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Kontoghiorghes GJ. Drug Selection and Posology, Optimal Therapies and Risk/Benefit Assessment in Medicine: The Paradigm of Iron-Chelating Drugs. Int J Mol Sci 2023; 24:16749. [PMID: 38069073 PMCID: PMC10706143 DOI: 10.3390/ijms242316749] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 11/19/2023] [Accepted: 11/22/2023] [Indexed: 12/18/2023] Open
Abstract
The design of clinical protocols and the selection of drugs with appropriate posology are critical parameters for therapeutic outcomes. Optimal therapeutic protocols could ideally be designed in all diseases including for millions of patients affected by excess iron deposition (EID) toxicity based on personalised medicine parameters, as well as many variations and limitations. EID is an adverse prognostic factor for all diseases and especially for millions of chronically red-blood-cell-transfused patients. Differences in iron chelation therapy posology cause disappointing results in neurodegenerative diseases at low doses, but lifesaving outcomes in thalassemia major (TM) when using higher doses. In particular, the transformation of TM from a fatal to a chronic disease has been achieved using effective doses of oral deferiprone (L1), which improved compliance and cleared excess toxic iron from the heart associated with increased mortality in TM. Furthermore, effective L1 and L1/deferoxamine combination posology resulted in the complete elimination of EID and the maintenance of normal iron store levels in TM. The selection of effective chelation protocols has been monitored by MRI T2* diagnosis for EID levels in different organs. Millions of other iron-loaded patients with sickle cell anemia, myelodysplasia and haemopoietic stem cell transplantation, or non-iron-loaded categories with EID in different organs could also benefit from such chelation therapy advances. Drawbacks of chelation therapy include drug toxicity in some patients and also the wide use of suboptimal chelation protocols, resulting in ineffective therapies. Drug metabolic effects, and interactions with other metals, drugs and dietary molecules also affected iron chelation therapy. Drug selection and the identification of effective or optimal dose protocols are essential for positive therapeutic outcomes in the use of chelating drugs in TM and other iron-loaded and non-iron-loaded conditions, as well as general iron toxicity.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol 3021, Cyprus
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Kontoghiorghes GJ. The Vital Role Played by Deferiprone in the Transition of Thalassaemia from a Fatal to a Chronic Disease and Challenges in Its Repurposing for Use in Non-Iron-Loaded Diseases. Pharmaceuticals (Basel) 2023; 16:1016. [PMID: 37513928 PMCID: PMC10384919 DOI: 10.3390/ph16071016] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Revised: 07/13/2023] [Accepted: 07/15/2023] [Indexed: 07/30/2023] Open
Abstract
The iron chelating orphan drug deferiprone (L1), discovered over 40 years ago, has been used daily by patients across the world at high doses (75-100 mg/kg) for more than 30 years with no serious toxicity. The level of safety and the simple, inexpensive synthesis are some of the many unique properties of L1, which played a major role in the contribution of the drug in the transition of thalassaemia from a fatal to a chronic disease. Other unique and valuable clinical properties of L1 in relation to pharmacology and metabolism include: oral effectiveness, which improved compliance compared to the prototype therapy with subcutaneous deferoxamine; highly effective iron removal from all iron-loaded organs, particularly the heart, which is the major target organ of iron toxicity and the cause of mortality in thalassaemic patients; an ability to achieve negative iron balance, completely remove all excess iron, and maintain normal iron stores in thalassaemic patients; rapid absorption from the stomach and rapid clearance from the body, allowing a greater frequency of repeated administration and overall increased efficacy of iron excretion, which is dependent on the dose used and also the concentration achieved at the site of drug action; and its ability to cross the blood-brain barrier and treat malignant, neurological, and microbial diseases affecting the brain. Some differential pharmacological activity by L1 among patients has been generally shown in relation to the absorption, distribution, metabolism, elimination, and toxicity (ADMET) of the drug. Unique properties exhibited by L1 in comparison to other drugs include specific protein interactions and antioxidant effects, such as iron removal from transferrin and lactoferrin; inhibition of iron and copper catalytic production of free radicals, ferroptosis, and cuproptosis; and inhibition of iron-containing proteins associated with different pathological conditions. The unique properties of L1 have attracted the interest of many investigators for drug repurposing and use in many pathological conditions, including cancer, neurodegenerative conditions, microbial conditions, renal conditions, free radical pathology, metal intoxication in relation to Fe, Cu, Al, Zn, Ga, In, U, and Pu, and other diseases. Similarly, the properties of L1 increase the prospects of its wider use in optimizing therapeutic efforts in many other fields of medicine, including synergies with other drugs.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol 3021, Cyprus
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Ibrahim AS, Abd El-Fatah AH, Abd El-Halim AF, Mohamed FF. Serum Ferritin Levels and Other Associated Parameters with Diabetes Mellitus in Adult Patients Suffering from Beta Thalassemia Major. J Blood Med 2023; 14:67-81. [PMID: 36785546 PMCID: PMC9921443 DOI: 10.2147/jbm.s390666] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 01/12/2023] [Indexed: 02/08/2023] Open
Abstract
Background Although beta thalassemia major (BTM) patients are properly treated with blood transfusions in accompany with iron chelation therapy, they suffer from complications, such as diabetes mellitus (DM). Purpose The purpose was to detect the critical serum ferritin level and other parameters correlated with DM among adult BTM patients. Also, it was to study whether each of these parameters is associated with a certain period of age. Patients and Methods This study included 200 adult BTM patients. A cross-sectional study was carried out. Patients clinical and laboratory variables, such as ferritin levels, and fasting blood glucose (FBS) were extracted from medical records at Zagazig University Hospital, Egypt. Liver and cardiac iron contents were assessed using MRI T2* methods. Statistical analysis was performed using IBM SPSS V26.0 software package. Results The overall frequency of DM over the total sample equals 6.5%. There were no impaired fasting glucose (IFG) in the medical records. Statistical significance between serum ferritin and DM was (P = 0.014). The serum ferritin 2500 ng/mL with age group (27-<32) years-old were risk factors. The distributions of DM according to BMI were (3.5%) of class overweight. Significant association between DM and BMI was (r = 0.357, P < 0.001). Liver MRI T2* has significant correlation with serum ferritin, but cardiac MRI T2* was poorly correlated. Association between liver and cardiac MRI T2* was not found. Conclusion Age group (27-<32) years-old and ferritin >2500 ng/mL should be properly treated immediately. The serum ferritin and BMI of class "overweight" were risk factors for DM. Factors such as diet should be followed. Serum ferritin can be used for estimating liver iron content for economic factors. But cardiac MRI T2* must be performed for evaluating cardiac iron accurately.
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Affiliation(s)
- Ahmed Saleh Ibrahim
- Department of Internal Medicine, Faculty of Medicine, Mansoura University, Mansoura, Egypt,Correspondence: Ahmed Saleh Ibrahim, Tel +20 109 232 6689, Email
| | | | | | - Farid Fawzy Mohamed
- Department of Internal Medicine, Faculty of Medicine, Zagazig University, Zagazig, Egypt
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Kontoghiorghes GJ. Deferiprone: A Forty-Year-Old Multi-Targeting Drug with Possible Activity against COVID-19 and Diseases of Similar Symptomatology. Int J Mol Sci 2022; 23:ijms23126735. [PMID: 35743183 PMCID: PMC9223898 DOI: 10.3390/ijms23126735] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 06/13/2022] [Accepted: 06/14/2022] [Indexed: 02/01/2023] Open
Abstract
The need for preparing new strategies for the design of emergency drug therapies against COVID-19 and similar diseases in the future is rather urgent, considering the high rate of morbidity and especially mortality associated with COVID-19, which so far has exceeded 18 million lives. Such strategies could be conceived by targeting the causes and also the serious toxic side effects of the diseases, as well as associated biochemical and physiological pathways. Deferiprone (L1) is an EMA- and FDA-approved drug used worldwide for the treatment of iron overload and also other conditions where there are no effective treatments. The multi-potent effects and high safety record of L1 in iron loaded and non-iron loaded categories of patients suggests that L1 could be developed as a “magic bullet” drug against COVID-19 and diseases of similar symptomatology. The mode of action of L1 includes antiviral, antimicrobial, antioxidant, anti-hypoxic and anti-ferroptotic effects, iron buffering interactions with transferrin, iron mobilizing effects from ferritin, macrophages and other cells involved in the immune response and hyperinflammation, as well as many other therapeutic interventions. Similarly, several pharmacological and other characteristics of L1, including extensive tissue distribution and low cost of production, increase the prospect of worldwide availability, as well as many other therapeutic approach strategies involving drug combinations, adjuvant therapies and disease prevention.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol 3021, Cyprus
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Marini V, Pinto VM, Stella M, Fucile C, Lantieri F, Luci G, Gianesin B, Bacigalupo L, Forni GL, Mattioli F. Effect of Aging on Deferasirox Therapy in Transfusion-dependent Patients. A Prospective- Retrospective, Cohort-study. Curr Drug Metab 2022; 23:1072-1079. [PMID: 36503397 DOI: 10.2174/1389200224666221209144420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 10/24/2022] [Accepted: 11/11/2022] [Indexed: 12/14/2022]
Abstract
BACKGROUND Iron-chelation therapy is life-saving in patients on a chronic transfusion regimen as it reduces organ damage related to iron deposition in the tissues. Deferasirox, an iron-chelator, is characterized by pharmacokinetics variability, and some patients may discontinue the treatment due to toxicities. OBJECTIVE Understanding whether deferasirox plasma levels are related to patients' specific characteristics could help to optimize DFX dosage. METHODS We analyzed deferasirox plasma concentration in 57 transfusion-dependent anemic patients using the HPLC method in this prospective-retrospective cohort study. All outpatients (3 to 98 years) were treated with deferasirox (film-coated tablet) for at least one year (median dose, 16.5 mg/Kg once a day). Deferasirox plasma concentration was normalized for dose/Kg (C/dose) and corrected with a linear regression model that relates C/dose and the time of blood sampling (Cref/dose). RESULTS No significant differences in Cref/dose were found between males and females, either between different types of hemoglobinopathies or depending on the presence of the UGT1A1*28 polymorphism. Cref/dose has a positive and significant correlation with age, creatinine, and direct bilirubin. Cref/dose, instead, has a negative and significant correlation with Liver Iron Concentration (LIC), ferritin, and eGFR. Cref/dose was significantly different between three age categories <18yrs, 18-50yrs, and >50yrs, with Cref/dose median values of 1.0, 1.2, and 1.5, respectively. CONCLUSION The study evidenced that to ensure the efficacy of deferasirox in terms of control over LIC and, at the same time, a lesser influence on renal function, the dose of the drug to be administered to an elderly patient could be reduced.
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Affiliation(s)
- Valeria Marini
- Clinical Pharmacology Unit, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
- Department of Internal Medicine, Clinical Pharmacology and Toxicology Unit, University of Genoa, Viale Benedetto XV, n. 2. I-16132 Genoa, Italy
| | - Valeria Maria Pinto
- Centro della Microcitemia, Anemie Congenite e Dismetabolismo del Ferro, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
| | - Manuela Stella
- Clinical Pharmacology Unit, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
- Department of Internal Medicine, Clinical Pharmacology and Toxicology Unit, University of Genoa, Viale Benedetto XV, n. 2. I-16132 Genoa, Italy
| | - Carmen Fucile
- Unit of Addiction and Hepatology, Alcohological Regional Center, ASL3 San Martino Hospital, Largo R. Benzi, n. 10, I-16132 Genoa, Italy
| | - Francesca Lantieri
- Health Science Department, Biostatistics Unit, University of Genoa, Via Pastore, n. 1. I-16132 Genoa, Italy
| | - Giacomo Luci
- Department of Clinical and Experimental Medicine, University of Pisa, Via Savi, n.10. I-56126 Pisa, Italy
| | - Barbara Gianesin
- Centro della Microcitemia, Anemie Congenite e Dismetabolismo del Ferro, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
- For Anemia Foundation, Via Garibaldi, n. 7. I-16124 Genoa, Italy
| | - Lorenzo Bacigalupo
- Department of Diagnostic Imaging, Radiology and Nuclear Medicine, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
| | - Gian Luca Forni
- Centro della Microcitemia, Anemie Congenite e Dismetabolismo del Ferro, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
| | - Francesca Mattioli
- Clinical Pharmacology Unit, EO Ospedali Galliera, Mura delle Cappuccine, n. 14. I-16128 Genoa, Italy
- Department of Internal Medicine, Clinical Pharmacology and Toxicology Unit, University of Genoa, Viale Benedetto XV, n. 2. I-16132 Genoa, Italy
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Ion-imprinted-based nanochelators for iron(III) removal from synthetic gastric fluid. Polym Bull (Berl) 2021. [DOI: 10.1007/s00289-021-03932-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Kontoghiorghes GJ. Differences between the European Union and United States of America in Drug Regulatory Affairs Affect Global Patient Safety Standards and Public Health Awareness: The Case of Deferasirox and Other Iron Chelating Drugs. MEDICINES (BASEL, SWITZERLAND) 2021; 8:36. [PMID: 34357152 PMCID: PMC8304852 DOI: 10.3390/medicines8070036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 06/17/2021] [Accepted: 07/05/2021] [Indexed: 06/13/2023]
Abstract
Regulatory policies on drugs have a major impact on patient safety and survival. Some pharmaceutical companies employ all possible methods to achieve maximum sales in relation to the monopoly of their patented drugs, leading sometimes to irregularities and illegal activities. Misinformation on the orphan drug deferasirox has reached the stage of criminal investigations and fines exceeding USD 100 million. Additional lawsuits of USD 3.5 billion for damages and civil fines were also filed by the FBI of the USA involving deferasirox and mycophenolic acid, which were later settled with an additional fine of USD 390 million. Furthermore, a USD 345 million fine was also settled for bribes and other illegal overseas operations including an EU country. However, no similar fines for illegal practises or regulatory control violations have been issued in the EU. Misconceptions and a lack of clear guidelines for the use of deferasirox in comparison to deferiprone and deferoxamine appear to reduce the effective treatment prospects and to increase the toxicity risks for thalassaemia and other iron loaded patients. Similar issues have been raised for the activities of other pharmaceutical companies promoting the use of new patented versus generic drugs. Treatments for different categories of patients using new patented drugs are mostly market driven with no clear safeguards or guidelines for risk/benefit assessment indications or for individualised effective and safe optimum therapies. There is a need for the establishment of an international organisation, which can monitor and assess the risk/benefit assessment and marketing of drugs in the EU and globally for the benefit of patients. The pivotal role of the regulatory drug authorities and the prescribing physicians for identifying individualised optimum therapies is essential for improving the survival and safety of millions of patients worldwide.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol 3021, Cyprus
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Kontoghiorghes GJ, Kontoghiorghe CN. Iron and Chelation in Biochemistry and Medicine: New Approaches to Controlling Iron Metabolism and Treating Related Diseases. Cells 2020; 9:E1456. [PMID: 32545424 PMCID: PMC7349684 DOI: 10.3390/cells9061456] [Citation(s) in RCA: 79] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/04/2020] [Accepted: 06/05/2020] [Indexed: 02/07/2023] Open
Abstract
Iron is essential for all living organisms. Many iron-containing proteins and metabolic pathways play a key role in almost all cellular and physiological functions. The diversity of the activity and function of iron and its associated pathologies is based on bond formation with adjacent ligands and the overall structure of the iron complex in proteins or with other biomolecules. The control of the metabolic pathways of iron absorption, utilization, recycling and excretion by iron-containing proteins ensures normal biologic and physiological activity. Abnormalities in iron-containing proteins, iron metabolic pathways and also other associated processes can lead to an array of diseases. These include iron deficiency, which affects more than a quarter of the world's population; hemoglobinopathies, which are the most common of the genetic disorders and idiopathic hemochromatosis. Iron is the most common catalyst of free radical production and oxidative stress which are implicated in tissue damage in most pathologic conditions, cancer initiation and progression, neurodegeneration and many other diseases. The interaction of iron and iron-containing proteins with dietary and xenobiotic molecules, including drugs, may affect iron metabolic and disease processes. Deferiprone, deferoxamine, deferasirox and other chelating drugs can offer therapeutic solutions for most diseases associated with iron metabolism including iron overload and deficiency, neurodegeneration and cancer, the detoxification of xenobiotic metals and most diseases associated with free radical pathology.
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Affiliation(s)
- George J. Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, CY-3021 Limassol, Cyprus;
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The History of Deferiprone (L1) and the Paradigm of the Complete Treatment of Iron Overload in Thalassaemia. Mediterr J Hematol Infect Dis 2020; 12:e2020011. [PMID: 31934321 PMCID: PMC6951358 DOI: 10.4084/mjhid.2020.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 12/18/2019] [Indexed: 01/19/2023] Open
Abstract
Deferiprone (L1) was originally designed, synthesised and screened in vitro and in vivo in 1981 by Kontoghiorghes G. J. following his discovery of the novel alpha-ketohydroxypyridine class of iron chelators (1978–1981), which were intended for clinical use. The journey through the years for the treatment of thalassaemia with L1 has been a very difficult one with an intriguing turn of events, which continue until today. Despite many complications, such as the extensive use of L1 suboptimal dose protocols, the aim of chelation therapy-namely, the complete removal of excess iron in thalassaemia major patients, has been achieved in most cases following the introduction of specific L1 and L1/deferoxamine combinations. Many such patients continue to maintain normal iron stores. Thalassemia has changed from a fatal to chronic disease; also thanks to L1 therapy and thalassaemia patients are active professional members in all sectors of society, have their own families with children and grandchildren and their lifespan is approaching that of normal individuals. No changes in the low toxicity profile of L1 have been observed in more than 30 years of clinical use and prophylaxis against the low incidence of agranulocytosis is maintained using mandatory monitoring of weekly white blood cells’ count. Thousands of thalassaemia patients are still denied the cardioprotective and other beneficial effects of L1 therapy. The safety of L1 in thalassaemia and other non-iron loaded diseases resulted in its selection as one of the leading therapeutics for the treatment of Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration and other similar cases. There are also increasing prospects for the application of L1 as a main, alternative or adjuvant therapy in many pathological conditions including cancer, infectious diseases and as a general antioxidant for diseases related to free radical pathology.
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Kontoghiorghes GJ, Kontoghiorghe CN. Prospects for the introduction of targeted antioxidant drugs for the prevention and treatment of diseases related to free radical pathology. Expert Opin Investig Drugs 2019; 28:593-603. [DOI: 10.1080/13543784.2019.1631284] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science Technology, Environment and Medicine, Limassol, Cyprus
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Saiviroonporn P, Korpraphong P, Viprakasit V, Krittayaphong R. An Automated Segmentation of R2* Iron-Overloaded Liver Images Using a Fuzzy C-Mean Clustering Scheme. J Comput Assist Tomogr 2018; 42:387-398. [PMID: 29443702 DOI: 10.1097/rct.0000000000000713] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
OBJECTIVES The objectives of this study were to develop and test an automated segmentation of R2* iron-overloaded liver images using fuzzy c-mean (FCM) clustering and to evaluate the observer variations. MATERIALS AND METHODS Liver R2* images and liver iron concentration (LIC) maps of 660 thalassemia examinations were randomly separated into training (70%) and testing (30%) cohorts for development and evaluation purposes, respectively. Two-dimensional FCM used R2* images, and the LIC map was implemented to segment vessels from the parenchyma. Two automated FCM variables were investigated using new echo time and membership threshold selection criteria based on the FCM centroid distance and LIC levels, respectively. The new method was developed on a training cohort and compared with manual segmentation for segmentation accuracy and to a previous semiautomated method, and a semiautomated scheme was suggested to improve unsuccessful results. The automated variables found from the training cohort were assessed for their effectiveness in the testing cohort, both quantitatively and qualitatively (the latter by 2 abdominal radiologists using a grading method, with evaluations of observer variations). A segmentation error of less than 30% was considered to be a successful result in both cohorts, whereas, in the testing cohort, a good grade obtained from satisfactory automated results was considered a success. RESULTS The centroid distance method has a segmentation accuracy comparable with the previous-best, semiautomated method. About 94% and 90% of the examinations in the training and testing cohorts were automatically segmented out successfully, respectively. The failed examinations were successfully segmented out with thresholding adjustment (3% and 8%) or by using alternative results from the previous 1-dimensional FCM method (3% and 2%) in the training and testing cohorts, respectively. There were no failed segmentation examinations in either cohort. The intraobserver and interobserver variabilities were found to be in substantial agreement. CONCLUSIONS Our new method provided a robust automated segmentation outcome with a high ease of use for routine clinical application.
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Affiliation(s)
| | | | - Vip Viprakasit
- Haematology/Oncology Division, Department of Pediatrics and Thalassemia Center, and
| | - Rungroj Krittayaphong
- Division of Cardiology, Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand
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Kontoghiorghe CN, Kontoghiorghes GJ. New developments and controversies in iron metabolism and iron chelation therapy. World J Methodol 2016; 6:1-19. [PMID: 27019793 PMCID: PMC4804243 DOI: 10.5662/wjm.v6.i1.1] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2015] [Revised: 11/17/2015] [Accepted: 12/17/2015] [Indexed: 02/06/2023] Open
Abstract
Iron is essential for all organisms including microbial, cancer and human cells. More than a quarter of the human population is affected by abnormalities of iron metabolism, mainly from iron deficiency and iron overload. Iron also plays an important role in free radical pathology and oxidative damage which is observed in almost all major diseases, cancer and ageing. New developments include the complete treatment of iron overload and reduction of morbidity and mortality in thalassaemia using deferiprone and selected deferiprone/deferoxamine combinations and also the use of the maltol iron complex in the treatment of iron deficiency anaemia. There is also a prospect of using deferiprone as a universal antioxidant in non iron overloaded diseases such as neurodegenerative, cardiovascular, renal, infectious diseases and cancer. New regulatory molecules of iron metabolism such as endogenous and dietary chelating molecules, hepcidin, mitochondrial ferritin and their role in health and disease is under evaluation. Similarly, new mechanisms of iron deposition, removal, distribution and toxicity have been identified using new techniques such as magnetic resonance imaging increasing our understanding of iron metabolic processes and the targeted treatment of related diseases. The uniform distribution of iron in iron overload between organs and within each organ is no longer valid. Several other controversies such as the toxicity impact of non transferrin bound iron vs injected iron, the excess levels of iron in tissues causing toxicity and the role of chelation on iron absorption need further investigation. Commercial interests of pharmaceutical companies and connections to leading journals are playing a crucial role in shaping worldwide medical opinion on drug sales and use but also patients' therapeutic outcome and safety. Major controversies include the selection criteria and risk/benefit assessment in the use of deferasirox in thalassaemia and more so in idiopathic haemochromatosis, thalassaemia intermedia and ex-thalassaemia transplanted patients who are safely treated with venesection. Iron chelating drugs can override normal regulatory pathways, correct iron imbalance and minimise iron toxicity. The use of iron chelating drugs as main, alternative or adjuvant therapy is in progress in many conditions, especially those with non established or effective therapies.
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Kontoghiorghe CN, Kontoghiorghes GJ. Efficacy and safety of iron-chelation therapy with deferoxamine, deferiprone, and deferasirox for the treatment of iron-loaded patients with non-transfusion-dependent thalassemia syndromes. DRUG DESIGN DEVELOPMENT AND THERAPY 2016; 10:465-81. [PMID: 26893541 PMCID: PMC4745840 DOI: 10.2147/dddt.s79458] [Citation(s) in RCA: 93] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The prevalence rate of thalassemia, which is endemic in Southeast Asia, the Middle East, and the Mediterranean, exceeds 100,000 live births per year. There are many genetic variants in thalassemia with different pathological severity, ranging from a mild and asymptomatic anemia to life-threatening clinical effects, requiring lifelong treatment, such as regular transfusions in thalassemia major (TM). Some of the thalassemias are non-transfusion-dependent, including many thalassemia intermedia (TI) variants, where iron overload is caused by chronic increase in iron absorption due to ineffective erythropoiesis. Many TI patients receive occasional transfusions. The rate of iron overloading in TI is much slower in comparison to TM patients. Iron toxicity in TI is usually manifested by the age of 30-40 years, and in TM by the age of 10 years. Subcutaneous deferoxamine (DFO), oral deferiprone (L1), and DFO-L1 combinations have been effectively used for more than 20 years for the treatment of iron overload in TM and TI patients, causing a significant reduction in morbidity and mortality. Selected protocols using DFO, L1, and their combination can be designed for personalized chelation therapy in TI, which can effectively and safely remove all the excess toxic iron and prevent cardiac, liver, and other organ damage. Both L1 and DF could also prevent iron absorption. The new oral chelator deferasirox (DFX) increases iron excretion and decreases liver iron in TM and TI. There are drawbacks in the use of DFX in TI, such as limitations related to dose, toxicity, and cost, iron load of the patients, and ineffective removal of excess iron from the heart. Furthermore, DFX appears to increase iron and other toxic metal absorption. Future treatments of TI and related iron-loading conditions could involve the use of the iron-chelating drugs and other drug combinations not only for increasing iron excretion but also for preventing iron absorption.
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Affiliation(s)
| | - George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus
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Kontoghiorghe CN, Kolnagou A, Kontoghiorghes GJ. Phytochelators Intended for Clinical Use in Iron Overload, Other Diseases of Iron Imbalance and Free Radical Pathology. Molecules 2015; 20:20841-72. [PMID: 26610453 PMCID: PMC6332094 DOI: 10.3390/molecules201119725] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/03/2015] [Accepted: 11/09/2015] [Indexed: 12/26/2022] Open
Abstract
Iron chelating drugs are primarily and widely used in the treatment of transfusional iron overload in thalassaemia and similar conditions. Recent in vivo and clinical studies have also shown that chelators, and in particular deferiprone, can be used effectively in many conditions involving free radical damage and pathology including neurodegenerative, renal, hepatic, cardiac conditions and cancer. Many classes of phytochelators (Greek: phyto (φυτό)—plant, chele (χηλή)—claw of the crab) with differing chelating properties, including plant polyphenols resembling chelating drugs, can be developed for clinical use. The phytochelators mimosine and tropolone have been identified to be orally active and effective in animal models for the treatment of iron overload and maltol for the treatment of iron deficiency anaemia. Many critical parameters are required for the development of phytochelators for clinical use including the characterization of the therapeutic targets, ADMET, identification of the therapeutic index and risk/benefit assessment by comparison to existing therapies. Phytochelators can be developed and used as main, alternative or adjuvant therapies including combination therapies with synthetic chelators for synergistic and or complimentary therapeutic effects. The development of phytochelators is a challenging area for the introduction of new pharmaceuticals which can be used in many diseases and also in ageing. The commercial and other considerations for such development have great advantages in comparison to synthetic drugs and could also benefit millions of patients in developing countries.
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Affiliation(s)
- Christina N Kontoghiorghe
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, 3 Ammochostou Street, Limassol 3021, Cyprus.
| | - Annita Kolnagou
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, 3 Ammochostou Street, Limassol 3021, Cyprus.
| | - George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, 3 Ammochostou Street, Limassol 3021, Cyprus.
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Saiviroonporn P, Viprakasit V, Krittayaphong R. Improved R2* liver iron concentration assessment using a novel fuzzy c-mean clustering scheme. BMC Med Imaging 2015; 15:52. [PMID: 26530825 PMCID: PMC4632332 DOI: 10.1186/s12880-015-0097-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2015] [Accepted: 10/29/2015] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND In thalassemia patients, R2* liver iron concentration (LIC) measurement is a common clinical tool for assessing iron overload and for determining necessary chelator dose and evaluating its efficacy. Despite the importance of accurate LIC measurement, existing methods suffer from LIC variability, especially at the severe iron overload range due to inclusion of vessel parts in LIC calculation. In this study, we build upon previous Fuzzy C-Mean (FCM) clustering work to formulate a scheme with superior performance in segmenting vessel pixels from the parenchyma. Our method (MIX-FCM) combines our novel 2D-FCM with the existing 1D-FCM algorithm. This study further assessed possible optimal clustering parameters (OP scheme) and proposed a semi-automatic (SA) scheme for routine clinical application. METHODS Segmentation of liver parenchyma and vessels was performed on T2* images and their LIC maps in 196 studies from 147 thalassemia major patients. We used manual segmentation as the reference. 1D-FCM clustering was performed on the acquired image alone and 2D-FCM used both the acquired image and its LIC data. To execute the MIX-FCM method, the best outcome (OP-MIX-FCM) was selected from the aforementioned methods and was compared to the SA-MIX-FCM scheme. We used the percent value of the normalized interquartile range (nIQR) to its median to evaluate the variability of all methods. RESULTS 2D-FCM clustering is more effective than 1D-FCM clustering at the severe overload range only, but inferior for other ranges (where 1D-FCM provides suitable results). This complementary performance between the two methods allows MIX-FCM to improve results for all ranges. OP-MIX-FCM clustering error was 2.1 ± 2.3%, compared with 10.3 ± 9.9% and 7.0 ± 11.9% from 1D- and 2D-FCM clustering, respectively. SA-MIX-FCM result was comparable to OP-MIX-FCM result, with both schemes showing ability to decrease overall nIQR by approximately 30%. CONCLUSION Our proposed 2D-FCM algorithm is not as superior to 1D-FCM as hypothesized. In contrast, our MIX-FCM method benefits from the best of both methods to obtain the highest segmentation accuracy at all ranges. Moreover, segmentation accuracy of the practical scheme (SA-MIX-FCM) is comparable to segmentation accuracy of the reference scheme (OP-MIX-FCM). Finally, we confirmed that segmentation is crucial to improving LIC assessments, especially at the severe iron overload range.
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Affiliation(s)
- Pairash Saiviroonporn
- Division of Diagnostic Radiology, Department of Radiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand.
| | - Vip Viprakasit
- Haematology/Oncology Division, Department of Pediatrics and Thalassemia Center, Mahidol University, Bangkok, Thailand.
| | - Rungroj Krittayaphong
- Division of Cardiology, Department of Medicine, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand.
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Kolnagou A, Kontoghiorghe CN, Kontoghiorghes GJ. Transition of Thalassaemia and Friedreich ataxia from fatal to chronic diseases. World J Methodol 2014; 4:197-218. [PMID: 25541601 PMCID: PMC4274580 DOI: 10.5662/wjm.v4.i4.197] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/25/2014] [Revised: 07/22/2014] [Accepted: 10/16/2014] [Indexed: 02/06/2023] Open
Abstract
Thalassaemia major (TM) and Friedreich’s ataxia (FA) are autosomal recessive inherited diseases related to the proteins haemoglobin and frataxin respectively. In both diseases abnormalities in iron metabolism is the main cause of iron toxicity leading to increased morbidity and mortality. Major efforts are directed towards the prevention of these diseases and also in their treatment using iron chelation therapy. Both TM and FA are endemic in Cyprus, where the frequency per total population of asymptomatic heterozygote carriers and patients is the highest worldwide. Cyprus has been a pioneering nation in preventing and nearly eliminating the birth of TM and FA patients by introducing an organized health structure, including prenatal and antenatal diagnosis. Effective iron chelation therapy, improved diagnostic methods and transfusion techniques as well as supportive therapy from other clinical specializations have improved the survival and quality of life of TM patients. Despite the tiresome clinical management regimes many TM patients are successful in their professional lives, have families with children and some are now living well into their fifties. The introduction of deferiprone led to the elimination of cardiac failure induced by iron overload toxicity, which was the major cause of mortality in TM. Effective combinations of deferiprone with deferoxamine in TM patients caused the fall of body iron to normal physiological ranges. In FA different mechanisms of iron metabolism and toxicity apply to that of TM, which can be targeted with specific iron chelation protocols. Preliminary findings from the introduction of deferiprone in FA patients have increased the hopes for improved and effective therapy in this untreatable condition. New and personalised treatments are proposed in TM and FA. Overall, advances in treatments and in particular of chelation therapy using deferiprone are transforming TM and FA from fatal to chronic conditions. The paradigm of Cyprus in the prevention and treatment of TM can be used for application worldwide.
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Kontoghiorghe CN, Andreou N, Constantinou K, Kontoghiorghes GJ. World health dilemmas: Orphan and rare diseases, orphan drugs and orphan patients. World J Methodol 2014; 4:163-188. [PMID: 25332915 PMCID: PMC4202455 DOI: 10.5662/wjm.v4.i3.163] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/05/2014] [Accepted: 06/27/2014] [Indexed: 02/06/2023] Open
Abstract
According to global annual estimates hunger/malnutrition is the major cause of death (36 of 62 million). Cardiovascular diseases and cancer (5.44 of 13.43 million) are the major causes of death in developed countries, while lower respiratory tract infections, human immunodeficiency virus infection/acquired immunodeficiency syndrome, diarrhoeal disease, malaria and tuberculosis (10.88 of 27.12 million) are the major causes of death in developing countries with more than 70% of deaths occurring in children. The majority of approximately 800 million people with other rare diseases, including 100000 children born with thalassaemia annually receive no treatment. There are major ethical dilemmas in dealing with global health issues such as poverty and the treatment of orphan and rare diseases. Of approximately 50000 drugs about 10% are orphan drugs, with annual sales of the latter approaching 100 billion USD. In comparison, the annual revenue in 2009 from the top 12 pharmaceutical companies in Western countries was 445 billion USD and the top drug, atorvastatin, reached 100 billion USD. In the same year, the total government expenditure for health in the developing countries was 410 billion USD with only 6%-7% having been received as aid from developed countries. Drugs cost the National Health Service in the United Kingdom more than 20 billion USD or 10% of the annual health budget. Uncontrollable drug prices and marketing policies affect global health budgets, clinical practice, patient safety and survival. Fines of 5.3 billion USD were imposed on two pharmaceutical companies in the United States, the regulatory authority in France was replaced and clinicians were charged with bribery in order to overcome recent illegal practises affecting patient care. High expenditure for drug development is mainly related to marketing costs. However, only 2 million USD was spent developing the drug deferiprone (L1) for thalassaemia up to the stage of multicentre clinical trials. The criteria for drug development, price levels and use needs to be readdressed to improve drug safety and minimise costs. New global health policies based on cheaper drugs can help the treatment of many categories of orphan and rare diseases and millions of orphan patients in developing and developed countries.
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Kontoghiorghe CN, Kolnagou A, Kontoghiorghes GJ. Potential clinical applications of chelating drugs in diseases targeting transferrin-bound iron and other metals. Expert Opin Investig Drugs 2013; 22:591-618. [PMID: 23586878 DOI: 10.1517/13543784.2013.787408] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
INTRODUCTION Iron is essential for normal, neoplasmic and microbial cells. Transferrin (Tf) is responsible for iron transport and its interactions with chelators are of physiological and toxicological importance and could lead to new therapeutic applications. AREAS COVERED Differential interactions of Tf with chelators such as deferiprone (L1) could be used to modify toxicity and disease pathways in relation to iron and other metal metabolism. Iron mobilization by L1 could achieve normal body iron stores in thalassemia patients. Iron mobilization from the reticuloendothelial system by L1 and exchange with Tf could be used to increase the production of hemoglobin in the anemia of chronic disease. Iron accumulation is pathogenic in neurodegenerative, acute kidney and other diseases and could be removed by L1 with therapeutic implications. Deprivation of iron from neoplasmic and microbial cells by chelators could increase the prospect of improved treatments in cancer and infectious diseases. Other applications include metal detoxification and inhibition of oxidative stress-related conditions. EXPERT OPINION Specific mechanisms apply in the interactions of chelators with Tf, which could be used in the design of targeted therapeutic strategies in many conditions. In each case specific chelator protocols have to be designed for achieving optimum therapeutic activity.
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Affiliation(s)
- Christina N Kontoghiorghe
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol CY 3021, Cyprus.
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19
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Kolnagou A, Natsiopoulos K, Kleanthous M, Ioannou A, Kontoghiorghes GJ. Liver iron and serum ferritin levels are misleading for estimating cardiac, pancreatic, splenic and total body iron load in thalassemia patients: factors influencing the heterogenic distribution of excess storage iron in organs as identified by MRI T2*. Toxicol Mech Methods 2013; 23:48-56. [PMID: 22943064 DOI: 10.3109/15376516.2012.727198] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A comparative assessment of excess storage iron distribution in the liver, heart, spleen and pancreas of β-thalassemia major (β-ΤΜ) patients has been carried out using magnetic resonance imaging (MRI) relaxation times T2*. The β-ΤΜ patients (8-40 years, 11 males, 9 females) had variable serum ferritin levels (394-5603 μg/L) and were treated with deferoxamine (n = 10), deferiprone (n = 5) and deferoxamine/deferiprone combination (n = 5). MRI T2* assessment revealed that excess iron is not proportionally distributed among the organs but is stored at different concentrations in each organ and the distribution is different for each β-ΤΜ patient. There is random variation in the distribution of excess storage iron from normal to severe levels in each organ among the β-ΤΜ patients by comparison to the same organs of ten normal volunteers. The correlation of serum ferritin with T2* was for spleen (r = -0.81), liver (r = -0.63), pancreas (r = -0.33) and none with heart. Similar trend was observed in the correlation of liver T2* with the T2* of spleen (r = 0.62), pancreas (r = 0.61) and none with heart. These studies contradict previous assumptions that serum ferritin and liver iron concentration is proportional to the total body iron stores in β-ΤΜ and especially cardiac iron load. The random variation in the concentration of iron in the organs of β-ΤΜ patients appears to be related to the chelation protocol, organ function, genetic, dietary, pharmacological and other factors. Monitoring of the iron load for all the organs is recommended for each β-ΤΜ patient.
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Affiliation(s)
- Annita Kolnagou
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus
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Kontoghiorghes GJ. The proceedings of the 20th International Conference on Chelation held in the USA: advances on new and old chelation therapies. Toxicol Mech Methods 2012; 23:1-4. [PMID: 22900514 DOI: 10.3109/15376516.2012.720305] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
New developments on chelation have been discussed during the 20th International Conference on Chelation in Grand Rapids, MI, USA, which could affect the treatments of millions of patients worldwide. The complete treatment of transfusional iron overload in thalassaemia using the deferiprone (L1) and deferoxamine combination is a paradigm to be followed in the treatment of many other metal toxicity conditions. Encouraging results from clinical testing increased the prospects of the application of L1 as a pharmaceutical chelator antioxidant in renal, neurodegenerative and other conditions. The development of new chelators for the detoxification of heavy and radioactive metals is in the final stages of approval for clinical use. EDTA chelation for heavy metal detoxification has been used in millions of patients worldwide in the last 50 years and continues to attract many categories of patients because of low toxicity and therapeutic benefits. Major changes on chelation therapy policy have been introduced by the FDA in the USA in the last few years, including the approval of L1 in 2011, the release of reports with 2474 fatalities which include thalassaemia and sickle cell anaemia patients in the period 2007-2011 in the case of deferasirox and the reappraisal of EDTA chelation therapy by NIH for patients who have suffered myocardial infraction. Major controversies in the use of chelating drugs worldwide include the risk/benefit assessment of different chelation protocols for different conditions and the commercial conflicts between generic and patented drugs.
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Saiviroonporn P, Viprakasit V, Sanpakit K, Wood JC, Krittayaphong R. Intersite validations of the pixel-wise method for liver R2* analysis in transfusion-dependent thalassemia patients: a more accessible and affordable diagnostic technology. Hematol Oncol Stem Cell Ther 2012; 5:91-5. [DOI: 10.5144/1658-3876.2012.91] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Kontoghiorghes GJ. A record of 1320 suspect, deferasirox-related, patient deaths reported in 2009: insufficient toxicity testing, low efficacy and lack of transparency may endanger the lives of iron loaded patients. Hemoglobin 2011; 35:301-11. [PMID: 21599442 DOI: 10.3109/03630269.2011.576906] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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Kolnagou A, Kleanthous M, Kontoghiorghes GJ. Efficacy, compliance and toxicity factors are affecting the rate of normalization of body iron stores in thalassemia patients using the deferiprone and deferoxamine combination therapy. Hemoglobin 2011; 35:186-98. [PMID: 21599431 DOI: 10.3109/03630269.2011.576153] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The international committee on chelation (ICOC) of deferiprone (L1) and deferoxamine (DFO) combination therapy was the first protocol reported to have achieved normal range body iron store levels (NRBISL) in β-thalassemia major (β-TM) patients. A follow-up study in eight β-TM patients has been designed to investigate the factors affecting the rate of iron removal leading to NRBISL. The patients had variable serum ferritin [mean ± SE (standard error) =1692 ± 366, range 539-3845 μg/L)] and magnetic resonance imaging (MRI) T2* relaxation times cardiac (mean ± SE =11.1 ± 2.5, range 4.5-24.2 ms) and liver (mean ± SE = 4.3 ± 1.8, range 1.4-14 ms). Organ function, blood and other biochemical parameters were regularly monitored for toxicity. The ICOC L1 (80-100 mg/kg/day) and DFO (40-60 mg/kg, at least 3 days per week) combination therapy caused an increase in cardiac (mean ± SE =30.2 ± 2.3, range 22-41 ms) and liver (mean ± SE =27.6 ± 2.8, range 9.1-35 ms) T2* and reduction in serum ferritin (mean ± SE = 158 ± 49, range 40-421 μg/L) to within the NRBISL. The rate of normalization was variable and in one case was achieved within 9 months, whereas the longest was about 3 years. The initial iron load, the rate of transfusions, the combination dose protocol and the level of compliance were the major factors affecting the rate of normalization of the iron stores. No serious toxicity was observed during the study period, which lasted a total of 24.7 patient years.
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Affiliation(s)
- Annita Kolnagou
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus
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Nick HP. Iron chelation therapy in hereditary hemochromatosis and thalassemia intermedia: regulatory and non regulatory mechanisms of increased iron absorption [Kontoghiorghes GJ, Spyrou A, Kolganou A. Hemoglobin. 2010;34(3); 251-264]. Hemoglobin 2011; 35:175-9. [PMID: 21417578 DOI: 10.3109/03630269.2011.557173] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Kontoghiorghes GJ. The proceedings of the 19Th international conference on chelation held in London, United Kingdom: major changes in iron chelation therapy in the last 25 years using deferiprone (L1) has resulted in the complete treatment of iron overload. Hemoglobin 2011; 35:181-5. [PMID: 21599430 DOI: 10.3109/03630269.2011.575663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
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.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science Technology, Environment and Medicine, Limassol, Cyprus.
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Kontoghiorghes GJ. The 18th ICOC Proceedings in Athens, Greece: New breakthrough in thalassemia leading to the complete treatment of iron overload and to hundreds of patients achieving and maintaining normal body iron stores. Ethical questions on chelation therapy. Hemoglobin 2011; 34:199-203. [PMID: 20524809 DOI: 10.3109/03630269.2010.484963] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A new era in thalassemia and other transfusional iron loading conditions was highlighted during the 18th International Conference on Chelation (ICOC) with reports that all excess iron accumulated from transfusions could be removed using the ICOC combination protocol of deferiprone (L1) (80-100 mg/kg/day) and subcutaneous deferoxamine (DFO) (40-60 mg/kg/day, at least 3 days per week), and that normal range body iron store levels (NRBISL) could be maintained using L1 monotherapy. Hundreds of patients in Cyprus, Greece, Italy, UK and elsewhere, maintain NRBISL, some for more than 9 years, and without complications. This gold standard of complete iron overload treatment is likely to change current practices, aims and protocols because it could prevent and also reverse cardiac, liver, endocrine and other organ complications as well as the incidence of infections and hepatocellular carcinomas. The overall morbidity and mortality in thalassemia and other transfusional iron loading conditions is expected to be substantially reduced. New applications of chelating drugs include renal, neurodegenerative, infectious diseases and ischemia reperfusion injury patients. Ethical questions have been raised on the role of pharmaceutical companies, the clinicians and the Hippocratic oath in relation to chelation therapy.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus.
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Kontoghiorghes GJ, Spyrou A, Kolnagou A. Iron chelation therapy in hereditary hemochromatosis and thalassemia intermedia: regulatory and non regulatory mechanisms of increased iron absorption. Hemoglobin 2011; 34:251-64. [PMID: 20524815 DOI: 10.3109/03630269.2010.486335] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
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.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus.
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Kolnagou A, Kontoghiorghes GJ. Maintenance of normal range body iron store levels for up to 4.5 years in thalassemia major patients using deferiprone monotherapy. Hemoglobin 2011; 34:204-9. [PMID: 20524810 DOI: 10.3109/03630269.2010.485890] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
New gold standard protocols are tested for the complete removal of iron overload in thalassemia using the International Committee on Chelation (ICOC) Maintaining Normal Body Iron combination protocol therapy of deferiprone (L1)/deferoxamine (DFO) and maintenance of normal range body iron store levels (NRBISL) using L1 monotherapy. Deferiprone (80-100 mg/kg/day) was administered for a mean of 21.3 months (range 7-91, total 171) in eight thalassemia major patients (four males and four females, 29-47 years) who have achieved serum ferritin (mean 108.5 microg/L, range 25-408), cardiac T2* (mean 31.5 ms, range 24-41) and liver T2* (30.1 ms, range 9.1-41) magnetic resonance imaging (MRI) relaxation times. At the end of the study normal range MRI T2* relaxation time was maintained in all eight patients with a cardiac mean of T2* 30.3 ms (range 23-37), liver T2* 28.8 ms (range 9.8-43) and serum ferritin with a mean of 173.7 microg/L (range 86-406). In one patient, this NRBISL was maintained for more than 4.5 years. No toxic side effects have been observed during the L1 monotherapy period.
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Affiliation(s)
- Annita Kolnagou
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, Limassol, Cyprus
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Kontoghiorghes GJ. Introduction of higher doses of deferasirox: better efficacy but not effective iron removal from the heart and increased risks of serious toxicities. Expert Opin Drug Saf 2010; 9:633-41. [PMID: 20553089 DOI: 10.1517/14740338.2010.497138] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
IMPORTANCE OF THE FIELD Thousands of iron loaded patients are using deferasirox, who are not aware of the new, fatal and irreversible serious toxic side effects, the need for prophylaxis and the availability of more effective and less toxic chelation therapies. AREAS COVERED IN THIS REVIEW Updating on efficacy issues in relation to the introduction of higher deferasirox doses and comparison to existing chelation therapies. A new maximum dose of 40 mg/kg/day has been introduced for deferasirox in an attempt to achieve negative iron balance in thalassemia and other transfused iron loaded patients. A marginal increase in cardiac iron removal using doses of 30 - 40 mg/kg/day suggests that the rate of iron removal by deferasirox is insufficient by comparison to the deferiprone/deferoxamine combination, where total and rapid clearance of excess cardiac iron and normalization of the body iron stores could be achieved. WHAT THE READER WILL GAIN Identification of drug interactions and new fatal and permanent toxic side effects of deferasirox and implications on efficacy, toxicity and cost of using higher doses. Deferasirox has been identified to cause fatal gastrointestinal hemorrhages, renal tubulopathy, hepatic and renal failure, alopecia and anaphylactic reactions in addition to previously reported fatal or serious toxic side effects such as agranulocytosis, renal and hepatic toxicity, skin rash and gastric intolerance. Interactions with UDP-glucuronosyl transferase inducers, CYP2C8 and CYP3A4 substrates and drugs affecting enterohepatic recycling are likely to affect deferasirox's efficacy and toxicity. Increased toxicity is expected from the use of higher doses of deferasirox and regular prophylactic monitoring is required to avoid fatal and permanent toxicity incidences. The increased costs from higher doses of deferasirox will mostly affect patients living in the developing countries. TAKE HOME MESSAGE Only few patients may benefit from the introduction of higher doses of deferasirox. There is a need for introducing more effective prophylactic measures. Safer, more effective and less costly chelation treatments are available using deferiprone, deferoxamine and their combination.
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Affiliation(s)
- George J Kontoghiorghes
- Postgraduate Research Institute of Science, Technology, Environment and Medicine, 3, Ammochostou Street, Limassol 3021, Cyprus.
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Waalen J. More pieces to the iron chelation puzzle. Transl Res 2010; 156:53-4. [PMID: 20627189 PMCID: PMC2949416 DOI: 10.1016/j.trsl.2010.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2010] [Accepted: 06/16/2010] [Indexed: 01/19/2023]
Affiliation(s)
- Jill Waalen
- The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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Abstract
Diamond-Blackfan anemia (DBA) is characterized by red cell failure, the presence of congenital anomalies, and cancer predisposition. In addition to being an inherited bone marrow failure syndrome, DBA is also categorized as a ribosomopathy as, in more than 50% of cases, the syndrome appears to result from haploinsufficiency of either a small or large subunit-associated ribosomal protein. Nonetheless, the exact mechanism by which haploinsufficiency results in erythroid failure, as well as the other clinical manifestations, remains uncertain. New knowledge regarding genetic and molecular mechanisms combined with robust clinical data from several international patient registries has provided important insights into the diagnosis of DBA and may, in the future, provide new treatments as well. Diagnostic criteria have been expanded to include patients with little or no clinical findings. Patient management is therefore centered on accurate diagnosis, appropriate use of transfusions and iron chelation, corticosteroids, hematopoietic stem cell transplantation, and a coordinated multidisciplinary approach to these complex patients.
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Kolnagou A, Kontoghiorghes GJ. New golden era of chelation therapy in thalassaemia: the achievement and maintenance of normal range body iron stores. Br J Haematol 2010; 150:489-90; author reply 491. [PMID: 20507309 DOI: 10.1111/j.1365-2141.2010.08229.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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