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2,230 result(s) for "Iron overload"
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Management of Iron Overload in Beta-Thalassemia Patients: Clinical Practice Update Based on Case Series
Thalassemia syndromes are characterized by the inability to produce normal hemoglobin. Ineffective erythropoiesis and red cell transfusions are sources of excess iron that the human organism is unable to remove. Iron that is not saturated by transferrin is a toxic agent that, in transfusion-dependent patients, leads to death from iron-induced cardiomyopathy in the second decade of life. The availability of effective iron chelators, advances in the understanding of the mechanism of iron toxicity and overloading, and the availability of noninvasive methods to monitor iron loading and unloading in the liver, heart, and pancreas have all significantly increased the survival of patients with thalassemia. Prolonged exposure to iron toxicity is involved in the development of endocrinopathy, osteoporosis, cirrhosis, renal failure, and malignant transformation. Now that survival has been dramatically improved, the challenge of iron chelation therapy is to prevent complications. The time has come to consider that the primary goal of chelation therapy is to avoid 24-h exposure to toxic iron and maintain body iron levels within the normal range, avoiding possible chelation-related damage. It is very important to minimize irreversible organ damage to prevent malignant transformation before complications set in and make patients ineligible for current and future curative therapies. In this clinical case-based review, we highlight particular aspects of the management of iron overload in patients with beta-thalassemia syndromes, focusing on our own experience in treating such patients. We review the pathophysiology of iron overload and the different ways to assess, quantify, and monitor it. We also discuss chelation strategies that can be used with currently available chelators, balancing the need to keep non-transferrin-bound iron levels to a minimum (zero) 24 h a day, 7 days a week and the risk of over-chelation.
The effect of quercetin on iron overload and inflammation in β-thalassemia major patients: A double-blind randomized clinical trial
•42 patients received a 500 mg/day quercetin and 42 others took a 500 mg/day placebo for 12 w.•Quercetin could significantly reduce ferritin and other serum iron factors (P > 0.05).•Quercetin significantly reduced hs-CRP (P = 0.046), but not TNF-α (p = 0.310).•According to our results, quercetin may be useful to reduce ferritin and inflammation in thalassemia major patients. The aim of this study was to determine whether quercetin can reduce iron overload and inflammation in thalassemic patients. Eighty four patients were recruited to this study and randomly assigned to two groups: 42 patients received a 500 mg/day quercetin tablet and 42 others took a 500 mg/day starch placebo for 12 weeks. Demographic, anthropometric and biochemical evaluation were performed. ANCOVA analysis revealed that compared to the control group, quercetin could reduce high sensitivity C-reactive protein (hs-CRP) (P = 0.046), iron (p = 0.036), ferritin (p = 0.043), and transferrin saturation (TS) (p = 0.008) and increase transferrin (p = 0.045) significantly, but it had no significant effect on total iron binding capacity (TIBC) (p = 0.734) and tumor necrosis factor α (TNF-α) (p = 0.310). Quercetin could ameliorate the iron status in thalassemia major, but its effect on inflammation is indistinctive.
Iron Homeostasis Disorder and Alzheimer’s Disease
Iron is an essential trace metal for almost all organisms, including human; however, oxidative stress can easily be caused when iron is in excess, producing toxicity to the human body due to its capability to be both an electron donor and an electron acceptor. Although there is a strict regulation mechanism for iron homeostasis in the human body and brain, it is usually inevitably disturbed by genetic and environmental factors, or disordered with aging, which leads to iron metabolism diseases, including many neurodegenerative diseases such as Alzheimer’s disease (AD). AD is one of the most common degenerative diseases of the central nervous system (CNS) threatening human health. However, the precise pathogenesis of AD is still unclear, which seriously restricts the design of interventions and treatment drugs based on the pathogenesis of AD. Many studies have observed abnormal iron accumulation in different regions of the AD brain, resulting in cognitive, memory, motor and other nerve damages. Understanding the metabolic balance mechanism of iron in the brain is crucial for the treatment of AD, which would provide new cures for the disease. This paper reviews the recent progress in the relationship between iron and AD from the aspects of iron absorption in intestinal cells, storage and regulation of iron in cells and organs, especially for the regulation of iron homeostasis in the human brain and prospects the future directions for AD treatments.
White matter hyperintensity-associated iron overload links glymphatic system dysfunction to cognitive impairment in cerebral small vessel disease
•An improved sub-voxel QSM separation method was applied to calculate WMH iron burden.•Multimodal neuroimaging was applied to explore the pathological mechanism of CSVD.•WMH iron overload mediates glymphatic dysfunction and cognitive impairment in CSVD. Glymphatic system function has been increasingly linked to cognition in cerebral small vessel disease (CSVD), although the underlying pathological mechanisms related to brain metabolism remain to be fully clarified. Iron overload within white matter hyperintensity (WMH), potentially reflecting metabolic abnormalities, may play a pivotal role in this process. This study investigated whether WMH iron burden mediates the association between glymphatic dysfunction and cognitive impairment in CSVD. A total of 102 patients with CSVD and 29 matched healthy controls (HCs) underwent brain MRI and cognitive assessments. WMH iron burden was quantified using a sub-voxel quantitative approach, while glymphatic function was assessed with the Diffusion Tensor Image Analysis aLong the Perivascular Space (DTI-ALPS) index. Correlation and mediation analyses were then conducted to evaluate relationships among WMH iron burden, DTI-ALPS index, and cognitive scores. Compared with HCs, CSVD patients exhibited significantly higher WMH iron burden, lower DTI-ALPS index, and poorer cognitive performances. Elevated WMH iron burden was associated with deficits in attention-executive (att-exe), memory, and visual-spatial domains, whereas reduced DTI-ALPS index correlated with impaired att-exe and memory function. Importantly, WMH iron burden fully mediated the link between DTI-ALPS index and both att-exe function (p < 0.001) and memory (p = 0.02) in the CSVD group. These findings noninvasively identify WMH iron overload, a probable representative of microglial activation, as a key mediator between glymphatic dysfunction and cognitive decline in CSVD, prompting a potential therapeutic target for disease management.
Hepatic hepcidin/intestinal HIF-2α axis maintains iron absorption during iron deficiency and overload
Iron-related disorders are among the most prevalent diseases worldwide. Systemic iron homeostasis requires hepcidin, a liver-derived hormone that controls iron mobilization through its molecular target ferroportin (FPN), the only known mammalian iron exporter. This pathway is perturbed in diseases that cause iron overload. Additionally, intestinal HIF-2α is essential for the local absorptive response to systemic iron deficiency and iron overload. Our data demonstrate a hetero-tissue crosstalk mechanism, whereby hepatic hepcidin regulated intestinal HIF-2α in iron deficiency, anemia, and iron overload. We show that FPN controlled cell-autonomous iron efflux to stabilize and activate HIF-2α by regulating the activity of iron-dependent intestinal prolyl hydroxylase domain enzymes. Pharmacological blockade of HIF-2α using a clinically relevant and highly specific inhibitor successfully treated iron overload in a mouse model. These findings demonstrate a molecular link between hepatic hepcidin and intestinal HIF-2α that controls physiological iron uptake and drives iron hyperabsorption during iron overload.
Relationship between cognitive impairment and hippocampal iron overload: A quantitative susceptibility mapping study of a rat model
•Iron overloaded rat groups showed significantly higher hippocampal magnetic susceptibility values compared to the control group.•Rats with iron overload had longer escape latencies and fewer platform crossings in the morris water maze, indicating impaired spatial reference memory.•Quantitative susceptibility mapping (QSM) effectively quantified brain iron overload in vivo, highlighting its potential for assessing cognitive impairment in thalassemia patients. The aim of this study was to establish an iron overload rat model to simulate the elevated iron levels in patients with thalassemia and to investigate the potential association between hippocampal iron deposition and cognition. Two groups of iron overloaded rats and one group of control rats were used for this study. The Morris water maze (MWM) was used to test spatial reference memory indicated by escape latency time and number of MWM platform crossings. The magnetic susceptibility value of the hippocampal tissue, a measure of iron deposition, was assessed by quantitative susceptibility mapping (QSM) and was correlated with spatial reference memory performance. The iron content in hippocampal tissue sections of the rats were assessed using diaminobenzidine (DAB)-enhanced Perl's Prussian blue (PPB) staining. The rat groups with iron overload including the Group H and Group L had higher hippocampal magnetic susceptibility values than the control rat group, i.e., Group D. In addition, the iron overloaded groups had longer MWM escape latency than the control group, and reduced number of MWM platform crossings. There was a positive correlation between the mean escape latency and the mean hippocampal magnetic susceptibility value, a negative correlation between the number of platform crossings and the mean hippocampal magnetic susceptibility value, and a negative correlation between the number of platform crossings and the latent escape time in Group H and Group L. This rat model simulating iron overload in thalassemia showed hippocampal iron overload being associated with impairment of spatial reference memory. QSM could be used to quantify brain iron overload in vivo, highlighting its potential clinical application for assessing cognitive impairment in patients with thalassemia.
Iron overload in alcoholic liver disease: underlying mechanisms, detrimental effects, and potential therapeutic targets
Alcoholic liver disease (ALD) is a global public health challenge due to the high incidence and lack of effective therapeutics. Evidence from animal studies and ALD patients has demonstrated that iron overload is a hallmark of ALD. Ethanol exposure can promote iron absorption by downregulating the hepcidin expression, which is probably mediated by inducing oxidative stress and promoting erythropoietin (EPO) production. In addition, ethanol may enhance iron uptake in hepatocytes by upregulating the expression of transferrin receptor (TfR). Iron overload in the liver can aggravate ethanol-elicited liver damage by potentiating oxidative stress via Fenton reaction, promoting activation of Kupffer cells (KCs) and hepatic stellate cells (HSCs), and inducing a recently discovered programmed iron-dependent cell death, ferroptosis. This article reviews the current knowledge of iron metabolism, regulators of iron homeostasis, the mechanism of ethanol-induced iron overload, detrimental effects of iron overload in the liver, and potential therapeutic targets.
Haemochromatosis
Haemochromatosis is one of the most common genetic diseases affecting patients of northern European ancestry. It is overdiagnosed in patients without iron overload and is underdiagnosed in many patients. Early diagnosis by genetic testing and therapy by periodic phlebotomy can prevent the most serious complications, which include liver cirrhosis, liver cancer, and death. This Seminar includes an update on the origins of haemochromatosis; and an overview pathophysiology, genetics, natural history, signs and symptoms, differential diagnoses, treatment with phlebotomy, outcomes, and future directions.
Impact of Inflammation on Ferritin, Hepcidin and the Management of Iron Deficiency Anemia in Chronic Kidney Disease
Iron deficiency anemia (IDA) is a major problem in chronic kidney disease (CKD), causing increased mortality. Ferritin stores iron, representing iron status. Hepcidin binds to ferroportin, thereby inhibiting iron absorption/efflux. Inflammation in CKD increases ferritin and hepcidin independent of iron status, which reduce iron availability. While intravenous iron therapy (IIT) is superior to oral iron therapy (OIT) in CKD patients with inflammation, OIT is as effective as IIT in those without. Inflammation reduces predictive values of ferritin and hepcidin for iron status and responsiveness to iron therapy. Upper limit of ferritin to predict iron overload is higher in CKD patients with inflammation than in those without. However, magnetic resonance imaging studies show lower cutoff levels of serum ferritin to predict iron overload in dialysis patients with apparent inflammation than upper limit of ferritin proposed by international guidelines. Compared to CKD patients with inflammation, optimal ferritin levels for IDA are lower in those without, requiring reduced iron dose and leading to decreased mortality. The management of IDA should differ between CKD patients with and without inflammation and include minimization of inflammation. Further studies are needed to determine the impact of inflammation on ferritin, hepcidin and therapeutic strategy for IDA in CKD.
Consensus Statement on the definition and classification of metabolic hyperferritinaemia
Hyperferritinaemia is a common laboratory finding that is often associated with metabolic dysfunction and fatty liver. Metabolic hyperferritinaemia reflects alterations in iron metabolism that facilitate iron accumulation in the body and is associated with an increased risk of cardiometabolic and liver diseases. Genetic variants that modulate iron homeostasis and tissue levels of iron are the main determinants of serum levels of ferritin in individuals with metabolic dysfunction, raising the hypothesis that iron accumulation might be implicated in the pathogenesis of insulin resistance and the related organ damage. However, validated criteria for the non-invasive diagnosis of metabolic hyperferritinaemia and the staging of iron overload are still lacking, and there is no clear evidence of a benefit for iron depletion therapy. Here, we provide an overview of the literature on the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction, and on the associated clinical outcomes. We propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, which has been agreed on by a multidisciplinary global panel of expert researchers. The goal is to foster studies into the epidemiology, genetics, pathophysiology, clinical relevance and treatment of metabolic hyperferritinaemia, for which we provide suggestions on the main unmet needs, optimal design and clinically relevant outcomes.This Consensus Statement discusses the relationship between hyperferritinaemia and iron accumulation in individuals with metabolic dysfunction. The authors propose an updated definition and a provisional staging system for metabolic hyperferritinaemia, highlight research gaps and provide suggestions for the design and outcome measures for future studies.