New trends in the treatment of beta-thalassemia

Papillary Thyroid Carcinoma in a Pediatric Patient With β-Thalassemia

β-Thalassemia is characterized by the abnormal synthesis of β-hemoglobin chains resulting in hemolytic anemia. Treatment involves frequent blood transfusions, which leads to deposition of iron in many organs, including endocrine glands. To date, several cases of papillary thyroid cancer (PTC) in patients with β-thalassemia have been reported in the adult literature, but there have been none in pediatrics. Here we report on an female adolescent with β-thalassemia who initially presented for evaluation of secondary amenorrhea. On examination, her thyroid gland was asymmetric, firm in consistency, with palpable lymph nodes along the right anterior cervical chain. A thyroid ultrasound revealed an enlarged right lobe containing 3 focal hypoechoic masses with calcific foci. Biopsy was consistent with PTC. She underwent total thyroidectomy and histological examination confirmed the diagnosis. Her postoperative course was uncomplicated and she was started on replacement therapy with levothyroxine. This is the first reported case of PTC in a pediatric patient with β-thalassemia. The incidence of thyroid cancer in patients with β-thalassemia is currently unknown; however, there may be utility in routine surveillance of this patient population.

An Expert Overview on Therapies in Non-Transfusion-Dependent Thalassemia: Classical to Cutting Edge in Treatment

The thalassemia issue is a growing worldwide health concern that anticipates the number of patients suffering from the disease will soon increase significantly. Patients with β-thalassemia intermedia (β-TI) manifest mild to intermediate levels of anemia, which is a reason for it to be clinically located between thalassemia minor and β-thalassemia major (β-TM). Notably, the determination of the actual rate of β-TI is more complicated than β-TM. The leading cause of this illness could be partial repression of β-globin protein production; accordingly, the rate of β-globin gene repression is different in patients, and the gene repression intensity creates a different clinical status. This review article provides an overview of functional mechanisms, advantages, and disadvantages of the classic to latest new treatments for this group of patients, depending on the disease severity divided into the typical management strategies for patients with β-TI such as fetal hemoglobin (Hb) induction, splenectomy, bone marrow transplantation (BMT), transfusion therapy, and herbal and chemical iron chelators. Recently, novel erythropoiesis-stimulating agents have been added. Novel strategies are subclassified into molecular and cellular interventions. Genome editing is one of the efficient molecular therapies for improving hemoglobinopathies, especially β-TI. It encompasses high-fidelity DNA repair (HDR), base and prime editing, clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 procedure, nuclease-free strategies, and epigenetic modulation. In cellular interventions, we mentioned the approach pattern to improve erythropoiesis impairments in translational models and patients with β-TI that involve activin II receptor traps, Janus-associated kinase 2 (JAK2) inhibitors, and iron metabolism regulation.

Brain iron content and cognitive function in patients with β-thalassemia

Patients with β-thalassemia (β-TM) may have brain iron overload from long-term blood transfusions, ineffective erythropoiesis, and increased intestinal iron absorption, leading to cognitive impairment. Brain magnetic resonance imaging (MRI) methods such as the transverse relaxation rate, susceptibility-weighted imaging, and quantitative susceptibility mapping can provide quantitative, in vivo measurements of brain iron. This review assessed these MRI methods for brain iron quantification and the measurements for cognitive function in patients with β-TM. We aimed to identify the neural correlates of cognitive impairment, which should help to evaluate therapies for improving cognition and quality of life in patients with β-TM.

Relation of hepcidin gene expression in blood mononuclear cells with iron overload severity among β-thalassemia major patients

Iron overload is the main cause of morbidity and mortality in β-thalassemia major patients, and cardiac iron overload is the most common reason for death in these transfusion-dependent patients. Hepcidin, a liver-derived peptide hormone, plays a key role in plasma iron levels regulation by controlling two main stages, digestive iron absorption in enterocytes, and iron recycling in macrophages. Although hepcidin is mainly secreted from hepatocytes in the liver, it is also synthesized from mononuclear cells consisting of monocytes and lymphocytes. Binding of this molecule to ferroportin, a specific cellular exporter of iron, leads to degradation of the ligand-receptor complex, which reduces the iron overload by lowering the amounts of iron released into the plasma. Likewise, the same mechanism has been proved to be true for lymphocyte-drived hepcidin. The expression levels of hepcidin mRNA were evaluated using quantitative real time PCR (qRT-PCR) in 50 β-thalassemia major patients, as well as 25 healthy volunteers as the group of control. There was a significantly positive correlation between the cardiac iron concentration, showed by higher T2 values, and hepcidin levels in the patients (p = 0.028; r = 0.311). However, hepcidin expression levels did not significantly correlate with ferritin and liver iron concentrations. Hepcidin can act as a beneficial marker to determine iron overload degrees, particularly in the heart, in β-thalassemia major patients and be used as a logical therapeutic agent for treatment of β-thalassemia disorders.

Metallomic profiling to evaluate the response to drug treatment: hydroxyurea as a case study in β-thalassemia patients

Metallomic profiles of β-thalassemia patients after hydroxyurea treatment reveal a reduction in biometal dysregulations.

Effects of hemin on heme oxygenase-1, gastric emptying, and symptoms in diabetic gastroparesis

BACKGROUND

Therapeutic options for management of diabetic gastroparesis are limited. Failure to maintain upregulation of heme oxygenase (HO1) leads to loss of interstitial cells of Cajal and delayed gastric emptying (GE) in non-obese diabetic mice. Our hypothesis was that hemin upregulation of HO1 would restore normal GE in humans with gastroparesis.

AIMS

To compare effects of hemin and placebo infusions on HO1 activity and protein, GE, autonomic function, and gastrointestinal symptoms in diabetic gastroparesis.

METHODS

In a single-center, double-blind, placebo-controlled, randomized clinical trial, we compared intravenous hemin, prepared in albumin, or albumin alone (placebo) in 20 patients, aged 41 ± 5 (SEM) years with diabetic gastroparesis. After infusions on days 1, 3, and 7, weekly infusions were administered for 7 additional weeks. Assessments included blood tests for HO1 protein and enzyme activity levels, GE with ¹³ C-spirulina breath test, autonomic functions (baseline and end), and gastrointestinal symptoms every 2 weeks.

KEY RESULTS

Nine of 11 patients randomized to hemin completed all study procedures. Compared to placebo, hemin increased HO1 protein on days 3 (p = 0.0002) and 7 (p = 0.008) and HO1 activity on day 3 (p = 0.0003) but not after. Gastric emptying, autonomic functions, and symptoms did not differ significantly in the hemin group relative to placebo.

CONCLUSIONS & INFERENCES

Hemin failed to sustain increased HO1 levels beyond a week and did not improve GE or symptoms in diabetic gastroparesis. Further studies are necessary to ascertain whether more frequent hemin infusions or other drugs would have a more sustained effect on HO1 and improve GE.

Morbidities and mortality in transfusion-dependent Beta-thalassemia patients (single-center experience)

BACKGROUND

The improvement of quality and duration of life of transfusion-dependent B thalassemia patients over the last years discloses several complications due to the underling disorder, iron overload and the treatment with iron chelators. Our Aim was to assess the morbidity patterns and mortality rate of transfusion-dependent thalassemia patients, and compare the outcomes in relation to age of onset, type, duration, and compliance to iron chelation therapy and frequency of blood transfusion.

PROCEDURE

This retrospective study included 447 transfusion-dependent β-thalassemia patients who attended the Thalassemia Center, Ain Shams University Children's Hospital over the last 10 years in the period between January 2000 and January 2010. Data were collected from the patients or their caregivers, as well as by reviewing follow up sheets for examinations and investigations done to detect morbidities as well as iron chelation therapies given. Determination of mortality rate and the causes of death were also done.

RESULTS

Results revealed that the most common morbidities were endocrinologic (44.7%) followed by cardiovascular (41.3%) and hepatic (40.5%), then renal (4%). The different iron chelation therapy groups showed a comparable prevalence of different morbidities. The mortality rate was 1.5% and infection was the most common cause of death. The 5, 10, 20 years' survival rate among the studied patients was 80%, 50%, 20%, respectively.

CONCLUSION

In the past 10 years, the survival and morbidity rates in our center have markedly improved as a result of regular blood transfusion, new iron chelators, and better compliance of the patients.

Targeting heme oxygenase-1 in vascular disease

Heme oxygenase-1 (HO-1) metabolizes heme to generate carbon monoxide (CO), biliverdin, and iron. Biliverdin is subsequently metabolized to bilirubin by biliverdin reductase. HO-1 has recently emerged as a promising therapeutic target in the treatment of vascular disease. Pharmacological induction or gene transfer of HO-1 ameliorates vascular dysfunction in animal models of atherosclerosis, post-angioplasty restenosis, vein graft stenosis, thrombosis, myocardial infarction, and hypertension, while inhibition of HO-1 activity or gene deletion exacerbates these disorders. The vasoprotection afforded by HO-1 is largely attributable to its end products: CO and the bile pigments, biliverdin and bilirubin. These end products exert potent anti-inflammatory, antioxidant, anti-apoptotic, and anti-thrombotic actions. In addition, CO and bile pigments act to preserve vascular homeostasis at sites of arterial injury by influencing the proliferation, migration, and adhesion of vascular smooth muscle cells, endothelial cells, endothelial progenitor cells, or leukocytes. Several strategies are currently being developed to target HO-1 in vascular disease. Pharmacological induction of HO-1 by heme derivatives, dietary antioxidants, or currently available drugs, is a promising near-term approach, while HO-1 gene delivery is a long-term therapeutic goal. Direct administration of CO via inhalation or through the use of CO-releasing molecules and/or CO-sensitizing agents provides an attractive alternative approach in targeting HO-1. Furthermore, delivery of bile pigments, either alone or in combination with CO, presents another avenue for protecting against vascular disease. Since HO-1 and its products are potentially toxic, a major challenge will be to devise clinically effective therapeutic modalities that target HO-1 without causing any adverse effects.

Fermented papaya preparation for β-thalassemia?

This article comments on the results obtained by Fibach et al., which showed reduction of oxidative status in red blood cells of patients with β- and E-β-thalassemia (β-thal) treated with fermented papaya preparation. The study was a three-center, prospective study, including eight patients with β-thal intermedia, four β-thal major and seven E-β-thal patients. The patients received 3 g of fermented papaya preparation (FPP) two- to three-times a day after meals, respectively, for 3 months. A marked decrease in reactive oxygen species, lipid peroxidation and phosphatidylserine externalization and an increase in GSH were detected in both groups of patients, indicating that FPP is efficient in reducing the oxidative stress of these red blood cells. The results are very encouraging as all parameters analyzed indicated the reduction of red blood cells oxidative stress by the action of a natural and inexpensive product.

First-in-human study demonstrating pharmacological activation of heme oxygenase-1 in humans

Heme oxygenase (HO)-1 degrades heme and protects against oxidative stress, but it has not been pharmacologically induced in humans. In this randomized study of 10 healthy volunteers, hemin (3 mg/kg intravenously in 25% albumin) was shown to increase plasma HO-1 protein concentration four- to fivefold and HO-1 activity ~15-fold relative to baseline at 24 and 48 h (placebo -56.41 +/- 6.31 (baseline), 69.79 +/- 13.00 (24 h), 77.44 +/- 10.62 (48 h) vs. hemin -71.70 +/- 9.20 (baseline), 1,126.20 +/- 293.30 (24 h), 1,192.20 +/- 333.30 (48 h)) in four of five subjects as compared with albumin alone (P </= 0.03). This represents the overcoming of a fundamental hurdle to HO-1 research in humans.

The Xmn1 polymorphic site 5' to the (G)gamma gene and its correlation to the (G)gamma:(A)gamma ratio, age at first blood transfusion and clinical features in beta-thalassemia patients from Western Iran

beta-Thalassemia is the most common single gene disorder in Iran and more than 25,000 affected individuals have been reported. It has been reported that in patients with beta-thalassemia in the presence of Xmn1 polymorphic site the level of Hb F and (G)gamma: (A)gamma ratio is increased. The prevalence of Xmn1 polymorphic site, (G)gamma: (A)gamma ratio and Hb F in 197 beta-thalassemia major patients from the Kermanshah Province of Iran were studied. The Xmn1 polymorphic site was determined by PCR-RFLP procedure. The levels of (G)gamma and (A)gamma chains were detected by HPLC. The percent of Hb F was determined using electrophoresis method. In beta-thalassemia major patients the frequency of presence Xmn1 was 0.39. The mean of (G)gamma: (A)gamma ratio was found to be 2.5. In the present study it was found that in the presence of Xmn1 polymorphic site (G)gamma percent and (G)gamma: (A)gamma ratio were significantly increased (P = 0.01) and the clinical features such as splenomegaly and bone marrow expansion were significantly improved (P = 0.01). We found that in the presence of Xmn1 polymorphic site on both chromosomes (+/+) the level of Hb F tended to be increased compared to the absence of Xmn1 (-/-). The present investigation has studied the frequency of Xmn1 polymorphic site in beta-thalassemia major patients from Western Iran and has revealed that the presence of this polymorphic site caused a positive influence on Hb F production and the (G)gamma percent which could improve the clinical symptoms of beta-thalassemia patients.

Cardiac related death in thalassaemia major: time trend and risk factors in a large Greek Unit

BACKGROUND

Cardiac complications are the leading cause of death in thalassaemic patients (TM) worldwide. Improved management protocols including new chelators and imaging have reduced cardiac-related deaths but also require more advanced analytical methods to reflect temporal fluctuations in mortality risk.

OBJECTIVES

To evaluate time patterns of risk of cardiac death in TM patients according to birth cohort, gender and degree of haemosiderosis and to apply new flexible methods of analysis that may allow assessment of trends in risks as affected by innovations in management.

DESIGN AND METHODS

Cardiac-free survival and time trend of the risk of cardiac-related death were assessed in 648 transfusion-depended thalassaemic patients (48.3% females) managed in a single unit located in Athens, Greece. Patients were classified according to birth cohort (prior or after 1/1/1975) and according to the severity of haemosiderosis (mild, moderate and severe) as estimated by the mean ferritin levels during the last 5 yr of follow-up.

RESULTS

The median time of observation was 27.8 yr and 84 cardiac deaths were recorded. A parametric analysis predicted a non-monotonous time pattern for the cardiac risk with an initial increasing phase until the fourth decade of life followed by a drop off in deaths. Women have 23% longer life expectancy than men (P = 0.010) while patients born after 1975 die of heart complications at an older age compared to those born prior to 1975 (time ratio = 1.34, P = 0.003). Patients with mild and moderate haemosiderosis lived 89% (P < 0.001) and 43% (P < 0.001) longer, respectively, compared with patients with severe haemosiderosis.

CONCLUSIONS

These results on risk of death in thalassaemia, accord with expectations. This type of analysis will be useful in the future when the expected impact of cardiac MRI with appropriate tailoring of chelation therapy using all current and future options will modify the pattern of risk of cardiac death observed to date.

Malignancies in beta-thalassemia patients: a single-center experience and a concise review of the literature

Thalassemia represents the world's most common monogenic disease, characterized by absence of or decreased globin chain production. The lifespan of thalassemia patients has been extended as a result of current supportive treatment. We report three cases of cancer (non-Hodgkin lymphoma, Hodgkin disease, and seminoma) in thalassemic patients. Factors that may contribute to the pathogenesis of cancer seem to be infections and iron overload through mechanisms of oxidative damage; immunomodulation or coexistence of the two diseases may only be coincidental.

Modern treatment of thalassaemia intermedia

The term thalassaemia intermedia includes a large spectrum of conditions of varying severity. Blood transfusion and chelation are necessary in some patients, especially during childhood, in order to promote growth and prevent bone deformities. Alloimunisation, however, is frequent and can be difficult to control. Splenectomy is usually needed at some time because of hypersplenism and mechanical encumbrance. Reactivation of HbF is possible only in a small proportion of patients: hydroxycarbamide (also known as hydroxyurea) appears to be the most effective drug for this purpose. Antioxidant agents, although theoretically useful, do not improve haemoglobin levels. Stem cell transplantation is an option limited to the severe forms. Gene therapy and other molecular approaches are subjects of intense study. Numerous complications, including pulmonary hypertension, thrombotic events, pseudoxanthoma elasticum and osteoporosis, have been described and all contribute to complicate the treatment of a disease that represents a significant burden for the patients and their families.

In vitro effects of vitamin C and selenium on NK activity of patients with beta-thalassemia major

In this study, the in vitro effects of vitamin C and selenium on natural killer (NK) cell activity of ss-thalassemia major patients was investigated. At first, significant decreased NK activity was found at E:T ratios of 1:1, 5:1, and 10:1 in whole thalassemia patients. Low-dose selenium treatment enhanced NK activity in patients but there was no change in the control group. High-dose selenium decreased NK activity significantly in splenectomized patients. Different doses vitamin C enhanced NK activity significantly in both splenectomized and unsplenectomized patients. According to these results, selenium dosage should be arranged carefully in thalassemia patients, whereas vitamin C can be used confidently.

Hemin Activation Ameliorates HIV-1 Infection via Heme Oxygenase-1 Induction

Hemin, a critical component of hemoglobin, is an active ingredient of a biologic therapeutic approved by the Food and Drug Administration for the treatment of acute porphyries. This report describes a biological function of this molecule in inducing host defense against HIV-1 infection via heme oxygenase-1 (HO-1) induction. Treatment of monocytes with hemin substantially inhibited HIV replication, as evident by nearly undetectable viral RNA and cell-free HIV-1 p24 protein in a dose-dependent manner. Hemin exposure of these cells before infection, at the time of infection, or after infection caused >90% reduction of HIV DNA with substantially low levels of HIV-1 p24 and HIV-associated cytopathic effects. In addition, hemin treatment significantly suppressed infection of both monocytes and T cells inoculated with R5, X4, R5X4 tropic strains, and reverse transcriptase-resistant, azidothymidine-resistant, ddC/ddI-resistant, nivirapine-resistant, and other clinical HIV isolates. Intraperitoneal administration of hemin 4 days after HIV infection reduced viral load in the serum of human PBMC-reconstituted nonobese diabetic SCID mice by >6-fold. Suppression of HIV replication in hemin-activated cells correlated with the induction of HO-1 and was attenuated by tin protoporphyrin (SnPP) IX, an inhibitor of HO-1 activity, suggesting a pivotal role of this endogenous enzyme in the regulation of HIV infection. Hemin-induced HO-1 induction in the CCR-5, CXCR-4, and CD4 coexpressing GHOST(3) cells was consistent with the inhibition of Tat-dependent activation of long terminal repeat promoter leading to reduced GFP expression. These findings suggest an important role of hemin-induced HO-1 activity as a host defense mechanism against HIV-1 infection.

Financial burden of national health insurance for treating patients with transfusion-dependent thalassemia in Taiwan

The thalassemias are a heterogeneous group of inherited hypochromic anemias of varying severity. The mainstay of supportive treatment is regular blood transfusion accompanied by iron-chelating therapy. Hematopoietic stem cell transplantation (HSCT) provides an alternative option when curative therapy is considered. More than 400 patients in Taiwan have beta-thalassemia major or other transfusion-dependent thalassemias, and their treatment costs account for a considerable percentage of the National Health Insurance expenditure. In this report, we estimated the treatment costs of conventional therapy (regular blood transfusion accompanied by iron-chelating agents) and HSCT. The undiscounted medical cost of 20 years of follow-up (20 years from diagnosis) and the undiscounted total lifetime cost were NT$ 4 739 888 (NT$ means New Taiwan Dollars)/US$ 149 288 and NT$ 11 529 990/US$ 363 149, respectively, for patients undergoing conventional therapy, and NT$ 2 639 982/US$ 83 149 and NT$ 3 511 172/US$ 110 588, respectively, for those undergoing successful HSCT. Comparisons of treatment costs and other parameters between these two modalities can add to the information base on which policy is made by health authorities or clinicians.

Antiproliferative and Apoptosis-Inducing Effects of Hemin in Hepatoma Cells

Hemin is an extremely versatile molecule that may have cytotoxic or cytoprotective effects on certain cells. We investigated the effect of hemin on the growth of hepatoma cells, including the multidrug-resistant ones. Searching for new tools that interfere with the growth of hepatomas is an important area of clinical research. Cell viability and proliferation of drug-sensitive and multidrug-resistant hepatoma cell lines was determined using the trypan-blue exclusion test XTT/PMS and colony-forming ability assays. Apoptosis was assessed by confocal microscopy and DNA ladder assay. Hemin inhibited the proliferation and induced apoptosis in both drug-sensitive and multidrug-resistant hepatoma cells overexpressing functional P-glycoprotein. zVAD-fmk inhibited the hemin-induced decrease in cell viability, pointing to a role of caspases in hemin-induced apoptosis. The antiproliferative and apoptosis-inducing effects of hemin might be considered in the design of treatment for patients with hepatoma.

Investigation of Helicobacter pylori infection in beta-thalassaemia major patients with recurrent abdominal pain

BACKGROUND

Recurrent abdominal pain (RAP) affects many children, especially those affected by beta-thalassaemia major. The role of Helicobacter pylori is still unclear in children with RAP.

OBJECTIVES

The aim of the present study was the comparison of beta-thalassaemia major patients and normal controls with RAP in H. pylori infection. The factors influencing H. pylori prevalence were also investigated.

METHODS

A series of 50 beta-thalassaemia major cases (30 female, 20 male; aged 6-25 years) and 50 age-matched and sex-matched controls, both presenting with RAP, were recruited during a period of 18 months. The study participants were obtained through a multistage random sampling method among those that met Apley's criteria. All the patients and controls had undergone diagnostic oesophagogastroduodenoscopy with biopsy. H. pylori infection was confirmed by two histopathological examinations on an endoscopy sample and a rapid urease test.

RESULTS

H. pylori infection in thalassaemic patients was more common than in controls [34/50 (68%) versus 30/50 (60%)], but this higher frequency was not statistically significant. A clear relationship was found between the prevalence of H. pylori and age, duration of transfusion/chelation programmes, pain duration and splenectomy. In contrast, H. pylori did not correlate with abdominal pain characteristics, blood group, serum ferritin level and pathology of the upper gastrointestinal tract. The most frequent endoscopy abnormality was gastritis (72%). Nausea and heartburn were the leading associated symptoms.

CONCLUSION

The high prevalence of H. pylori infection suggests that H. pylori should be remembered as a probable cause of RAP in beta-thalassaemia major patients.

Hemin-activated macrophages home to the pancreas and protect from acute pancreatitis via heme oxygenase-1 induction

Hemin upregulates heme oxygenase-1 (HO-1), a stress-induced enzyme implicated in protection from a variety of injuries while its related isoform HO-2 is constitutively expressed. The role of hemin or HO-1 in the pancreas and their potential modulation of pancreatic injury are unknown. We show that HO-1 is induced in pancreatitis caused by caerulein and more prominently in severe pancreatitis caused by feeding a choline-deficient diet (CDD). Intraperitoneal hemin administration dramatically increases peritoneal and pancreas macrophages that overexpress HO-1 in association with pancreatic induction of the chemoattractants monocyte chemotactic protein-1 and macrophage inflammatory protein-1alpha but not RANTES or macrophage inflammatory protein-2. Hemin administration before CDD feeding protected 8 of 8 mice from lethality while 7 of 16 controls died. Protection is mediated by HO-1-overexpressing macrophages since hemin-primed macrophages home to the pancreas after transfer to naive mice and protect from CDD-induced pancreatitis. Suppression of hemin-primed peritoneal cell HO-1 using HO-1-specific small interfering RNA prior to cell transfer abolishes protection from CDD-induced pancreatitis. Similarly, hemin pretreatment in caerulein-induced pancreatitis reduces serum amylase and lipase, decreases pancreatic trypsin generation, and protects from lung injury. Therefore, hemin-like compounds or hemin-activated macrophages may offer novel therapeutic approaches for preventing acute pancreatitis and its pulmonary complication via upregulation of HO-1.

Cutaneous adverse reactions to hydroxyurea in patients with intermediate thalassemia

Although the cutaneous effects of hydroxyurea have been described for patients with sickle cell anemia, myeloproliferative disorders, and psoriasis, there are no reports of cutaneous adverse effects from hydroxyurea when used for patients with intermediate thalassemia. Therefore 43 patients with intermediate thalassemia treated with hydroxyurea were examined by a dermatologist, and pertinent cutaneous findings were recorded. These patients had received hydroxyurea for a mean of 15.5 months. Nineteen had cutaneous hyperpigmentation, eight had xerosis, and three were found to have one cafe au lait macule each. Eleven patients had nail abnormalities, including nail ridging, partial leukonychia, and longitudinal melanonychia. There were no cases of leg ulceration. It was concluded that the risk of developing leg ulcers and pigmentary disorders appears to be related to the underlying disease being treated, as well as to a patient's age, gender, and pigmentation.

Efficacy of erythropoietin on dialysis in patients with beta thalassemia minor

BACKGROUND

It is unknown whether chronic erythropoietin (EPO) treatment is able to normalize hemoglobin (Hb) levels and ameliorate cardiac remodeling avoiding blood transfusions in uremic blood transfusion-dependent patients with beta-thalassemia minor (beta-thal).

METHODS

In 12 hemodialysis (HD) patients with beta-thal, requiring blood transfusions despite EPO therapy, we planned to increase Hb levels up to the target levels (11-12 g/dl) within a one-year period by administering progressively higher doses of EPO (correction phase). We also planned to maintain the Hb target for an additional year (maintenance phase).

RESULTS

In the year before the study, patients required 3.3 +/- 0.9 units of packed red blood cells. At baseline, the Hb level obtained with an EPO dose of 212 +/- 73 U/kg/week i.v. was 8.2 +/- 0.8 g/dl. The EPO dose was gradually increased within the first year up to 458 +/- 78 U/kg/week at month 12 (correction phase) and then significantly tapered down during the maintenance phase (390 +/- 54 U/kg/week at month 24). During the correction phase, the Hb levels markedly increased (11.1 +/- 0.3 g/dl at month 12) and did not change in the maintenance phase. No blood transfusion was required throughout the 2 years of follow-up. Left ventricular (LV) mass index progressively decreased from the basal value of 144 +/- 12 to 124 +/- 11 g/m2 in the first year and normalized in all patients at month 24 (109 +/- 12 g/m2, p < 0.001); this occurred in the absence of any change of LV cavity volume index (<90 ml/m2).

CONCLUSIONS

In HD transfusion-dependent patients with beta-thal, the administration of high EPO dose for 2 years permits the attainment and the maintenance of Hb targets without blood transfusions. This therapeutic approach permits a complete remission of concentric LV hypertrophy without any adverse effects on the vascular system.

Factors associated with the attitudes and expectations of patients suffering from beta-thalassaemia: a cross-sectional study

Regular transfusions and iron chelation therapy have transformed the life expectancy of homozygous beta-thalassaemia patients, so that it can now be considered a chronic condition. A health questionnaire survey of all adults suffering from beta-thalassaemia major receiving treatment on the Island of Crete, Greece was carried out with the aim of ascertaining the factors that are associated with their attitudes and expectations. The responses of 67 of the 72 patients, aged 18-45 years, were analyzed using Principal Component Analysis to extract three component indicators (Adaptability, Optimism and Pessimism Indicators), which reflected their attitudes towards life and two component indicators (Healing and Therapy Indicators) that reflected their expectations from life. These were then tested against the respondents' socio-demographic characteristics, their health status and satisfaction with the services. It was found that the Optimism Indicator was associated with a positive comparative assessment of health status, while the Adaptability Indicator was associated with a positive subjective assessment of health status. The Adaptability Indicator was also higher in those satisfied with the services but it was lower in the best-educated group. The pessimism indicator was associated with a negative comparative assessment of health status and with the lowest level education. The expectation indicators showed an interaction with gender and other parameters such as admission to hospital. The relationship between the attitudes and the expectations of patients suffering from a chronically disability condition and specific experiences during their treatment regimens raises several issues related to the need for better health education and psychological support of the group of patients, as well as issues related to the communication skills of the staff caring for them.

High-level expression of hemoglobin A in human thalassemic erythroid progenitor cells following lentiviral vector delivery of an antisense snRNA

Mutations at nucleotides 654, 705, or 745 in intron 2 of the human beta-globin gene activate aberrant 3' and 5' splice sites within the intron and prevent correct splicing of beta-globin pre-mRNA, resulting in inhibition of beta-globin synthesis and in consequence beta-thalassemia. Transfection of HeLa cells expressing the 3 thalassemic mutants with modified U7 snRNA (U7.623), containing a sequence antisense to a region between the aberrant splice sites, reduced the incorrect splicing of pre-mRNA and led to increased levels of the correctly spliced beta-globin mRNA and protein. A lentiviral vector carrying the U7.623 gene was effective in restoration of correct splicing in the model cell lines for at least 6 months. Importantly, the therapeutic value of this system was demonstrated in hematopoietic stem cells and erythroid progenitor cells from a patient with IVS2-745/IVS2-1 thalassemia. Twelve days after transduction of the patient cells with the U7.623 lentiviral vector, the levels of correctly spliced beta-globin mRNA and hemoglobin A were approximately 25-fold over background. These results should be regarded as a proof of principle for lentiviral vector-based gene therapy for beta-thalassemia.

Bone marrow transplantation for beta-thalassaemia major: the UK experience in two paediatric centres

Stem cell transplantation (SCT) remains the only cure for thalassaemia major. Recent advances in medical treatment make it even more important that accurate information is available regarding outcome of SCT in relevant patient populations in order to guide informed decisions regarding the most appropriate treatment for individual thalassaemia patients. We report the results of 55 consecutive first related allogeneic bone marrow transplants (BMT) for children with beta-thalassaemia major performed in two UK paediatric centres over 10 years. Between February 1991 and February 2001, 55 children underwent 57 allogeneic BMT. The median age at BMT was 6.4 years and the majority of patients (73%) originated from the Indian subcontinent. Using the Pesaro risk classification, 17 patients were class 1, 27 were class 2 and 11 were class 3. Actuarial overall survival and thalassaemia-free survival at 8 years were 94.5% (95% CI 85.1-98.1) and 81.8% (95% CI 69.7-89.8) respectively. Despite the majority of patients being in class 2 or 3, transplant-related mortality was low (5.4%). The principal complication was graft rejection accompanied by autologous reconstitution that occurred in 13.2% of transplants. Following modification of the conditioning regimen in 1993, the rejection rate fell to 4.6% and remained low. Acute graft-versus-host disease (GVHD) of grade II-IV occurred in 31% and chronic GVHD in 14.5%. These data compare favourably with survival with medical treatment for thalassaemia major and suggest that allogeneic BMT remains an important treatment option for children with beta-thalassaemia major, particularly when compliance with iron chelation is poor.

Orally active iron chelators

In patients with transfusion-dependent anemias, iron accumulation is fatal in the absence of chelating therapy. Extended survival, free of most complications of iron overload is observed in patients treated with early, adequate parenteral deferoxamine. Despite its success in prevention and treatment of iron toxicity, the expense and inconvenience of this therapy have stimulated a continued quest for an effective chelating agent that is orally active. Unfortunately, studies emerging over the last five years have confirmed that the most widely administered orally active agent, deferiprone (L1; 1,2-dimethyl-3-hydropyrid-4-one) may be harmfully ineffective in many patients: 18-65% of patients in six studies which obtained hepatic irons after long term deferiprone treatment had body iron exceeding the threshold for cardiac disease and premature death. The impact of deferiprone on cardiac and liver disease must be evaluated further, while the association between deferiprone and accelerated hepatic fibrosis still awaits refutation in large prospective trials. In view of the striking therapeutic successes of deferoxamine over the past 20 years, administration of deferiprone outside the setting of prospective clinical trials may need to be reconsidered. Meanwhile, an orally active iron chelator of demonstrated safety and effectiveness remains an objective for development for transfused patients.

Successful treatment of murine beta-thalassemia intermedia by transfer of the human beta-globin gene

The beta-thalassemias are caused by more than 200 mutations that reduce or abolish beta-globin production. The severity of the resulting anemia can lead to lifelong transfusion dependency. A genetic treatment based on globin gene transfer would require that transgene expression be erythroid specific, elevated, and sustained over time. We report here that long-term synthesis of chimeric hemoglobin (mualpha(2):hubeta(A)(2)) could be achieved in mice with beta-thalassemia intermedia following engraftment with bone marrow cells transduced with a lentiviral vector encoding the human beta-globin gene. In the absence of any posttransduction selection, the treated chimeras exhibit durably increased hemoglobin levels without diminution over 40 weeks. Ineffective erythropoiesis and extramedullary hematopoiesis (EMH) regress, as reflected by normalization of spleen size, architecture, hematopoietic colony formation, and disappearance of liver EMH. These findings establish that a sustained increase of 3 to 4 g/dL hemoglobin is sufficient to correct ineffective erythropoiesis. Hepatic iron accumulation is markedly decreased in 1-year-old chimeras, indicating persistent protection from secondary organ damage. These results demonstrate for the first time that viral-mediated globin gene transfer in hematopoietic stem cells effectively treats a severe hemoglobin disorder.

Globin gene transfer for the treatment of severe hemoglobinopathies: a paradigm for stem cell-based gene therapy

The prospect of treating blood disorders with genetically modified stem cells is highly promising. This therapeutic approach, however, raises a number of fundamental biological questions, spanning several research fields. Further investigation is required to better understand how to isolate and efficiently transduce hematopoietic stem cells (HSCs), while preserving optimal homing and self-renewing properties; how to design safe vectors permitting controlled expression of the transgene products; and how to promote host repopulation by engrafted HSCs. This article addresses basic issues in stem cell-based gene therapy from the perspective of regulating transgene expression, taking globin gene transfer for the treatment of severe hemoglobinopathies as a paradigm.

Chelation therapy in beta-thalassemia: an optimistic update

Iron chelation therapy with desferrioxamine (DFO) has dramatically improved the outlook in beta-thalassemia. Parenteral DFO reduces tissue iron stores, prevents iron-induced organ damage, and reduces morbidity and mortality, with little serious toxicity. However, the burden of prolonged subcutaneous portable pump infusions, high cost, and patient noncompliance have prompted the development of new methods of administration and new formulations of DFO as well as oral iron chelators. Deferiprone (L1), the only oral iron chelator studied in large long-term clinical trials, is less effective and more toxic than DFO and may not adequately control iron overload; however, compliance and quality of life are improved. Combinations of two iron chelators (such as parenteral DFO plus oral L1, or 2,3-DHB; or oral L1 plus HBED) have been shown to produce additive and synergistic effects, explained by the shuttle hypothesis. Iron bound to a "shuttle"--an oral agent that mobilizes tissue iron--is exchanged in the bloodstream with a "sink"--such as parenteral DFO--and excreted via the kidneys, while the shuttle is reutilized. Combination therapy may produce enhanced iron excretion, target specific iron compartments, minimize side effects, increase treatment options, improve compliance, and facilitate individualization of therapy. Better understanding of the kinetics of iron metabolism, iron overload, and chelation should improve therapeutic strategies.