RESUMEN
α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and ß globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.
Asunto(s)
Enfermedades Hematológicas , Sobrecarga de Hierro , Talasemia alfa , Talasemia beta , Humanos , Talasemia beta/terapia , Talasemia alfa/diagnóstico , Talasemia alfa/genética , Talasemia alfa/terapia , Eritropoyesis , Transfusión de Eritrocitos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapiaRESUMEN
Importance: HFE gene-associated hereditary hemochromatosis type 1 (HH1) is underdiagnosed, resulting in missed opportunities for preventing morbidity and mortality. Objective: To assess whether screening for p.Cys282Tyr homozygosity is associated with recognition and management of asymptomatic iron overload. Design, Setting, and Participants: This cross-sectional study obtained data from the Geisinger MyCode Community Health Initiative, a biobank of biological samples and linked electronic health record data from a rural, integrated health care system. Participants included those who received a p.Cys282Tyr homozygous result via genomic screening (MyCode identified), had previously diagnosed HH1 (clinically identified), and those negative for p.Cys282Tyr homozygosity between 2017 and 2018. Data were analyzed from April 2020 to August 2023. Exposure: Disclosure of a p.Cys282Tyr homozygous result. Main Outcomes and Measures: Postdisclosure management and HFE-associated phenotypes in MyCode-identified participants were analyzed. Rates of HFE-associated phenotypes in MyCode-identified participants were compared with those of clinically identified participants. Relevant laboratory values and rates of laboratory iron overload among participants negative for p.Cys282Tyr homozygosity were compared with those of MyCode-identified participants. Results: A total of 86â¯601 participants had available exome sequences at the time of analysis, of whom 52 994 (61.4%) were assigned female at birth, and the median (IQR) age was 62.0 (47.0-73.0) years. HFE p.Cys282Tyr homozygosity was disclosed to 201 participants, of whom 57 (28.4%) had a prior clinical HH1 diagnosis, leaving 144 participants who learned of their status through screening. There were 86â¯300 individuals negative for p.Cys282Tyr homozygosity. After result disclosure, among MyCode-identified participants, 99 (68.8%) had a recommended laboratory test and 36 (69.2%) with laboratory or liver biopsy evidence of iron overload began phlebotomy or chelation. Fifty-three (36.8%) had iron overload; rates of laboratory iron overload were higher in MyCode-identified participants than participants negative for p.Cys282Tyr homozygosity (females: 34.1% vs 2.1%, P < .001; males: 39.0% vs 2.9%, P < .001). Iron overload (females: 34.1% vs 79.3%, P < .001; males: 40.7% vs 67.9%, P = .02) and some liver-associated phenotypes were observed at lower frequencies in MyCode-identified participants compared with clinically identified individuals. Conclusions and Relevance: Results of this cross-sectional study showed the ability of genomic screening to identify undiagnosed iron overload and encourage relevant management, suggesting the potential benefit of population screening for HFE p.Cys282Tyr homozygosity. Further studies are needed to examine the implications of genomic screening for health outcomes and cost-effectiveness.
Asunto(s)
Hemocromatosis , Sobrecarga de Hierro , Masculino , Recién Nacido , Humanos , Femenino , Persona de Mediana Edad , Anciano , Hemocromatosis/diagnóstico , Hemocromatosis/genética , Hemocromatosis/terapia , Estudios Transversales , Proteína de la Hemocromatosis/genética , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/genética , Sobrecarga de Hierro/complicaciones , Pruebas GenéticasRESUMEN
The intricate interplay of anemia and iron overload under the pathophysiological umbrella of ineffective erythropoiesis in non-transfusion-dependent ß-thalassemia (NTDT) results in a complex variety of clinical phenotypes that are challenging to diagnose and manage. In this article, we use a clinical framework rooted in pathophysiology to present 4 common scenarios of patients with NTDT. Starting from practical considerations in the diagnosis of NTDT, we delineate our strategy for the longitudinal care of patients who exhibit different constellations of symptoms and complications. We highlight the use of transfusion therapy and novel agents, such as luspatercept, in the patient with anemia-related complications. We also describe our approach to chelation therapy in the patient with iron overload. Although tackling every specific complication of NTDT is beyond the scope of this article, we touch on the management of the various morbidities and multisystem manifestations of the disease.
Asunto(s)
Sobrecarga de Hierro , Talasemia , Talasemia beta , Humanos , Talasemia beta/terapia , Talasemia beta/tratamiento farmacológico , Quelantes del Hierro/uso terapéutico , Talasemia/tratamiento farmacológico , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapia , Terapia por Quelación/efectos adversosRESUMEN
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.
Asunto(s)
Terapia por Quelación , Sobrecarga de Hierro , Humanos , Terapia por Quelación/efectos adversos , Quelantes del Hierro/uso terapéutico , Deferasirox/uso terapéutico , Deferiprona/uso terapéutico , Deferoxamina/uso terapéutico , Piridonas/uso terapéutico , Benzoatos/uso terapéutico , Triazoles , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , HierroRESUMEN
Non-transfusion-dependent thalassemia (NTDT) has been considered less severe than its transfusion-dependent variants. The most common forms of NTDT include ß-thalassemia intermedia, hemoglobin E/beta thalassemia, and hemoglobin H disease. Patients with NTDT develop several clinical complications, despite their regular transfusion independence. Ineffective erythropoiesis, iron overload, and hypercoagulability are pathophysiological factors that lead to morbidities in these patients. Therefore, an early and accurate diagnosis of NTDT is essential to ascertaining early interventions. Currently, several conventional management options are available, with guidelines suggested by the Thalassemia International Federation, and novel therapies are being developed in light of the advancement of the understanding of this disease. This review aimed to increase clinicians' awareness of NTDT, from its basic medical definition and genetics to its pathophysiology. Specific complications to NTDT were reviewed, along with the risk factors for its development. The indications of different therapeutic options were outlined, and recent advancements were reviewed.
Asunto(s)
Sobrecarga de Hierro , Talasemia , Humanos , Transfusión Sanguínea , Hemoglobina E/uso terapéutico , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/tratamiento farmacológico , Talasemia/complicaciones , Talasemia/terapia , Talasemia/diagnósticoRESUMEN
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.
Asunto(s)
Sobrecarga de Hierro , Síndromes Mielodisplásicos , Anciano de 80 o más Años , Humanos , Terapia por Quelación , Ferritinas , Adhesión a Directriz , Hierro , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , Síndromes Mielodisplásicos/diagnóstico , Síndromes Mielodisplásicos/tratamiento farmacológicoRESUMEN
BACKGROUND: Screening program participants with iron overload (IO) phenotypes without HFE p.C282Y/p.C282Y are incompletely characterized. METHODS: We studied white participants who had IO phenotypes without p.C282Y/p.C282Y in post-screening clinical examinations (CE). We defined IO phenotypes as a) elevated serum ferritin (SF) and transferrin saturation (TS) at screening and CE, and b) absence of IO treatment, anemia, transfusion >10 units, alcohol intake >30 g/d, hepatitis B or C, and pregnancy. We defined IO-related disease as elevated alanine or aspartate aminotransferase (ALT/AST) or swelling/tenderness of 2nd/3rd metacarpophalangeal (MCP) joints. All participants had HFE p.C282Y and p.H63D genotyping. RESULTS: There were 32 men and 26 women (mean age 54±16 y). Median food/supplemental iron intakes were 14.3/0.0 mg/d. Relative risks of HFE genotypes were 12.9 (p.C282Y/p.H63D), 3.0 (p.H63D/p.H63D), 1.9 (p.C282Y/wt), 0.9 (p.H63D/wt), and 0.5 (wt/wt) compared to 42,640 white screening participants without IO phenotypes or p.C282Y/p.C282Y. Regression on SF revealed positive associations: MCV (p = 0.0006; ß coefficient = 0.4531); swelling/tenderness of MCP joints (p = 0.0033; ß = 0.3455); and p.H63D/wt (p = 0.0015; ß = 0.4146). IO-related disease (18 elevated ALT/AST, one swelling/tenderness of MCP joints) occurred in 19 participants (7 men, 12 women). Median MCV was higher in participants with IO-related disease (97 fL vs. 94 fL; p = 0.0007). Logistic regression on IO-related disease revealed a significant association with diabetes (p = 0.0416; odds ratio 18.9 (95% confidence interval 1.0, 341.1)). CONCLUSIONS: In the present 58 screening program participants who had IO phenotypes without HFE p.C282Y/p.C282Y, relative risks of HFE genotypes p.C282Y/p.H63D, p.H63D/p.H63D, and p.C282Y/wt were significantly higher than in 42,640 white screening participants with neither IO phenotypes nor p.C282Y/p.C282Y. SF was significantly associated with MCV, swelling/tenderness of 2nd/3rd MCP joints, and p.H63D/wt. IO-related disease was significantly associated with MCV and diabetes.
Asunto(s)
Hemocromatosis , Sobrecarga de Hierro , Adulto , Anciano , Femenino , Ferritinas , Genotipo , Hemocromatosis/complicaciones , Proteína de la Hemocromatosis/genética , Humanos , Sobrecarga de Hierro/diagnóstico , Masculino , Persona de Mediana Edad , Fenotipo , Transferrina/genéticaRESUMEN
Thalassaemia is caused by genetic globin defects leading to anaemia, transfusion-dependence and comorbidities. Reduced survival and systemic organ disease affect transfusion-dependent thalassaemia major and thalassaemia intermedia. Recent improvements in clinical management have reduced thalassaemia mortality. The therapeutic landscape of thalassaemia may soon include gene therapies as functional cures. An analysis of the adult US thalassaemia population has not been performed since the Thalassemia Clinical Research Network cohort study from 2000 to 2006. The Centers for Disease Control and Prevention supported US thalassaemia treatment centres (TTCs) to compile longitudinal information on individuals with thalassaemia. This dataset provided an opportunity to evaluate iron balance, chelation, comorbidities and demographics of adults with thalassaemia receiving care at TTCs. Two adult cohorts were compared: those over 40 years old (n = 75) and younger adults ages 18-39 (n = 201). The older adult cohort was characterized by higher numbers of iron-related comorbidities and transfusion-related complications. By contrast, younger adults had excess hepatic and cardiac iron and were receiving combination chelation therapy. The ethnic composition of the younger cohort was predominantly of Asian origin, reflecting the demographics of immigration. These findings demonstrate that comprehensive care and periodic surveys are needed to ensure optimal health and access to emerging therapies.
Asunto(s)
Talasemia/epidemiología , Adolescente , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Terapia Combinada/efectos adversos , Terapia Combinada/métodos , Comorbilidad , Manejo de la Enfermedad , Susceptibilidad a Enfermedades , Femenino , Predisposición Genética a la Enfermedad , Humanos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapia , Masculino , Persona de Mediana Edad , Vigilancia en Salud Pública , Estudios Retrospectivos , Factores Sociodemográficos , Talasemia/diagnóstico , Talasemia/etiología , Talasemia/terapia , Estados Unidos/epidemiología , Adulto JovenRESUMEN
BACKGROUND: In the western world, 10-15% of women of child-bearing age suffer from iron-deficiency anemia. Iron overload due to chronic treatment with blood transfusions or hereditary hemochromatosis is much rarer. METHODS: This review is based on pertinent publications retrieved by a selective search on the pathophysiology, clinical features, and diagnostic evaluation of iron deficiency and iron overload. RESULTS: The main causes of iron deficiency are malnutrition and blood loss. Its differential diagnosis includes iron-refractory iron deficiency anemia (IRIDA), a rare congenital disease in which the hepcidin level is pathologically elevated, as well as the more common anemia of chronic disease (anemia of chronic inflammation), in which increased amounts of hepcidin are formed under the influence of interleukin-6 and enteric iron uptake is blocked as a result. Iron overload comes about through long-term transfusion treatment or a congenital disturbance of iron metabolism (hemochromatosis). Its diagnostic evaluation is based on clinical and laboratory findings, imaging studies, and specific mutation analyses. CONCLUSION: Our improving understanding of the molecular pathophysiology of iron metabolism aids in the evaluation of iron deficiency and iron overload and may in future enable treatment not just with iron supplementation or iron chelation, but also with targeted pharmacological modulation of the hepcidin regulatory system.
Asunto(s)
Anemia Ferropénica , Anemia , Deficiencias de Hierro , Sobrecarga de Hierro , Anemia Ferropénica/complicaciones , Anemia Ferropénica/diagnóstico , Anemia Ferropénica/genética , Femenino , Humanos , Hierro/análisis , Hierro/metabolismo , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/metabolismoRESUMEN
Iatrogenic iron overload, which is not uncommon in patients undergoing long-term haemodialysis, arises from a combination of multiple red cell transfusions and parenteral iron infusions that are administered to maintain a haemoglobin concentration of approximately 10 g/dL. Although iron overload due to genetic haemochromatosis is conventionally managed by phlebotomy, patients with haemoglobinopathies and chronic transfusion-induced iron overload are treated with iron-chelation therapy. However, the management of iron overload in our patient who presented with hepatic dysfunction and immunosuppressive drug-induced mild anaemia in the post-renal transplant setting posed unique challenges. We report on the decision-making process used in such a case that led to a successful clinical resolution of hepatic iron overload through the combined use of phlebotomy and erythropoiesis stimulating agents, while avoiding use of iron-chelating agents that could potentially compromise both hepatic and renal function.
Asunto(s)
Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapia , Trasplante de Riñón , Biopsia , Transfusión de Eritrocitos , Femenino , Hematínicos/administración & dosificación , Humanos , Hierro/administración & dosificación , Sobrecarga de Hierro/diagnóstico , Pruebas de Función Hepática , Imagen por Resonancia Magnética , Persona de Mediana Edad , Factores de RiesgoRESUMEN
Red blood cell (RBC) transfusion is an effective therapy for anemia, but repeated transfusions may cause iron overload-related damage to various organs. Iron chelation therapy, now widely available for patients who have received transfusions, is expected to reduce organ damage even in patients who received many transfusions. Therefore, determining when to start iron chelation therapy is important. In guidelines for iron chelation therapy, the serum ferritin level has been widely accepted as a practical marker for estimating iron overload. However, guidelines recommend multiple measurements of serum ferritin, because levels often fluctuate. Here, we investigated the usefulness of glycosylated ferritin as a marker of iron overload using a cohort consisted of 103 patients who had a total ferritin value over 1000 ng/mL. We found that the volume of RBCs transfused was clearly associated with the glycosylated ferritin level. We also found that acute inflammation, as represented by C-reactive protein values, was associated with increased non-glycosylated ferritin and that patients with hematopoietic diseases had higher glycosylated ferritin levels, possibly because of repeated RBC transfusions. We thus conclude that glycosylated ferritin may be an improved marker for predicting iron overload status.
Asunto(s)
Biomarcadores , Ferritinas/sangre , Sobrecarga de Hierro/sangre , Sobrecarga de Hierro/diagnóstico , Anciano , Transfusión Sanguínea , Comorbilidad , Transfusión de Eritrocitos , Femenino , Humanos , Sobrecarga de Hierro/etiología , Sobrecarga de Hierro/terapia , Masculino , Persona de Mediana Edad , PronósticoAsunto(s)
Deferasirox/uso terapéutico , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , Talasemia beta/complicaciones , Biomarcadores , Deferasirox/administración & dosificación , Deferasirox/efectos adversos , Estudios de Seguimiento , Humanos , Quelantes del Hierro/administración & dosificación , Quelantes del Hierro/efectos adversos , Sobrecarga de Hierro/complicaciones , Sobrecarga de Hierro/diagnóstico , Pronóstico , Resultado del TratamientoRESUMEN
BACKGROUND AND OBJECTIVES: Patients with beta-thalassemia require lifelong blood transfusions, leading to chronic iron overload, which can lead to growth retardation, as well as hinder sexual development during the adolescent period and dysfunction of organs such as heart, pancreas, and endocrine glands. These patients are in need of lifelong transfusion therapy and hence lifelong iron chelation therapy as well. Hence, this study was aimed to assess the effectiveness of deferasirox for iron chelation in pediatric thalassemia cases in a tertiary care hospital of Eastern India. SUBJECTS AND METHODS: This prospective, observational, hospital-based study was conducted from June 2015 to December 2016. Two hundred and fifty patients were assessed for eligibility, of which 174 were included. Effectiveness of deferasirox was observed by measuring serum ferritin levels which were monitored at the end of every 3 months till 1 year. We also evaluated the compliance with deferasirox therapy in the same study cohort. RESULTS: The serum ferritin level reduced significantly at the end of 12 months in comparison to baseline (P = 0.04). There was a mean absolute decrease in serum ferritin only in the dose range of 21-30 mg/kg/day. Approximately 90% of the patients had 100% compliance with deferasirox therapy. CONCLUSIONS: Deferasirox is an effective iron chelator when started at an optimum time and with optimum dose. At least 1 year of deferasirox therapy is needed for a significant lowering of serum ferritin levels of pediatric thalassemia patients on multiple blood transfusions.
Asunto(s)
Transfusión Sanguínea , Deferasirox/uso terapéutico , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/prevención & control , Talasemia beta/terapia , Adolescente , Factores de Edad , Biomarcadores/sangre , Niño , Preescolar , Deferasirox/efectos adversos , Femenino , Ferritinas/sangre , Humanos , India , Quelantes del Hierro/efectos adversos , Sobrecarga de Hierro/sangre , Sobrecarga de Hierro/diagnóstico , Masculino , Estudios Prospectivos , Centros de Atención Terciaria , Factores de Tiempo , Resultado del Tratamiento , Talasemia beta/sangre , Talasemia beta/diagnósticoRESUMEN
Aceruloplasminemia is a rare iron-overload disease that should be better known by physicians. It is an autosomal recessive disorder due to mutations in ceruloplasmin gene causing systemic iron overload, including cerebral and liver parenchyma. The impairment of ferroxidase ceruloplasmin activity leads to intracellular iron retention leading aceruloplasminemia symptoms. Neurologic manifestations include cognitive impairment, ataxia, extrapyramidal syndrome, abnormal movements, and psychiatric-like syndromes. Physicians should search for aceruloplasminemia in several situations with high ferritin levels: microcytic anaemia, diabetes mellitus, neurological and psychiatric disorders. Diagnosis approach is based on the study of transferrin saturation and hepatic iron content evaluated by magnetic resonance imaging of the liver. Ceruloplasmin dosage is required in case of low transferrin saturation and high hepatic iron content and genetic testing is mandatory in case of serum ceruloplasmin defect. Neurological manifestations occur in the sixties decade and leads to disability. Iron chelators are widely used. Despite their efficacy on systemic and cerebral iron overload, iron chelators tolerance is poor. Early initiation of iron chelation therapy might prevent or slowdown neurodegeneration, highlighting the need for an early diagnosis but their clinical efficacy remains uncertain.
Asunto(s)
Ceruloplasmina/deficiencia , Trastornos del Metabolismo del Hierro/diagnóstico , Enfermedades Neurodegenerativas/diagnóstico , Ceruloplasmina/genética , Ceruloplasmina/metabolismo , Diagnóstico Diferencial , Humanos , Hierro/metabolismo , Trastornos del Metabolismo del Hierro/complicaciones , Trastornos del Metabolismo del Hierro/genética , Trastornos del Metabolismo del Hierro/terapia , Sobrecarga de Hierro/complicaciones , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/patología , Enfermedades Neurodegenerativas/complicaciones , Enfermedades Neurodegenerativas/genética , Enfermedades Neurodegenerativas/terapia , Trastornos Parkinsonianos/diagnóstico , Trastornos Parkinsonianos/etiología , Trastornos Parkinsonianos/metabolismo , Enfermedades RarasRESUMEN
Iron overload (IOL) in patients with myelodysplastic syndromes (MDS) is mainly attributable to chronic transfusion therapy. The importance of iron chelation therapy (ICT) in MDS has been a matter of debate. The Telesto study, the only randomized, placebo-controlled trial of ICT with deferasirox in MDS, showed improved event-free survival with ICT in patients with lower-risk MDS. Although Telesto was not powered to detect differences between deferasirox and placebo for single-event categories of the composite primary endpoint for event-free survival, results are consistent with the view that iron-related cardiac dysfunction is ameliorated by ICT in elderly patients with MDS.
Asunto(s)
Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , Síndromes Mielodisplásicos/complicaciones , Biomarcadores , Transfusión Sanguínea , Terapia por Quelación , Humanos , Quelantes del Hierro/administración & dosificación , Quelantes del Hierro/efectos adversos , Sobrecarga de Hierro/diagnóstico , Síndromes Mielodisplásicos/mortalidad , Síndromes Mielodisplásicos/terapia , Pronóstico , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del TratamientoRESUMEN
Thalassemia is a genetic mutation of the α- or ß-globin chains that lead to defective erythropoiesis. This study aimed to collect evidences from all published studies that investigated the clinical effectiveness of calcium channel blockers (CCBs) in conjunction with chelation therapy for reducing iron overload in patients with thalassemia. A systematic search was conducted in PubMed, Institute for Scientific Information (ISI) Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Virtual Health Library. Original studies reporting the use of CCBs in patients with thalassemia were included for meta-analysis. A total of five randomized studies including 210 patients were included with a follow-up period of 3-12 months. There was no significant difference between amlodipine and control groups in increasing the heart T2* magnetic resonance imaging (MRI) [mean difference (MD) 95% confidence interval (95% CI) = -1.9 (-4.4 to 0.5), p = 0.119] or reducing the liver iron concentration [MD 95% CI = -0.046 (-0.325 to 0.2), p = 0.746]. Although there were no serious adverse events reported in the included trials, further studies are recommended to strengthen our findings.
Asunto(s)
Bloqueadores de los Canales de Calcio/uso terapéutico , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/tratamiento farmacológico , Sobrecarga de Hierro/etiología , Talasemia beta/complicaciones , Amlodipino/administración & dosificación , Amlodipino/efectos adversos , Amlodipino/uso terapéutico , Biomarcadores , Bloqueadores de los Canales de Calcio/administración & dosificación , Bloqueadores de los Canales de Calcio/efectos adversos , Terapia por Quelación , Quimioterapia Combinada , Humanos , Quelantes del Hierro/administración & dosificación , Quelantes del Hierro/efectos adversos , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/metabolismo , Imagen por Resonancia Magnética , Ensayos Clínicos Controlados Aleatorios como Asunto , Resultado del Tratamiento , Talasemia beta/diagnóstico , Talasemia beta/genéticaRESUMEN
The increased usage of intravenous iron in hemodialysis patients during recent years has led to increasing concern over the potential development of iron overload. Current methods for detecting iron overload, transferrin saturation, and serum ferritin are neither sensitive nor specific. Labile plasma iron (LPI) represents a component of nontransferrin-bound iron and may be a more accurate indicator of impending iron overload. We studied whether LPI measured can serve as an early indicator of impending iron overload and mortality in hemodialysis patients. Chronic hemodialysis patients from two medical centers in Israel and Poland who received intravenous iron were included. Baseline clinical and laboratory parameters were recorded. LPI was measured before and 48 hours after a single IV administration. Correlation of positive LPI with laboratory parameters and 2-year mortality was evaluated. One hundred and one hemodialysis patients were included in the study. LPI became positive post-administration in 18 (17.8%) patients. Ferritin levels >526 ng/mL and monthly iron doses >250 mg were associated with positive LPI after intravenous iron. At a 2-year follow-up, higher mortality was observed in the positive LPI group (61.1% compared to 25.3%, P ≤ .05), although this effect was not statistically significant after multivariate adjustment. A substantial number of hemodialysis patients have positive LPI after intravenous iron administration. LPI positively correlates with laboratory parameters that are currently in routine clinical use for detecting iron overload and with higher intravenous iron dose. Further studies should be conducted to establish the clinical implications of LPI monitoring in hemodialysis patients.
Asunto(s)
Sobrecarga de Hierro/sangre , Sobrecarga de Hierro/diagnóstico , Hierro/sangre , Hierro/uso terapéutico , Diálisis Renal , Administración Intravenosa , Anciano , Femenino , Humanos , Hierro/administración & dosificación , Israel , Masculino , Persona de Mediana Edad , Polonia , Estudios ProspectivosRESUMEN
Hypothyroidism is one of the common endocrine complications described in patients with ß-thalassemia major (ß-TM). Studies have reported its incidence and severity depending on the region, quality of management and treatment protocols. The reported thyroid dysfunction includes overt hypothyroidism, subclinical hypothyroidism and rarely, central hypothyroidism. The main aims of this study were to identify the incidence of hypothyroidism in 82 patients with ß-TM in Syria, and also to evaluate the effect of compliance with deferoxamine (DFO) therapy on the patients' thyroid function. Out of the 82 patients included in this study, 24 had subclinical hypothyroidism (29.27%) and one patient had overt hypothyroidism (1.22%). It was demonstrated by this study that noncompliance with DFO therapy increases the risk of thyroid dysfunction 6.38-times compared to compliance with DFO [risk ratio (RR) = 6.385; 95% confidence interval (95% CI) 2.40-16.95)]. These results emphasize the importance of compliance with chelation therapy to minimize the burden of thyropathy on patients' quality of life, and also augment the rationale for a routine follow-up and endocrine evaluation for early detection and management of these complications.
Asunto(s)
Sobrecarga de Hierro/epidemiología , Sobrecarga de Hierro/etiología , Cumplimiento de la Medicación , Enfermedades de la Tiroides/epidemiología , Enfermedades de la Tiroides/etiología , Talasemia beta/complicaciones , Talasemia beta/epidemiología , Adolescente , Adulto , Biomarcadores , Estudios de Casos y Controles , Niño , Estudios Transversales , Deferoxamina/farmacología , Deferoxamina/uso terapéutico , Femenino , Humanos , Hipotiroidismo/diagnóstico , Hipotiroidismo/tratamiento farmacológico , Hipotiroidismo/epidemiología , Hipotiroidismo/etiología , Quelantes del Hierro/farmacología , Quelantes del Hierro/uso terapéutico , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/tratamiento farmacológico , Masculino , Cooperación del Paciente , Siria/epidemiología , Enfermedades de la Tiroides/diagnóstico , Enfermedades de la Tiroides/tratamiento farmacológico , Resultado del Tratamiento , Adulto Joven , Talasemia beta/genéticaRESUMEN
Sickle cell disease (SCD) is a frequent indication for chronic transfusion, which can cause iron overload. Excess iron often affects the liver, but not the heart in SCD. Magnetic resonance (MR) is recommended to detect myocardial iron overload (MIO) but its elevated cost requires optimized indication. We aimed to compile all published data on MIO in SCD upon the description of a fatal case of severe MIO in our institution, and to determine associated risk factors. We performed a systematic review using the PRISMA guidelines in two databases (PubMed and Web of Science). Inclusion criteria were publication in English, patients diagnosed with SCD, and reporting ferritin and MIO by MR. Twenty publications reported on 865 SCD adult and pediatric patients, with at least 10 other cases of MIO. The prevalence of MIO in chronically transfused SCD patients can be estimated to be 3% or less, and is associated with high transfusion burden, top-up transfusions, and low adherence to iron chelation. Cardiac siderosis in SCD is rarely reported, and increased awareness with better use of the available screening tools are necessary. Prospective studies should define the recommended chelation regimens depending on the severity of MIO.
Asunto(s)
Anemia de Células Falciformes/terapia , Ferritinas/metabolismo , Sobrecarga de Hierro/diagnóstico , Sobrecarga de Hierro/etiología , Miocardio/metabolismo , Reacción a la Transfusión/diagnóstico , Anemia de Células Falciformes/metabolismo , Biomarcadores/metabolismo , Resultado Fatal , Femenino , Humanos , Sobrecarga de Hierro/epidemiología , Sobrecarga de Hierro/prevención & control , Persona de Mediana Edad , Reacción a la Transfusión/epidemiología , Reacción a la Transfusión/prevención & controlRESUMEN
BACKGROUND: In patients with thalassemia major, examination routinely used for the evaluation of iron load in Indonesia is serum ferritin, but it is strongly influenced by other factors such as infections, inflammation and vitamin C levels. Evaluation of urinary iron excretion is an important and easy method to indicate iron chelation efficacy. OBJECTIVE: To determine the efficacy of iron chelation therapy by urinary iron examination and to evaluate its correlation with the time of transfusion, serum ferritin level, transferrin saturation and T2* MRI. METHODS: Prospective cohort study was conducted in children with thalassemia major aged 7-<18â¯years old who received DFP therapy. Twenty-four-hour urine collections were examined through inductively coupled plasma - mass spectrometry (ICP-MS). Patient's serum ferritin, transferrin saturation, peripheral blood, differential count and T2* MRI was documented during the study. Data analysis is based on urine iron level, body iron balance and the correlation between urine iron level, serum ferritin, transferrin saturation and T2* MRI and dosage of DFP. RESULTS: Thirty (55%) subjects showed a higher urine iron level on the day prior to transfusion (mean: 12,828 SD ±12,801⯵g/24â¯h) in comparison to post transfusion (mean: 10,985 SD ±10,023⯵g/24â¯h). All subjects had positive iron balance (mean 524 SD ±230â¯mg). There were positive correlation between urine iron level and transferrin saturation (râ¯=â¯0.559, pâ¯=â¯0.01) and serum ferritin (râ¯=â¯0.291, pâ¯=â¯0.03), no correlation found with T2* MRI results. CONCLUSIONS: There is a relationship to urinary iron excretion in response to chelation therapy and the degree of iron load.