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1.
Biomolecules ; 14(1)2024 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-38254692

RESUMO

Because of their capacity to bind metals, metal chelators are primarily employed for therapeutic purposes, but they can also find applications as colorimetric reagents and cleaning solutions as well as in soil remediation, electroplating, waste treatment, and so on. For instance, iron-chelation therapy, which is used to treat iron-overload disorders, involves removing excess iron from the blood through the use of particular molecules, like deferoxamine, that have the ability to chelate the metal. The creation of bioinspired and biodegradable chelating agents is a crucial objective that draws inspiration from natural products. In this context, starting from bioavailable molecules such as maltol and pyrogallol, new molecules have been synthetized and characterized by potentiometry, infrared spectroscopy and cyclic voltammetry. Finally, the ability of these to bind iron has been investigated, and the stability constants of ferric complexes are measured using spectrophotometry. These compounds offer intriguing scaffolds for an innovative class of versatile, multipurpose chelating agents.


Assuntos
Produtos Biológicos , Quelantes de Ferro , Ferro , Terapia por Quelação , Colorimetria , Ligantes
2.
Int J Mol Sci ; 24(23)2023 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-38069073

RESUMO

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.


Assuntos
Sobrecarga de Ferro , Talassemia beta , Humanos , Deferiprona/uso terapêutico , Desferroxamina/uso terapêutico , Piridonas/efeitos adversos , Quelantes de Ferro/efeitos adversos , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/induzido quimicamente , Terapia por Quelação/métodos , Ferro/metabolismo , Talassemia beta/tratamento farmacológico , Talassemia beta/complicações , Quimioterapia Combinada
3.
Hemoglobin ; 47(6): 237-244, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38111324

RESUMO

BACKGROUND: Adherence to iron chelation therapy (ICT) remains an issue among thalassemia patients. This study aimed to determine the prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia and the factors associated with it. METHODS: This was a cross-sectional study conducted between November 2019 and November 2021 at seven tertiary hospitals in Malaysia. Participants registered with Malaysian Thalassemia Registry were recruited by convenience sampling. Adherence was measured via pill count and self-reported adherence. Knowledge about thalassemia and ICT was measured using a questionnaire from Modul Thalassemia by Ministry of Health of Malaysia. A decision tree was used to identify predictors of non-adherence. RESULTS: A total of 135 patients were recruited. The prevalence of non-adherence to ICT in those who took subcutaneous ± oral medications was 47.5% (95% CI: 31.5%, 63.9%) and the prevalence of non-adherence to ICT in those who took oral medications only was 21.1% (95% CI: 13.4%, 30.6%). The median knowledge score was 67.5% (IQR 15%). A decision tree has identified two factors associated with non-adherence. They were ICT's route of administration and knowledge score. Out of 100 patients who were on oral medications only, 79 were expected to adhere. Out of 100 patients who were on subcutaneous ± oral medications and scored less than 56.25% in knowledge questionnaire, 86 were expected to non-adhere. Based on the logistic regression, the odds of non-adherence in patients who took oral medications only was 71% lower than the odds of non-adherence in patients who took subcutaneous ± oral medications (OR = 0.29; 95% CI = 0.13, 0.65; p = .002). CONCLUSION: The prevalence of non-adherence to ICT among children with beta thalassemia major in Malaysia was 20/95 (21.1%) in those who took oral medications only and the prevalence of non-adherence was 19/40 (47.5%) in those who took subcutaneous ± oral medications. The factors associated with non-adherence were ICT's route of administration and knowledge score.


Assuntos
Sobrecarga de Ferro , Talassemia , Talassemia beta , Criança , Humanos , Terapia por Quelação , Talassemia beta/tratamento farmacológico , Talassemia beta/epidemiologia , Estudos Transversais , Talassemia/tratamento farmacológico , Ferro , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/tratamento farmacológico
4.
Proc Natl Acad Sci U S A ; 120(45): e2309156120, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37903261

RESUMO

Cobalt-containing alloys are useful for orthopedic applications due to their low volumetric wear rates, corrosion resistance, high mechanical strength, hardness, and fatigue resistance. Unfortunately, these prosthetics release significant levels of cobalt ions, which was only discovered after their widespread implantation into patients requiring hip replacements. These cobalt ions can result in local toxic effects-including peri-implant toxicity, aseptic loosening, and pseudotumor-as well as systemic toxic effects-including neurological, cardiovascular, and endocrine disorders. Failing metal-on-metal (MoM) implants usually necessitate painful, risky, and costly revision surgeries. To treat metallosis arising from failing MoM implants, a synovial fluid-mimicking chelator was designed to remove these metal ions. Hyaluronic acid (HA), the major chemical component of synovial fluid, was functionalized with British anti-Lewisite (BAL) to create a chelator (BAL-HA). BAL-HA effectively binds cobalt and rescues in vitro cell vitality (up to 370% of cells exposed to IC50 levels of cobalt) and enhances the rate of clearance of cobalt in vivo (t1/2 from 48 h to 6 h). A metallosis model was also created to investigate our therapy. Results demonstrate that BAL-HA chelator system is biocompatible and capable of capturing significant amounts of cobalt ions from the hip joint within 30 min, with no risk of kidney failure. This chelation therapy has the potential to mitigate cobalt toxicity from failing MoM implants through noninvasive injections into the joint.


Assuntos
Artroplastia de Quadril , Prótese de Quadril , Humanos , Prótese de Quadril/efeitos adversos , Ácido Hialurônico , Dimercaprol , Terapia por Quelação , Falha de Prótese , Artroplastia de Quadril/efeitos adversos , Metais , Cobalto , Quelantes/uso terapêutico , Íons
6.
Acta Biomed ; 94(4): e2023195, 2023 08 03.
Artigo em Inglês | MEDLINE | ID: mdl-37539597

RESUMO

BACKGROUND AND AIM: Hypogonadism and abnormalities of glucose homeostasis, resulting from iron-induced pituitary and pancreatic ß-cell dysfunction respectively, are the most frequently reported endocrine abnormalities in patients with ß-thalassemia major (ß-TM), also identified as transfusion-dependent thalassemia (TDT). STUDY DESIGN AND PATIENTS: The aim of the present retrospective study was to evaluate the long-term effects of hormone replacement therapy (HRT) on glucose metabolism and insulin secretion/sensitivity during 3-h oral glucose tolerance test (OGTT) in adolescent and young ß-TM women with acquired hypogonadototropic -hypogonadism (AHH).Twelve hypogonadal ß-TM females with AHH on HRT were followed for 8.26 ± 1.49 years. RESULTS: At baseline, 10 patients (83.3%) had normal OGTT, 1 patient presented with impaired glucose tolerance (IGT) and 1 patient had an isolated PG level of 165 mg/dL at 1-h during OGTT (H-NGT). At last evaluation, 7 patients (58.4 %) had normal OGTT, while 5 patients (41.6%) had abnormal OGTT. Reduced insulin sensitivity and impaired first-phase insulin secretion were also documented. Three of 4 ß-TM patients on treatment with estradiol hemihydrate MX 50 patches plus oral medroxyprogesterone acetate (MPA), associated with a very effective iron chelation therapy, maintained normal glucose tolerance from baseline to last evaluation. Significant adverse events due to HRT or additional endocrine complications were not documented in any cases during the follow-up. CONCLUSION: Deterioration of glycemia (dysglycemia) occurred in 45.4% (5/11) of thalassemic females on long-term HRT. Additional studies are needed to elucidate the validity of our preliminary observations.


Assuntos
Doenças do Sistema Endócrino , Intolerância à Glucose , Hipogonadismo , Resistência à Insulina , Talassemia beta , Adolescente , Feminino , Humanos , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Glicemia/metabolismo , Terapia por Quelação , Glucose , Homeostase , Terapia de Reposição Hormonal , Hipogonadismo/etiologia , Hipogonadismo/complicações , Secreção de Insulina , Ferro , Estudos Retrospectivos , Adulto Jovem
7.
Indian J Pediatr ; 90(12): 1227-1231, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37133752

RESUMO

Thalassemia is one of the most common hemoglobinopathies affecting a large number of people in India and other countries of South-East Asia. For patients with most severe form of the disease- Transfusion Dependent Thalassemia (TDT), stem cell transplantation or gene therapy are only curative treatment which are not available to most of the patients because of lack of experts, financial constraints and lack of suitable donors. In such situations, most cases are managed with regular blood transfusion and iron chelation therapy. With this treatment, over the years, survival of the patients has improved and 20-40% cases are entering into adulthood. In the absence of structured transition of care programs, currently most adult TDT patients are being managed by pediatricians. This article highlights the need for transition of care for TDT patients, barriers to transition and how to overcome the barriers and process of transition of care to adult care team. The importance of empowering the patients in self-management of the disease and educating the adult care team to achieve the desired outcome of transition program is highlighted.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Talassemia , Talassemia beta , Adulto , Humanos , Talassemia beta/terapia , Terapia por Quelação , Transferência de Pacientes , Transplante de Células-Tronco , Talassemia/terapia , Transição para Assistência do Adulto
8.
Chem Biol Interact ; 378: 110488, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-37054935

RESUMO

Internal exposure to plutonium can occur through inhalation for the nuclear worker, but also for the public if the radionuclide was released into the atmosphere in the context of a nuclear accident or terrorist attack. DieThylenetriaminePentaAcetic acid (DTPA) is currently still the only authorized chelator that can be used to decorporate internalized plutonium. The Linear HydrOxyPyridinOne-based ligand named 3,4,3-Li(1,2-HOPO) remains the most promising drug candidate to replace it in the hopes of improving chelating treatment. This study aimed to assess the efficacy of 3,4,3-Li(1,2-HOPO) in removing plutonium from rats exposed to the lungs, depending on the timing and route of treatment, and almost always compared to DTPA at a ten-fold higher dose used as a reference chelator. First, early intravenous injection or inhalation of 3,4,3-Li(1,2-HOPO) demonstrated superior efficacy over DTPA in preventing plutonium accumulation in liver and bone in rats exposed by injection or lung intubation. However, this superiority of 3,4,3-Li(1,2-HOPO) was much less pronounced with delayed treatment. In rats given plutonium in the lungs, the experiments also showed that 3,4,3-Li-HOPO reduced pulmonary retention of plutonium more effectively than DTPA only when the chelators were injected early but not at delayed times, while it was always the better of the two chelators when they were inhaled. Under our experimental conditions, the rapid oral administration of 3,4,3-Li(1,2-HOPO) was successful in preventing systemic accumulation of plutonium, but not in decreasing lung retention. Thus, after exposure to plutonium by inhalation, the best emergency treatment would be the rapid inhalation of a 3,4,3-Li(1,2-HOPO) aerosol to limit pulmonary retention of plutonium and prevent extrapulmonary deposition of plutonium in target systemic tissues.


Assuntos
Plutônio , Ratos , Animais , Plutônio/análise , Plutônio/farmacologia , Terapia por Quelação , Quelantes/farmacologia , Quelantes/uso terapêutico , Ácido Pentético/farmacologia , Ácido Pentético/uso terapêutico , Pulmão , Lítio/farmacologia
9.
Transfus Apher Sci ; 62(3): 103702, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37055329

RESUMO

Drug-induced nephrolithiasis can arise from insoluble components within medications or crystallization of metabolites due to changes in metabolism and urinary pH. The connection between drugs utilized for iron chelation therapy (ICT) and nephrolithiasis is not well understood. In this report, we describe two pediatric patients diagnosed with nephrolithiasis while undergoing treatment with the chelating agents deferasirox, deferiprone, and deferoxamine for iron overload secondary to repeat blood transfusion.


Assuntos
Sobrecarga de Ferro , Nefrolitíase , Talassemia beta , Humanos , Criança , Terapia por Quelação/efeitos adversos , Quelantes de Ferro/efeitos adversos , Deferasirox/efeitos adversos , Deferiprona/uso terapêutico , Desferroxamina/efeitos adversos , Benzoatos/efeitos adversos , Triazóis , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Nefrolitíase/induzido quimicamente , Nefrolitíase/complicações , Nefrolitíase/tratamento farmacológico , Ferro/uso terapêutico , Talassemia beta/terapia
10.
Cochrane Database Syst Rev ; 3: CD012349, 2023 03 06.
Artigo em Inglês | MEDLINE | ID: mdl-36877640

RESUMO

BACKGROUND: Regularly transfused people with sickle cell disease (SCD) and people with thalassaemia are at risk of iron overload. Iron overload can lead to iron toxicity in vulnerable organs such as the heart, liver and endocrine glands, which can be prevented and treated with iron-chelating agents. The intensive demands and uncomfortable side effects of therapy can have a negative impact on daily activities and wellbeing, which may affect adherence. OBJECTIVES: To identify and assess the effectiveness of different types of interventions (psychological and psychosocial, educational, medication interventions, or multi-component interventions) and interventions specific to different age groups, to improve adherence to iron chelation therapy compared to another listed intervention, or standard care in people with SCD or thalassaemia. SEARCH METHODS: We searched CENTRAL (Cochrane Library), MEDLINE, PubMed, Embase, CINAHL, PsycINFO, ProQuest Dissertations & Global Theses, Web of Science & Social Sciences Conference Proceedings Indexes and ongoing trial databases (13 December 2021). We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register (1 August 2022). SELECTION CRITERIA: For trials comparing medications or medication changes, only randomised controlled trials (RCTs) were eligible for inclusion. For studies including psychological and psychosocial interventions, educational interventions, or multi-component interventions, non-randomised studies of interventions (NRSIs), controlled before-after studies, and interrupted time series studies with adherence as a primary outcome were also eligible for inclusion. DATA COLLECTION AND ANALYSIS: For this update, two authors independently assessed trial eligibility and risk of bias, and extracted data. We assessed the certainty of the evidence using GRADE. MAIN RESULTS: We included 19 RCTs and one NRSI published between 1997 and 2021. One trial assessed medication management, one assessed an education intervention (NRSI) and 18 RCTs were of medication interventions. Medications assessed were subcutaneous deferoxamine, and two oral chelating agents, deferiprone and deferasirox. We rated the certainty of evidence as very low to low across all outcomes identified in this review. Four trials measured quality of life (QoL) with validated instruments, but provided no analysable data and reported no difference in QoL. We identified nine comparisons of interest. 1. Deferiprone versus deferoxamine We are uncertain whether or not deferiprone affects adherence to iron chelation therapy (four RCTs, unpooled, very low-certainty evidence), all-cause mortality (risk ratio (RR) 0.47, 95% confidence interval (CI) 0.18 to 1.21; 3 RCTs, 376 participants; very low-certainty evidence), or serious adverse events (SAEs) (RR 1.43, 95% CI 0.83 to 2.46; 1 RCT, 228 participants; very low-certainty evidence).  Adherence was reported as "good", "high" or "excellent" by all seven trials, though the data could not be analysed formally: adherence ranged from 69% to 95% (deferiprone, mean 86.6%), and 71% to 93% (deferoxamine, mean 78.8%), based on five trials (474 participants) only. 2. Deferasirox versus deferoxamine We are uncertain whether or not deferasirox affects adherence to iron chelation therapy (three RCTs, unpooled, very low-certainty evidence), although medication adherence was high in all trials. We are uncertain whether or not there is any difference between the drug therapies in serious adverse events (SAEs) (SCD or thalassaemia) or all-cause mortality (thalassaemia). 3. Deferiprone versus deferasirox We are uncertain if there is a difference between oral deferiprone and deferasirox based on a single trial in children (average age 9 to 10 years) with any hereditary haemoglobinopathy in adherence, SAEs and all-cause mortality. 4. Deferasirox film-coated tablet (FCT) versus deferasirox dispersible tablet (DT) One RCT compared deferasirox in different tablet forms. There may be a preference for FCTs, shown through a trend for greater adherence (RR 1.10, 95% CI 0.99 to 1.22; 1 RCT, 88 participants), although medication adherence was high in both groups (FCT 92.9%; DT 85.3%). We are uncertain if there is a benefit in chelation-related AEs with FCTs. We are uncertain if there is a difference in the incidence of SAEs, all-cause mortality or sustained adherence. 5. Deferiprone and deferoxamine combined versus deferiprone alone We are uncertain if there is a difference in adherence, though reporting was usually narrative as triallists report it was "excellent" in both groups (three RCTs, unpooled). We are uncertain if there is a difference in the incidence of SAEs and all-cause mortality.  6. Deferiprone and deferoxamine combined versus deferoxamine alone We are uncertain if there is a difference in adherence (four RCTs), SAEs (none reported in the trial period) and all-cause mortality (no deaths reported in the trial period). There was high adherence in all trials. 7. Deferiprone and deferoxamine combined versus deferiprone and deferasirox combined There may be a difference in favour of deferiprone and deferasirox (combined) in rates of adherence (RR 0.84, 95% CI 0.72 to 0.99) (one RCT), although it was high (> 80%) in both groups. We are uncertain if there is a difference in SAEs, and no deaths were reported in the trial, so we cannot draw conclusions based on these data (one RCT). 8. Medication management versus standard care We are uncertain if there is a difference in QoL (one RCT), and we could not assess adherence due to a lack of reporting in the control group. 9. Education versus standard care One quasi-experimental (NRSI) study could not be analysed due to the severe baseline confounding. AUTHORS' CONCLUSIONS: The medication comparisons included in this review had higher than average adherence rates not accounted for by differences in medication administration or side effects, though often follow-up was not good (high dropout over longer trials), with adherence based on a per protocol analysis. Participants may have been selected based on higher adherence to trial medications at baseline. Also, within the clinical trial context, there is increased attention and involvement of clinicians, thus high adherence rates may be an artefact of trial participation. Real-world, pragmatic trials in community and clinic settings are needed that examine both confirmed or unconfirmed adherence strategies that may increase adherence to iron chelation therapy. Due to lack of evidence this review cannot comment on intervention strategies for different age groups.


Assuntos
Anemia Falciforme , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Talassemia , Criança , Humanos , Anemia Falciforme/complicações , Anemia Falciforme/tratamento farmacológico , Quelantes , Terapia por Quelação , Desferroxamina/efeitos adversos , Ferro
11.
Turk J Pediatr ; 65(1): 170-175, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36867000

RESUMO

BACKGROUND: The clinical presentation of mercury (Hg) intoxication may mimic rheumatic diseases. Hg exposure is associated with systemic lupus erythematosus (SLE)-like disease in genetically susceptible rodents and Hg is among the environmental factors in the development of SLE in humans. Herein, we presented a case with clinical and immunological features suggestive of SLE but diagnosed with Hg intoxication. CASE: A thirteen-year-old female with myalgia, weight loss, hypertension and proteinuria was referred to our clinic for the evaluation of possible SLE. Physical examination of the patient was unremarkable except for a cachectic appearance and hypertension, laboratory investigation revealed positive anti-nuclear antibody, dsDNA antibody and hypocomplementemia with nephrotic range proteinuria. Inquiry for toxic exposures revealed a continuous exposure to an unknown silverly shiny liquid for a month which was thought to be Hg. Due to the fulfillment of Systemic Lupus International Collaborating Clinics (SLICC) classification criteria for SLE, a percutaneous kidney biopsy was performed whether proteinuria resulted because of the Hg exposure or flare of lupus nephritis. Blood and 24-hour urine Hg levels were high, and no findings associated with SLE were observed in the examination of the kidney biopsy. The patient was diagnosed with Hg intoxication and, clinical and laboratory findings, including hypocomplementemia, positive ANA and anti-dsDNA antibody, improved with chelation therapy. Also, no findings associated with SLE were observed in the follow-up of the patient. CONCLUSIONS: In addition to the toxic effects, Hg exposure may cause autoimmune features. As far as we know, this is the first-time Hg exposure was associated with hypocomplementemia and anti-dsDNA antibody in a patient. Also, this case highlights the inconvenience of the use of classification criteria for diagnostic purposes.


Assuntos
Hipertensão , Lúpus Eritematoso Sistêmico , Mercúrio , Feminino , Humanos , Adolescente , Lúpus Eritematoso Sistêmico/induzido quimicamente , Lúpus Eritematoso Sistêmico/diagnóstico , Terapia por Quelação , Proteinúria
12.
Hematol Oncol Clin North Am ; 37(2): 393-411, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36907611

RESUMO

Because women with transfusion-dependent thalassemia are seeking pregnancy, ensuring the best outcomes for both mother and baby require concerted and collaborative efforts between the hematologist, obstetrician, cardiologist, hepatologist, and genetic counselor among others. Proactive counseling, early fertility evaluation, optimal management of iron overload and organ function, and application of advances in reproductive technology and prenatal screening are important in ensuring a healthy outcome. Many unanswered questions remain requiring further study, including fertility preservation, non-invasive prenatal diagnosis, chelation therapy during pregnancy, and indications and duration of anticoagulation.


Assuntos
Sobrecarga de Ferro , Talassemia , Talassemia beta , Gravidez , Feminino , Humanos , Talassemia/terapia , Sobrecarga de Ferro/etiologia , Terapia por Quelação/efeitos adversos , Diagnóstico Pré-Natal/efeitos adversos , Fertilidade , Quelantes de Ferro/uso terapêutico , Talassemia beta/terapia
13.
Hematol., Transfus. Cell Ther. (Impr.) ; 45(1): 7-15, Jan.-Mar. 2023. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1421549

RESUMO

Abstract Introduction Magnetic resonance imaging (MRI) T2* technique is used to assess iron overload in the heart, liver and pancreas of thalassaemic patients. Optimal iron chelation and expected tissue iron response rates remain under investigation. The objective of this study was to analyse serum ferritin and the iron concentration in the heart, liver and pancreas measured by MRI T2*/R2* during regular chelation therapy in a real-world cohort of patients with thalassemia. Methods We evaluated thalassaemic patients ≥ 7 years old undergoing chelation/transfusion therapy by MRI and assessed serum ferritin at baseline and follow-up from 2004-2011. Results We evaluated 136 patients, 92% major thalassaemic, with a median age of 18 years, and median baseline ferritin 2.033ng/ml (range: 59-14,123). Iron overload distribution was: liver (99%), pancreas (74%) and heart (36%). After a median of 1.2 years of follow-up, the iron overload in the myocardium reduced from 2,63 Fe mg/g to 2,05 (p 0.003). The optimal R2* pancreas cut-off was 148 Hertz, achieving 78% sensitivity and 73% specificity. However, when combining the R2* pancreas cut off ≤ 50 Hertz and a ferritin ≤ 1222 ng/ml, we could reach a negative predictive value (NPV) of 98% for cardiac siderosis. Only 28% were undergoing combined chelation at baseline assessment, which increased up to 50% on follow up evaluation. Conclusions Chelation therapy significantly reduced cardiac siderosis in thalassaemic patients. In patients with moderate/severe liver iron concentration undergoing chelation therapy, ferritin levels and myocardium iron improved earlier than the liver siderosis.


Assuntos
Humanos , Criança , Talassemia , Sobrecarga de Ferro , Terapia por Quelação
15.
Eur J Haematol ; 110(5): 490-497, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36708354

RESUMO

Iron overload is a pathological condition resulting from a congenital impairment of its regulation, increased intestinal iron absorption secondary to bone marrow erythroid hyperplasia, or a chronic transfusional regimen. In normal conditions, intracellular and systemic mechanisms contribute to maintaining iron balance. When this complex homeostatic mechanism fails, an iron overload could be present. Detecting an iron overload is not easy. The gold standard remains the liver biopsy, even if it is invasive and dangerous. Identifying iron using noninvasive techniques allowed a better understanding of the rate of iron overload in different organs, with a low risk for the patient. Estimating serum ferritin (mg/L) is the easiest and, consequently, the most employed diagnostic tool for assessing body iron stores, even if it could be a not specific method. The most common hematological causes of iron overload are myelodysplastic syndromes, sickle cell disease, and thalassemia. In all of these conditions, three drugs have been approved for the treatment of iron overload: deferiprone, deferoxamine, and deferasirox. These chelators have been demonstrated to help lower tissue iron levels and prevent iron overload complications, improving event-free survival (EFS). Nowadays, the decision to start chelation and which chelator to choose remains the joint decision of the clinician and patient.


Assuntos
Terapia por Quelação , Sobrecarga de Ferro , Humanos , Terapia por Quelação/efeitos adversos , Quelantes de Ferro/uso terapêutico , Deferasirox/uso terapêutico , Deferiprona/uso terapêutico , Desferroxamina/uso terapêutico , Piridonas/uso terapêutico , Benzoatos/uso terapêutico , Triazóis , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Ferro
16.
J Inorg Biochem ; 241: 112131, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36706491

RESUMO

Capillary electrophoresis was used to estimate the solvolytic dissociation rate (kd) of metal complexes of deferasirox (DFX, H3L), a drug used to treat iron overload. Inert CoIIIL23- did not dissociate. The estimated kd value for FeIIIL23- was (2.7 ± 0.3) × 10-4 s-1 (298 K, pH 7.4). The kd values of other complexes (AlIIIL23-, NiIIL24-, and MnIIL-) were in the range 10-3-10-4 s-1. In contrast, ZnIIL- and CuIIL- were too labile to allow kd estimation. The fact that the half-life of FeIIIL23- (43.3 min) is shorter than the blood half-life of DFX (8-16 h) implies that the blood concentration of DFX should be high enough to prevent dissociation of FeIIIL23-. The possibility of a safer iron-chelation therapy that avoids excretion of other essential metal ions such as ZnII is discussed, highlighting the importance of selectivity in terms of kinetic stability.


Assuntos
Sobrecarga de Ferro , Ferro , Humanos , Deferasirox/uso terapêutico , Terapia por Quelação , Quelantes de Ferro , Eletroforese Capilar , Benzoatos
18.
Eur J Haematol ; 109(6): 772-778, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36130872

RESUMO

OBJECTIVES: In patients with myelodysplastic syndromes (MDS) with >20 transfusions and ferritin levels >1000 µg/L, international guidelines recommend iron chelation therapy (ICT). The study's objective was to determine guideline adherence and the intensity of ferritin monitoring in clinical practice. METHODS: We performed an observational population-based study using the HemoBase Registry, which contains data of all MDS patients diagnosed since 2005 in Friesland, the Netherlands. Clinical information on transfusions, ferritin measurements, ICT, and clinical performance as defined by age ≤ 80 years, Charlson Comorbidity Index <2 and lower-risk MDS was collected from health records. RESULTS: Two hundred and thirty seven of 292 patients (81.1%) received ≥1 transfusion, and 121 (41.4%) received >20 transfusions. In 57 of these 121 patients (47.1%), ferritin measurements were performed at least once. Clinical performance was significantly associated with monitoring ferritin around the 20th transfusion (RR: 2.49, p = .016). Clinical performance was also associated with initiating ICT (RR: 5.99, p < .001). ICT was offered to 22.3% (n = 25) of eligible patients. CONCLUSIONS: In this population-based study, ferritin levels were measured in <50% of MDS patients who received >20 transfusions, and clinical performance was significantly associated with measuring ferritin. Our study suggests that in heavily transfused MDS patients, ferritin monitoring is primarily based on patients' clinical performance rather than guideline recommendations.


Assuntos
Sobrecarga de Ferro , Síndromes Mielodisplásicas , Idoso de 80 Anos ou mais , Humanos , Terapia por Quelação , Ferritinas , Fidelidade a Diretrizes , Ferro , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/tratamento farmacológico
20.
Leuk Lymphoma ; 63(13): 3165-3174, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36095125

RESUMO

Patients with lower-risk (LR) myelodysplastic syndromes (MDS) with ring sideroblasts (RS) have better prognosis than those without RS, but how they fare over time is not fully understood. This study's objective was to assess the natural history of LR MDS with RS ≥5% using MDS-CAN registry individual data. Kaplan-Meier estimates and generalized linear mixed models were used to describe time-to-event outcomes and continuous outcomes, respectively. One hundred and thirty-eight patients were enrolled; median times from diagnosis to enrollment and follow-up were 6.6 and 39.6 months, respectively. Within 5 years of enrollment, 65% of patients had ≥1 red blood cell transfusion dependence episode. Within 5 years of diagnosis, 59% developed iron overload, 38% received iron chelation therapy, 14% progressed to acute myeloid leukemia, and 42% died. Patients exhibited inferior health-related quality of life trends. These first real-world data in LR MDS-RS in Canada indicate a high level of morbidity and mortality over a 5-year period. Clinical Trial Registration: ClinicalTrials.gov Identifier: NCT02537990.


Assuntos
Síndromes Mielodisplásicas , Humanos , Terapia por Quelação , Síndromes Mielodisplásicas/diagnóstico , Síndromes Mielodisplásicas/epidemiologia , Síndromes Mielodisplásicas/terapia , Prognóstico , Qualidade de Vida , Sistema de Registros
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