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One-year results from a prospective randomized trial comparing phlebotomy with deferasirox for the treatment of iron overload in pediatric patients with thalassemia major following curative stem cell transplantation.
Inati, A, Kahale, M, Sbeiti, N, Cappellini, MD, Taher, AT, Koussa, S, Nasr, TA, Musallam, KM, Abbas, HA, Porter, JB
Pediatric blood & cancer. 2017;(1):188-196
Abstract
BACKGROUND Iron overload is well documented in patients with β-thalassemia major, and patients who have undergone hematopoietic stem cell transplantation (HSCT) remain at risk as a result of pre- and immediate post-HSCT transfusions. PROCEDURE This is a prospective, randomized, 1-year clinical trial that compares the efficacy and safety of the once-daily oral iron chelator deferasirox versus phlebotomy for the treatment of iron overload in children with β-thalassemia major following HSCT. RESULTS Patients (aged 12.4 years) received deferasirox (n = 12, 10 mg/kg/day starting dose) or phlebotomy (n = 14, 6 ml/kg/2 weeks) for 1 year. In two and five patients, deferasirox dose was increased to 15 and 20 mg/kg/day, respectively. Magnetic resonance imaging (MRI)-assessed liver iron concentration (LIC) decreased with deferasirox (mean 12.5 ± 10.1 to 8.5 ± 9.3 mg Fe/g dry weight [dw]; P = 0.0005 vs. baseline) and phlebotomy (10.2 ± 6.8 to 8.3 ± 9.2 mg Fe/g dw; P = 0.05). LIC reductions were greater with deferasirox than with phlebotomy for patients with baseline serum ferritin 1,000 ng/ml or higher (-8.1 ± 1.5 vs. -3.5 ± 5.7 mg Fe/g dw; P = 0.048). Serum ferritin and non-transferrin-bound iron also decreased significantly. In two patients with severe cardiac siderosis, a clinically relevant improvement in myocardial T2* was seen, following phlebotomy and deferasirox therapy (n = 1 each). Adverse effects with deferasirox were skin rash, gastrointestinal upset, and increased liver function tests (all n = 1), while those for phlebotomy were difficulty with venous access (n = 4) and distress during procedure (n = 1). Parents of 13/14 children receiving phlebotomy wished to switch to deferasirox, with 1/14 being satisfied with phlebotomy. CONCLUSIONS Deferasirox treatment or phlebotomy reduces iron burden in pediatric patients with β- thalassemia major post-HSCT, with a manageable safety profile.
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Early identification of cardiovascular involvement in patients with β-thalassemia major.
Cusmà Piccione, M, Piraino, B, Zito, C, Khandheria, BK, Di Bella, G, De Gregorio, C, Oreto, L, Rigoli, L, Ferraù, V, Salpietro, CD, et al
The American journal of cardiology. 2013;(8):1246-51
Abstract
The aim of the present study was to evaluate left ventricular myocardial deformation and carotid arterial stiffness using 2-dimensional strain and echo-tracking in patients with asymptomatic β-thalassemia major (β-TM) without significant myocardial iron overload to determine whether early subclinical cardiovascular abnormalities would be detectable. We enrolled 32 patients with β-TM (23 women, mean age 35 ± 8 years) and 33 healthy volunteers (20 women, mean age 35 ± 6 years). All subjects underwent echocardiography with 2-dimensional strain analysis (XStrain) and ultrasonography of the carotid arteries with measurement of the stiffness parameters (ProSound Alpha 10). Cardiac magnetic resonance imaging using a T2* algorithm (37.7 ± 5.6 ms) for the assessment of myocardial iron overload was performed in each patient. The clinical and standard echocardiographic parameters were comparable between the patients and healthy subjects. The global left ventricular longitudinal strain was significantly impaired in the patients compared with the controls (-17.9 ± 3.5% vs -24.3 ± 3.4%, p = 0.002), although the radial and circumferential strain values were similar between the 2 groups (p = NS for both). The carotid intima-media thickness was comparable between the patients and healthy subjects (0.67 ± 0.20 mm vs 0.66 ± 0.15 mm, p = NS). In contrast, the arterial stiffness was significantly increased in the patients compared with the controls (stiffness index 6.16 ± 1.31 vs 4.65 ± 0.82, p <0.001; arterial compliance 1.10 ± 0.26 vs 1.28 ± 0.30 cm(2)/mm Hg, p = 0.027; elastic modulus 74.1 ± 19.5 vs 59.1 ± 12.1 mm Hg, p = 0.001). In conclusion, cardiovascular abnormalities, although often subclinical, occur at an early stage of β-TM and also in the absence of significant iron overload. Thus, 2-dimensional strain and echo-tracking might be more accurate than standard echocardiography and vascular parameters in the early identification of cardiovascular involvement.
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Comparison of pharmacokinetics and urinary iron excretion of two single doses of deferiprone in β-thalassemia/hemoglobin E patients.
Rodrat, S, Yamanont, P, Tankanitlert, J, Chantraraksri, U, Fucharoen, S, Morales, NP
Pharmacology. 2012;(1-2):88-94
Abstract
Dose-related pharmacokinetics and urinary iron excretion (UIE) of an orally active iron chelator, deferiprone (L1), was investigated in 12 severe β-thalassemia/hemoglobin E patients. The patients received two single doses of 25 and 50 mg/kg with a 2-week washout period. Deferiprone was rapidly absorbed and reached maximum concentration (C(max)) within 1 h after administration. Pharmacokinetic parameters including C(max) and area under concentration time curve from time zero to infinity (AUC(0-∞)) as well as urinary excretion of non-conjugated and glucuronide-conjugated deferiprone (L1 and L1-G) increased proportionally with the dose of deferiprone. A constant ratio of AUC(0-∞) of L1-G to L1 and a percentage of urinary excretion of L1-G indicated that increasing the dosage does not influence deferiprone biotransformation. Longer terminal elimination half-lifeand higher volume of distribution of L1 were observed with the high dose and correlated with deferiprone-chelated iron in serum. Unexpectedly, UIE did not show a linear relationship with the increased dose of deferiprone. The correlation between UIE and creatinine clearance suggested the possibility of L1-iron complex redistribution in patients with renal impairment treated with high-dose deferiprone.
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R2* imaging of transfusional iron burden at 3T and comparison with 1.5T.
Storey, P, Thompson, AA, Carqueville, CL, Wood, JC, de Freitas, RA, Rigsby, CK
Journal of magnetic resonance imaging : JMRI. 2007;(3):540-7
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Abstract
PURPOSE To determine normative R2* values in the liver and heart at 3T, and establish the relationship between R2* at 3T and 1.5T over a range of tissue iron concentrations. MATERIALS AND METHODS A total of 20 healthy control subjects and 14 transfusion-dependent patients were scanned at 1.5T and 3T. At each field strength R2* imaging was performed in the liver and heart. RESULTS Normative R2* values in the liver were estimated from the control group to be 39.2 +/- 9.0 second(-1) at 1.5T and 69.1 +/- 21.9 second(-1) at 3T. Normative cardiac values were estimated as 23.4 +/- 2.2 second(-1) at 1.5T and 30.0 +/- 3.7 second(-1) at 3T. The combined R2* data from patients and control subjects exhibited a linear relationship between 3T and 1.5T. In the liver, the line of best fit to the 3T vs. 1.5T data had a slope of 2.00 +/- 0.06 and an intercept of -11 +/- 4 second(-1). In the heart, it had a slope of 1.88 +/- 0.14 and an intercept of -15 +/- 4 second(-1). CONCLUSION These preliminary data suggest that the iron-dependent component of R2* scales linearly with field strength over a wide range of tissue iron concentrations. The incidence of susceptibility artifacts may, however, also increase with field strength.
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A randomized controlled study evaluating the safety and efficacy of deferiprone treatment in thalassemia major patients from Hong Kong.
Ha, SY, Chik, KW, Ling, SC, Lee, AC, Luk, CW, Lam, CW, Ng, IO, Chan, GC
Hemoglobin. 2006;(2):263-74
Abstract
A controlled, open-label and randomized study was conducted to evaluate the safety and efficacy of the oral iron chelator deferiprone (L1) in thalassemia major patients from Hong Kong. Forty-nine patients were recruited in total (median age: 20 years; range: 8 to 40 years). The division of the patients was determined based on liver iron content and put into either the poorly-chelated (Group I) or well-chelated (Group II) groups. In Group I, 20 patients received combined therapy of L1 daily plus desferrioxamine (DFO), in a reduced frequency of twice weekly, while the control group consisted of 16 patients who were treated with DFO alone. In Group II, six patients received L1 only, while the control group consisted of seven patients treated with DFO alone. Only patients who participated for longer than 6 months were analyzed for efficacy (n = 44). The median study period was 18 months. Transient and mild gastrointestinal upset (31%), joint pain (15%) and liver enzyme elevation (23%) were the most common side effects noted for L1. No case of neutropenia was observed in this study. Serum ferritin (SF) levels showed significant decline in the poorly-chelated patients using combined therapy (L1 and reduced frequency DFO) as compared to those on DFO alone. However, their pre- and post-study liver iron content was not significantly different. Evaluation of the well-chelated group demonstrated no significant change in SF or liver iron content in both the study and control arms. We conclude that the short-term use of L1, with or without DFO, was safe and efficacious in our Chinese patient cohort. The long-term efficacy of reducing iron overload by treatment regimens including L1 requires further study.
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Subcutaneous bolus injection of deferoxamine is an alternative method to subcutaneous continuous infusion.
Yarali, N, Fişgin, T, Duru, F, Kara, A, Ecin, N, Fitoz, S, Erden, I
Journal of pediatric hematology/oncology. 2006;(1):11-6
Abstract
The objective of this study was to compare the short- and long-term efficacy of deferoxamine (DFO) given by subcutaneous (SC) continuous infusion over 10 hours via a pump (n = 10) versus a twice-daily subcutaneous bolus injection of the same overall dose (n = 10) in 20 thalassemic children. Urinary iron excretion was measured in 24-hour urine samples after DFO treatment in the 20 patients. The patients were randomized to two groups: 10 patients continued SC continuous infusion with a pump and the remaining 10 received the same overall dose of DFO by twice-daily SC bolus injection for a year. Serum ferritin levels and T1-weighted spin-echo and T2-weighted fast spin-echo signal intensities of liver and paraspinal muscle were determined at initiation and 1 year after initiation of the therapy. In 12 patients, six from each group, liver biopsies were performed and hepatic iron concentration was determined at initiation of therapy and 1 year after treatment. A similar and significant decrease in ferritin levels and improvement in signal intensities of the liver were observed in response to chelation therapy with DFO in both groups (P < 0.01, within each group). Hepatic iron concentration decreased in all patients in the SC bolus injection group (P < 0.05) and in four patients in the SC continuous infusion group (P > 0.05). Hepatic iron concentration was noted to be slightly increased in two patients in the SC continuous infusion group, which may be due to poor compliance. Based on these results, twice-daily SC bolus injection of DFO is as effective as administration via SC continuous infusion using a pump. Subcutaneous bolus injection, being more convenient for the patient, may be a more preferable method of DFO administration.
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Effects of silymarin on the proliferation and glutathione levels of peripheral blood mononuclear cells from beta-thalassemia major patients.
Alidoost, F, Gharagozloo, M, Bagherpour, B, Jafarian, A, Sajjadi, SE, Hourfar, H, Moayedi, B
International immunopharmacology. 2006;(8):1305-10
Abstract
Iron toxicity in beta-thalassemia major is the main cause of oxidative stress and cell mediated immune deficiencies. Despite indicative signs of severe oxidative deficiencies associated with beta-thalassemia major, such as decreased level of plasma antioxidants and depletion of erythrocyte glutathione, little is known about intracellular redox status of immune cells. Since glutathione is a primary intracellular antioxidant and plays an essential role in several functions in T cells, in this study intracellular glutathione (GSH) levels as well as proliferation of PHA-activated peripheral blood mononuclear cells (PBMC) were investigated in 28 beta-thalassemia major patients and 28 healthy age-matched individuals. Considering the potential benefits of flavonoids in the therapy of oxidative stress, the effects of silymarin on the GSH levels and proliferation of PBMC from normal and thalassemia individuals were further examined. Quantitative determination of intracellular GSH and proliferative response of PBMC to PHA were performed before and after 72 h incubation of PBMC with various concentrations of silymarin (0, 5, 10, or 20 mug/ml). Results demonstrated a significant reduction of GSH and proliferation in beta-thalassemia major cells; however treatment with silymarin led to restoration of both GSH levels and PBMC proliferation in thalassemia patients. Considerably low levels of GSH and depressed proliferative response of PBMC in beta-thalassemia major may be responsible for the cell mediated immune abnormalities in iron overload conditions. Moreover, the GSH restoration and improvement of PBMC growth by silymarin is a possible explanation for its recently reported antioxidant and immunostimulatory activities. These data suggest the benefit of using flavonoids to normalize immune dysfunction in beta-thalassemia major. The immunomodulatory effects of silymarin in beta-thalassemia major are currently under further investigation in a double blind clinical trial.