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1.
New developments in the area of iron and other metal metabolism and toxicity and the effects and uses of chelators have been presented at the 16th International Conference on Chelation (ICOC), Limassol, Cyprus in October 2006. Marketing practices by pharmaceutical companies, contradictory policies by regulatory authorities and ineffective policies by health authorities deprive thousands of thalassemia and other transfused patients of life saving iron chelating drugs and of efficacious chelation treatments. Thousands of patients were using deferasirox (DFRA) worldwide a few months after the European Union (EU) authorities, and about 1 year after the Food and Drugs Administration (FDA), proceeded to its accelerated approval with no sufficient evidence that the drug was efficacious, especially for clearing excess cardiac iron, and also safe. Cases of fatal, acute, irreversible renal and liver failure, fatal agranulocytosis and other toxicities have recently been reported with DFRA. The FDA has not yet approved deferiprone (L1) depriving thousands of patients of potentially life saving treatment. The high cost of DFRA at 60 euros/g, L1 at 5.5 euros/g and deferoxamine (DFO) at 8.3 euros/g, diminishes the prospects of universal chelation therapy, especially for patients in developing countries. The safety and efficacy record of L1, DFO, and their combination in particular, appear to provide universal solutions in the treatment of transfusional iron overload, and also in reducing mortality because of their ability to clear rapidly and effectively excess cardiac iron.  相似文献   

2.
《Hemoglobin》2013,37(5):332-338
A new era in iron chelation therapy began with the successful removal of excess iron load and the maintenance of normal iron stores in thalassemia patients using the International Committee on Chelation (ICOC) protocols. This achievement was based on two phases, firstly the introduction of deferiprone (L1) (80–100 mg/kg/day) and deferoxamine (DFO) (40–60 mg/kg at least 3 days per week) combination therapy, which appears to progressively remove all excess storage iron and thereafter by the introduction of L1 monotherapy that can maintain physiological range levels of serum ferritin, cardiac and liver magnetic resonance imaging (MRI) T2*. This new development is likely to change current practices and set a new gold standard in the treatment of transfusional iron loaded patients leading to an increased survival and the change of thalassemia from a fatal to a chronic disease. A major aspect of the improved therapies is the ability of L1 to mobilize and remove excess cardiac iron and reduce congestive cardiac failure, which is the main cause of death in thalassemia patients. Further, new developments include the use of alternating sequential chelation therapies and selected dose protocols with L1, DFO and deferasirox (DFRA) for overcoming toxicity and efficacy complications observed in some patients treated with monotherapies or combination therapies. The selection and adjustment of dose protocols is crucial for providing optimum chelation therapy for each individual patient.  相似文献   

3.
《Hemoglobin》2013,37(5):304-311
Over the past few decades, Taiwan has seen striking improvements in the life expectancy of its 400 registered β-thalassemia major (β-TM) patients due mainly to adequate transfusion regimens and effective iron chelation therapy. Since 1995, Taiwanese citizens have enjoyed universal health care through National Health Insurance (NIH), receiving comprehensive treatment at minimal cost. In 1984, a national program for thalassemia prevention, control, and hematopoietic stem cell transplantation (HSCT) was initiated. Recent data show 1- and 2-year event-free survival rates of 85 and 78%, respectively. Chelation agents like deferoxamine (DFO), deferiprone (L1) and deferasirox (DFRA) are available in Taiwan, and therapy is tailored to individuals based on drug availability and tissue distribution of iron load. Intensive chelation regimens combining L1 and DFO are recommended in patients with cardiac complications, while DFRA has been found to be effective in reducing serum ferritin, with acceptable side effects. Here, we report advances in thalassemia treatment in Taiwan and suggest treatment guidelines.  相似文献   

4.
Major advances were presented at the 19th International Conference on Chelation (ICOC) in London, UK including changes in iron chelation therapy that led to the complete treatment of transfusional iron overload. The first oral iron chelation results in animals using deferiprone (L1) were published in 1985, and effective iron removal in thalassemia and myelodysplasia patients were reported 2 years later. The results of multicenter clinical trials of L1 were presented at the 1st ICOC in London, UK in 1989. Long-term use of L1 resulted in the reduction of the mortality rate in thalassemia patients due to the effective removal of all excess iron from the heart. In 2008, specific combinations of L1 and deferoxamine (DFO) were reported to cause the complete removal of excess iron load and the achievement of normal range body iron store levels (NRBISL) in thalassemia patients. Patients with NRBISL were identified to require lower doses of L1 for the maintenance of negative iron balance. The introduction of deferasirox (DFRA) may benefit patients not tolerating L1, DFO or their combination. A simple, inexpensive synthesis of L1 has encouraged its manufacture in developing countries for the benefit of patients who could not afford the expensive imported chelating drugs or formulations.  相似文献   

5.
《Hemoglobin》2013,37(3):251-256
Millions of people are affected by hereditary hemochromatosis (HH) and thalassemia intermedia (TI), the iron overloading disorders caused by chronic increases in iron absorption. Genetic factors, regulatory pathways involving proteins of iron metabolism, non regulatory molecules, dietary constituents and iron binding drugs could affect iron absorption and could lead to iron overload or iron deficiency. Chelators and chelating drugs can affect both iron absorption and excretion. Deferoxamine (DFO), deferiprone (L1) and the DFO/L1 combination therapies have been used effectively for reversing the toxic side effects of iron overload including cardiac and liver damage in TI and HH patients where venesection is contraindicated. Selected protocols using DFO, L1 and their combination could be designed for optimizing chelation therapy in TI and HH. The use of deferasirox (DFRA) in HH and TI could cause an increase in iron and other toxic metal absorption. Future treatments of HH and TI could involve the use of iron chelating and other drugs not only for increasing iron excretion but also for preventing iron absorption.  相似文献   

6.
Forty-eight patients with early myelodysplastic syndrome (MDS) without excess of blasts, with average initial serum ferritin levels of 2739.5 μg/L (range 825-11287 μg/L), were treated with deferiprone (L1) in a daily dose of 40-90 mg/kg. Median duration of chelation treatment was 10.9 months (range 4-24 months). Chelation was effective (maintained or decreased iron stores) in 16 out of 22 patients (73%) with serum ferritin levels <2000 μg/L in contrast to only 12 out of 26 patients with serum ferritin levels >2000 μg/L. Combination of L1 with recombinant human erythropoietin (rHuEPO) (30-40 kU/week) resulted in effective chelation in five additional patients with serum ferritin levels >3000 μg/L. Incidence of adverse effects was comparable to that in thalassemic patients. Gastrointestinal symptoms represented the most frequent adverse effect of L1 therapy (37.5% of patients) that limited an effective escalation of the daily dose of the drug and led to discontinuation of the treatment for six patients. A decreased number of granulocytes was observed in five (13%) patients and agranulocytosis occurred in two patients (4%). Granulocyte counts were restored after cessation of L1 treatment and administration of granulocyte colony stimulating factor (G-CSF) in all but one patient. Administration of L1 in a daily dose of at least 75 mg/kg may represent an alternative approach in treatment of mild and moderate iron overload in MDS patients who cannot be treated with deferasirox (DFRA) or deferoxamine (DFO).  相似文献   

7.
The benefits of combined deferoxamine (DFO) and deferiprone (L1) chelation therapy, focusing on reducing myocardial iron loading, have been widely reported. Herein, we present the efficacy of combined chelation and its effects on iron load indices. Five thalassemia major (TM) patients who were undergoing chelation monotherapy with DFO were enrolled. Inclusion criteria were magnetic resonance imaging (MRI) T2* values, indicating serious heart and/or liver transfusional hemosiderosis. Combined therapy was started with the same dose of DFO and the addition of L1. The MRI T2* studies were repeated 18 months later. An Echo-Doppler study was performed in order to further evaluate the left ventricular (LV) systolic function. Within the 18 months' follow-up period, there was a significant statical decrease in mean serum ferritin levels. All patients increased their MRI T2* liver values, while two patients with very low MRI T2* also increased their myocardial values. The MRI ejection fraction (EF) and Echo-Doppler study measurements confirmed the improvement of systolic function. No adverse effects were reported. Combined L1 and DFO therapy seems to be effective in reducing iron excess in organ iron overloaded thalassemic patients. Magnetic resonance imaging can accurately quantify iron load, while echocardiography remains a reliable monitoring technology.  相似文献   

8.
Ototoxicity due to iron chelation therapy, especially deferoxamine (DFO), is frequently observed in patients who have a higher chelation index (>0.025). However, there is limited data on patients who are less well-chelated and on other chelating regimens, including deferiprone (L1), deferasirox (DFX), and a combination of DFO and L1. To determine the incidence of ototoxicity from iron chelators, we retrospectively analyzed our clinical records from January 1997 to December 2010. All transfusion-dependent thalassemia (TDT) patients received iron chelation therapy with mono DFX, DFO, L1, or a combination. All patients underwent routine otolaryngologic examination and pure-tone audiometry before starting each chelation regimen and were regularly followed every 6 months. One hundred thalassemic patients were enrolled and analyzed (48 males and 52 females), with a mean age of 12.11?±?4.48 years (range 2.5–22.5 years). Total summative duration of iron chelation therapy in all patients was 596.50 years. Nine patients were found to have conductive hearing loss. Sensorineural hearing loss (SNHL) was identified in seven patients but only four were determined to be associated with iron chelators; three patients were detected while undergoing DFO therapy and one patient with L1 therapy. None of patients undergoing DFO therapy had reached over the levels of chelation index. In our resource-limited setting with poor treatment compliance, there was a rather low incidence of ototoxicity after exposure to iron chelators. However, a routine audiometry remains recommended for early detection and intervention since SNHL still develops and results in a long-term morbidity.  相似文献   

9.
For the past 2–6 years, two groups of thalassemia patients, one of 16 patients on deferoxamine (DFO) monotherapy (35–80 mg/kg, 2–5 days/week) and the other group comprising 19 patients on a deferiprone (L1) and DFO combination therapy (L1 75–100 mg/kg/day and DFO 30–60 mg/kg, 1–5 days/week), have been studied and compared before and after the introduction of the combination therapy. The patients on the combination therapy were mainly those not complying or experiencing toxicity with DFO. The effects of chelation therapy on iron load was monitored using regular serum ferritin measurements and also magnetic resonance imaging (MRI) T2* relaxation time measurements at the end of the study. In both groups, cardiac MRI T2* levels were within the normal range (>19 ms) in more than 75% of the patients. There was a substantial improvement in serum ferritin levels and normalization of the MRI T2* levels of the liver in many cases treated with the combination therapy at effective doses by comparison to the DFO group, where the serum ferritin and MRI T2* levels were largely unchanged. It would appear that the major overall determining factor in the rapid clearance of excess iron in thalassemia patients and the maintenance of normal iron stores is the selection and implementation of effective chelation dose protocols. The International Committee on Chelation (ICOC) combination protocol L1 (80–110 mg/kg/day)/DFO (40–60 mg/kg at least 3 days per week) and to a lesser extent, DFO monotherapy at about 50 mg/kg/day, 5 days/week, appears to achieve this goal.  相似文献   

10.
Treatment of β-thalassemia major (β-TM) includes regular blood transfusions and iron chelation with subcutaneous injection of deferoxamine (DFO). During the last decade, a new chelation agent, deferiprone (L1), was introduced. The purpose of our study was to determine the level of awareness/education regarding chelation therapy, the degree of compliance to this therapy and their views of L1 in patients with β-TM. A relevant questionnaire was administered to 36 patients (12–26 years old) who were on combination chelation therapy with both DFO and L1. The majority of patients was well aware/educated about chelation therapy (76.6%), was compliant with this therapy (74.4%) and had a positive view towards oral chelation (86.0%). In conclusion, most patients with β-TM who were on combination chelation therapy with DFO and L1 were satisfied with this treatment and this results in high compliance rates.  相似文献   

11.
Iron mobilization from transferrin is one of the most important screening methods for the selection of chelators intended for clinical use in the treatment of iron overload in thalassemia and other conditions. In vitro and in vivo screening of approved and experimental chelating drugs has shown that only the α-ketohydroxypyridines deferiprone (L1) and 1-allyl-2 methyl-3-hydroxypyrid-4-one (L1NAll), are effective in the mobilization of iron from transferrin. Iron mobilization from transferrin and non-transferrin-bound-iron (NTBI) can be used to optimize existing chelation therapy protocols for the treatment of iron loaded patients. New chelation strategies involving L1 and its combination with deferoxamine (DFO) and other chelators can be used to increase iron excretion and reduce or prevent excess iron deposition in the heart and other vital organs of iron loaded patients by comparison to monotherapies. Deferiprone and its combinations may also have potential applications in the treatment of cancer, the anemia of chronic disease and other conditions.  相似文献   

12.
《Hemoglobin》2013,37(5):323-331
Our previous study showed that combined therapy with deferiprone (L1) and deferoxamine (DFO) was safe and efficacious in reducing iron overload in poorly-chelated thalassemia major patients for the short-term but the magnetic resonance imaging (MRI) T2* evaluation was not available at that time. Since October 2006, we applied a standardized chelation protocol by stratifying transfusion-dependent thalassemic patients into three groups, namely well-chelated group (A), poorly-chelated group without (B) or with (C) risk of cardiac complications, based on their serum ferritin (SF) levels and magnetic resonance imaging (MRI) cardiac T2* measurements. The patients in each group were given options of chelation regimens to improve their iron overload status. Chelation regimens included continuation or intensification of DFO alone (Regimen Ic or Ii, respectively), L1 alone (Regimen II), and combined therapy with L1 and DFO (Regimen III). Group A patients continued with Regimen Ic. Group B patients could opt for either Regimen Ii or II/III. Group C patients could opt for either Regimen Ii or III. Serum ferritin levels and MRI cardiac and liver T2* measurements were evaluated after 1 year of treatment. Fifty-seven patients (27 males, 30 females; age range 5–34 years, median: 25 years) were categorized into Group A (n = 3), B (n = 20) and C (n = 34). All Group A patients continued with DFO treatment. In Group B, seven were on Regimen Ii, five on Regimen II and five on Regimen III. In Group C, five were on Regimen Ii, two on Regimen II and 26 on Regimen III. Significant improvement was noted only for Group C patients using Regimen III (combined therapy) in SF levels, cardiac T2* and liver T2* measurements.  相似文献   

13.
《Hemoglobin》2013,37(5):287-295
Thalassemia is endemic in Cyprus with a frequency of 1 in 6 persons being a heterozygote and about 1 in 1,000 a homozygous thalassemia major patient. Cyprus has been a pioneer nation in reducing and almost eliminating the number of births of thalassemia major patients by introducing prenatal and antenatal diagnosis. The risks associated with bone marrow transplantation (BMT) make transfusion and chelation therapy the major form of treatment for the vast majority of thalassemia patients. Improved transfusion techniques, diagnostic methods, iron chelation and supportive therapy have increased the quality of life and survival of patients, some of whom are exceeding 50 years of age. The introduction of effective chelation therapy protocols using primarily deferiprone (L1) in combination with deferoxamine (DFO) resulted in the reduction of iron overload induced cardiac failures, which is the main cause of death in thalassemia major. Despite their chronic condition and tedious clinical management many patients are successful professionals, married and have children. The advancement in treatment is transforming thalassemia from a fatal to a chronic condition and some families are opting for giving birth to a thalassemic child rather than abortion.  相似文献   

14.
The benefits of combined deferoxamine (DFO) and deferiprone (L1) chelation therapy, focusing on reducing myocardial iron loading, have been widely reported. Herein, we present the efficacy of combined chelation and its effects on iron load indices. Five thalassemia major (TM) patients who were undergoing chelation monotherapy with DFO were enrolled. Inclusion criteria were magnetic resonance imaging (MRI) T2* values, indicating serious heart and/or liver transfusional hemosiderosis. Combined therapy was started with the same dose of DFO and the addition of L1. The MRI T2* studies were repeated 18 months later. An Echo-Doppler study was performed in order to further evaluate the left ventricular (LV) systolic function. Within the 18 months' follow-up period, there was a significant statical decrease in mean serum ferritin levels. All patients increased their MRI T2* liver values, while two patients with very low MRI T2* also increased their myocardial values. The MRI ejection fraction (EF) and Echo-Doppler study measurements confirmed the improvement of systolic function. No adverse effects were reported. Combined L1 and DFO therapy seems to be effective in reducing iron excess in organ iron overloaded thalassemic patients. Magnetic resonance imaging can accurately quantify iron load, while echocardiography remains a reliable monitoring technology.  相似文献   

15.
《Hemoglobin》2013,37(5):352-360
Infections are among the leading causes of death for thalassemia major patients. The known predisposing factors of infection include prior splenectomy, iron overload and use of iron chelator such as deferoxamine (DFO). While encapsulated organisms frequently found in splenectomized patients were readily controlled by prophylactic vaccination and vigilant antibiotic treatment, ferrophilic organisms such as Yersinia and Klebsiella remain common pathogens in thalassemic patients. Yersinia infections are more prevalent in temperate regions and Klebsiella infections are commonly found in tropical and subtropical areas. While the use of DFO further aggravates the risk of Yersinia infection, oral chelators such as deferiprone (L1) do not enhance the growth of Yersinia in vitro or in vivo. We found that the growth of Klebsiella was marginally enhanced by DFO in vitro when compared to Yersinia. Such an unfavorable effect was not found in either L1 or deferasirox (DFRA) in vitro. The growth of Aeromonas was not affected by the presence of all three forms of chelators. Therefore, we suggest that factors other than DFO may account for the increased prevalence of Klebsiella and Aeromonas infection in Asian thalassemic patients.  相似文献   

16.
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.  相似文献   

17.
《Hemoglobin》2013,37(5):386-397
Tissue damage caused by oxidative stress is a common characteristic of many conditions involving different major organs such as the brain, heart, liver and kidneys. The treatment of such conditions using classical antioxidants is not in most cases sufficient or effective because it lacks specificity and has a low therapeutic index. Increased evidence from in vitro, in vivo and clinical studies suggest that deferiprone (L1) can be used as a potent pharmaceutical antioxidant by mobilizing labile iron and copper and/or inhibiting their catalytic activity in the formation of free radicals and oxidative stress in tissue damage. The high therapeutic index, tissue penetration, rapid iron binding and clearance of the iron complex, and the low toxicity of L1, support its application as an antioxidant pharmaceutical for adjuvant, alternative or main therapy, especially in conditions where other treatments have failed. Substantial clinical improvement and reversal in most cases of the tissue damage has been observed in cardiomyopathy in thalassemia, diabetic nephropathy and glomerulonephritis in kidney disease, Friedreich's Ataxia and Fanconi Anemia patients. In contrast to L1, both deferoxamine (DFO) and deferasirox (DFRA) have major disadvantages in their use in non iron loading conditions due to toxicity implications. Further studies in the above and other conditions and optimization of the L1 therapy in each individual will increase the prospects of the application and role of L1 as a universal antioxidant pharmaceutical.  相似文献   

18.
《Hemoglobin》2013,37(5):312-322
Excess cardiac iron deposition leads to congestive cardiac failure and accounts for more than 70% of deaths in thalassemia major patients. In three separate studies involving 145 thalassemia patients, serum ferritin and magnetic resonance imaging (MRI) relaxation times T2 and T2* have been compared for assessing iron load levels during chelation treatment. In two studies, variable levels of cardiac iron load have been detected by T2 and T2* in patients treated with deferoxamine (DFO), which, however, were unrelated to serum ferritin. In most cases, similar range levels from normal to severe cardiac iron load could be identified by both the T2 and T2* methods. However, in a few cases there were substantial differences in the levels detected between the two methods. In the third study, the ferrikinetics of the normalization of the iron stores during the International Committee on Chelation (ICOC) deferiprone (L1)/DFO combination protocol was followed up using T2 and T2* and serum ferritin. Iron deposits were found not to be proportionally distributed between the liver and the heart or uniformly distributed within each organ. Iron mobilization in each patient varied and iron deposits in each organ were cleared at different rates. Despite some limitations, the application of the MRI relaxation times T2 and T2* offers the best diagnostic methods for iron overload estimations in most organs and especially the heart. These MRI methods and serum ferritin could also be used for the ferrikinetics of iron mobilization and removal during chelation therapy and the normalization of the iron stores during the ICOC L1/DFO combination protocol. There is a need to standardize the two MRI relaxation times T2 and T2* methods and identify the factors causing the differences between them.  相似文献   

19.
Annita Kolnagou 《Hemoglobin》2013,37(2):239-249
The International Committee on Oral Chelators (ICOC) combination therapy protocol involving the administration of deferiprone (L1) during the day (80–110 mg/kg/day) and deferoxamine (DFO) (40–60 mg/kg at least 3 days/week) during the night for 8–12 hours using a pump, or the whole 24 hours using an elastomeric pump infuser, has been tested in 11 thalassemia patients (seven males, four females) over a period of 9–28 months. The patients had variable serum ferritin levels (0.54–4.6 mg/L) and cardiac iron load ranging from normal to severe siderosis levels (MRI T2*: 4.7–45 ms). There was a substantial overall reduction in serum ferritin levels (0.17–2.16 mg/L) and normalization of cardiac iron (MRI T2* >20 ms) in all patients. In two patients with severe and moderate cardiac iron load range levels, cardiac iron normalization was achieved within 9–10 months. Two patients on L1 monotherapy (80–120 mg/kg/day) maintained normal range MRI T2* cardiac iron levels over the same period. The ICOC combination therapy protocol appears to be the most effective and least cumbersome form of chelation treatment for the rapid clearance of excess iron from the heart.  相似文献   

20.
For the past 2-6 years, two groups of thalassemia patients, one of 16 patients on deferoxamine (DFO) monotherapy (35-80 mg/kg, 2-5 days/week) and the other group comprising 19 patients on a deferiprone (L1) and DFO combination therapy (L1 75-100 mg/kg/day and DFO 30-60 mg/kg, 1-5 days/week), have been studied and compared before and after the introduction of the combination therapy. The patients on the combination therapy were mainly those not complying or experiencing toxicity with DFO. The effects of chelation therapy on iron load was monitored using regular serum ferritin measurements and also magnetic resonance imaging (MRI) T2* relaxation time measurements at the end of the study. In both groups, cardiac MRI T2* levels were within the normal range (>19 ms) in more than 75% of the patients. There was a substantial improvement in serum ferritin levels and normalization of the MRI T2* levels of the liver in many cases treated with the combination therapy at effective doses by comparison to the DFO group, where the serum ferritin and MRI T2* levels were largely unchanged. It would appear that the major overall determining factor in the rapid clearance of excess iron in thalassemia patients and the maintenance of normal iron stores is the selection and implementation of effective chelation dose protocols. The International Committee on Chelation (ICOC) combination protocol L1 (80-110 mg/kg/day)/DFO (40-60 mg/kg at least 3 days per week) and to a lesser extent, DFO monotherapy at about 50 mg/kg/day, 5 days/week, appears to achieve this goal.  相似文献   

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