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Shah FT, Porter JB, Sadasivam N, Kaya B, Moon JC, Velangi M, Ako E, Pancham S. Guidelines for the monitoring and management of iron overload in patients with haemoglobinopathies and rare anaemias. Br J Haematol 2022; 196:336-350. [PMID: 34617272 DOI: 10.1111/bjh.17839] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 08/10/2021] [Accepted: 09/02/2021] [Indexed: 01/19/2023]
Affiliation(s)
- Farrukh T Shah
- Department of Haematology, Whittington Health, London, UK
| | - John B Porter
- Department of Haematology, University College Hospitals, London, UK
| | - Nandini Sadasivam
- Department of Haematology, Manchester Royal Infirmary, Manchester, UK
| | - Banu Kaya
- Department of Paediatric Haematology and Oncology, Barts Health NHS Trust, London, UK
| | - James C Moon
- Department of Cardiovascular Imaging, Barts Heart Centre, St Bartholomew's Hospital, London, UK
- Institutes for Cardiovascular Science, University College London, London, UK
| | - Mark Velangi
- Department of Haematology, Birmingham Children's Hospital, Birmingham, UK
| | - Emmanuel Ako
- Department of Cardiology, Chelsea and Westminster Hospital, London, UK
| | - Shivan Pancham
- Department of Haematology, Sandwell and West Birmingham NHS Trust, West Bromwich, UK
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2
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Cabantchik IZ, Hershko C. Plasma nontransferrin bound iron-nontransferrin bound iron revisited: Implications for systemic iron overload and in iv iron supplementation. Am J Hematol 2022; 97:7-9. [PMID: 34637551 DOI: 10.1002/ajh.26374] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 12/24/2022]
Affiliation(s)
- Ioav Z Cabantchik
- Institute of Life Sciences, Faculty of Natural Sciences, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Chaim Hershko
- Institute of Medicine, Faculty of Medicine, Hebrew University of Jerusalem, Jerusalem, Israel
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3
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Rombout-Sestrienkova E, Brandts L, Koek GH, van Deursen CTBM. Patients with hereditary hemochromatosis reach safe range of transferrin saturation sooner with erythrocytaphereses than with phlebotomies. J Clin Apher 2021; 37:100-105. [PMID: 34897777 PMCID: PMC9299622 DOI: 10.1002/jca.21956] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 11/28/2021] [Accepted: 11/29/2021] [Indexed: 01/01/2023]
Abstract
Introduction For the maintenance treatment of patients with hereditary hemochromatosis (HH), it is advised to keep the transferrin saturation (TSAT) <70% to prevent formation of non‐transferrin‐bound iron and labile plasma iron. The period of the initial iron depletion may last up to 1 year or longer and during this period, the patient is exposed to elevated TSAT levels. Therapeutic erythrocytapheresis (TE) is a modality which has proven to reduce treatment duration of patients with iron overload from HH. In this study, we investigated the time to reach TSAT <70% for both treatment modalities. Methods From a previous randomized controlled trial comparing erythrocytaphereses with phlebotomies (PBMs), we performed an analysis in a subgroup of patients who presented with TSAT >70%. Mann‐Whitney U tests were performed to compare the number of treatments and the number of weeks to reach the interim goal of a persistent level of <70% for TSAT between TE and PBM. Results The period to reach TSAT levels of <70% was statistically significant shorter for the TE group compared to the PBM treatment group (median treatment procedures [IQR] 2.0 (5) vs 16.0 (23), P‐value: <.001, and median treatment duration [IQR]: 5.5 (11) vs 19.0 (29) weeks, P‐value: .007). Conclusion Patients with HH reach a safe TSAT <70% significantly sooner and with less treatment procedures with TE compared to PBM.
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Affiliation(s)
- Eva Rombout-Sestrienkova
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands.,Department of Transfusion Medicine, Sanquin Blood Supply, Maastricht, The Netherlands
| | - Lloyd Brandts
- Clinical Epidemiology and Medical Technology Assessment (KEMTA), Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Ger H Koek
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands.,School of Nutrition and Translational Research in Metabolism (NUTRIM), University Maastricht, Maastricht, The Netherlands
| | - Cees Th B M van Deursen
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Maastricht University Medical Centre+, Maastricht, The Netherlands.,Department of Internal Medicine Gastroenterology and Clinical Geriatrics, Zuyderland Medical Center, Heerlen, The Netherlands
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4
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Time to Start Delivering Iron Chelation Therapy in Newly Diagnosed Severe β-Thalassemia. BIOMED RESEARCH INTERNATIONAL 2021; 2020:8185016. [PMID: 33415156 PMCID: PMC7752293 DOI: 10.1155/2020/8185016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 11/20/2020] [Accepted: 12/04/2020] [Indexed: 12/31/2022]
Abstract
Background Iron overload is still a major complication of severe β-thalassemia. Indication to start iron chelation therapy is based on serum ferritin (SF) or transferrin saturation (TS) level or the amount of transfusion. The goal of this study is to analyse the pattern of iron status, the amount of transfusion regarding the time to start iron chelator, and serum hepcidin levels in newly diagnosed severe β-thalassemia. Methods A prospective cohort study was performed at Hasan Sadikin General Hospital on newly diagnosed severe β-thalassemia patients. Subjects had not received any blood transfusion with normal liver function test, CRP, and IL-6 levels who consumed normal diet according to age. The SF and TS levels indicate iron status, while hepcidin level indicates iron regulator status. Main indicator to start iron chelation therapy when SF level ≥1.000 ng/mL, TS level ≥70%, or after receiving transfusion at least 10 times. Statistical analysis used Mann–Whitney and Spearman. Results Forty-two newly severe β-thalassemia, 30 (71.4%), were diagnosed before 1 year old, mean 9.9 ± 6.4 months, range 2–24 months. Range amount of transfusion until SF level reached ≥1,000 ng/mL were 4-12 times, mean 7 ± 2 times. Mean SF and TS level at diagnosis were 365.6 ± 194.9 ng/mL and 67.3 ± 22.5%, while hepcidin level was normal, mean 242.6 ± 58 ng/mL. 36/42 patients have reached SF >1000 ng/mL with amount of transfusion less than 10 times. There was no significant difference of SF, TS, and hepcidin levels when SF >1000 ng/mL in the group with amount of transfusion 7–12 and less than 7 (p = 0.454, p = 0.084, p = 0.765), respectively. A significant positive correlation between SF and amount of transfusion was observed (p < 0.001; r = 0.781). Conclusion Iron overload in severe β-thalassemia patients might occur earlier even before they received 10 times transfusion. Hepcidin serum level tends to increase when iron overload just started.
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El-Gamal RAER, Abdel-Messih IY, Habashy DM, Zaiema SEG, Pessar SA. Erythroferrone, the new iron regulator: evaluation of its levels in Egyptian patients with beta thalassemia. Ann Hematol 2020; 99:31-39. [DOI: https:/doi.org/10.1007/s00277-019-03882-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 12/02/2019] [Indexed: 04/02/2024]
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6
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El-Gamal RAER, Abdel-Messih IY, Habashy DM, Zaiema SEG, Pessar SA. Erythroferrone, the new iron regulator: evaluation of its levels in Egyptian patients with beta thalassemia. Ann Hematol 2019; 99:31-39. [PMID: 31834456 DOI: 10.1007/s00277-019-03882-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Accepted: 12/02/2019] [Indexed: 01/20/2023]
Abstract
Since iron overload is the commonest cause of morbidity and mortality in β thalassemia major (β-TM), it represents one major target in therapeutic management of the disease. The recently discovered erythroid regulator, erythroferrone (ERFE), governed by high levels of erythropoietin, was found to suppress hepcidin expression, thus increasing iron availability for developing erythroid progenitors. We aimed to investigate ERFE levels in Egyptian β-TM patients as an attempt to understand its role in the prediction of iron overload states. Our study included 70 β-TM patients, divided into two subgroups according to the degree of iron overload, and 30 sex and age-matched healthy subjects. ERFE gene expression was analyzed by quantitative real-time polymerase chain reaction (qRT-PCR), and serum hepcidin was measured using enzyme-linked immunosorbent assay (ELISA) technique. Both ERFE gene expression levels and transferrin saturation (TS%) values were able to discriminate among cases with different degrees of iron overload, in contrast to hepcidin. TS% was acknowledged as the best predictor of iron overload (AUC 0.893) in comparison with serum hepcidin and ERFE gene levels (AUC 0.807 and 0.677, respectively), and ERFE gene expression was an independent predictor for the estimated TS%. In conclusion, we suggest that using the ERFE gene expression, combined with serum hepcidin estimation, can substantiate the role of estimated TS% as a promising tool in screening for iron overload in β-TM patients.
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Affiliation(s)
| | | | - Deena Mohamed Habashy
- Clinical Pathology Department, Faculty of Medicine, Ain Shams University, Abbasseya, Cairo, 11566, Egypt
| | - Shams Eldoha Galal Zaiema
- Clinical Pathology Department, Faculty of Medicine, Ain Shams University, Abbasseya, Cairo, 11566, Egypt
| | - Shaimaa Abdelmalik Pessar
- Clinical Pathology Department, Faculty of Medicine, Ain Shams University, Abbasseya, Cairo, 11566, Egypt.
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7
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Steinberg-Shemer O, Yacobovich J, Cohen M, Cabantchik IZ, Tamary H. Labile plasma iron as an indicator of patient adherence to iron chelation treatment. Blood Cells Mol Dis 2018; 71:1-4. [PMID: 29395830 DOI: 10.1016/j.bcmd.2018.01.001] [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: 11/28/2017] [Revised: 01/13/2018] [Accepted: 01/15/2018] [Indexed: 10/18/2022]
Abstract
Poor adherence of transfusion-dependent patients to chelation treatment is often the cause of persistent iron overload and ensuing morbidity. However, a tool to assess patient compliance with therapy is lacking in clinical practice. Labile plasma iron (LPI, the redox-active component of non-transferrin bound iron) has been studied as an indicator of systemic iron overload and of chelation efficacy, and may particularly reflect recent iron equilibrium. We considered the use of LPI as a potential indicator for recent chelation treatment in 18 transfusion-dependent pediatric patients. Samples were collected under chelation treatment or after a short interruption of the treatment, and LPI was measured by the FeROS assay (Aferrix, Tel Aviv, Israel). LPI was significantly higher after a short-term interruption of the chelation (median of 0.4 μM off-therapy [range:0-4] vs 0 μM on-therapy [range:0-2.8] (p < .001)). Conversely, serum iron, serum ferritin and calculated transferrin saturation were not significantly higher in the "off-therapy" samples compared to "on-therapy". In addition, in multivariate logistic regression analysis LPI was the variable most significantly associated with recent chelation treatment (p = .001). We conclude that LPI could serve as a useful indicator of compliance to chelation therapy.
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Affiliation(s)
- Orna Steinberg-Shemer
- Department of Hematology-Oncology, Schneider Children's Medical Center of Israel, Petach Tikva 49202, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Joanne Yacobovich
- Department of Hematology-Oncology, Schneider Children's Medical Center of Israel, Petach Tikva 49202, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Miriam Cohen
- Department of Hematology-Oncology, Schneider Children's Medical Center of Israel, Petach Tikva 49202, Israel
| | - Ioav Z Cabantchik
- Institute of Life Sciences, Hebrew University of Jerusalem, Jerusalem 91904, Israel
| | - Hannah Tamary
- Department of Hematology-Oncology, Schneider Children's Medical Center of Israel, Petach Tikva 49202, Israel; Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel.
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8
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Elalfy MS, Adly A, Awad H, Tarif Salam M, Berdoukas V, Tricta F. Safety and efficacy of early start of iron chelation therapy with deferiprone in young children newly diagnosed with transfusion-dependent thalassemia: A randomized controlled trial. Am J Hematol 2018; 93:262-268. [PMID: 29119631 DOI: 10.1002/ajh.24966] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Accepted: 11/06/2017] [Indexed: 12/28/2022]
Abstract
Iron overload is inevitable in patients who are transfusion dependent. In young children with transfusion-dependent thalassemia (TDT), current practice is to delay the start of iron chelation therapy due to concerns over toxicities, which have been observed when deferoxamine was started too early. However, doing so may increase the risk of iron accumulation that will be manifested as toxicities later in life. This study investigated whether deferiprone, a chelator with a lower affinity for iron than deferoxamine, could postpone transfusional iron overload while maintaining a good safety profile. Recently diagnosed TDT infants (N = 64 their age ranged from 10 to 18 (median 12) months, 54.7% males; receiving ≤6 transfusions; serum ferittin (SF) >400 to < 1000 ng/mL were randomized to "early start deferiprone" (.ES-DFP) at a low dose (50 mg/kg/day) or to "delay chelation" (DC), and remained in the study until their serum ferritin (SF) level reached ≥1000 μg/L. 61 patients continued the study Levels of transferrin saturation (TSAT) and labile plasma iron (LPI) were measured as well. By approximately 6 months postrandomization, 100% of the subjects in DC group had achieved SF > 1000 µg/L and TSAT > 70% compared with none in the ES-DFP group. LPI level > 0.6 µM was observed in 97% vs. 40% of the DS and ES groups, respectively, (P < 0.001). The time to reach SF > 1000 µg/L was delayed by 6 months in the ES-DFP group (P < 0.001) without escalating DFP dose. No unexpected, serious, or severe adverse events were seen in the ES-DFP group.
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Affiliation(s)
| | - Amira Adly
- Hematology Center; Children Hospital, Ain Shams University; Cairo Egypt
| | - Hanem Awad
- Department of Tanning Materials and Leather Technology National Research Center; Cairo Egypt
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9
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Origa R, Tatti F, Zappu A, Leoni GB, Dessì C, Moi P, Morittu M, Orecchia V, Denotti AR, Pilia MP, Anni F, Perra M, Casini MR, Barella S. Earlier initiation of transfusional and iron chelation therapies in recently born children with transfusion-dependent thalassemia. Am J Hematol 2017; 92:E627-E628. [PMID: 28741691 DOI: 10.1002/ajh.24869] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 07/19/2017] [Accepted: 07/21/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Raffaella Origa
- Department of Medical Sciences and Public Health; University of Cagliari; Cagliari Italy
| | - Federica Tatti
- Department of Medical Sciences and Public Health; University of Cagliari; Cagliari Italy
| | - Antonietta Zappu
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | | | - Carlo Dessì
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | - Paolo Moi
- Department of Medical Sciences and Public Health; University of Cagliari; Cagliari Italy
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | - Maddalena Morittu
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | - Valeria Orecchia
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | - Anna Rita Denotti
- Department of Medical Sciences and Public Health; University of Cagliari; Cagliari Italy
| | - Maria Paola Pilia
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | - Franco Anni
- Department of Medical Sciences and Public Health; University of Cagliari; Cagliari Italy
| | - Maria Perra
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
| | | | - Susanna Barella
- Ospedale Pediatrico Microcitemico “A.Cao”-A.O. G.Brotzu; Cagliari Italy
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10
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Di Maggio R, Maggio A. The new era of chelation treatments: effectiveness and safety of 10 different regimens for controlling iron overloading in thalassaemia major. Br J Haematol 2017; 178:676-688. [DOI: 10.1111/bjh.14712] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Rosario Di Maggio
- Campus of Haematology Franco and Piera Cutino; AOR Villa Sofia-V. Cervello; Palermo Italy
| | - Aurelio Maggio
- Campus of Haematology Franco and Piera Cutino; AOR Villa Sofia-V. Cervello; Palermo Italy
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11
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Vichinsky E. Non-transfusion-dependent thalassemia and thalassemia intermedia: epidemiology, complications, and management. Curr Med Res Opin 2016; 32:191-204. [PMID: 26479125 DOI: 10.1185/03007995.2015.1110128] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVE The non-transfusion-dependent thalassemias (NTDTs), including thalassemia intermedia (TI), hemoglobin E beta thalassemia, and hemoglobin H disease, have sometimes been regarded as less severe than their transfusion-dependent variants; however, these disorders carry a substantial disease burden (e.g., splenomegaly, iron overload, skeletal effects, and cardiopulmonary disease). The aim of this review is to increase clinician awareness of the growing global problem of NTDT and TI, and discuss the current management strategies for these conditions. METHODS Recent peer-reviewed articles (publication years 2000 through 2015) addressing the epidemiology, complications, management, and monitoring of NTDT were identified in the PubMed database and reviewed. RESULTS The changing epidemiology of thalassemia constitutes a growing health problem. Increased clinician awareness is necessary for the appropriate diagnosis and management of patients with NTDT. CONCLUSIONS Management of NTDT requires a comprehensive approach, beginning with screening and prenatal diagnosis, monitoring for iron overload and associated complications, and iron chelation therapy. Several novel strategies are in the early stages of investigation and may help increase treatment options in patients with NTDT. Importantly, ethnic or cultural barriers may exist within the affected populations and need to be considered in the management approach.
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Affiliation(s)
- Elliott Vichinsky
- a UCSF Benioff Children's Hospital, Oakland , University of California , San Francisco, CA , USA
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12
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Abstract
With repeated blood transfusions, patients with thalassemia major rapidly become loaded with iron, often surpassing hepatic metal accumulation capacity within ferritin shells and infiltrating heart and endocrine organs. That pathological scenario contrasts with the physiological one, which is characterized by an efficient maintenance of all plasma iron bound to circulating transferrin, due to a tight control of iron ingress into plasma by the hormone hepcidin. Within cells, most of the acquired iron becomes protein-associated, as once released from endocytosed transferrin, it is used within mitochondria for the synthesis of protein prosthetic groups or it is incorporated into enzyme active centers or alternatively sequestered within ferritin shells. A few cell types also express the iron extrusion transporter ferroportin, which is under the negative control of circulating hepcidin. However, that system only backs up the major cell regulated iron uptake/storage machinery that is poised to maintain a basal level of labile cellular iron for metabolic purposes without incurring potentially toxic scenarios. In thalassemia and other transfusion iron-loading conditions, once transferrin saturation exceeds about 70%, labile forms of iron enter the circulation and can gain access to various types of cells via resident transporters or channels. Within cells, they can attain levels that exceed their ability to chemically cope with labile iron, which has a propensity for generating reactive oxygen species (ROS), thereby inducing oxidative damage. This scenario occurs in the heart of hypertransfused thalassemia major patients who do not receive adequate iron-chelation therapy. Iron that accumulates in cardiomyocytes forms agglomerates that are detected by T2* MRI. The labile forms of iron infiltrate the mitochondria and damage cells by inducing noxious ROS formation, resulting in heart failure. The very rapid relief of cardiac dysfunction seen after intensive iron-chelation therapy in some patients with thalassemia major is thought to be due to the relief of the cardiac mitochondrial dysfunction caused by oxidative stress or to the removal of labile iron interference with calcium fluxes through cardiac calcium channels. In fact, improvement occurs well before there is any significant improvement in the total level of cardiac iron loading. The oral iron chelator deferiprone, because of its small size and neutral charge, demonstrably enters cells and chelates labile iron, thereby rapidly reducing ROS formation, allowing better mitochondrial activity and improved cardiac function. Deferiprone may also rapidly improve arrhythmias in patients who do not have excessive cardiac iron. It maintains the flux of iron in the direction hemosiderin to ferritin to free iron, and it allows clearance of cardiac iron in the presence of other iron chelators or when used alone. To date, the most commonly used chelator combination therapy is deferoxamine plus deferiprone, whereas other combinations are in the process of assessment. In summary, it is imperative that patients with thalassemia major have iron chelators continuously present in their circulation to prevent exposure of the heart to labile iron, reduce cardiac toxicity, and improve cardiac function.
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Affiliation(s)
- Vasilios Berdoukas
- Section of Hematology, Division of Hematology, Oncology, and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA 90027, USA.
| | - Thomas D Coates
- Section of Hematology, Division of Hematology, Oncology, and Blood & Marrow Transplantation, Children's Center for Cancer and Blood Diseases, Children's Hospital Los Angeles, University of Southern California Keck School of Medicine, Los Angeles, CA 90027, USA
| | - Zvi Ioav Cabantchik
- Alexander Silberman Institute of Life Science, Hebrew University of Jerusalem, E Safra Campus at Givat Ram, Jerusalem 91904, Israel
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13
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de Swart L, Hendriks JCM, van der Vorm LN, Cabantchik ZI, Evans PJ, Hod EA, Brittenham GM, Furman Y, Wojczyk B, Janssen MCH, Porter JB, Mattijssen VEJM, Biemond BJ, MacKenzie MA, Origa R, Galanello R, Hider RC, Swinkels DW. Second international round robin for the quantification of serum non-transferrin-bound iron and labile plasma iron in patients with iron-overload disorders. Haematologica 2015; 101:38-45. [PMID: 26385212 DOI: 10.3324/haematol.2015.133983] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 09/18/2015] [Indexed: 01/19/2023] Open
Abstract
Non-transferrin-bound iron and its labile (redox active) plasma iron component are thought to be potentially toxic forms of iron originally identified in the serum of patients with iron overload. We compared ten worldwide leading assays (6 for non-transferrin-bound iron and 4 for labile plasma iron) as part of an international inter-laboratory study. Serum samples from 60 patients with four different iron-overload disorders in various treatment phases were coded and sent in duplicate for analysis to five different laboratories worldwide. Some laboratories provided multiple assays. Overall, highest assay levels were observed for patients with untreated hereditary hemochromatosis and β-thalassemia intermedia, patients with transfusion-dependent myelodysplastic syndromes and patients with transfusion-dependent and chelated β-thalassemia major. Absolute levels differed considerably between assays and were lower for labile plasma iron than for non-transferrin-bound iron. Four assays also reported negative values. Assays were reproducible with high between-sample and low within-sample variation. Assays correlated and correlations were highest within the group of non-transferrin-bound iron assays and within that of labile plasma iron assays. Increased transferrin saturation, but not ferritin, was a good indicator of the presence of forms of circulating non-transferrin-bound iron. The possibility of using non-transferrin-bound iron and labile plasma iron measures as clinical indicators of overt iron overload and/or of treatment efficacy would largely depend on the rigorous validation and standardization of assays.
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Affiliation(s)
- Louise de Swart
- Departments of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Jan C M Hendriks
- Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Lisa N van der Vorm
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Z Ioav Cabantchik
- Department of Biochemical Chemistry, Hebrew University of Jerusalem, Israel
| | | | - Eldad A Hod
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Gary M Brittenham
- Department of Pediatrics, Columbia University Medical Center, New York, NY, USA
| | | | - Boguslaw Wojczyk
- Department of Pathology and Cell Biology, Columbia University Medical Center, New York, NY, USA
| | - Mirian C H Janssen
- Department of Internal Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
| | - John B Porter
- Department of Haematology, University College London, UK
| | | | - Bart J Biemond
- Department of Hematology, Academic Medical Center, Amsterdam, The Netherlands
| | - Marius A MacKenzie
- Departments of Hematology, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Raffaella Origa
- Department of Biomedical Science and Biotechnology, Regional Microcythemia Hospital, University of Cagliari, Italy
| | - Renzo Galanello
- Department of Biomedical Science and Biotechnology, Regional Microcythemia Hospital, University of Cagliari, Italy
| | - Robert C Hider
- Institute of Pharmaceutical Science, King's College London, UK
| | - Dorine W Swinkels
- Department of Laboratory Medicine, Radboud University Medical Center, Nijmegen, The Netherlands
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14
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Abstract
The practice of intravenous iron supplementation has grown as nephrologists have gradually moved away from the liberal use of erythropoiesis-stimulating agents as the main treatment for the anemia of CKD. This approach, together with the introduction of large-dose iron preparations, raises the future specter of inadvertent iatrogenic iron toxicity. Concerns have been raised in original studies and reviews about cardiac complications and severe infections that result from long-term intravenous iron supplementation. Regarding the iron preparations specifically, even though all the currently available preparations appear to be relatively safe in the short term, little is known regarding their long-term safety. In this review we summarize current knowledge of iron metabolism with an emphasis on the sources and potentially harmful effects of labile iron, highlight the approaches to identifying labile iron in pharmaceutical preparations and body fluids and its potential toxic role as a pathogenic factor in the complications of CKD, and propose methods for its early detection in at-risk patients.
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Affiliation(s)
- Itzchak Slotki
- Division of Adult Nephrology, Shaare Zedek Medical Center and Hadassah Hebrew University of Jerusalem, Jerusalem, Israel; and
| | - Zvi Ioav Cabantchik
- Department of Biological Chemistry, Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel
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Abstract
Iron overload is becoming an increasing problem as haemoglobinopathy patients gain greater access to good medical care and as therapies for myelodysplastic syndromes improve. Therapeutic options for iron chelation therapy have increased and many patients now receive combination therapies. However, optimal utilization of iron chelation therapy requires knowledge not only of the total body iron burden but the relative iron distribution among the different organs. The physiological basis for extrahepatic iron deposition is presented in order to help identify patients at highest risk for cardiac and endocrine complications. This manuscript reviews the current state of the art for monitoring global iron overload status as well as its compartmentalization. Plasma markers, computerized tomography, liver biopsy, magnetic susceptibility devices and magnetic resonance imaging (MRI) techniques are all discussed but MRI has come to dominate clinical practice. The potential impact of recent pancreatic and pituitary MRI studies on clinical practice are discussed as well as other works-in-progress. Clinical protocols are derived from experience in haemoglobinopathies but may provide useful guiding principles for other iron overload disorders, such as myelodysplastic syndromes.
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Affiliation(s)
- John C Wood
- Division of Cardiology, Children's Hospital Los Angeles, Los Angeles, CA, USA
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Cabantchik ZI. Labile iron in cells and body fluids: physiology, pathology, and pharmacology. Front Pharmacol 2014; 5:45. [PMID: 24659969 PMCID: PMC3952030 DOI: 10.3389/fphar.2014.00045] [Citation(s) in RCA: 206] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2014] [Accepted: 02/26/2014] [Indexed: 12/25/2022] Open
Abstract
In living systems iron appears predominantly associated with proteins, but can also be detected in forms referred as labile iron, which denotes the combined redox properties of iron and its amenability to exchange between ligands, including chelators. The labile cell iron (LCI) composition varies with metal concentration and substances with chelating groups but also with pH and the medium redox potential. Although physiologically in the lower μM range, LCI plays a key role in cell iron economy as cross-roads of metabolic pathways. LCI levels are continually regulated by an iron-responsive machinery that balances iron uptake versus deposition into ferritin. However, LCI rises aberrantly in some cell types due to faulty cell utilization pathways or infiltration by pathological iron forms that are found in hemosiderotic plasma. As LCI attains pathological levels, it can catalyze reactive O species (ROS) formation that, at particular threshold, can surpass cellular anti-oxidant capacities and seriously damage its constituents. While in normal plasma and interstitial fluids, virtually all iron is securely carried by circulating transferrin (Tf; that renders iron essentially non-labile), in systemic iron overload (IO), the total plasma iron binding capacity is often surpassed by a massive iron influx from hyperabsorptive gut or from erythrocyte overburdened spleen and/or liver. As plasma Tf approaches iron saturation, labile plasma iron (LPI) emerges in forms that can infiltrate cells by unregulated routes and raise LCI to toxic levels. Despite the limited knowledge available on LPI speciation in different types and degrees of IO, LPI measurements can be and are in fact used for identifying systemic IO and for initiating/adjusting chelation regimens to attain full-day LPI protection. A recent application of labile iron assay is the detection of labile components in intravenous iron formulations per se as well as in plasma (LPI) following parenteral iron administration.
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Affiliation(s)
- Zvi Ioav Cabantchik
- Department of Biological Chemistry, Institute of Life Sciences, Hebrew University of Jerusalem Jerusalem, Israel
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