Thalassemia and hypercoagulability

Acute bone infarction: a rare complication in thalassemia

Acute bone infarction is a well-described complication in sickle cell hemoglobinopathy but it is rarely reported in patients with thalassemia. This report describes an 18-year-old man with homozygous β-thalassemia presenting with a fever and severe acute bilateral ankle pain. The acute onset of severe pain and fever were clinical mimics of infectious arthritis and osteomyelitis. Magnetic resonance imaging revealed acute bone infarction in the meta-diaphysis of bilateral tibias presenting as central unenhanced devitalized bone with T1-high signal intensity fluid in the subperiosteum and soft tissue. Characteristic imaging features are discussed, emphasizing the benefit of fat suppression pre-and post-intravenous gadolinium T1-weighted images. The etiologies of bone infarction in thalassemia are reviewed.

Analysis of the genetic variants associated with recurrent thromboembolism in a patient with hemoglobin H disease following splenectomy: A case report

Reports of recurrent thromboembolism in thalassemia, particularly in hemoglobin H (HbH) disease associated with congenital thrombophilic mutations, are scarce. However, several mutations were detected in a 22-year-old woman with HbH disease. The patient experienced the first thrombotic event at the age of 20 years and had four recurrent thromboses in a short time interval, despite receiving anticoagulant treatment. The present study reports a case with six nucleotide substitutions, including a missense 565C>T (Arg189Trp) mutation and two synonymous mutations, 66T>C (Pro22Pro) and 423G>T (Ser141Ser), identified in the protein C gene. The other three mutations, 947G>A (Arg316His), 981A>G (Val327Val), and 775C>A (rs13146272), were identified in the protein S, antithrombin and cytochrome P450, family 4, subfamily V, polypeptide 2 genes, respectively. These findings suggest that if thrombotic events repeatedly occur in a patient with thalassemia, not only the risk factors associated with a hypercoagulable state, but the acquired and congenital thrombophilia should be screened for.

β-thalassemia patients and gynecological approach: review and clinical experience

Significant improvements in therapy and life expectancy of β-thalassemia patients in last decades result in the need of commitment for gynecologists and obstetricians as the complexity of organ impairment needs a specific multidisciplinary approach. After a review of clinical manifestations of β-thalassemia from a gynecologic point of view, we present the experience of a gynecologic center in treating β-thalassemia patients from more than 20 years.

The frequency of silent cerebral ischemia in patients with transfusion-dependent β-thalassemia major

The aim of this study is to determine the frequency of silent cerebral ischemia (SCI) in a group of patients with β-thalassemia major and correlate them with demographic parameters, blood and spleen status, volume and frequency of transfusions. In this cross-sectional study, 40 β-thalassemic patients over 10 years old who had no neurologic deficit were studied. Brain MRI was performed to detect SCI. Silent cerebral ischemia was classified according to number and size. Silent cerebral ischemia was found in 15 patients (37.5 %). Mean number of SCI was 6.73 ± 10.33 (1-40), and mean size of the brain lesions was 3.07 ± 2.81 mm (1-11 mm). The patients with SCI were significantly older (31.1 ± 6.5 vs. 25 ± 6.8 years, P = 0.009), and most of them were splenectomized (80% vs. 36 %, P = 0.01). Interestingly, 10 out of 15 patients with SCI had platelet count less than 500,000/mm(3). Eight of these patients (80 %) were splenectomized. Other variables had no statistically significant association with the presence of SCI. Older age and splenectomized multitransfused β-thalassemic patients even with normal platelet count have a higher incidence of SCI. The effect of splenectomy is more significant in statistical analysis. In splenectomized patients with a high platelet count and even with normal platelet count, aspirin therapy is indicated. Based on the results, it seems that regular blood transfusions are not going to have a significant effect on the number and size of SCI.

The simultaneous occurrence of both hypercoagulability and hypofibrinolysis in blood and serum during systemic inflammation, and the roles of iron and fibrin(ogen)

Although the two phenomena are usually studied separately, we summarise a considerable body of literature to the effect that a great many diseases involve (or are accompanied by) both an increased tendency for blood to clot (hypercoagulability) and the resistance of the clots so formed (hypofibrinolysis) to the typical, 'healthy' or physiological lysis. We concentrate here on the terminal stages of fibrin formation from fibrinogen, as catalysed by thrombin. Hypercoagulability goes hand in hand with inflammation, and is strongly influenced by the fibrinogen concentration (and vice versa); this can be mediated via interleukin-6. Poorly liganded iron is a significant feature of inflammatory diseases, and hypofibrinolysis may change as a result of changes in the structure and morphology of the clot, which may be mimicked in vitro, and may be caused in vivo, by the presence of unliganded iron interacting with fibrin(ogen) during clot formation. Many of these phenomena are probably caused by electrostatic changes in the iron-fibrinogen system, though hydroxyl radical (OH˙) formation can also contribute under both acute and (more especially) chronic conditions. Many substances are known to affect the nature of fibrin polymerised from fibrinogen, such that this might be seen as a kind of bellwether for human or plasma health. Overall, our analysis demonstrates the commonalities underpinning a variety of pathologies as seen in both hypercoagulability and hypofibrinolysis, and offers opportunities for both diagnostics and therapies.

Effect of acetylsalicylic acid on thalassemia with pulmonary arterial hypertension

OBJECTIVE

To compare pulmonary artery systolic pressure (PASP) between thalassemic patients with pulmonary arterial hypertension (PAH) for whom acetylsalicylic acid (ASA) was and was not prescribed after 1 year.

METHODS

A retrospective cohort study was conducted at the hematological outpatient clinic at Chiang Rai Hospital, Chiang Rai, Thailand. All new cases of thalassemia with PAH from January 2007 to January 2012 were studied at the first month and at 12 months. The patients were classified into two groups. In one group, ASA 81 mg daily was prescribed for 1 year, whereas in another group no ASA was prescribed, due to its contraindications, which included bleeding, gastrointestinal side effects, and thrombocytopenia. PASP, estimated by a Doppler echocardiography, was measured by the same cardiologist. Propensity score adjustment was used to control confounding variables by indication and contraindication. Multivariable regression analysis was used to evaluate the effects of ASA.

RESULTS

Of the 63 thalassemia patients with PAH, there were 47 (74.6%) in the ASA group and 16 (25.4%) in the no ASA group. ASA, as compared with no ASA, did not significantly reduce PASP (adjusted difference -0.95; 95% confidence interval -16.99 to 15.10; P=0.906).

CONCLUSION

Low-dose ASA may not have a beneficial effect on PASP after 1 year of treatment of PAH in thalassemia.

Gene therapy for hemoglobinopathies: the state of the field and the future

After nearly two decades of struggle, gene therapy for hemoglobinopathies using vectors carrying β or γ-globin gene has finally reached the clinical doorsteps. This was made possible by advances made in our understanding of critical regulatory elements required for high level of globin gene expression and improved gene transfer vectors and methodologies. Development of gene editing technologies and reprogramming somatic cells for regenerative medicine holds the promise of genetic correction of hemoglobinopathies in the future. This article will review the state of the field and the upcoming technologies that will allow genetic therapeutic correction of hemoglobinopathies.

The hypercoagulable status in common Mediterranean β-thalassaemia mutations trait

INTRODUCTION

The coagulation activation in β-thalassaemia is multifactorial and most likely a consequence of the exposure of phosphatidylserine (PS) on RBCs surface. The degree of PS exposure and procoagulant activity of RBCs in β-thalassaemia trait (BTT) subjects carrying common Mediterranean mutations were assessed.

METHODS

Eighty BTT subjects carrying common Mediterranean mutations (β+, n = 53 and β0 , n = 27) and sixty healthy subjects served as controls were studied. Plasma prothrombin fragment 1+2 (F1+2), percentage of PS expression on RBCs membrane, clotting times of modified thromboplastin generation test (MTGT) and modified partial thromboplastin with kaolin (MPTTK) were estimated.

RESULTS

The percentage of annexin V positive RBCs and plasma F1+2 had a significant increase and MTGT had a significant decrease in BTT subjects versus controls and in β0 group versus β+ group. MPTTK was significantly shorter in BTT subjects than controls, but no significant deference between BTT subjects. The percentage of annexin V positive RBCs showed a significant negative correlation with haemoglobin level, MTGT and MPTTK, and a significant positive correlation with plasma F1+2.

CONCLUSION

BTT subjects may have a risk of hypercoagulable state particularly in β0 genotype. Measurement of PS exposure on RBCs and the plasma F1+2 is useful to evaluate hypercoagulability state.

Benefits of chronic blood transfusion in hemoglobin E/β thalassemia with pulmonary arterial hypertension

Objective

The aim of the research reported here was to compare pulmonary artery systolic pressure (PASP) and 6-minute walk distance after 1 year of follow-up in hemoglobin E/β thalassemia (E/β-Thal) with pulmonary arterial hypertension (PAH) patients who received chronic blood transfusions versus those who received occasional transfusions.

Methods

A nonrandomized clinical trial was conducted at the Hematological Outpatient Clinic of Chiang Rai Hospital, Thailand. All adult cases of E/β-Thal with PAH (defined as PASP >35 mmHg by Doppler echocardiography) were evaluated and followed for the next 12 months. The patients were classified into two groups by patient preference. Group 1 patients received chronic blood transfusions – one to two units of leukocyte-poor packed red cells every 2–4 weeks – over 1 year to maintain pre-transfusion hemoglobin levels of ≥7.0 g/dL. Group 2 patients received occasional transfusions over the course of 1 year, with more than 4 weeks between transfusions. All patients were treated with iron chelation when serum ferritin levels were ≥1,000 μg/dL. PASP and the 6-minute walk distance were evaluated at baseline and at 6 and 12 months. Propensity score adjustment was used to control for confounding by indication and contraindication. Multivariable regression analysis was used to evaluate the effects of chronic blood transfusion.

Results

There were 16 (53.3%) patients in Group 1 and 14 (46.7%) in Group 2. At 12 months, patients in Group 1 had a greater reduction in PASP than those in Group 1 (adjusted mean difference, −16.83; 95% confidence interval, −26.35 to −7.32; P=0.001). The 6-minute walk distance at 12 months in Group 1 patients was greater than that in Group 2 patients (adjusted mean difference, 46.55; 95% confidence interval, 18.08 to 75.02; P=0.001).

Conclusion

This study found evidence that chronic blood transfusions may have beneficial effects in PAH in thalassemia patients over 1 year.

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.

Thromboelastometry profile in children with beta-thalassemia

Beta (β)-thalassemia is characterized by a hypercoagulable state and an increased risk of thrombosis, which can result in significant morbidity and mortality. The coagulation pattern and determinants of thrombosis in patients with β-thalassemia remain largely unknown. The aim of this study was to evaluate the whole blood thromboelastometry (TEM) profile of β-thalassemic children by ROTEM(®). ROTEM(®) assays (INTEM, EXTEM) and traditional coagulation parameters (platelet count, prothrombin time, activated partial thromboplastin time, and fibrinogen) were performed on blood samples from 17 subjects with β-thalassemia and 19 non-thalassemic controls. Maximum clot firmness (MCF) was significantly higher in subjects with β-thalassemia than in controls on EXTEM and INTEM analysis (p < 0.001 and p < 0.001, respectively). Of the patients with β-thalassemia, MCF was higher and clot formation time was shorter in splenectomized subjects than in non-splenectomized subjects on EXTEM and INTEM (p = 0.026, p = 0.002, p < 0.001, p < 0.001, respectively). TEM profiles in β-thalassemic children were more hypercoagulable compared with controls. Larger prospective studies are needed to evaluate the relevance of the association between ROTEM(®) profile and thromboembolic events in patients with β-thalassemia.

Harvesting autologous stem cells from a patient with red blood cell abnormalities of β-thalassemia intermedia

BACKGROUND

Autologous stem cell transplants in patients with hemoglobinopathies are limited. Previous reports used granulocyte-colony-stimulating factor (G-CSF) for mobilization of stem cells; there are no reported cases undergoing plerixafor mobilization. We report such a patient, providing guidance for peripheral blood stem cells collection when aberrant red blood cells (RBCs) disrupt normal separation.

STUDY DESIGN AND METHODS

A patient with β-thalassemia intermedia and hereditary persistence of fetal hemoglobin presented for peripheral blood stem cell collection for autologous transplant for myeloma. He underwent splenectomy for anemia secondary to hemoglobinopathy and chemotherapy, ceasing RBC transfusions. The patient was mobilized using plerixafor after collection with G-CSF failed.

RESULTS

Collections were performed using an apheresis system, processing 24 L daily. Peripheral blood and apheresis product CD34 determinations were performed daily. On Day 1, the product yield was 0.04 × 10(6) CD34 cells/kg, less than expected based on white blood cell count and CD34-positive cells. Peripheral blood smear showed nucleated RBCs and RBC morphologic abnormalities. Changes in instrument variables were made after consultation with Terumo BCT to adjust for variable distribution of mononuclear and stem cells during centrifugation. Collecting stem cells at a deeper location and centrifuging faster improved collection, and a cumulative total of 4.40 × 10(6) CD34 cells/kg was achieved after four collections. The patient underwent tandem autologous transplantation and engrafted within 12 to 13 days of each transplant.

CONCLUSIONS

Adjustments in apheresis variables allowed successful collection of peripheral blood stem cells from a patient with RBC anomalies of β-thalassemia that interfered with standard stem cell harvesting.

Morphologically homogeneous red blood cells present a heterogeneous response to hormonal stimulation

Red blood cells (RBCs) are among the most intensively studied cells in natural history, elucidating numerous principles and ground-breaking knowledge in cell biology. Morphologically, RBCs are largely homogeneous, and most of the functional studies have been performed on large populations of cells, masking putative cellular variations. We studied human and mouse RBCs by live-cell video imaging, which allowed single cells to be followed over time. In particular we analysed functional responses to hormonal stimulation with lysophosphatidic acid (LPA), a signalling molecule occurring in blood plasma, with the Ca²⁺ sensor Fluo-4. Additionally, we developed an approach for analysing the Ca²⁺ responses of RBCs that allowed the quantitative characterization of single-cell signals. In RBCs, the LPA-induced Ca²⁺ influx showed substantial diversity in both kinetics and amplitude. Also the age-classification was determined for each particular RBC and consecutively analysed. While reticulocytes lack a Ca²⁺ response to LPA stimulation, old RBCs approaching clearance generated robust LPA-induced signals, which still displayed broad heterogeneity. Observing phospatidylserine exposure as an effector mechanism of intracellular Ca²⁺ revealed an even increased heterogeneity of RBC responses. The functional diversity of RBCs needs to be taken into account in future studies, which will increasingly require single-cell analysis approaches. The identified heterogeneity in RBC responses is important for the basic understanding of RBC signalling and their contribution to numerous diseases, especially with respect to Ca²⁺ influx and the associated pro-thrombotic activity.

Flow cytometric assessment of circulating platelet and erythrocytes microparticles in young thalassemia major patients: relation to pulmonary hypertension and aortic wall stiffness

Heart disease is the leading cause of mortality and morbidity in β-thalassemia major (β-TM). Aggregability of abnormal red cells and membrane-derived microparticles (MPs) stemming from activated platelets and erythrocytes are responsible for thrombotic risk. We measured platelet and erythrocyte MPs (PMPs and ErMPs) in 60 young β-TM patients compared with 40 age- and sex-matched healthy controls and assessed their relation to clinicopathological characteristics and aortic elastic properties. Patients were studied stressing on transfusion history, splenectomy, thrombotic events, chelation therapy, hematological and coagulation profiles, flow cytometric measurement of PMPs (CD41b(+) ) and ErMPs (glycophorin A(+) ) as well as echocardiographic assessment of aortic elastic properties. Aortic stiffness index and pulmonary artery pressure were significantly higher, whereas aortic strain and distensibility were lower in TM patients than controls (P < 0.001). Both PMPs and ErMPs were significantly elevated in TM patients compared with controls, particularly patients with risk of pulmonary hypertension, history of thrombosis, splenectomy or serum ferritin >2500 μg/L (P < 0.001). Compliant patients on chelation therapy had lower MPs levels than non-compliant patients (P < 0.001). PMPs and ErMPs were positively correlated to markers of hemolysis, serum ferritin, D-dimer, vWF Ag, and aortic stiffness, whereas negatively correlated to hemoglobin level and aortic distensibility (P < 0.05). We suggest that increased MPs may be implicated in vascular dysfunction, pulmonary hypertension risk, and aortic wall stiffness observed in thalassemia patients. Their quantification could provide utility for early detection of cardiovascular abnormalities and monitoring the biological efficacy of chelation therapy.

Cause of deep venous thrombosis and pulmonary embolism in young patients from India as compared with other ethnic groups

Venous thromboembolism (VTE), which consists of deep vein thrombosis (DVT) and pulmonary embolism, is a potentially fatal disease. The existing Asian literature has shown a wide variation in the prevalence of VTE, with very limited data from India. In the present study, the risk factors for VTE in Indian patients were compared with Caucasians and Blacks. We used data prospectively collected from total of 1396 Indian patients (716 males, 680 females) enrolled over a decade and compared with White (n = 2002) and Black (n = 395) patients objectively diagnosed with VTE. When compared with females, males had significantly higher episodes of pulmonary embolism and VTE (P = 0.0001). Amongst the known thrombophilia markers, only homocysteine was found to be significantly higher in males as compared with females (P = 0.006). Males had a higher proportion of rheumatic heart disease (RHD) and ischaemic heart disease (IHD) as compared with females. The prevalence of DVT amongst Indians was significantly higher as compared with Whites and Blacks. However, the rate of pulmonary embolism and VTE was lower in Indians as compared with both the races. Amongst the baseline characteristics identified as risk factors for VTE, Indians had a higher prevalence of infection as compared to both Whites and Blacks, but lower HIV infection as compared to Blacks. As compared to Whites, Indians had lower prevalence of idiopathic VTE (but similar to blacks) and had higher prevalence of idiopathic pulmonary embolism (P < 0.0001). This can be explained by different inherited and environment risk factors between these three populations.

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.

D-dimer and portal vein status in splenectomized Egyptian β-thalassemia major patients: a prospective single-thalassemia center experience

Splenectomy is a recognized cause of portal vein thrombosis. Thirty-six β-thalassemia major (β-TM) patients were followed up for 36 months to evaluate changes in D-dimer levels (as a possible marker for thrombosis development) and portal vein status (by portal duplex ultrasound) at both early and late postlaparoscopic splenectomy periods. They were classified into group I if they were splenectomized in the study period (n = 12), or group II if they were splenectomized during the 5 years preceding the period (n = 24). In group I, D-dimer was measured 5 times: 1 day presplenectomy, the 1st week, 6th week, and 6th month postsplenectomy, and at the study end, whereas in group II, D-dimer was measured twice: at the study entry and end. Portal duplex was done 1 week postsplenectomy (group I) and at study end in both groups. Presplenectomy D-dimer levels in group I were significantly higher compared with the 6th month (P = .042) and study end (P = .03), whereas 1st week (postsplenectomy) D-dimer levels had a high mean of 3497.3 ng/mL, lowered at the 6th week (P = .017), at the 6th month (P = .008), and at study end (P = .005). D-dimer levels in group II showed no difference between study entry and end (P = .104). Portal vein "diameter and flow" were within normal findings in both groups. In this 3-year prospective study, a subclinical hypercoagulable state was detected 1 day prior to splenectomy and in the early postsplenectomy period, as evidenced by high D-dimer levels. Laparoscopic splenectomy was not associated with portal venous thrombosis either clinically or by duplex sonography.

Intracranial Blood Flow Velocity in Patients with β-Thalassemia Intermedia Using Transcranial Doppler Sonography: A Case-Control Study

Introduction. Patients with β-thalassemia intermedia have a higher incidence of thromboembolic events compared to the general population. Previous studies have shown that patients with sickle cell disease, who are also prone to ischemic events, have higher intracranial arterial blood flow velocities measured by transcranial Doppler sonography (TCD). The aim of this study is to evaluate intracranial arterial flow velocities in patients with β-thalassemia intermedia and compare the results with those found in healthy subjects. Methods. Sixty-four patients with β-thalassemia intermedia and 30 healthy subjects underwent transcranial Doppler sonography. Results. Significantly higher flow velocities were found in intracranial arteries of patients compared to controls (P = 0.001). Previously splenectomized patients with thrombocytosis showed higher flow velocities than nonsplenectomized patients without thrombosis. Conclusion. The increased flow velocities in patients with β-thalassemia intermedia may point to a higher risk of ischemic events. Preventive measures such as blood transfusion or antiplatelet treatment may be beneficial in these patients.

Clinicopathological and radiological study of Egyptian β-thalassemia intermedia and β-thalassemia major patients: relation to complications and response to therapy

The clinico epidemiological characteristics, frequency of complications, and response to various therapeutic modalities in 80 Egyptian β-thalassemia intermedia (β-TI) patients were compared with 70 β-thalassemia major (β-TM) patients. β-Thalassemia intermedia patients had a higher incidence of left atrium dilatation, right ventricular dilatation and pulmonary hypertension, whereas, β-TM patients showed a higher incidence of left ventricular (LV) dilatation, restrictive LV filling and impaired LV contractility, with an overall higher incidence of heart disease (p <0.001). Short stature, delayed puberty, osteoporosis, bone fractures, diabetes mellitus and viral hepatitis was frequently observed in β-TM patients compared with β-TI patients (p <0.05). Administration of hydroxyurea (HU) alone was associated with significant improvement in hematological parameters and quality of life for β-TI patients. In conclusion, the risk of complications still burdens the life of Egyptian thalassemia patients and their frequency varies between β-TI and β-TM. We provide evidence that calls for the use of HU in β-TI patients.

Hematopoietic stem cell mobilization for gene therapy of adult patients with severe β-thalassemia: results of clinical trials using G-CSF or plerixafor in splenectomized and nonsplenectomized subjects

The safety and efficacy of hematopoietic stem cell (HSC) mobilization was investigated in adult splenectomized (SPL) and non-SPL patients with thalassemia major, in two clinical trials, using different mobilization modes: granulocyte-colony-stimulating factor (G-CSF)-alone, G-CSF following pretreatment with hydroxyurea (HU), plerixafor-alone. G-CSF-mobilization was both safe and effective in non-SPL patients. However, in SPL patients the procedure resulted in excessive response to G-CSF, expressed as early hyperleukocytosis necessitating significant dose reduction, and suboptimal CD34(+) cells yields. One-month HU-pretreatment prevented hyperleukocytosis and allowed successful CD34(+) cell collections when an optimal washout period was maintained, but it significantly prolonged the mobilization procedure. Plerixafor resulted in rapid and effective mobilization in both SPL and non-SPL patients and was well-tolerated. For gene therapy of thalassemia, G-CSF or Plerixafor could be used as mobilization agents in non-SPL patients whereas Plerixafor appears to be the mobilization agent of choice in SPL adult thalassemics in terms of safety and efficacy.

Major risk of blood transfusion in hemolytic anemia patients

Thalassemia is a congenital hemolytic disease caused by defective globin synthesis treated by blood transfusion. Transfusion-transmitted infections still make a great challenge in the management of patients with thalassemia major. The most important worldwide transfusion-transmitted infections are hepatitis B virus (HBV), hepatitis C virus (HCV) and HIV. The objective of this study is to update the prevalence of the three major transfusion-transmitted infections HCV, HBV and HIV among thalassemic patients followed up in the Hematology Department, Children Hospital, Cairo University. The study included 174 multitransfused thalassemic patients (162 major and 12 intermedia), registered at the Pediatric Hematology Clinic, Cairo University. Their age ranged from 2 to 27 years with a mean of 11.26 ± 5.4 years. Patients were subjected to full history taking, stressing on history of blood transfusions (onset, frequency and duration) at a single or multiple centers and abdominal examination. Laboratory investigations including complete blood count, aminotransferases (aspartate aminotransferase and alanine aminotransferase), ferritin and viral markers of HBV surface antigen (HBsAg), HCV antibodies (anti-HCV) and anti-HIV were assayed for all cases by a third-generation ELISA method. HCV PCR was performed for 75 cases. Of the 174 patients, none of them were HBsAg and anti-HIV positive. However, 90 patients were anti-HCV positive (51.7%). HCV PCR was positive in 56 patients (74.3%) of the 75 with positive antibody tested. HCV antibody positivity is statistically significant with age of the patient, serum ferritin and liver transaminases (P < 0.01). HCV-RNA by PCR positivity was significantly related to patients' age and serum ferritin (P < 0.05). Serum ferritin showed statistically significant positive correlation with liver transaminases. Despite the decrease in prevalence of HCV antibody in our patients from 71% in 1995 to 51.7% in our study, yet HCV infection still represents a major health problem for our thalassemic patients, which requires more attention and efforts to challenge. There is a dramatic decrease in the prevalence of HBV infection over the last decade, thanks to mass compulsory vaccination and blood screening. HIV infection does not represent a problem owing to very low population prevalence.

Thrombosis in thalassemia: why are we so concerned?

Although life expectancy of thalassemia patients has markedly improved over the last few decades, patients still suffer from many complications of this congenital disease. The presence of a high incidence of thromboembolic events (TEE), mainly in β-thalassemia intermedia (β-TI), has led to the identification of a hypercoagulable state in these patients. In this review, the molecular and cellular mechanisms leading to hypercoagulability in thalassemia are highlighted, with a special focus on thalassemia intermedia being the group with the highest incidence of thrombotic events as compared to other types of thalassemia. Clinical experience and available clues on optimal management are also discussed.

Complications of β-thalassemia intermedia in Iran during 1996-2010 (single-center study)

Patients with thalassemia intermedia (TI) experience many complications, of which the incidence varies greatly among cases. Considering the high prevalence of thalassemia in Iran, the study was carried out to determine the frequency of TI complications in Iranian patients and to find possible risk factors for each of them. Using the sampling method of "census," the authors included 153 patients who were seen in their tertiary hematology clinic with the diagnosis of TI during 1996-2010; an analytical cross-sectional study was performed and the data was analyzed by SPSS software using univariate and regression analyses. Mean age of the patients at the time of the study was 17.4 years and 36.5% were receiving transfusions (regularly or occasionally). Mean hemoglobin was 9.2 g/dL and mean serum ferritin was 858 ng/mL. Splenectomy was performed in 46.9% and it was correlated with age and the age at diagnosis in regression analysis. Cholelithiasis was found in 25.5% and was correlated with age and history of splenectomy. Pulmonary hypertension, detected in 23.5%, was correlated with thrombocytosis and mitral valve regurgitation in univariate analysis. Endocrine disease (hypogonadism, hypothyroidism, and adrenal insufficiency) was detected in 8% of the patients. In univariate analysis, endocrine disease was correlated with age of the patients. Regarding bone density of the spine, 53% of cases had osteoporosis. Thrombocytosis was present in 42% of patients and was correlated with their age. Since the severity of thalassemia intermedia vary greatly among patients, a careful evaluation of clinical, laboratory, and genetic aspects is necessary to differentiate TI in a patient at presentation. Moreover, TI patients should be carefully followed up for early detection and management of newly developed complications. The authors also suggest confirmatory controlled studies with larger sample sizes to assist in developing guidelines for surveillance and treatment of TI.

β-thalassemia: a model for elucidating the dynamic regulation of ineffective erythropoiesis and iron metabolism

β-thalassemia is a disease characterized by anemia and is associated with ineffective erythropoiesis and iron dysregulation resulting in iron overload. The peptide hormone hepcidin regulates iron metabolism, and insufficient hepcidin synthesis is responsible for iron overload in minimally transfused patients with this disease. Understanding the crosstalk between erythropoiesis and iron metabolism is an area of active investigation in which patients with and models of β-thalassemia have provided significant insight. The dependence of erythropoiesis on iron presupposes that iron demand for hemoglobin synthesis is involved in the regulation of iron metabolism. Major advances have been made in understanding iron availability for erythropoiesis and its dysregulation in β-thalassemia. In this review, we describe the clinical characteristics and current therapeutic standard in β-thalassemia, explore the definition of ineffective erythropoiesis, and discuss its role in hepcidin regulation. In preclinical experiments using interventions such as transferrin, hepcidin agonists, and JAK2 inhibitors, we provide evidence of potential new treatment alternatives that elucidate mechanisms by which expanded or ineffective erythropoiesis may regulate iron supply, distribution, and utilization in diseases such as β-thalassemia.

Thalassemia and venous thromboembolism

Although the life expectancy of thalassemia patients has markedly improved over the last few decades, patients still suffer from many complications of this congenital disease. The presence of a high incidence of thromboembolic events, mainly in thalassemia intermedia, has led to the identification of a hypercoagulable state in these patients. In this review, the molecular and cellular mechanisms leading to hypercoagulability in thalassemia are highlighted, with a special focus on thalassemia intermedia being the group with the highest incidence of thrombotic events as compared to other types of thalassemia. Clinical experience and available clues on optimal management are also discussed.

Stimulation of human red blood cells leads to Ca2+-mediated intercellular adhesion

Red blood cells (RBCs) are a major component of blood clots, which form physiologically as a response to injury or pathologically in thrombosis. The active participation of RBCs in thrombus solidification has been previously proposed but not yet experimentally proven. Holographic optical tweezers and single-cell force spectroscopy were used to study potential cell-cell adhesion between RBCs. Irreversible intercellular adhesion of RBCs could be induced by stimulation with lysophosphatidic acid (LPA), a compound known to be released by activated platelets. We identified Ca(2+) as an essential player in the signaling cascade by directly inducing Ca(2+) influx using A23187. Elevation of the internal Ca(2+) concentration leads to an intercellular adhesion of RBCs similar to that induced by LPA stimulation. Using single-cell force spectroscopy, the adhesion of the RBCs was identified to be approximately 100 pN, a value large enough to be of significance inside a blood clot or in pathological situations like the vasco-occlusive crisis in sickle cell disease patients.

Thalassemia trait and arterial thromboembolic events: a systematic review and a meta-analysis of the literature

BACKGROUND

An increased risk of venous thromboembolic events has been reported in thalassemic patients, in particular in patients with thalassemia intermedia. The association between β-thalassemia trait and atherothrombotic cardiovascular events is not well established.

METHODS

In a systematic review and meta-analysis of the literature, we evaluated the association between β-thalassemia trait and arterial cardiovascular disease. Studies were identified from the MEDLINE and EMBASE (until July 2010) electronic databases. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated with a random-effects model. Statistical heterogeneity was evaluated with the I(2) statistic.

RESULTS

Of the 354 identified articles, eight case-control studies were eligible for the analysis. β-Thalassemia trait was associated with a reduced risk of arterial cardiovascular disease (OR 0.45; 95% CI 0.45-0.60). Heterogeneity among studies was low (I(2) = 13%). The protective effect of β-thalassemia trait was confined to male patients (OR 0.39; 95% CI 0.24-0.62), and was not observed in female subjects (OR 0.89; 95% CI 0.52-1.53).

CONCLUSIONS

β-Thalassemia trait may act as a protective factor against the development of arterial cardiovascular and cerebrovascular disease in male subjects. Larger prospective studies are necessary to confirm these preliminary findings and to further investigate the mechanisms underlying this protective effect.

The surgeon and the patient with β-thalassaemia intermedia

Background

Unlike patients with β-thalassaemia major, where lifelong transfusion and iron chelation therapy are necessary for survival, patients with β-thalassaemia intermedia (TI) generally have a milder course and anaemia. The underlying pathophysiology of the disease still allows several complications to manifest. Surgical management during the course of the disease is common but relevant data from the literature have never been reviewed constructively. This aim of this review was to highlight this clinical entity to the surgeon, and ensure optimal and timely intervention.

Methods

The review was based on potentially relevant studies identified from an electronic search of MEDLINE and PubMed databases. There were no language or publication year restrictions. References in published articles were also reviewed.

Results

Surgical intervention is often essential to ensure optimal control of the associated morbidity in TI. Several general considerations are necessary before surgical intervention with regard to anaemia, cardiovascular disease, thromboembolic events and the effects of iron overload. Splenectomy, cholecystectomy, leg ulcers, fractures and extramedullary pseudotumours are the most commonly encountered surgical problems related to TI.

Conclusion

Awareness of TI and its associated morbidity is important so that appropriate preoperative care can occur.

Thalassemia intermedia is associated with a proatherogenic biochemical phenotype

OBJECTIVE

Unlike beta thalassemia major (β-TM) in which cardiac siderosis represents the leading cause of mortality and morbidity, in beta thalassemia intermedia (β-TI), pulmonary hypertension (PHT) and thrombosis seems to be the major cardiovascular complications. However, the mechanism underlying these complications in β-TI is still unclear. Endothelial dysfunction, the key early event in atherogenesis, is now emerging as an important cardiovascular risk determiner in β-TI patients. Among the factors known to affect endothelial function, iron and cholesterol merit particular consideration in β-TI patients. Therefore, with the aim to extend our knowledge on the mechanisms connecting atherosclerosis to β-TI, in this study, we compared lipid and iron metabolism in serum and in peripheral blood mononuclear cells (PBMCs) from β-TI and β-TM patients and controls.

METHODS AND RESULTS

In this study the iron status and the lipid profile in serum and in peripheral blood mononuclear cells (PBMCs) of 22 adult β-TI patients were examined, and compared with 70 adult β-TM, and 50 age-matched controls. Despite the great variability, levels of serum iron and transferrin saturation were significantly higher in β-TI compared to both controls and β-TM. By contrast, transferrin and hepcidin levels were lower in β-TI patients. Changes in serum indicators in β-TI patients were associated with altered expressions in PBMCs of hepcidin and IL-1α, involved in some way in the regulation of iron homeostasis. In addition β-TI exhibited a reduction of total and high density lipoprotein cholesterol in serum and of neutral cholesterol ester hydrolase in PBMCs, and an increase of cytoplasmic neutral lipids and mRNA levels of acetyl-coenzymeA:cholesterol acyltransferase.

CONCLUSIONS

Taken together, these findings provide experimental support for the idea that β-TI patients exhibit a proatherogenic biochemical phenotype which may contribute to enhance cardiovascular risk in these subjects.

Bone marrow as a source of hematopoietic stem cells for human gene therapy of β-thalassemia

β-Thalassemia is a severe inherited anemia caused by insufficient production of β-globin chains. Allogeneic hematopoietic stem cell (HSC) transplantation is currently the only cure, and is limited by donor availability and regimen-related toxicity and mortality. Gene therapy is a promising therapeutic tool for all thalassemic patients lacking a compatible donor and potentially provides transfusion independence in the absence of transplant-related complications, such as graft rejection and graft-versus-host disease. The issue of HSC procurement is critical in this setting because of the specific features of thalassemic syndromes, which include bone marrow (BM) expansion, ineffective erythropoiesis, and splenomegaly. Little is known about the efficiency of CD34(+) cell yield from steady-state BM harvests from thalassemic patients. We have collected data on safety and cell yield from 20 pediatric patients with β-thalassemia who underwent autologous BM harvest before allogeneic HSC transplantation, and from 49 age-matched sibling donors who also underwent BM harvest. The procedure was safe, as no significant adverse events occurred. In terms of cell yield, no difference was found between patients and normal donors in the number of CD34(+) cells and total nucleated cells harvested. Most importantly, no difference was found in the proportion of myeloid and erythroid progenitors, suggesting a similar repopulating capacity. On the basis of these results, we conclude that steady-state BM can be used as a safe and efficient source of HSC for gene therapy of β-thalassemia.

Reconstruction of the thumb with a modified wrap-around flap in a patient suffering from β-thalassemia minor

Thalassemia is a congenital hemolytic disorder caused by a partial or complete deficiency of α- or β-globin chain synthesis. It has been seen that thalassemic patients exhibit an increased frequency of thrombotic events. The article presents the first case of thumb reconstruction with a modified wrap-around flap in a patient suffering from β-thalassemia minor.

Correction of beta-thalassemia major by gene transfer in haematopoietic progenitors of pediatric patients

β-Thalassemia is a common monogenic disorder due to mutations in the β-globin gene and gene therapy, based on autologous transplantation of genetically corrected haematopoietic stem cells (HSCs), holds the promise to treat patients lacking a compatible bone marrow (BM) donor. We recently showed correction of murine β-thalassemia by gene transfer in HSCs with the GLOBE lentiviral vector (LV), expressing a transcriptionally regulated human β-globin gene. Here, we report successful correction of thalassemia major in human cells, by studying a large cohort of pediatric patients of diverse ethnic origin, carriers of different mutations and all candidates to BM transplantation. Extensive characterization of BM-derived CD34⁺ cells before and following gene transfer shows the achievement of high frequency of transduction, restoration of haemoglobin A synthesis, rescue from apoptosis and correction of ineffective erythropoiesis. The procedure does not significantly affect the differentiating potential and the relative proportion of haematopoietic progenitors. Analysis of vector integrations shows preferential targeting of transcriptionally active regions, without bias for cancer-related genes. Overall, these results provide a solid rationale for a future clinical translation.

Beta-globin mutations are associated with parenchymal siderosis and fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

Parenchymal liver siderosis is associated with increased fibrosis in patients with non-alcoholic fatty liver disease (NAFLD). The aim of this study was to assess whether a panel of genetic variants previously reported to influence iron metabolism, including the C282Y/H63D HFE, the PiZ/PiS alpha1-antitrypsin, the IVS1-24 ferroportin polymorphisms, and the beta-thalassemia trait, may be able to predict the presence of parenchymal siderosis and of progressive fibrosis in NAFLD.

METHODS

We considered 274 Italian patients with biopsy-proven NAFLD. Genetic polymorphisms were searched for by sequence allele specific-polymerase chain reaction and restriction analysis, whereas beta-trait was determined according to blood count and HbA(2) determination.

RESULTS

Parenchymal iron deposition was predominantly observed in 32 (11.7%) patients. Heterozygosity for the C282Y (OR 1.87, 95% CI 1.04-3.25), homozygosity for the H63D HFE (OR 2.31, 95% CI 1.04-4) mutations, and the beta-thalassemia trait (OR 2.57 95% CI 1.49-4.47) were all predominantly associated with parenchymal siderosis, independently of age, sex, body mass index, alcohol intake, ferritin, and transferrin saturation. Sixty-three percent of patients with hepatocellular siderosis were positive for at least one of the aforementioned genetic variants. The beta-thalassemia trait had the highest positive and the lowest negative likelihood ratios for predominantly parenchymal iron accumulation (5.05 and 0.74, respectively), and was independently associated with moderate/severe fibrosis (OR 2.50, 95% CI 1.26-5.19).

CONCLUSIONS

In patients with NAFLD, predominant hepatocellular iron deposition is often related to genetic factors, among which beta-globin mutations play a major role, predisposing to parenchymal iron accumulation and to progressive liver fibrosis.

Splenectomy and thrombosis: the case of thalassemia intermedia

BACKGROUND

 Hypercoagulability in splenectomized patients with thalassemia intermedia (TI) has been extensively evaluated. However, clinical and laboratory characteristics of patients who eventually develop overt thromboembolic events (TEE) are poorly studied.

PATIENTS/METHODS

 Three Groups of TI patients (n=73 each) were retrospectively identified from a registry involving six centers across the Middle East and Italy: Group I, all splenectomized patients with a documented TEE; Group II, age- and sex-matched splenectomized patients without TEE; and Group III, age- and sex-matched non-splenectomized patients without TEE. Retrieved data included demographics, laboratory parameters, clinical complications, and received treatments that may influence TEE development, and reflected the period prior to TEE occurrence in Group I.

RESULTS

 The mean age of Group I patients at development of TEE was 33.1±11.7years, with a male to female ratio of 33:40. TEE were predominantly venous (95%) while four patients (5%) had documented stroke. Among studied parameters, Group I patients were more likely to have a nucleated red blood cell (NRBC) count ≥300×10(6) L(-1) , a platelet count ≥500×10(9)  L(-1) and evidence of pulmonary hypertension (PHT), or be transfusion naïve. The median time to thrombosis following splenectomy was 8years. Patients with an NRBC count ≥300×10(6) L(-1) , a platelet count ≥500×10(9) L(-1) , or who were transfusion naive also had a shorter time to thrombosis following splenectomy.

CONCLUSION

 Splenectomized TI patients who will develop TEE may be identified early on by high NRBC and platelet counts, evidence of PHT, and transfusion naivety.

Iron metabolism and ineffective erythropoiesis in beta-thalassemia mouse models

beta-thalassemia is a disease associated with decreased beta-globin production leading to anemia, ineffective erythropoiesis, and iron overload. New mechanisms associated with modulation of erythropoiesis and iron metabolism have recently been discovered in thalassemic mice, improving our understanding of the pathophysiology of this disease. These discoveries have the potential to be translated into clinically-relevant therapeutic options to reduce ineffective erythropoiesis and iron overload. A new generation of therapies based on limiting ineffective erythropoiesis, iron absorption, and the correction of iron maldistribution could be on the way, possibly complementing and improving the current standard of patient care.

Redefining thalassemia as a hypercoagulable state

As the life expectancy of beta-thalassemia patients has markedly improved over the last decade, several new complications are being recognized. The presence of a high incidence of thromboembolic events, mainly in thalassemia intermedia patients, has led to the identification of a hypercoagulable state in thalassemia. In this review, the molecular and cellular mechanisms leading to hypercoagulability in thalassemia are highlighted, and the current clinical experience is summarized. Recommendations for thrombosis prophylaxis are also discussed.

Beta-thalassemia

Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta globin gene on chromosome 11, leading to reduced (beta⁺) or absent (beta⁰) synthesis of the beta chains of hemoglobin (Hb). Transmission is autosomal recessive; however, dominant mutations have also been reported. Diagnosis of thalassemia is based on hematologic and molecular genetic testing. Differential diagnosis is usually straightforward but may include genetic sideroblastic anemias, congenital dyserythropoietic anemias, and other conditions with high levels of HbF (such as juvenile myelomonocytic leukemia and aplastic anemia). Genetic counseling is recommended and prenatal diagnosis may be offered. Treatment of thalassemia major includes regular RBC transfusions, iron chelation and management of secondary complications of iron overload. In some circumstances, spleen removal may be required. Bone marrow transplantation remains the only definitive cure currently available. Individuals with thalassemia intermedia may require splenectomy, folic acid supplementation, treatment of extramedullary erythropoietic masses and leg ulcers, prevention and therapy of thromboembolic events. Prognosis for individuals with beta-thalassemia has improved substantially in the last 20 years following recent medical advances in transfusion, iron chelation and bone marrow transplantation therapy. However, cardiac disease remains the main cause of death in patients with iron overload.

Insight onto the pathophysiology and clinical complications of thalassemia intermedia

Our understanding of the molecular and pathophysiological mechanisms underlying the disease process in patients with thalassemia intermedia (TI) has substantially increased over the past decade. TI encompasses a wide clinical spectrum of beta-thalassemia phenotypes. Some TI patients are asymptomatic until adult life, whereas others are symptomatic from as young as 2 years. A number of clinical complications commonly associated with TI are rarely seen in thalassemia major, including extramedullary hematopoiesis, leg ulcers, gallstones, thrombosis, and pulmonary hypertension. There are a number of options currently available for managing patients with TI, including transfusion therapy, iron chelation therapy, modulation of fetal hemoglobin production, and hematopoietic stem cell transplantation. However, at present, there are no clear guidelines for an orchestrated optimal treatment plan.