beta-thalassemias with a clinical disorder whose severity falls between thalassemia minor and thalassemia major. Different genetic defects are involved in this disorder and, based on severity of disease, clinical complications like skeletal deformities and growth retardation, splenomegaly, extramedullary hematopoiesis, heart failure, and endocrine disorders may be present in untreated patients. Precise diagnosis and management are essential in these patients for prevention of later clinical complications. Diagnosis of TI is based on clinical and laboratory data. There are some treatment strategies like modulation of gamma-globulin chain production with hydroxyurea or other drugs, transfusion, splenectomy, and stem cell transplantation. Iron chelation therapy is also needed in many of these patients even if they are not transfused. The aim of this manuscript is to review the clinical manifestations, complications, genetic defects, and unmet treatments needs in TI.

A thalassaemia intermedia case with concomitant left atrial thrombus

Although marked improvements have been observed in the life expectancy of patients with thalassaemia by regular blood transfusion and strict iron chelation therapies in recent years, these patients still have to deal with several complications, mainly cardiovascular. One of the life-threatening complications is the chronic hypercoagulable state and thromboembolic events which develop due to haemostatic alterations in patients with thalassaemia, although they are more frequently seen in those with thalassaemia intermedia. Many thromboembolic complications, mainly deep venous thrombosis and cerebral thrombosis, have been reported in thalassaemia. However, intracardiac thrombosis is rarely seen. In this manuscript, we presented a case that underwent splenectomy 6 years ago but not regularly attended the control visits and presented to our clinic with gradually increasing exercise dyspnoea for 2 months.

Elevated tricuspid regurgitant jet velocity in subgroups of thalassemia patients: insight into pathophysiology and the effect of splenectomy

A high tricuspid regurgitant jet velocity (TRV) signifies a risk for or established pulmonary hypertension (PH), which is a serious complication in thalassemia patients. The underlying pathophysiology in thalassemia subgroups and potential biomarkers for early detection and monitoring are not well defined, in particular as they relate to spleen removal. To better understand some of these unresolved aspects, we examined 76 thalassemia patients (35 non-transfused), 25 splenectomized non-thalassemia patients (15 with hereditary spherocytosis), and 12 healthy controls. An elevated TRV (>2.5 m/s) was found in 25/76 (33 %) of the patients, confined to non-transfused or those with a late start of transfusions, including patients with hemoglobin H-constant spring, a finding not previously described. These non or late-transfused patients (76 % splenectomized) had significantly increased platelet activation (sCD40L), high platelet count, endothelial activation (endothelin-1), and hemolysis (LDH, plasma-free Hb), while hypercoagulable and inflammatory markers were not significantly increased. The same markers were increased in the seven patients with confirmed PH on cardiac catheterization, suggesting their possible role for screening patients at risk for PH. A combination of hemolysis and absence of spleen is necessary for developing a high TRV, as neither chronic hemolysis in the non-splenectomized thalassemia patients nor splenectomy without hemolysis, in the non-thalassemia patients, resulted in an increase in TRV.

β -thalassemia intermedia in Northern Iraq: a single center experience

To investigate the molecular basis of β-thalassemia intermedia in Northern Iraq and evaluate its management practices, a total of 74 patients from 51 families were enrolled. The patients were clinically and hematologically reevaluated, and had their β-thalassemia mutations characterized, as well as the number of α-globin genes and Xmn I ^Gγ −158 (C>T) polymorphism studied. Out of 14 β-thalassemia mutations identified, the four most common were IVS-I-6 (T>C) [33.3%], IVS-II-I (G>A) [21.1%], codon 82/83(−G) [10.1%], and codon 8 (−AA) [8.1%]. The most common contributing factors to the less severe phenotype of thalassemia intermedia were found to be the inheritance of mild β-thalassemia alleles and the Xmn I polymorphism, while concomitant α-thalassemia had a limited role. Several complications were documented including: pulmonary hypertension in 20.4%, diabetes mellitus in 1.4%, hypothyroidism in 2.9%, and heart failure in 2.7%, while no documented cases of venous thrombosis were found. Compared to their counterparts in several Mediterranean countries, it appears that our patients were much less frequently transfused and had a lower proportion of patients who were splenectomized, on iron chelation, or hydroxycarbamide therapy. Such practices require further scrutiny to ensure that a better level of care is provided and that growth retardation, skeletal changes, and other complications are prevented or reduced.

Effect of genotype on pulmonary hypertension risk in patients with thalassemia

INTRODUCTION

Pulmonary hypertension is one of the major complications in patients with non-transfusion-dependent thalassemia (NTDT). Patients with NTDT have distinct genetic subgroups. Therefore, the effects of different genotype groups on pulmonary hypertension risk in patients with NTDT were assessed.

METHODS

A cross-sectional study was conducted in patients with NTDT aged ≥ 10 yr old at Srinagarind University Hospital and Udonthani Hospital, Thailand. Pulmonary hypertension risk was defined as peak tricuspid regurgitation velocity > 2.9 m/s by trans-thoracic echocardiography. Clinical characteristics and laboratory data that literature has indicated as risk factors for pulmonary hypertension were collected. The effect of genotype group on pulmonary hypertension risk was evaluated by using multivariate logistic regression analysis.

RESULTS

Of 219 patients, pulmonary hypertension risk was found in 24 patients (10.96%). All patients were categorized into two groups according to genetic data that included: (i) β-thalassemia (139, 63.5%), (ii) α-thalassemia and combined α and β-thalassemia (80, 36.5%). Genotype groups were statistically and significantly associated with pulmonary hypertension risk based on the adjusted odds ratios after adjustment for other factors. Patients with β-thalassemia had a statistically significant higher risk for pulmonary hypertension risk (odds ratio = 9.47, P = 0.036) compared to patients with α-thalassemia and patients with combined α and β-thalassemia.

CONCLUSION

The genotype group is an independent risk factor for pulmonary hypertension in patients with NTDT. Echocardiography should be routinely recommended for all patients with β-thalassemia. Routine screening in patients with α-thalassemia and combined α and β-thalassemia, however, may not be necessary or should focus on the older population.

Prevalence and risk factors for pulmonary hypertension in patients with hemoglobin E/β-thalassemia disease

OBJECTIVES

To find the prevalence and risk factors of pulmonary hypertension (PHT) in adult patients with hemoglobin E/β-thalassemia disease (E/β-Thal).

METHODS

One hundred and ten clinically stable E/β-Thal outpatients, sixty-one of whom had undergone splenectomy, were prospectively studied using their clinical profiles, selected blood tests, chest roentgenogram, and transthoracic echocardiogram. Based on the pulmonary artery systolic pressure (PASP) values estimated by the echocardiogram of ≥36 mmHg, they were dichotomized into those with (PHT+) and without (PHT-) PHT.

RESULTS

PHT was found in 41 (37.3%) patients without gender preponderance. It was not due to the left heart and was not severe (PASP = 46.3 ± 10.4 mmHg). PASP was higher in splenectomized patients (48.0 ± 11 vs. 40.3 ± 4.7 mmHg (P = 0.004)). PHT was found in 32 of 61 (52.5%) splenectomized patients, mostly (53%) in the second decade, and rarely (6.3%) during the first 5 yr after splenectomy. PHT+ patients had more hemolysis (P = 0.001-0.04 depending on the parameters), more asplenic cases (P < 0.001), and higher serum soluble vascular cell adhesion molecule-1 (sVCAM-1) and high-sensitivity C-reactive protein levels (P = 0.004 and 0.008, respectively). Strong risk factors by univariate analysis were serum sVCAM-1 levels ≥1600 ng/mL, serum cell-free Hb ≥ 3 mg/dL, asplenia, and amount of NRBCs/100 WBCs >40.

CONCLUSIONS

Prevalence of PHT in E/β-Thal patients was 37.3% without gender preponderance. Those with severe hemolysis and asplenia invariably had severer PHT. Strong risk factors were asplenia and associated markedly elevated values of sVCAM-1, cell-free Hb, and NRBCs in blood.

Non-transfusion-dependent thalassemias

Non-transfusion-dependent thalassemias include a variety of phenotypes that, unlike patients with beta (β)-thalassemia major, do not require regular transfusion therapy for survival. The most commonly investigated forms are β-thalassemia intermedia, hemoglobin E/β-thalassemia, and α-thalassemia intermedia (hemoglobin H disease). However, transfusion-independence in such patients is not without side effects. Ineffective erythropoiesis and peripheral hemolysis, the hallmarks of disease process, lead to a variety of subsequent pathophysiologies including iron overload and hypercoagulability that ultimately lead to a number of serious clinical morbidities. Thus, prompt and accurate diagnosis of non-transfusion-dependent thalassemia is essential to ensure early intervention. Although several management options are currently available, the need to develop more novel therapeutics is justified by recent advances in our understanding of the mechanisms of disease. Such efforts require wide international collaboration, especially since non-transfusion-dependent thalassemias are no longer bound to low- and middle-income countries but have spread to large multiethnic cities in Europe and the Americas due to continued migration.

Iron overload in β-thalassemia intermedia: an emerging concern

PURPOSE OF REVIEW

The aim is to overview recent evidence on consequences, assessment, and management of iron overload in transfusion-independent patients with β-thalassemia intermedia.

RECENT FINDINGS

Despite their transfusion-independence, β-thalassemia intermedia patients can still accumulate iron due to increased intestinal absorption. Recent observational studies show that iron burden in this group of patients can ultimately reach considerably high thresholds, and leads to a variety of serious morbidities involving the liver, endocrine glands, and arguably the vascular system. The diagnosis of iron overload in this patient population can follow established guidelines from β-thalassemia major patients, although with careful interpretation of spot serum ferritin levels. Data from a recent randomized clinical trial demonstrated the efficacy and safety of iron chelation therapy in decreasing liver iron concentration in this group of patients, which may ultimately help in reducing morbidity risk.

SUMMARY

Iron overload in transfusion-independent patients with β-thalassemia intermedia deserves careful attention, and prompt diagnosis and management are recommended.

Pulmonary hypertension in β thalassaemia

Pulmonary hypertension is one of the leading causes of morbidity and mortality in patients with haemolytic disorders and is a frequent finding in echocardiographic screening of patients with β thalassaemia. Substantial progress has been made in understanding of the multifactorial pathophysiology of pulmonary hypertension in β thalassaemia. Haemolysis, reduced nitric oxide bioavailability, iron overload, and hypercoagulopathy are among the main pathogenetic mechanisms. Various disease-directed therapeutic methods, such as transfusion, chelation, and splenectomy, have important roles in the development of pulmonary hypertension in β thalassaemia. Studies investigating the prevalence of pulmonary hypertension in β thalassaemia are mostly based on echocardiographic findings, and are thus limited by the scarcity of information derived from right heart catheterisation. Invasive pulmonary haemodynamic data are needed to clarify the true prevalence of pulmonary hypertension in β thalassaemia, to better understand the underlying pathophysiology and risk factors, and to define the optimum therapy for this devastating complication.

Pulmonary hypertension risk in patients with hemoglobin h disease: low incidence and absence of correlation with splenectomy

Pulmonary hypertension (PHT) is a common complication for patients with β thalassemia intermediate (TI), especially splenectomized patients. However, the frequency and risk factors of PHT in patients with hemoglobin H (HbH) disease is unknown. The purpose of this study was to identify the prevalence of PHT risk manifested as tricuspid regurgitant jet velocity (TRV) ≥2.5 m/s in patients with HbH disease and its correlation with splenectomy. One hundred and ninety-eight patients with HbH disease who visited the 303rd Hospital of the People's Liberation Army (Nanning, China) were investigated. Thirteen subjects (6.5%) were diagnosed as having a risk of PHT. Regression analyses showed that the prevalence of PHT risk was correlated only with age (r = 0.195, p = 0.006) and not with splenectomy. The risk of PHT in patients older than 35 years was 5.7 times (range 1.8-18.6) greater than that for patients younger than 35 years. For splenectomized patients compared to those with HbH disease, patients with TI had a higher frequency of PHT risk, higher nucleated red blood cell counts (46.03 ± 41.11 × 10(9)/l vs. 0.18 ± 1.19 × 10(9)/l, p < 0.001) and a higher platelet counts (837.6 ± 178.9 × 10(9)/l vs. 506.7 ± 146.2 × 10(9)/l, p < 0.001). PHT risk is low in patients with HbH disease and does not correlate with splenectomy. Patients older than 35 years should be monitored regularly.

Sildenafil therapy in thalassemia patients with Doppler-defined risk of pulmonary hypertension

Pulmonary hypertension is a common but often overlooked complication associated with thalassemia syndromes. There are limited data on the safety and efficacy of selective pulmonary vasodilators in this at-risk population. We, therefore, designed a 12-week, open-label, phase 1/2, pilot-scale, proof-of-principle trial of sildenafil therapy in 10 patients with β-thalassemia and at increased risk of pulmonary hypertension based on an elevated tricuspid regurgitant jet velocity >2.5 m/s on Doppler-echocardiography. Variables compared at baseline and after 12 weeks of sildenafil treatment included Doppler-echocardiographic parameters, 6-minute walked distance, Borg Dyspnea Score, New York Heart Association functional class, pulmonary function, and laboratory parameters. Treatment with sildenafil resulted in a significant decrease in tricuspid regurgitant jet velocity by 13.3% (3.0±0.7 versus 2.6±0.5 m/s, P=0.04), improved left ventricular end systolic/diastolic volume, and a trend towards a improved New York Heart Association functional class. No significant change in 6-minute walked distance was noted. Sildenafil was well tolerated, although minor expected adverse events were commonly reported. The total dose of sildenafil (mg) was strongly correlated with percent change in nitric oxide metabolite concentration in the plasma (ρ=0.80, P=0.01). There were also significant increases in plasma and erythrocyte arginine concentrations. Our study suggests that sildenafil is safe and may improve pulmonary hemodynamics in patients at risk of pulmonary hypertension; however, it was not demonstrated to improve the distance walked in 6 minutes. Clinical trials are needed to identify the best treatment strategy for pulmonary hypertension in patients with β-thalassemia. (clinicaltrials.gov identifier: NCT00872170).

β-thalassemia intermedia: a clinical perspective

Our understanding of the molecular and pathophysiological mechanisms underlying the disease process in patients with β-thalassemia intermedia has substantially increased over the past decade. Earlier studies observed that patients with β-thalassemia intermedia experience a clinical-complications profile that is different from that in patients with β-thalassemia major. In this article, a variety of clinical morbidities are explored, and their associations with the underlying disease pathophysiology and risk factors are examined. These involve several organs and organ systems including the vasculature, heart, liver, endocrine glands, bone, and the extramedullary hematopoietic system. The effects of some therapeutic interventions on the development of clinical complications are also discussed.