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1.
BMJ Open ; 14(3): e081926, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38479735

RESUMO

OBJECTIVES: HFE haemochromatosis genetic variants have an uncertain clinical penetrance, especially to older ages and in undiagnosed groups. We estimated p.C282Y and p.H63D variant cumulative incidence of multiple clinical outcomes in a large community cohort. DESIGN: Prospective cohort study. SETTING: 22 assessment centres across England, Scotland, and Wales in the UK Biobank (2006-2010). PARTICIPANTS: 451 270 participants genetically similar to the 1000 Genomes European reference population, with a mean of 13.3-year follow-up through hospital inpatient, cancer registries and death certificate data. MAIN OUTCOME MEASURES: Cox proportional HRs of incident clinical outcomes and mortality in those with HFE p.C282Y/p.H63D mutations compared with those with no variants, stratified by sex and adjusted for age, assessment centre and genetic stratification. Cumulative incidences were estimated from age 40 years to 80 years. RESULTS: 12.1% of p.C282Y+/+ males had baseline (mean age 57 years) haemochromatosis diagnoses, with a cumulative incidence of 56.4% at age 80 years. 33.1% died vs 25.4% without HFE variants (HR 1.29, 95% CI: 1.12 to 1.48, p=4.7×10-4); 27.9% vs 17.1% had joint replacements, 20.3% vs 8.3% had liver disease, and there were excess delirium, dementia, and Parkinson's disease but not depression. Associations, including excess mortality, were similar in the group undiagnosed with haemochromatosis. 3.4% of women with p.C282Y+/+ had baseline haemochromatosis diagnoses, with a cumulative incidence of 40.5% at age 80 years. There were excess incident liver disease (8.9% vs 6.8%; HR 1.62, 95% CI: 1.27 to 2.05, p=7.8×10-5), joint replacements and delirium, with similar results in the undiagnosed. p.C282Y/p.H63D and p.H63D+/+ men or women had no statistically significant excess fatigue or depression at baseline and no excess incident outcomes. CONCLUSIONS: Male and female p.C282Y homozygotes experienced greater excess morbidity than previously documented, including those undiagnosed with haemochromatosis in the community. As haemochromatosis diagnosis rates were low at baseline despite treatment being considered effective, trials of screening to identify people with p.C282Y homozygosity early appear justified.


Assuntos
Delírio , Hemocromatose , Hepatopatias , Adulto , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Bancos de Espécimes Biológicos , Delírio/complicações , Genótipo , Hemocromatose/diagnóstico , Hemocromatose/epidemiologia , Hemocromatose/genética , Proteína da Hemocromatose/genética , Antígenos de Histocompatibilidade Classe I/genética , Homozigoto , Hepatopatias/complicações , Mutação , Estudos Prospectivos , 60682 , Idoso
2.
Int J Mol Sci ; 25(5)2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38473913

RESUMO

Hemochromatosis represents clinically one of the most important genetic storage diseases of the liver caused by iron overload, which is to be differentiated from hepatic iron overload due to excessive iron release from erythrocytes in patients with genetic hemolytic disorders. This disorder is under recent mechanistic discussion regarding ferroptosis, reactive oxygen species (ROS), the gut microbiome, and alcohol abuse as a risk factor, which are all topics of this review article. Triggered by released intracellular free iron from ferritin via the autophagic process of ferritinophagy, ferroptosis is involved in hemochromatosis as a specific form of iron-dependent regulated cell death. This develops in the course of mitochondrial injury associated with additional iron accumulation, followed by excessive production of ROS and lipid peroxidation. A low fecal iron content during therapeutic iron depletion reduces colonic inflammation and oxidative stress. In clinical terms, iron is an essential trace element required for human health. Humans cannot synthesize iron and must take it up from iron-containing foods and beverages. Under physiological conditions, healthy individuals allow for iron homeostasis by restricting the extent of intestinal iron depending on realistic demand, avoiding uptake of iron in excess. For this condition, the human body has no chance to adequately compensate through removal. In patients with hemochromatosis, the molecular finetuning of intestinal iron uptake is set off due to mutations in the high-FE2+ (HFE) genes that lead to a lack of hepcidin or resistance on the part of ferroportin to hepcidin binding. This is the major mechanism for the increased iron stores in the body. Hepcidin is a liver-derived peptide, which impairs the release of iron from enterocytes and macrophages by interacting with ferroportin. As a result, iron accumulates in various organs including the liver, which is severely injured and causes the clinically important hemochromatosis. This diagnosis is difficult to establish due to uncharacteristic features. Among these are asthenia, joint pain, arthritis, chondrocalcinosis, diabetes mellitus, hypopituitarism, hypogonadotropic hypogonadism, and cardiopathy. Diagnosis is initially suspected by increased serum levels of ferritin, a non-specific parameter also elevated in inflammatory diseases that must be excluded to be on the safer diagnostic side. Diagnosis is facilitated if ferritin is combined with elevated fasting transferrin saturation, genetic testing, and family screening. Various diagnostic attempts were published as algorithms. However, none of these were based on evidence or quantitative results derived from scored key features as opposed to other known complex diseases. Among these are autoimmune hepatitis (AIH) or drug-induced liver injury (DILI). For both diseases, the scored diagnostic algorithms are used in line with artificial intelligence (AI) principles to ascertain the diagnosis. The first-line therapy of hemochromatosis involves regular and life-long phlebotomy to remove iron from the blood, which improves the prognosis and may prevent the development of end-stage liver disease such as cirrhosis and hepatocellular carcinoma. Liver transplantation is rarely performed, confined to acute liver failure. In conclusion, ferroptosis, ROS, the gut microbiome, and concomitant alcohol abuse play a major contributing role in the development and clinical course of genetic hemochromatosis, which requires early diagnosis and therapy initiation through phlebotomy as a first-line treatment.


Assuntos
Alcoolismo , Ferroptose , Microbioma Gastrointestinal , Hemocromatose , Sobrecarga de Ferro , Neoplasias Hepáticas , Humanos , Hemocromatose/genética , Hepcidinas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Alcoolismo/complicações , Inteligência Artificial , Fatores de Confusão Epidemiológicos , Antígenos de Histocompatibilidade Classe I/genética , Proteína da Hemocromatose/metabolismo , Proteínas de Membrana/metabolismo , Ferro/metabolismo , Sobrecarga de Ferro/genética , Ferritinas , Etanol , Neoplasias Hepáticas/complicações
4.
Liver Int ; 44(3): 838-847, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38263707

RESUMO

BACKGROUND AND AIMS: Haemochromatosis is characterized by progressive iron overload affecting the liver and can cause cirrhosis and hepatocellular carcinoma. Most haemochromatosis patients are homozygous for p.C282Y in HFE, but only a minority of individuals with this genotype will develop the disease. The aim was to assess the penetrance of iron overload, fibrosis, hepatocellular carcinoma and life expectancy. METHODS: A total of 8839 individuals from the Austrian region of Tyrol were genotyped for the p.C282Y variant between 1997 and 2021. Demographic, laboratory parameters and causes of death were assessed from health records. Penetrance, survival, and cancer incidence were ascertained from diagnosed cases, insurance- and cancer registry data. Outcomes were compared with a propensity score-matched control population. RESULTS: Median age at diagnosis in 542 p.C282Y homozygous individuals was 47.8 years (64% male). At genotyping, the prevalence of iron overload was 55%. The cumulative penetrance of haemochromatosis defined as the presence of provisional iron overload was 24.2% in males and 10.5% in females aged 60 years or younger. Among p.C282Y homozygotes of the same ages, the cumulative proportion of individuals without fibrosis (FIB-4 score < 1.3) was 92.8% in males and 96.7% in females. Median life expectancy was reduced by 6.8 years in individuals homozygous for p.C282Y when compared with population-matched controls (p = .001). Hepatocellular carcinoma incidence was not significantly higher in p.C282Y homozygotes than in controls matched for age and sex. CONCLUSION: Reduced survival and the observed age-dependent increase in penetrance among p.C282Y homozygotes call for earlier diagnosis of haemochromatosis to prevent complications.


Assuntos
Carcinoma Hepatocelular , Hemocromatose , Sobrecarga de Ferro , Neoplasias Hepáticas , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Hemocromatose/epidemiologia , Hemocromatose/genética , Hemocromatose/complicações , Penetrância , Carcinoma Hepatocelular/epidemiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/complicações , Estudos de Coortes , Incidência , Antígenos de Histocompatibilidade Classe I/genética , Proteína da Hemocromatose/genética , Sobrecarga de Ferro/complicações , Homozigoto , Cirrose Hepática/complicações , Neoplasias Hepáticas/epidemiologia , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/complicações , Mutação
5.
BMJ Case Rep ; 17(1)2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38195192

RESUMO

We report the case of a man in his 50s with extravascular haemolysis, fluctuating indirect hyperbilirubinaemia, elevated transferrin saturation with hyperferritinaemia and normal liver enzymes. Spherocytes were detected in a blood smear and a mutation of unknown significance, c.1626+1G>A p.?, in intron 13 of the SLC4A1 gene, was identified by next-generation sequencing (NGS). The same mutation was found in his daughter, who presented with similar laboratory changes, confirming the diagnosis of hereditary spherocytosis. Abdominal MRI showed hepatosplenomegaly with hepatic iron overload. In this context of haemolysis (without anaemia) and iron overload, a diagnosis of haemochromatosis was presumed. NGS confirmed the presence of the variants p.(His63Asp) and p.(Cys282Tyr) in heterozygosity in the HFE gene. We report this case for the rarity of co-existing two haematological diseases counteracting each other.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Esferocitose Hereditária , Humanos , Masculino , Hemocromatose/complicações , Hemocromatose/diagnóstico , Hemocromatose/genética , Hemólise , Sequenciamento de Nucleotídeos em Larga Escala , Íntrons , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/genética , Esferocitose Hereditária/complicações , Esferocitose Hereditária/diagnóstico , Esferocitose Hereditária/genética , Pessoa de Meia-Idade
6.
Leukemia ; 38(1): 96-108, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37857886

RESUMO

Iron overload (IOL) is hypothesized to contribute to dysplastic erythropoiesis. Several conditions, including myelodysplastic syndrome, thalassemia and sickle cell anemia, are characterized by ineffective erythropoiesis and IOL. Iron is pro-oxidant and may participate in the pathophysiology of these conditions by increasing genomic instability and altering the microenvironment. There is, however, lack of in vivo evidence demonstrating a role of IOL and oxidative damage in dysplastic erythropoiesis. NRF2 transcription factor is the master regulator of antioxidant defenses, playing a crucial role in the cellular response to IOL in the liver. Here, we crossed Nrf2-/- with hemochromatosis (Hfe-/-) or hepcidin-null (Hamp1-/-) mice. Double-knockout mice developed features of ineffective erythropoiesis and myelodysplasia including macrocytic anemia, splenomegaly, and accumulation of immature dysplastic bone marrow (BM) cells. BM cells from Nrf2/Hamp1-/- mice showed increased in vitro clonogenic potential and, upon serial transplantation, recipients disclosed cytopenias, despite normal engraftment, suggesting defective differentiation. Unstimulated karyotype analysis showed increased chromosome instability and aneuploidy in Nrf2/Hamp1-/- BM cells. In HFE-related hemochromatosis patients, NRF2 promoter SNP rs35652124 genotype TT (predicted to decrease NRF2 expression) associated with increased MCV, consistent with erythroid dysplasia. Our results suggest that IOL induces ineffective erythropoiesis and dysplastic hematologic features through oxidative damage in Nrf2-deficient cells.


Assuntos
Anemia , Hemocromatose , Sobrecarga de Ferro , Síndromes Mielodisplásicas , Animais , Humanos , Camundongos , Anemia/metabolismo , Eritropoese/genética , Hemocromatose/genética , Hemocromatose/metabolismo , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/metabolismo , Camundongos Knockout , Síndromes Mielodisplásicas/genética , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo
7.
Liver Int ; 44(2): 389-398, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37971775

RESUMO

BACKGROUND & AIMS: Ferritin has been investigated as a biomarker for liver fibrosis and iron in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). However, whether metabolic hyperferritinaemia predicts progression of liver disease remains unknown. In this study, we sought to understand associations between hyperferritinaemia and (1) adverse clinical outcomes and (2) common genetic variants related to iron metabolism and liver fibrosis. METHODS: This was a retrospective analysis of adults with MASLD seen at the University of Michigan Health System, where MASLD was defined by hepatic steatosis on imaging, biopsy or vibration-controlled transient elastography, plus metabolic risk factors in the absence of chronic liver diseases other than hemochromatosis. The primary predictor was serum ferritin level, which was dichotomized based on a cut-off of 300 or 450 mcg/L for women or men. Primary outcomes included (1) incident cirrhosis, liver-related events, congestive heart failure (CHF), and mortality and (2) distribution of common genetic variants associated with hepatic fibrosis and hereditary hemochromatosis. RESULTS: Of 7333 patients with MASLD, 1468 (20%) had elevated ferritin. In multivariate analysis, ferritinaemia was associated with increased mortality (HR 1.68 [1.35-2.09], p < .001) and incident liver-related events (HR 1.92 [1.11-3.32], p = .019). Furthermore, elevated ferritin was associated with carriage of cirrhosis-promoting alleles including PNPLA3-rs738409-G allele (p = .0068) and TM6SF2-rs58542926-T allele (p = 0.0083) but not with common HFE mutations. CONCLUSIONS: In MASLD patients, metabolic hyperferritinaemia was associated with increased mortality and higher incidence of liver-related events, and cirrhosis-promoting alleles but not with iron overload-promoting HFE mutations.


Assuntos
Fígado Gorduroso , Hemocromatose , Adulto , Masculino , Humanos , Feminino , Hemocromatose/complicações , Hemocromatose/genética , Alelos , Estudos Retrospectivos , Fígado Gorduroso/complicações , Fígado Gorduroso/genética , Fígado Gorduroso/patologia , Fígado/patologia , Cirrose Hepática/complicações , Cirrose Hepática/genética , Cirrose Hepática/patologia , Fibrose , Ferro , Ferritinas
8.
Br J Haematol ; 204(1): 306-314, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37990447

RESUMO

Haemochromatosis (HC) encompasses a range of genetic disorders. HFE-HC is by far the most common in adults, while non-HFE types are rare due to mutations of HJV, HAMP, TFR2 and gain-of-function mutations of SLC40A1. HC is often unknown to paediatricians as it is usually asymptomatic in childhood. We report clinical and biochemical data from 24 paediatric cases of HC (10 cases of HFE-, 5 TFR2-, 9 HJV-HC), with a median follow-up of 9.6 years. Unlike in the adult population, non-HFE-HC constitutes 58% (14/24) of the population in our series. Transferrin saturation was significantly higher in TFR2- and HJV-HC compared to HFE-HC, and serum ferritin and LIC were higher in HJV-HC compared to TFR2- and HFE-HC. Most HFE-HC subjects had relatively low ferritin and LIC at the time of diagnosis, so therapy could be postponed for most of them after the age of 18. Our results confirm that HJV-HC is a severe form already in childhood, emphasizing the importance of early diagnosis and treatment to avoid the development of organ damage and reduce morbidity and mortality. Although phlebotomies were tolerated by most patients, oral iron chelators could be a valid option in early-onset HC.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Adulto , Humanos , Criança , Hemocromatose/diagnóstico , Hemocromatose/genética , Hemocromatose/terapia , Estudos Retrospectivos , Proteína da Hemocromatose/genética , Mutação , Ferritinas , Antígenos de Histocompatibilidade Classe I/genética , Sobrecarga de Ferro/genética
9.
Mol Genet Genomic Med ; 12(1): e2321, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37930135

RESUMO

BACKGROUND: We sought to evaluate height in white adults with hemochromatosis. METHODS: We analyzed the height of (1) post-screening examination participants with HFE p.C282Y/p.C282Y (rs1800562) and wt/wt (absence of p.C282Y and p.H63D (rs1799945)) and (2) referred hemochromatosis probands with p.C282Y/p.C282Y. RESULTS: There were 762 participants (270 p.C282Y/p.C282Y, 492 wt/wt; 343 men, 419 women) and 180 probands (104 men, 76 women). Median height of male participants with p.C282Y/p.C282Y or wt/wt was 177.8 cm. Median height of female participants was greater in those with p.C282Y/p.C282Y than wt/wt (165.1 cm vs 162.6 cm, respectively; p = 0.0298). Median height of p.C282Y/p.C282Y participants and probands was the same (men 177.8 cm; women 165.1 cm). Regressions on height of male and female participants revealed no associations with HFE genotype and inverse and positive associations with age and weight, respectively. Height of female participants was positively and inversely associated with transferrin saturation and serum ferritin, respectively. Regressions on height of male and female probands revealed positive associations with weight. CONCLUSIONS: The height of men with HFE p.C282Y/p.C282Y and wt/wt does not differ significantly. The height of female participants was greater in those with p.C282Y/p.C282Y than wt/wt. We found no independent association of HFE genotype with the height of men or women.


Assuntos
Estatura , Hemocromatose , População Branca , Adulto , Feminino , Humanos , Masculino , Estatura/etnologia , Estatura/genética , Ferritinas , Genótipo , Hemocromatose/diagnóstico , Hemocromatose/etnologia , Hemocromatose/genética , Proteína da Hemocromatose/genética , Antígenos de Histocompatibilidade Classe I/genética , Ferro , População Branca/genética
10.
Int J Cardiovasc Imaging ; 40(1): 45-53, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37821712

RESUMO

PURPOSE: Hereditary hemochromatosis (HH) may cause iron deposition in cardiac tissue. We aimed to describe the echocardiographic findings in patients with HH and identify risk factors for cardiac dysfunction. METHODS: In this retrospective study, we included patients with HH who underwent transthoracic echocardiography at our tertiary care center between August 2000 and July 2022. We defined three primary outcomes for cardiac dysfunction: 1) left ventricular ejection fraction (LVEF) < 55%, 2) ratio between early mitral inflow velocity and mitral annular early diastolic velocity (E/e') > 15, and 3) global longitudinal strain (GLS) < 18. Multivariable logistic regression was utilized to identify predictors of cardiac dysfunction. RESULTS: 582 patients (median age 57 years, 61.2% male) were included. The frequency of LVEF < 55%, E/e' > 15 and GLS < 18 was 9.0% (52/580), 9.6% (51/534) and 20.2% (25/124), respectively. In multivariable analysis, non-White race, age, and hypertension were associated with E/e' > 15. No specific HFE genetic mutation was associated with LVEF < 55%. A history of myocardial infarction was strongly associated with both LVEF < 55% and E/e' > 15. In patients with LVEF ≥ 55%, the C282Y/H63D genetic mutation was associated with reduced likelihood of E/e' > 15, p = 0.024. Patients with C282Y/H63D had a higher frequency of myocardial infarction. Smoking and alcohol use were significantly associated with GLS < 18 in unadjusted analysis. CONCLUSION: We found the traditional risk factors of male sex, and history of myocardial infarction or heart failure, were associated with a reduced LVEF, irrespective of the underlying HFE genetic mutation. Patients with a C282Y/H63D genetic mutation had a higher frequency of myocardial infarction, yet this mutation was associated with reduced odds of diastolic dysfunction compared to other genetic mutations in patients with a normal LVEF.


Assuntos
Hemocromatose , Infarto do Miocárdio , Humanos , Masculino , Pessoa de Meia-Idade , Feminino , Hemocromatose/complicações , Hemocromatose/diagnóstico por imagem , Hemocromatose/genética , Volume Sistólico , Estudos Retrospectivos , Função Ventricular Esquerda , Valor Preditivo dos Testes , Ecocardiografia , Valva Mitral
11.
Clin Nutr ESPEN ; 58: 277-294, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38057018

RESUMO

PURPOSE (BACKGROUND): The presented review is an updating of Iron metabolism in context of normal physiology and pathological phases. Iron is one of the vital elements in humans and associated into proteins as a component of heme (e.g. hemoglobin, myoglobin, cytochromes proteins, myeloperoxidase, nitric oxide synthetases), iron sulfur clusters (e.g. respiratory complexes I-III, coenzyme Q10, mitochondrial aconitase, DNA primase), or other functional groups (e.g. hypoxia inducible factor prolyl hydroxylases). All these entire iron-containing proteins ar e needed for vital cellular and organismal functions together with oxygen transport, mitochondrial respiration, intermediary and xenobiotic metabolism, nucleic acid replication and repair, host defense, and cell signaling. METHODS (METABOLIC STRATEGIES): Cells have developed metabolic strategies to import and employ iron safely. Regulatory process of iron uptake, storage, intracellular trafficking and utilization is vital for the maintenance of cellular iron homeostasis. Cellular iron utilization and intracellular iron trafficking pathways are not well established and very little knowledge about this. The predominant organs, which are associated in the metabolism of iron, are intestine, liver, bone marrow and spleen. Iron is conserved, recycled and stored. The reduced bioavailability of iron in humans has developed extremely efficient mechanisms for iron conservation. Prominently, the losses of iron cannot considerably enhance through physiologic mechanisms, even if iron intake and stores become excessive. Loss of iron is balanced or maintained from dietary sources. RESULTS (OUTCOMES): Numerous physiological abnormalities are associated with impaired iron metabolism. These abnormalities are appeared in the form of several diseases. There are duodenal ulcer, inflammatory bowel disease, sideroblastic anaemia, congenital dyserythropoietic anemias and low-grade myelodysplastic syndromes. Hereditary hemochromatosis and anaemia are two chronic diseases, which are responsible for disturbing the iron metabolism in various tissues, including the spleen and the intestine. Impairment in hepatic hepcidin synthesis is responsible for chronic liver disease, which is grounding from alcoholism or viral hepatitis. This condition directs to iron overload that can cause further hepatic damage. Iron has important role in several infectious diseases are tuberculosis, malaria trypanosomatid diseases and acquired immunodeficiency syndrome (AIDS). Iron is also associated with Systemic lupus erythematosus [SLE], cancer, Alzheimer's disease (AD) and post-traumatic epilepsy. CONCLUSION: Recently, numerous research studies are gradually more dedicated in the field of iron metabolism, but a number of burning questions are still waiting for answer. Cellular iron utilization and intracellular iron trafficking pathways are not well established and very little knowledge about this. Increased information of the physiology of iron homeostasis will support considerate of the pathology of iron disorders and also make available the support to advance treatment.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Hepatopatias , Humanos , Ferro/metabolismo , Hemocromatose/genética , Homeostase/fisiologia
12.
Rinsho Ketsueki ; 64(11): 1410-1414, 2023.
Artigo em Japonês | MEDLINE | ID: mdl-38072426

RESUMO

An asymptomatic woman in her early 40s with a history of hyperferritinemia (5,412 ng/ml) was referred to our hospital after repeated phlebotomy for hemosiderosis. She had unexplained hyperferritinemia, low-normal transferrin saturation, and high hepcidin levels, in the absence of iron overload-induced organ injury. She was diagnosed with ferroportin disease based on detection of the SLC40A1 variant SLC40A1 c.485_487del (p.Val162del) on genetic analysis. Her ferritin levels remained stable during pregnancy, and postpartum anemia was successfully treated with 2-week oral iron therapy. Ferroportin disease is characterized by impaired iron export and preferential iron trapping in tissue macrophages. To reduce risk of anemia, a non-aggressive phlebotomy regimen is recommended in patients with ferroportin disease, which shows a milder clinical course compared with other classical hemochromatosis subtypes.


Assuntos
Anemia , Hemocromatose , Hiperferritinemia , Sobrecarga de Ferro , Humanos , Feminino , Gravidez , Hemocromatose/terapia , Hemocromatose/diagnóstico , Hemocromatose/genética , Sobrecarga de Ferro/etiologia , Ferro , Hepcidinas
13.
FASEB J ; 37(11): e23245, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37874260

RESUMO

Iron overload is one of the secondary osteoporosis etiologies. Cellular and molecular mechanisms involved in iron-related osteoporosis are not fully understood. AIM: The aim of the study was to investigate the respective roles of iron excess and hepcidin, the systemic iron regulator, in the development of iron-related osteoporosis. MATERIAL AND METHODS: We used mice models with genetic iron overload (GIO) related to hepcidin deficiency (Hfe-/- and Bmp6-/- ) and secondary iron overload (SIO) exhibiting a hepcidin increase secondary to iron excess. Iron concentration and transferrin saturation levels were evaluated in serum and hepatic, spleen, and bone iron concentrations were assessed by ICP-MS and Perl's staining. Gene expression was evaluated by quantitative RT-PCR. Bone micro-architecture was evaluated by micro-CT. The osteoblastic MC3T3 murine cells that are able to mineralize were exposed to iron and/or hepcidin. RESULTS: Despite an increase of bone iron concentration in all overloaded mice models, bone volume/total volume (BV/TV) and trabecular thickness (Tb.Th) only decreased significantly in GIO, at 12 months for Hfe-/- and from 6 months for Bmp6-/- . Alterations in bone microarchitecture in the Bmp6-/- model were positively correlated with hepcidin levels (BV/TV (ρ = +.481, p < .05) and Tb.Th (ρ = +.690, p < .05). Iron deposits were detected in the bone trabeculae of Hfe-/- and Bmp6-/- mice, while iron deposits were mainly visible in bone marrow macrophages in secondary iron overload. In cell cultures, ferric ammonium citrate exposure abolished the mineralization process for concentrations above 5 µM, with a parallel decrease in osteocalcin, collagen 1, and alkaline phosphatase mRNA levels. Hepcidin supplementation of cells had a rescue effect on the collagen 1 and alkaline phosphatase expression level decrease. CONCLUSION: Together, these data suggest that iron in excess alone is not sufficient to induce osteoporosis and that low hepcidin levels also contribute to the development of osteoporosis.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Osteoporose , Animais , Camundongos , Ferro/metabolismo , Hepcidinas/genética , Hepcidinas/metabolismo , Hemocromatose/genética , Fosfatase Alcalina/metabolismo , Proteína da Hemocromatose/genética , Antígenos de Histocompatibilidade Classe I/genética , Sobrecarga de Ferro/complicações , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/metabolismo , Fígado/metabolismo , Osteoporose/genética , Colágeno/metabolismo , Camundongos Knockout
14.
JAMA Netw Open ; 6(10): e2338995, 2023 10 02.
Artigo em Inglês | MEDLINE | ID: mdl-37870835

RESUMO

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 86 601 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 86 300 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.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Masculino , Recém-Nascido , Humanos , Feminino , Pessoa de Meia-Idade , Idoso , Hemocromatose/diagnóstico , Hemocromatose/genética , Hemocromatose/terapia , Estudos Transversais , Proteína da Hemocromatose/genética , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/complicações , Testes Genéticos
16.
Vitam Horm ; 123: 249-284, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37717987

RESUMO

The peptide hormone hepcidin is central to the regulation of iron metabolism, influencing the movement of iron into the circulation and determining total body iron stores. Its effect on a cellular level involves binding ferroportin, the main iron export protein, preventing iron egress and leading to iron sequestration within ferroportin-expressing cells. Hepcidin expression is enhanced by iron loading and inflammation and suppressed by erythropoietic stimulation. Aberrantly increased hepcidin leads to systemic iron deficiency and/or iron restricted erythropoiesis as occurs in anemia of chronic inflammation. Furthermore, insufficiently elevated hepcidin occurs in multiple diseases associated with iron overload such as hereditary hemochromatosis and iron loading anemias. Abnormal iron metabolism as a consequence of hepcidin dysregulation is an underlying factor resulting in pathophysiology of multiple diseases and several agents aimed at manipulating this pathway have been designed, with some already in clinical trials. In this chapter, we assess the complex regulation of hepcidin, delineate the many binding partners involved in its regulation, and present an update on the development of hepcidin agonists and antagonists in various clinical scenarios.


Assuntos
Hemocromatose , Hepcidinas , Humanos , Hepcidinas/genética , Hemocromatose/genética , Ferro , Eritropoese , Inflamação
17.
BMJ Case Rep ; 16(9)2023 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-37699741

RESUMO

COVID-19 infection and hereditary haemochromatosis (HH) have something in common; the disease course can be monitored with ferritin levels. Throughout the pandemic, physicians have looked for markers to help predict disease severity. Ferritin levels are commonly used to predict and monitor disease severity in hospitalised patients with COVID-19. While ferritin is elevated as part of the acute-phase reaction in response to infection, it can also be elevated due to iron overload. We report a case of undiagnosed, asymptomatic HH that was unveiled after COVID-19 infection via monitoring for resolution of ferritin levels that were found to be extremely elevated during a moderate COVID-19 infection. This diagnosis allowed the patient to initiate phlebotomy treatment before symptoms of HH arose.


Assuntos
COVID-19 , Hemocromatose , Sobrecarga de Ferro , Humanos , Hemocromatose/complicações , Hemocromatose/diagnóstico , Hemocromatose/genética , Ferritinas , Hospitalização
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