1
|
Effect of pharmacogenetic markers of vitamin D pathway on deferasirox pharmacokinetics in children. Pharmacogenet Genomics 2018; 28:17-22. [PMID: 29099735 DOI: 10.1097/fpc.0000000000000315] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Patients with β-thalassemia major have extremely low vitamin D levels, owing to reduced intestinal absorption, subicteric tint, and/or iron-induced higher pigmentation. We investigated whether some polymorphisms within the VDR, CYP24A1, CYP27B1, and GC genes could play a role in deferasirox pharmacokinetics in a cohort of pediatric patients. PATIENTS AND METHODS Eighteen children with β-thalassemia were enrolled. Drug plasma concentrations at the end of dosing interval (Ctrough) and after 0, 2, 4, 6, and 24 h of drug administration were measured by a HPLC-UV method. Allelic discrimination for VDR (TaqI, FokI, BsmI, Cdx2, and ApaI), CYP24A1 (22776, 3999 and 8620), CYP27B1 (2838 and -1260), and GC (1296) single nucleotide polymorphisms was performed by real-time PCR. RESULTS CYP24A1 8620 AG/GG group negatively predicted Ctrough in regression analysis (P=0.012). ApaI AA genotype resulted as a negative predictor of Ctrough (P=0.025) and area under the concentration curve (P=0.007); FoKI CC genotype remained as area under the concentration curve positive predictor (P=0.008) and TC/CC group as half-life (t1/2) (P=0.003) and volume of distribution (Vd) (P=0.011) negative one; TaqI TC/CC was retained as a negative predictor of drug maximum concentration (Cmax) (P=0.004). Moreover, GC 1296 TG/GG seemed able to predict lower time to reach drug maximum concentration (Tmax) (P=0.033). CONCLUSION Our preliminary experience suggested the potential usefulness of vitamin D pharmacogenetic to better understand deferasirox interindividual variability, also in pediatric patients.
Collapse
|
2
|
Allegra S, Cusato J, De Francia S, Arduino A, Longo F, Pirro E, Massano D, De Nicolò A, Piga A, D'Avolio A. Role of CYP24A1, VDR and GC gene polymorphisms on deferasirox pharmacokinetics and clinical outcomes. THE PHARMACOGENOMICS JOURNAL 2017; 18:506-515. [PMID: 29160302 DOI: 10.1038/tpj.2017.43] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2017] [Revised: 06/01/2017] [Accepted: 08/04/2017] [Indexed: 02/06/2023]
Abstract
β-Thalassemia patients develop deficiency in vitamin D absorption and liver hydroxylation, resulting in extremely low calcitriol levels. We explored the role of single-nucleotide polymorphisms (SNPs) involved in vitamin D metabolism, transport and activity on deferasirox pharmacokinetics and outcomes (effectiveness trough levels (Ctrough) and the area under the curve (AUC) cutoffs of 20 μg ml-1 and 360 μg ml-1 h-1, respectively; nonresponse AUC limit of 250 μg ml-1 h-1). Ninety-nine β-thalassemic patients were enrolled. Drug plasma Ctrough and AUC were measured by the high-performance liquid chromatography system coupled with an ultraviolet determination method. Allelic discrimination for VDR, CYP24A1, CYP27B1 and GC gene SNPs was performed by real-time PCR. CYP24A1 22776 TT significantly influenced Cmin and negatively predicted it in regression analysis. CYP24A1 3999 CC was associated with Ctrough and Cmin and was a negative predictor of Tmax, whereas CYP24A1 8620 GG seemed to have a role in Ctrough, AUC, t1/2 and Cmin, and was an AUC negative predictor factor. Considering treatment outcome, Cdx2 and GC 1296 were retained in regression analysis as AUC efficacy cutoff negative predictors.
Collapse
Affiliation(s)
- S Allegra
- Unit of Infectious Diseases, University of Turin, Department of Medical Sciences, Amedeo di Savoia Hospital, Turin, Italy
| | - J Cusato
- Unit of Infectious Diseases, University of Turin, Department of Medical Sciences, Amedeo di Savoia Hospital, Turin, Italy
| | - S De Francia
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Italy
| | - A Arduino
- Unit of Infectious Diseases, University of Turin, Department of Medical Sciences, Amedeo di Savoia Hospital, Turin, Italy
| | - F Longo
- Department of Paediatrics, Centre for Microcitemie, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Italy
| | - E Pirro
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Italy
| | - D Massano
- Department of Paediatrics, Centre for Microcitemie, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Italy
| | - A De Nicolò
- Unit of Infectious Diseases, University of Turin, Department of Medical Sciences, Amedeo di Savoia Hospital, Turin, Italy
| | - A Piga
- Department of Paediatrics, Centre for Microcitemie, University of Turin, S. Luigi Gonzaga Hospital, Orbassano, Italy
| | - A D'Avolio
- Unit of Infectious Diseases, University of Turin, Department of Medical Sciences, Amedeo di Savoia Hospital, Turin, Italy
| |
Collapse
|
3
|
Dong M, Mizuno T, Vinks AA. Opportunities for model-based precision dosing in the treatment of sickle cell anemia. Blood Cells Mol Dis 2017; 67:143-147. [PMID: 28807656 DOI: 10.1016/j.bcmd.2017.08.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 08/07/2017] [Indexed: 12/16/2022]
Abstract
Hydroxyurea is the primary pharmacotherapy to prevent complications of sickle cell anemia (SCA). Accumulated clinical experience across multiple age ranges has suggested that the use of an individualized maximum tolerated dose (MTD) will achieve optimal benefit of hydroxyurea treatment. However, the current empirical and trial-and-error approach for dose escalation often results in a lengthy titration process and is not strictly implemented in many clinics. Opportunities exist for pharmacokinetics model-based precision dosing of hydroxyurea to quickly achieve individual MTD. This review intends to introduce the use of a quantitative modeling approach including a Bayesian adaptive control strategy for the precision dosing of hydroxyurea. The rationale and practical considerations for the implementation of this approach are discussed. Future research directions with a focus on integrating specific safety and other clinical outcome endpoints into dose selection decision making are also discussed.
Collapse
Affiliation(s)
- Min Dong
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Tomoyuki Mizuno
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Alexander A Vinks
- Division of Clinical Pharmacology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
| |
Collapse
|
4
|
Maximova N, Gregori M, Simeone R, Sonzogni A, Boz G, Fucile C, Marini V, Martelli A, Mattioli F. Safety and tolerability of deferasirox in pediatric hematopoietic stem cell transplant recipients: one facility's five years' experience of chelation treatment. Oncotarget 2017; 8:63177-63186. [PMID: 28968980 PMCID: PMC5609912 DOI: 10.18632/oncotarget.18725] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 05/23/2017] [Indexed: 01/19/2023] Open
Abstract
42 pediatric patients with iron overload, who underwent liver biopsy and DFX treatment after hematopoietic stem cell transplantation were included in the study group. The patients were divided into two groups diversified according to deferasirox trough plasma concentrations (DFX Ctrough) with cut-off equal to10 mcg/mL. The average dose of DFX was 25.9 mg/kg in the DFX Ctrough < 10 mcg/mL group versus 19.2 mg/kg in the DFX Ctrough > 10 mcg/mL group (p=0,0003). The mean duration of DFX treatment was 135.7 days in the DFX Ctrough < 10 mcg/mL group versus 41.8 days in the DFX Ctrough > 10 mcg/mL group (p<0.0001). The mean tissue iron concentration in the DFX Ctrough < 10 mcg/mL group was 261.9 μmol/g versus 133.4 μmol/g in the DFX Ctrough > 10 mcg/mL group (p < 0.0001). 21 patients (100%) in the DFX Ctrough > 10 mcg/mL group had ductopenia which was complete in 47.6% of them and severe in 52.4%. All patients with particularly high Ctrough (> 25 mcg/mL) were found to have total ductopenia. 90.5% of all deferasirox-related adverse events and 100% of major adverse events occurred in the DFX Ctrough > 10 mcg/mL group. In the DFX Ctrough < 10 mcg/mL group only one patient interrupted chelation therapy versus 16 (84.2%) patients in the DFX Ctrough > 10 mcg/mL group. We would recommend a close monitoring in pediatric hematopoietic transplant recipients subjected to deferasirox-based therapy because we have observed a high incidence of adverse events and discontinuation of chelation treatment.
Collapse
Affiliation(s)
- Natalia Maximova
- Bone Marrow Transplant Unit, Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | - Massimo Gregori
- Department of Pediatric Radiology, Institute for Maternal and Child Health - IRCCS Burlo Garofolo, Trieste, Italy
| | | | - Aurelio Sonzogni
- Department of Pathology, Ospedale Beato Papa Giovanni XIII, Bergamo, Italy
| | - Giulia Boz
- University of Cagliari, Faculty of Medicine, Cagliari, Italy
| | - Carmen Fucile
- Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | - Valeria Marini
- Pharmacology and Toxicology Unit, University of Genoa, Genoa, Italy
| | | | | |
Collapse
|
5
|
Allegra S, De Francia S, Cusato J, Arduino A, Massano D, Longo F, Piga A, D'Avolio A. Deferasirox pharmacogenetic influence on pharmacokinetic, efficacy and toxicity in a cohort of pediatric patients. Pharmacogenomics 2017; 18:539-554. [PMID: 28346059 DOI: 10.2217/pgs-2016-0176] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
AIM We aimed to evaluate the influence of genetic polymorphisms involved in deferasirox metabolism and transport on its pharmacokinetics and treatment toxicity, in a cohort of β-thalassaemic children. PATIENTS & METHODS Drug plasma concentrations were measured by a HPLC-UV method. Allelic discrimination for UGT1A1, UGT1A3, CYP1A1, CYP1A2, CYP2D6, MRP2 and BCRP1 polymorphisms was performed by real-time PCR. RESULTS CYP1A1 rs2606345AA influenced Ctrough (p = 0.001) and t1/2 (p = 0.042), CYP1A1 rs4646903TC/CC (p = 0.005) and BCRP1 rs2231142GA/AA (p = 0.005) influenced Tmax and CYP2D6 rs1135840CG/GG influenced Cmax (p = 0.044). UGT1A1 rs887829TT (p = 0.002) and CYP1A2 rs762551CC (p = 0.019) resulted as predictive factor of ferritin levels and CYP1A1 rs2606345CA/AA (p = 0.021) and CYP1A2 rs762551AC/CC (p = 0.027) of liver iron concentration. CONCLUSION Our data suggest the usefulness of deferasirox pharmacogenetics in pediatric treatment optimization.
Collapse
Affiliation(s)
- Sarah Allegra
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, 10149 Turin, Italy
| | - Silvia De Francia
- Department of Biological & Clinical Sciences, S Luigi Gonzaga Hospital, University of Turin, 10043 Orbassano (TO), Italy
| | - Jessica Cusato
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, 10149 Turin, Italy
| | - Arianna Arduino
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, 10149 Turin, Italy
| | - Davide Massano
- Department of Biological & Clinical Sciences, S Luigi Gonzaga Hospital, University of Turin, 10043 Orbassano (TO), Italy
| | - Filomena Longo
- Department of Biological & Clinical Sciences, S Luigi Gonzaga Hospital, University of Turin, 10043 Orbassano (TO), Italy
| | - Antonio Piga
- Department of Biological & Clinical Sciences, S Luigi Gonzaga Hospital, University of Turin, 10043 Orbassano (TO), Italy
| | - Antonio D'Avolio
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, 10149 Turin, Italy
| |
Collapse
|
6
|
Nurchi VM, Crisponi G, Lachowicz JI, Medici S, Peana M, Zoroddu MA. Chemical features of in use and in progress chelators for iron overload. J Trace Elem Med Biol 2016; 38:10-18. [PMID: 27365273 DOI: 10.1016/j.jtemb.2016.05.010] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/20/2016] [Accepted: 05/30/2016] [Indexed: 01/19/2023]
Abstract
An excessive amount of iron may become extremely toxic both for its ability to generate reactive oxygen species, and for the lack of regulatory mechanisms for iron excretion in humans. Chelation therapy has been introduced in clinical practice in the 1970's to defend thalassemia patients from the effects of iron overload and it has dramatically changed both life expectancy and quality of life. The disadvantages of the drugs in clinical use make the research for new, more suitable iron chelating agents, urgent. This review defines the requirements of an iron chelator, then points out the principal chemical features of the iron chelators in use. Finally, a survey on the last ten years of the literature relative to iron chelators is done, and the most interesting ligands are presented, with particular emphasis to those that reached clinical trials.
Collapse
Affiliation(s)
- Valeria Marina Nurchi
- Department of Chemical and Geological Sciences, University of Cagliari, Cittadella Universitaria, 09042 Monserrato-Cagliari, Italy.
| | - Guido Crisponi
- Department of Chemical and Geological Sciences, University of Cagliari, Cittadella Universitaria, 09042 Monserrato-Cagliari, Italy
| | - Joanna I Lachowicz
- Department of Chemical and Geological Sciences, University of Cagliari, Cittadella Universitaria, 09042 Monserrato-Cagliari, Italy
| | - Serenella Medici
- Department of Chemistry and Pharmacy, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
| | - Massimiliano Peana
- Department of Chemistry and Pharmacy, University of Sassari, Via Vienna 2, 07100 Sassari, Italy
| | | |
Collapse
|
7
|
Allegra S, De Francia S, Longo F, Massano D, Cusato J, Arduino A, Pirro E, Piga A, D'Avolio A. Deferasirox pharmacokinetics evaluation in a woman with hereditary haemochromatosis and heterozygous β-thalassaemia. Biomed Pharmacother 2016; 84:1510-1512. [PMID: 27881236 DOI: 10.1016/j.biopha.2016.11.041] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 10/24/2016] [Accepted: 11/11/2016] [Indexed: 01/19/2023] Open
Abstract
We present the deferasirox pharmacokinetics evaluation of a female patient on iron chelation, for the interesting findings from her genetic background (hereditary haemochromatosis and heterozygous β-thalassaemia) and clinical history (ileostomy; iron overload from transfusions). Drug plasma concentrations were measured by an HPLC-UV validated method, before and after ileum resection. Area under deferasirox concentration curve over 24h (AUC) values were determined by the mixed log-linear rule, using Kinetica software. AUC was low also with high deferasirox dose as well as tolerability. Non invasive tissue iron quantification by magnetic resonance imaging or superconducting quantum interference device were prevented by a metal hip replacement. Good efficacy and normalisation of iron markers was obtained on long term. Therapeutic drug monitoring in patient in critical conditions may help to understand reasons for non response and set individualised treatment.
Collapse
Affiliation(s)
- Sarah Allegra
- Department of Medical Sciences, Unit of Infectious Diseases, University of Turin, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149, Turin, Italy.
| | - Silvia De Francia
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10043, Orbassano (TO), Italy
| | - Filomena Longo
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10043, Orbassano (TO), Italy
| | - Davide Massano
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10043, Orbassano (TO), Italy
| | - Jessica Cusato
- Department of Medical Sciences, Unit of Infectious Diseases, University of Turin, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149, Turin, Italy
| | - Arianna Arduino
- Department of Medical Sciences, Unit of Infectious Diseases, University of Turin, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149, Turin, Italy
| | - Elisa Pirro
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10043, Orbassano (TO), Italy
| | - Antonio Piga
- Department of Biological and Clinical Sciences, University of Turin, S. Luigi Gonzaga Hospital, Regione Gonzole 10, 10043, Orbassano (TO), Italy
| | - Antonio D'Avolio
- Department of Medical Sciences, Unit of Infectious Diseases, University of Turin, Amedeo di Savoia Hospital, Corso Svizzera 164, 10149, Turin, Italy
| |
Collapse
|
8
|
|
9
|
Allegra S, De Francia S, Cusato J, Pirro E, Massano D, Piga A, D'Avolio A. Deferasirox pharmacokinetic and toxicity correlation in β-thalassaemia major treatment. ACTA ACUST UNITED AC 2016; 68:1417-1421. [PMID: 27672004 DOI: 10.1111/jphp.12638] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 08/10/2016] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Deferasirox adverse effects include the following: gastrointestinal disturbance, mild elevations in serum creatinine levels and intermittent proteinuria; these events are dose-dependent and reversible with drug discontinuation, but this solution can lead to an inadequate iron chelation. For these reasons, interindividual variability of drug plasma concentration could help the clinical management of deferasirox dosage. We sought to describe deferasirox plasma exposure in a cohort of 60 adult patients. METHODS A fully validated chromatographic method was used to quantify deferasirox concentration in plasma collected from β-thalassaemia adult patients. Samples obtained before and after 2, 4, 6 and 24 h drug administration were evaluated. Associations between variables were tested using the Pearson test. KEY FINDINGS Concerning pharmacokinetic parameters, a higher interindividual variability was shown. A positive correlation was found between deferasirox area under the concentration curve over 24 h and serum creatinine (r = 0.314; P = 0.018) and between area and drug dose (r = 0.311; P = 0.016). Moreover, a negative correlation resulted among area under the concentration curve over 24 h and serum ferritin (r = -0.291; P = 0.026) and among drug half-life and its dose (r = -0.319; P = 0.013). CONCLUSIONS Treatment decision based on the individual characteristics could strongly contribute to minimize toxicity and increase efficacy of deferasirox therapy.
Collapse
Affiliation(s)
- Sarah Allegra
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Silvia De Francia
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano (TO), Italy
| | - Jessica Cusato
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Elisa Pirro
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano (TO), Italy
| | - Davide Massano
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano (TO), Italy
| | - Antonio Piga
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano (TO), Italy
| | - Antonio D'Avolio
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy.
| |
Collapse
|
10
|
Allegra S, Cusato J, De Francia S, Pirro E, Massano D, Piga A, D'Avolio A. Deferasirox pharmacokinetic evaluation in β-thalassaemia paediatric patients. ACTA ACUST UNITED AC 2016; 69:525-528. [PMID: 27230486 DOI: 10.1111/jphp.12559] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2016] [Accepted: 03/29/2016] [Indexed: 01/19/2023]
Abstract
OBJECTIVES Iron chelation in the transfusion-dependent anaemias management is essential to prevent end-organ damage and to improve survival. Deferasirox is a once-daily orally active tridentate selective iron chelator which pharmacokinetic disposition could influence treatment efficacy and toxicity. Therapeutic drug monitoring is an important tool for optimizing drug utilization and doses. METHODS A fully validated chromatographic method was used to quantify deferasirox concentration in plasma collected from paediatric patients with β-thalassaemia. Samples obtained after 5 days of washout or in naïve patients before and after 2, 4, 6 and 24 h drug administration were evaluated. KEY FINDINGS Associations between variables were tested using the Pearson test. Twenty paediatric patients were enrolled; they were mainly men (13.65%), with median age of 6.35 years and body mass index of 15.45 kg/m2 . Concerning pharmacokinetic parameters, a higher interindividual variability was shown. A positive, but not significant, correlation (r = 0.363; P = 0.115) was found between deferasirox area under the concentration curve over 24 h (AUC) and drug dose. CONCLUSIONS Monitoring plasma deferasirox concentrations appears beneficial for guiding appropriate patient treatment, enhancing effectiveness and minimizing toxicity.
Collapse
Affiliation(s)
- Sarah Allegra
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Jessica Cusato
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| | - Silvia De Francia
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano, Turin, Italy
| | - Elisa Pirro
- Department of Biological and Clinical Sciences, S. Luigi Gonzaga Hospital, University of Turin, Orbassano, Turin, Italy
| | - Davide Massano
- Department of Pediatrics, Centre for Microcitemie, S. Luigi Gonzaga Hospital, University of Turin, Orbassano, Turin, Italy
| | - Antonio Piga
- Department of Pediatrics, Centre for Microcitemie, S. Luigi Gonzaga Hospital, University of Turin, Orbassano, Turin, Italy
| | - Antonio D'Avolio
- Unit of Infectious Diseases, Department of Medical Sciences, Amedeo di Savoia Hospital, University of Turin, Turin, Italy
| |
Collapse
|
11
|
Crisponi G, Nurchi VM, Crespo-Alonso M, Sanna G, Zoroddu MA, Alberti G, Biesuz R. A Speciation Study on the Perturbing Effects of Iron Chelators on the Homeostasis of Essential Metal Ions. PLoS One 2015; 10:e0133050. [PMID: 26192307 PMCID: PMC4508027 DOI: 10.1371/journal.pone.0133050] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 06/22/2015] [Indexed: 01/19/2023] Open
Abstract
A number of reports have appeared in literature calling attention to the depletion of essential metal ions during chelation therapy on β-thalassaemia patients. We present a speciation study to determine how the iron chelators used in therapy interfere with the homeostatic equilibria of essential metal ions. This work includes a thorough analysis of the pharmacokinetic properties of the chelating agents currently in clinical use, of the amounts of iron, copper and zinc available in plasma for chelation, and of all the implied complex formation constants. The results of the study show that a significant amount of essential metal ions is complexed whenever the chelating agent concentration exceeds the amount necessary to coordinate all disposable iron--a frequently occurring situation during chelation therapy. On the contrary, copper and zinc do not interfere with iron chelation, except for a possible influence of copper on iron speciation during deferiprone treatment.
Collapse
Affiliation(s)
- Guido Crisponi
- Dipartimento di Scienze Chimiche e Geologiche, University of Cagliari, Cagliari, Italy
| | - Valeria Marina Nurchi
- Dipartimento di Scienze Chimiche e Geologiche, University of Cagliari, Cagliari, Italy
| | - Miriam Crespo-Alonso
- Dipartimento di Scienze Chimiche e Geologiche, University of Cagliari, Cagliari, Italy
| | - Gavino Sanna
- Dipartimento di Chimica e Farmacia, University of Sassari, Sassari, Italy
| | | | | | | |
Collapse
|
12
|
Abstract
The availability of oral iron chelators and new non-invasive methods for early detection and treatment of iron overload, have significantly improved the life expectancy and quality of life of patients with β thalassemia major. However, monotherapy is not effective in all patients for a variety of reasons. We analyzed the most relevant reports recently published on alternating or combined chelation therapies in thalassemia major with special attention to safety aspects and to their effects in terms of reduction of iron overload in different organs, improvement of complications, and survival. When adverse effects, such as gastrointestinal upset with deferasirox or infusional site reactions with deferoxamine are not tolerable and organ iron is in an acceptable range, alternating use of two chelators (drugs taken sequentially on different days, but not taken on the same day together) may be a winning choice. The association deferiprone and deferoxamine should be the first choice in case of heart failure and when dangerously high levels of cardiac iron exist. Further research regarding the safety and efficacy of the most appealing combination treatment, deferiprone and deferasirox, is needed before recommendations for routine clinical practice can be made.
Collapse
|
13
|
Galanello R, Campus S, Origa R. Deferasirox: pharmacokinetics and clinical experience. Expert Opin Drug Metab Toxicol 2011; 8:123-34. [DOI: 10.1517/17425255.2012.640674] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
|
14
|
Abstract
Beta-thalassemias are a group of hereditary blood disorders characterized by anomalies in the synthesis of the beta chains of hemoglobin resulting in variable phenotypes ranging from severe anemia to clinically asymptomatic individuals. The total annual incidence of symptomatic individuals is estimated at 1 in 100,000 throughout the world and 1 in 10,000 people in the European Union. Three main forms have been described: thalassemia major, thalassemia intermedia and thalassemia minor. Individuals with thalassemia major usually present within the first two years of life with severe anemia, requiring regular red blood cell (RBC) transfusions. Findings in untreated or poorly transfused individuals with thalassemia major, as seen in some developing countries, are growth retardation, pallor, jaundice, poor musculature, hepatosplenomegaly, leg ulcers, development of masses from extramedullary hematopoiesis, and skeletal changes that result from expansion of the bone marrow. Regular transfusion therapy leads to iron overload-related complications including endocrine complication (growth retardation, failure of sexual maturation, diabetes mellitus, and insufficiency of the parathyroid, thyroid, pituitary, and less commonly, adrenal glands), dilated myocardiopathy, liver fibrosis and cirrhosis). Patients with thalassemia intermedia present later in life with moderate anemia and do not require regular transfusions. Main clinical features in these patients are hypertrophy of erythroid marrow with medullary and extramedullary hematopoiesis and its complications (osteoporosis, masses of erythropoietic tissue that primarily affect the spleen, liver, lymph nodes, chest and spine, and bone deformities and typical facial changes), gallstones, painful leg ulcers and increased predisposition to thrombosis. Thalassemia minor is clinically asymptomatic but some subjects may have moderate anemia. Beta-thalassemias are caused by point mutations or, more rarely, deletions in the beta globin gene on chromosome 11, leading to reduced (beta+) or absent (beta0) synthesis of the beta chains of hemoglobin (Hb). Transmission is autosomal recessive; however, dominant mutations have also been reported. Diagnosis of thalassemia is based on hematologic and molecular genetic testing. Differential diagnosis is usually straightforward but may include genetic sideroblastic anemias, congenital dyserythropoietic anemias, and other conditions with high levels of HbF (such as juvenile myelomonocytic leukemia and aplastic anemia). Genetic counseling is recommended and prenatal diagnosis may be offered. Treatment of thalassemia major includes regular RBC transfusions, iron chelation and management of secondary complications of iron overload. In some circumstances, spleen removal may be required. Bone marrow transplantation remains the only definitive cure currently available. Individuals with thalassemia intermedia may require splenectomy, folic acid supplementation, treatment of extramedullary erythropoietic masses and leg ulcers, prevention and therapy of thromboembolic events. Prognosis for individuals with beta-thalassemia has improved substantially in the last 20 years following recent medical advances in transfusion, iron chelation and bone marrow transplantation therapy. However, cardiac disease remains the main cause of death in patients with iron overload.
Collapse
Affiliation(s)
- Renzo Galanello
- Dipartimento di Scienze Biomediche e Biotecnologie- Università di Cagliari, Ospedale Regionale, Microcitemie ASL Cagliari, Cagliari, Italy.
| | | |
Collapse
|
15
|
|