Iron incorporation in red blood cells of pediatric sickle cell anemia: a stable isotope pilot investigation.

BACKGROUND/OBJECTIVES: Sickle cell anemia (SCA) is marked by hypoxia, inflammation, and secondary iron overload (IO), which potentially modulate hepcidin, the pivotal hormone governing iron homeostasis. The aim was to evaluate the iron incorporation in red blood cells (RBC) in SCA pediatric patients, considering the presence or absence of IO. SUBJECTS/METHODS: SCA children (n = 12; SCAtotal) ingested an oral stable iron isotope (57Fe) and iron incorporation in RBC was measured after 14 days. Patients with ≥1000 ng/mL serum ferritin were considered to present IO (SCAio+; n = 4) while the others were classified as being without IO (SCAio-; n = 8). Liver iron concentration (LIC) was determined by Magnetic Resonance Imaging (MRI) T2* method. RESULTS: The SCAio+ group had lower iron incorporation (mean ± SD: 0.166 ± 0.04 mg; 3.33 ± 0.757%) than SCAio- patients (0.746 ± 0.303 mg; 14.9 ± 6.05%) (p = 0.024). Hepcidin was not different between groups. Iron incorporation was inversely associated with serum ferritin level (SCAtotal group: r = -0.775, p = 0.041; SCAio- group: r = -0.982; p = 0.018) and sickle hemoglobin (HbS) presented positive correlation with iron incorporation (r = 0.991; p = 0.009) in SCAio- group. LIC was positively associated with ferritin (SCAtotal: r = 0.921; p = 0.026) and C reactive protein (SCAio+: r = 0.999; p = 0.020). CONCLUSION: SCAio+ group had lower iron incorporation in RBC than SCAio- group, suggesting that they may not need to reduce their intake of iron-rich food, as usually recommended. Conversely, a high percentage of HbS may indirectly exacerbate hypoxia and seems to increase iron incorporation in RBC. TRIAL REGISTRATION: This trial was registered at www.ensaiosclinicos.gov.br . Identifier RBR-4b7v8pt.

Blood utilization and characteristics of patients treated with chronic transfusion therapy in a large cohort of Brazilian patients with sickle cell disease.

BACKGROUND: Red blood cell (RBC) transfusions are used in sickle cell disease (SCD) to treat acute complications or as chronic transfusion therapy (CTT) to prevent severe manifestations. The objectives of this study were to describe blood utilization and adverse events (AEs) associated with RBCs in the Brazilian SCD population and compare characteristics of patients treated or not with CTT. STUDY DESIGN AND METHODS: A SCD cohort was established at six Brazilian centers. Medical and blood bank records were abstracted for clinical and transfusion history. Two controls not treated with CTT matched on center, SCD genotype, sex, and age were selected for each CTT case within the cohort to compare characteristics between the two groups. RESULTS: Most of the 2794-member cohort had received a transfusion (75.0% of children and 89.2% of adults) with 29.2% of patients receiving transfusion in the prior year. There were 170 (10.6%) children and 115 (9.2%) adults treated with CTT. Children not treated with CTT were more likely to have pain and acute chest hospitalizations in the prior year (25.3% vs. 11.9%, p = 0.0003; and 22.0% vs. 10.7%, p = 0.002, respectively). Both iron overload and alloimmunization were more common in CTT cases compared to controls (65.6% vs. 17.0% and 36.2% vs. 15.9%, respectively). A higher proportion of adults treated with CTT demonstrated oxygen saturation of greater than 95% compared to controls not treated (51.1% vs. 39.2%), while there was no difference in oxygenation between children treated or not. Of 4501 transfusion episodes, 28 (0.62%) AEs were reported. There was no difference in AEs associated with transfusions for acute indications versus CTT. CONCLUSION: Red blood cell transfusion was common in Brazilian SCD patients, with utilization driven by CTT. Transfusion reactions were not common; however, alloimmunization and iron overload were frequent among those on CTT, highlighting the need for novel clinical strategies to mitigate these risks.

Novel Mutation in the Hemojuvelin Gene (HJV) in a Patient with Juvenile Hemochromatosis Presenting with Insulin-dependent Diabetes Mellitus, Secondary Hypothyroidism and Hypogonadism.

BACKGROUND Juvenile hemochromatosis is a rare genetic disease that leads to intense iron accumulation. The disease onset usually occurs before the third decade of life and causes severe dysfunction in various organs. The most classical clinical findings are hypogonadotropic hypogonadism, cardiomyopathy, liver fibrosis, glycemic changes, arthropathy and skin pigmentation. However, secondary hypothyroidism is not reported in these patients. Juvenile hemochromatosis has an autosomal recessive inheritance and might be type 2A or type 2B, due to mutation in either the hemojuvelin gene (HJV) or hepcidin antimicrobial peptide (HAMP) gene. CASE REPORT A 26-year-old female patient was admitted with a recent history of diabetic ketoacidosis. Three months after that admission, she presented with arthralgia, diffuse abdominal pain, adynamia, hair loss, darkening of the skin and amenorrhea. Severe iron overload was found and findings in the hepatic biopsy were compatible with hemochromatosis. An upper abdominal magnetic resonance imaging (MRI) showed iron deposition in the liver and pancreas and pituitary MRI exhibited accumulation on the anterior pituitary. After 16 months the patient presented with dyspnea and lower limb edema, and cardiac MRI indicated iron deposition in the myocardium. The patient was diagnosed with juvenile hemochromatosis presenting with hypogonadotropic hypogonadism, cardiomyopathy, insulin-dependent diabetes mellitus, and secondary hypothyroidism. A novel homozygous mutation, c.697delC, in the HJV gene was detected. CONCLUSIONS We describe for the first time a severe and atypical case of juvenile hemochromatosis type 2A presenting classical clinical features, as well as secondary hypothyroidism resulting from a novel mutation in the HJV gene.

Hepcidin is a useful biomarker to evaluate hyperferritinemia associated with metabolic syndrome.

Investigation of hyperferritinemia in metabolic syndrome patients represents a diagnostic challenge, but it is essential for the identification of individuals with iron overload. Hepcidin negatively regulates iron absorption and release. An increase in hepcidin occurs when iron levels are sufficient or in inflammatory states, conditions often associated with hyperferritinemia. Hemochromatosis causes hyperferritinemia due to iron overload, but frequently has low hepcidin levels. Our aim was to evaluate biochemical and molecular parameters related to iron metabolism in patients with metabolic syndrome. We evaluated 94 patients with metabolic syndrome according to the International Diabetes Federation criteria in a cross-sectional study. Anthropometric data and diagnostic criteria for metabolic syndrome, iron dosage, ferritin, transferrin saturation, hepcidin, and the C282Y and H63D mutations in the HFE hemochromatosis gene were evaluated. Prevalence of hyperferritinemia in the study population was 27.7% and was higher in males (46.2%) than in females (14.5%). Increase in transferrin saturation correlated with mutations in the hemochromatosis gene. Hyperferritinemia was associated to transferrin saturation and hepcidin after logistic regression analysis. In conclusion, hyperferritinemia is a frequent finding in metabolic syndrome patients, most frequently in men; and hepcidin assessment can be useful for the investigation of ferritin increase in those subjects.

The unexpected presence of iron in bone biopsies of hemodialysis patients.

PURPOSE: Bone biopsy defines classical diseases that constitute the renal osteodystrophy. There is a recent concern regarding other histological findings that are not appreciated by using the turnover, mineralization, and volume (TMV) classification. Iron (Fe) overload has been considered a new challenge and the real significance of the presence of this metal in bones is not completely elucidated. Therefore, the main goal of the current study was to not only to identify bone Fe, but also correlate its presence with demographic, and biochemical characteristics. METHODS: This is a cross-sectional analysis of bone biopsies performed in 604 patients on dialysis from 2010 to 2014 in a tertiary academic Hospital. RESULTS: Histomorphometric findings revealed the presence of Fe in 29.1%. Fe was associated with higher levels of serum ferritin and serum calcium. No TMV status was related to Fe bone overload. CONCLUSION: Our study has highlighted that the presence of Fe in one-third of bone samples has unknown clinical significance. The lack of other contemporary bone biopsy study reporting Fe prevents us from comparison. The findings presented here should be specifically addressed in a future research and will require attention prior to implementation of any clinical guideline. If any proposed treatment, however, would change the bone Fe-related morbidity is undetermined.

Increased serum iron in preeclamptic women is likely due to low hepcidin levels.

The role of hepcidin in iron homeostasis in preeclamptic pregnant women is unclear. To test the hypothesis that increased serum iron in women diagnosed with preeclampsia results from decreased production of hepcidin, we performed an observational case-control study in which serum hepcidin concentration, dietary iron intake, hematological indices, iron status, liver function, and inflammatory markers in 18 preeclamptic women and 18 healthy normotensive pregnant women of similar age range were evaluated. Iron intake was established via a food frequency questionnaire, whereas hematological indices, iron status, liver function, and inflammatory markers were assessed using standard protocols. Hematocrit was significantly higher (P = .031) in the preeclamptic group compared with the control, whereas erythropoietin level was significantly lower (P = .003). The pronounced inflammatory status of preeclamptic women was confirmed by significantly higher concentrations of interleukin-6 (P = .001), tumor necrosis factor-α (P < .001), and ferritin (P < .001). Nonetheless, the preeclamptic group exhibited significantly higher serum iron (P = .012) and transferrin saturation (P = .006), and these alterations were accompanied by lower hepcidin levels (P = .047). No significant correlations between hepcidin concentration and iron status parameters were observed in either group. However, a positive and significant correlation between hepcidin concentration and C-reactive protein was observed in the preeclamptic group (r = 0.474; P = .047). We conclude that high serum iron in preeclamptic women is likely caused by low production of hepcidin, thus supporting the hypothesis originally stated.

Quality of life scores differs between genotypic groups of patients with suspected hereditary hemochromatosis.

BACKGROUND: Hereditary hemochromatosis (HH) encompasses a group of autosomal recessive disorders mainly characterized by enhanced intestinal absorption of iron and its accumulation in parenchymal organs. HH diagnosis is based on iron biochemical and magnetic resonance imaging (MRI) assessment, and genetic testing. Questionnaires, such as SF-36 (short form health survey), have been increasingly used to assess the impact of diseases on the patient's quality of life (QL). In addition, different genotypes are identified as results of genetic tests in patients with suspected primary iron overload. In the present study, our aim was to evaluate whether domains of QL are different according to genotypic groups in patients suspected of HH. METHODS: Seventy-nine patients with primary iron overload were included and two genotypic groups were formed (group 1: homozygous genotype for the HFE p.Cys282Tyr mutation; group 2: other genotypes). RESULTS: Group 1 had higher means of plasma transferrin saturation (86 ± 19%) and serum ferritin (1669 ± 1209 ng/mL) compared to group 2 (71 ± 12%, 1252 ± 750 ng/mL, respectively; p = 0.001). Four domains were significantly different among groups 1 and 2: physical functioning (p = 0.03), bodily pain (p = 0.03), vitality (p = 0.02) and social functioning (p = 0.01). CONCLUSIONS: Our main finding was that patients with p.Cys282Tyr homozygosity had a worse QL scenario assessed by SF-36, compared with patients with iron overload without the same genotype. Being aware of this relationship between genotypes and QL might be helpful in the overall management of patients suspected of hereditary hemochromatosis.

Clinical and Laboratory Associations with Persistent Hyperferritinemia in 373 Black Hemochromatosis and Iron Overload Screening Study Participants.

BACKGROUND: 373 black participants had elevated screening and post-screening serum ferritin (SF) (> 300 µg/L men; > 200 µg/L women). MATERIAL AND METHODS: We retrospectively studied SF and post-screening age; sex; body mass index; transferrin saturation (TS); ALT; AST; GGT; elevated C-reactive protein; ß-thalassemia; neutrophils; lymphocytes; monocytes; platelets; metacarpophalangeal joint hypertrophy; hepatomegaly; splenomegaly; diabetes; HFE H63D positivity; iron/alcohol intakes; and blood/erythrocyte transfusion units. Liver disease was defined as elevated ALT or AST. We computed correlations of SF and TS with: age; body mass index; ALT; AST; GGT; C-reactive protein; blood cell counts; and iron/alcohol. We compared participants with SF > 1,000 and ≤ 1,000 µg/L and performed regressions on SF. RESULTS: There were 237 men (63.5%). Mean age was 55 ± 13 (SD) y. 143 participants had liver disease (62 hepatitis B or C). There were significant correlations of SF: TS, ALT, AST, GGT, and monocytes (positive); and SF and TS with platelets (negative). 22 participants with SF > 1,000 µg/L had significantly higher median TS, ALT, and AST, and prevalences of anemia and transfusion > 10 units; and lower median platelets. Regression on SF revealed significant associations: TS; male sex; age; GGT; transfusion units (positive); and splenomegaly (negative) (p < 0.0001, 0.0016, 0.0281, 0.0025, 0.0001, and 0.0096, respectively). Five men with SF > 1,000 µg/L and elevated TS had presumed primary iron overload (hemochromatosis). Four participants had transfusion iron overload. CONCLUSION: Persistent hyperferritinemia in 373 black adults was associated with male sex, age, TS, GGT, and transfusion. 2.4% had primary iron overload (hemochromatosis) or transfusion iron overload.

Hyperferritinemia in patients with nonalcoholic fatty liver disease.

OBJECTIVE:: In liver diseases, hyperferritinemia (HYF) is related to injured cells in acquired and genetic conditions with or without iron overload. It is frequent in patients with nonalcoholic fatty liver disease (NAFLD), in which it is necessary to define the mean of HYF to establish the better approach for them. The present study evaluated the significance of elevated ferritin in patients with NAFLD and steatohepatitis (NASH). METHOD:: The review was performed using search instruments of indexed scientific material, including MEDLINE (by PubMed), Web of Science, IBECS and LILACS, to identify articles published in Portuguese, English and Spanish, from 2005 to May, 2016. Studies eligible included place and year of publication, diagnose criteria to NAFLD, specifications of serum ferritin measurements and/or liver histopathologic study. Exclusion criteria included studies with patients with alcohol consumption ≥ 20 g/day and other liver diseases. RESULTS:: A total of 11 from 30 articles were selected. It included 3,564 patients and they were cross-sectional, retrospective, case series and case-control. The result's analyses showed in 10 of these studies a relationship between ferritin elevated serum levels and NAFLD/NASH with and without fibrosis and insulin resistance. CONCLUSION:: Hyperferritinemia in patients with NAFLD/NASH is associated more frequently with hepatocellular injury than hemochromatosis. These data suggest the relevance to evaluate carefully HYF in patients with NAFLD/NASH to establish appropriate clinical approach.

Hyperferritinemia in patients with nonalcoholic fatty liver disease / Hiperferritinemia em pacientes com doença hepática gordurosa não alcoólica

Summary Objective: In liver diseases, hyperferritinemia (HYF) is related to injured cells in acquired and genetic conditions with or without iron overload. It is frequent in patients with nonalcoholic fatty liver disease (NAFLD), in which it is necessary to define the mean of HYF to establish the better approach for them. The present study evaluated the significance of elevated ferritin in patients with NAFLD and steatohepatitis (NASH). Method: The review was performed using search instruments of indexed scientific material, including MEDLINE (by PubMed), Web of Science, IBECS and LILACS, to identify articles published in Portuguese, English and Spanish, from 2005 to May, 2016. Studies eligible included place and year of publication, diagnose criteria to NAFLD, specifications of serum ferritin measurements and/or liver histopathologic study. Exclusion criteria included studies with patients with alcohol consumption ≥ 20 g/day and other liver diseases. Results: A total of 11 from 30 articles were selected. It included 3,564 patients and they were cross-sectional, retrospective, case series and case-control. The result's analyses showed in 10 of these studies a relationship between ferritin elevated serum levels and NAFLD/NASH with and without fibrosis and insulin resistance. Conclusion: Hyperferritinemia in patients with NAFLD/NASH is associated more frequently with hepatocellular injury than hemochromatosis. These data suggest the relevance to evaluate carefully HYF in patients with NAFLD/NASH to establish appropriate clinical approach.

Resumo Objetivo: A hiperferritinemia (HPF) está associada à agressão hepatocelular nas doenças do fígado e à sobrecarga de ferro, em doenças genéticas e adquiridas. A HPF é frequente em pacientes com doença hepática gordurosa não alcoólica (DHGNA) e é necessário definir seu significado para estabelecer as melhores condutas para esses indivíduos. Esta revisão avaliou o significado da HPF em portadores de DHGNA e esteato-hepatite não alcoólica (EHNA). Método: A busca de artigos foi realizada através do PubMed (Medline), Web of Science e Lilacs, e foram selecionados aqueles publicados em português, inglês e espanhol de 2005 a maio de 2016. Os artigos foram elegíveis quando informavam data e local da publicação, critérios diagnósticos para DHGNA, especificações das dosagens de ferritina sérica e/ou estudo histopatológico. Foram excluídos os artigos cujos pacientes relataram ingestão alcoólica ≥ 20 g/dia ou eram portadores de outras doenças do fígado. Resultados: Foram selecionados 11 de 30 artigos, totalizando 3.564 pacientes. Os artigos eram de corte transversal, retrospectivos, série de casos e caso-controles. Em dez artigos, observou-se correlação entre alteração de ferritina e DHGNA/EHNA com e sem fibrose hepática e resistência à insulina. Conclusão: Hiperferritinemia em pacientes com DHGNA/EHNA se associa com maior frequência à agressão hepatocelular do que com sobrecarga de ferro hepático. Os resultados da revisão sugerem a necessidade de um maior cuidado na interpretação da elevação da ferritina sérica em pacientes com DHGNA/EHNA para o estabelecimento de condutas clínicas apropriadas.

Differences in Hepatic Expression of Iron, Inflammation and Stress-Related Genes in Patients with Nonalcoholic Steatohepatitis

Abstract: Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. We have previously shown that hepatic reticuloendothelial system (RES) iron deposition is associated with an advanced degree of nonalcoholic steatohepatitis (NASH) in humans. In this study, we aimed to determine differentially expressed genes related to iron overload, inflammation and oxidative stress pathways, with the goal of identifying factors associated with NASH progression. Seventy five patients with NAFLD were evaluated for their biochemical parameters and their liver tissue analyzed for NASH histological characteristics. Gene expression analysis of pathways related to iron homeostasis, inflammation and oxidative stress was performed using real-time PCR. Gene expression was compared between subjects based on disease status and presence of hepatic iron staining. We observed increased gene expression of hepcidin (HAMP) (2.3 fold, p = 0.027), transmembrane serine proteinase 6 (TMPRSS6) (8.4 fold, p = 0.003), signal transducer and activator of transcription 3 (STAT3) (5.5 fold, p = 0.004), proinflammatory cytokines; IL-1β (2.7 fold, p = 0.046) and TNF-α (3.8 fold, p = 0.001) in patients with NASH. TMPRSS6, a negative regulator of HAMP, is overexpressed in patients with NASH and HIF1α (hypoxia inducible factor-1) is downregulated. NAFLD patients with hepatic iron deposition exhibited higher hepcidin expression (3.1 fold, p = 0.04) but lower expression of cytokines. In conclusion, we observed elevated hepatic HAMP expression in patients with NASH and in NAFLD patients who had hepatic iron deposition, while proinflammatory cytokines displayed elevated expression only in patients with NASH, suggesting a regulatory role for hepcidin in NAFL to NASH transition and in mitigating inflammatory responses.

Differences in hepatic expression of iron, inflammation and stress-related genes in patients with nonalcoholic steatohepatitis.

 Nonalcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease worldwide. We have previously shown that hepatic reticuloendothelial system (RES) iron deposition is associated with an advanced degree of nonalcoholic steatohepatitis (NASH) in humans. In this study, we aimed to determine differentially expressed genes related to iron overload, inflammation and oxidative stress pathways, with the goal of identifying factors associated with NASH progression. Seventy five patients with NAFLD were evaluated for their biochemical parameters and their liver tissue analyzed for NASH histological characteristics. Gene expression analysis of pathways related to iron homeostasis, inflammation and oxidative stress was performed using real-time PCR. Gene expression was compared between subjects based on disease status and presence of hepatic iron staining. We observed increased gene expression of hepcidin (HAMP) (2.3 fold, p = 0.027), transmembrane serine proteinase 6 (TMPRSS6) (8.4 fold, p = 0.003), signal transducer and activator of transcription 3 (STAT3) (5.5 fold, p = 0.004), proinflammatory cytokines; IL-1? (2.7 fold, p = 0.046) and TNF-? (3.8 fold, p = 0.001) in patients with NASH. TMPRSS6, a negative regulator of HAMP, is overexpressed in patients with NASH and HIF1? (hypoxia inducible factor-1) is downregulated. NAFLD patients with hepatic iron deposition exhibited higher hepcidin expression (3.1 fold, p = 0.04) but lower expression of cytokines. In conclusion, we observed elevated hepatic HAMP expression in patients with NASH and in NAFLD patients who had hepatic iron deposition, while proinflammatory cytokines displayed elevated expression only in patients with NASH, suggesting a regulatory role for hepcidin in NAFL to NASH transition and in mitigating inflammatory responses.

Acute iron overload leads to hypothalamic-pituitary-gonadal axis abnormalities in female rats.

Iron plays a critical role in a mammal's physiological processes. However, iron tissue deposits have been shown to act as endocrine disrupters. Studies that evaluate the effect of acute iron overload on hypothalamic-pituitary-gonadal (HPG) axis health are particularly sparse. This study demonstrates that acute iron overload leads to HPG axis abnormalities, including iron accumulation and impairment in reproductive tract morphology. Female rats were treated with iron-dextran (Fe rats) to assess their HPG morphophysiology. The increasing serum iron levels due to iron-dextran treatment were positively correlated with higher iron accumulation in the HPG axis and uterus of Fe rats than in control rats. An increase in the production of superoxide anions was observed in the pituitary, uterus and ovary of Fe rats. Morphophysiological reproductive tract abnormalities, such as abnormal ovarian follicular development and the reduction of serum estrogen levels, were observed in Fe rats. In addition, a significant negative correlation was obtained between ovary superoxide anion and serum estrogen levels. Together, these data provide in vivo evidence that acute iron overload is toxic for the HPG axis, a finding that may be associated with the subsequent development of the risk of reproductive dysfunction.

Effects of Iron Overload on the Activity of Na,K-ATPase and Lipid Profile of the Human Erythrocyte Membrane.

Iron is an essential chemical element for human life. However, in some pathological conditions, such as hereditary hemochromatosis type 1 (HH1), iron overload induces the production of reactive oxygen species that may lead to lipid peroxidation and a change in the plasma-membrane lipid profile. In this study, we investigated whether iron overload interferes with the Na,K-ATPase activity of the plasma membrane by studying erythrocytes that were obtained from the whole blood of patients suffering from iron overload. Additionally, we treated erythrocytes of normal subjects with 0.8 mM H2O2 and 1 µM FeCl3 for 24 h. We then analyzed the lipid profile, lipid peroxidation and Na,K-ATPase activity of plasma membranes derived from these cells. Iron overload was more frequent in men (87.5%) than in women and was associated with an increase (446%) in lipid peroxidation, as indicated by the amount of the thiobarbituric acid reactive substances (TBARS) and an increase (327%) in the Na,K-ATPase activity in the plasma membrane of erythrocytes. Erythrocytes treated with 1 µM FeCl3 for 24 h showed an increase (132%) in the Na,K-ATPase activity but no change in the TBARS levels. Iron treatment also decreased the cholesterol and phospholipid content of the erythrocyte membranes and similar decreases were observed in iron overload patients. In contrast, erythrocytes treated with 0.8 mM H2O2 for 24 h showed no change in the measured parameters. These results indicate that erythrocytes from patients with iron overload exhibit higher Na,K-ATPase activity compared with normal subjects and that this effect is specifically associated with altered iron levels.

Iron homeostasis and its disruption in mouse lung in iron deficiency and overload.

NEW FINDINGS: What is the central question of this study? The aim was to explore the role and hitherto unclear mechanisms of action of iron proteins in protecting the lung against the harmful effects of iron accumulation and the ability of pulmonary cells to mobilize iron in iron deficiency. What is the main finding and its importance? We show that pulmonary hepcidin appears not to modify cellular iron mobilization in the lung. We propose pathways for supplying iron to the lung in iron deficiency and for protecting the lung against iron excess in iron overload, mediated by the co-ordinated action of iron proteins, such as divalent metal transporter 1, ZRT-IRE-like-protein 14, transferrin receptor, ferritin, haemochromatosis-associated protein and ferroportin. Iron dyshomeostasis is associated with several forms of chronic lung disease, but its mechanisms of action remain to be elucidated. The aim of the present study was to determine the role of the lung in whole-animal models with iron deficiency and iron overload, studying the divalent metal transporter 1 (DMT1), ZRT-IRE-like protein 14 (ZIP14), transferrin receptor (TfR), haemochromatosis-associated protein (HFE), hepcidin, ferritin and ferroportin (FPN) expression. In each model, adult CF1 mice were divided into the following groups (six mice per group): (i) iron-overload model, iron saccharate i.p. and control group (iron adequate), 0.9% NaCl i.p.; and (ii) iron-deficiency model, induced by repeated bleeding, and control group (sham operated). Proteins were assessed by immunohistochemistry and Western blot. In control mice, DMT1 was localized in the cytoplasm of airway cells, and in iron deficiency and overload it was in the apical membrane. Divalent metal transporter 1 and TfR increased in iron deficiency, without changes in iron overload. ZRT-IRE-like protein 14 decreased in airway cells in iron deficiency and increased in iron overload. In iron deficiency, HFE and FPN were immunolocalized close to the apical membrane. Ferroportin increased in iron overload. Prohepcidin was present in control groups, with no changes in iron deficiency and iron overload. In iron overload, ferritin showed intracytoplasmic localization close to the apical membrane of airway cells and intense immunostaining in macrophage-like cells. The results show that pulmonary hepcidin does not appear to modify cellular iron mobilization in the lung. We propose the following two novel pathways in the lung: (i) for supplying iron in iron deficiency, mediated principally by DMT1 and TfR and regulated by the action of FPN and HFE; and (ii) for iron detoxification in order to protect the lung against iron overload, facilitated by the action of DMT1, ZIP14, FPN and ferritin.

Serum ferritin is a biomarker for liver mortality in the Hemochromatosis and Iron Overload Screening Study.

BACKGROUND: We identified no reports of long-term follow-up of participants in hemochromatosis screening programs. We evaluated causes of death and survival in non-C282Y homozygous Canadian participants in the primary care-based hemochromatosis and iron overload screening (HEIRS) study. MATERIAL AND METHODS: Initial screening (IS) included transferrin saturation (TS), serum ferritin (SF), HFE genotyping (C282Y, H63D), and health questionnaire responses. By definition, participants without C282Y or H63D had HFE wt/wt. We linked 20,306 Canadian participants to the Ontario Death Registry for dates and causes of death 9 y after IS. We computed Cox proportional hazards to identify factors with increased death risks and Kaplan-Meier curves to estimate survival of non-C282Y homozygous participants with SF ≤ 1,000 µg/L and > 1,000 µg/dL. RESULTS: There were 19,052 evaluable participants (IS mean age 49 y; 60% women; 93 C282Y homozygotes). There were 988 deaths. Significantly increased hazard ratios for all-cause mortality were positively associated with TS, SF, men, and C282Y homozygosity, and liver disease, diabetes, and heart failure reports. Non-C282Y homozygous participants with SF > 1,000 µg/L had lower survival than those with SF ≤ 1,000 µg/L (p < 0.0001). CONCLUSIONS: Nine years after initial screening, non-C282Y homozygous participants and SF > 1,000 µg/L was associated with decreased survival.

HFE genotyping in patients with elevated serum iron indices and liver diseases.

Iron abnormalities in chronic liver disease may be the result of genetic diseases or secondary factors. The present study aimed to identify subjects with HFE-HH in order to describe the frequency of clinical manifestations, identify risk factors for iron elevation, and compare the iron profile of HFE-HH to other genotypes in liver disease patients. A total of 108 individuals with hepatic disease, transferrin saturation (TS) > 45%, and serum ferritin (SF) > 350 ng/mL were tested for HFE mutations. Two groups were characterized: C282Y/C282Y or C282Y/H63D genotypes (n = 16) were the HFE hereditary hemochromatosis (HFE-HH) group; and C282Y and H63D single heterozygotes, the H63D/H63D genotype, and wild-type were considered group 2 (n = 92). Nonalcoholic liver disease, alcoholism, and chronic hepatitis C were detected more frequently in group 2, whereas arthropathy, hepatocarcinoma, diabetes, and osteoporosis rates were significantly higher in the HFE-HH group. TS > 82%, SF > 2685 ng/mL, and serum iron > 178 µg/dL were the cutoffs for diagnosis of HFE-HH in patients with liver disease. Thus, in non-Caucasian populations with chronic liver disease, HFE-HH diagnosis is more predictable in those with iron levels higher than those proposed in current guidelines for the general population.

Metabolic alterations, HFE gene mutations and atherogenic lipoprotein modifications in patients with primary iron overload.

Iron overload (IO) has been associated with glucose metabolism alterations and increased risk of cardiovascular disease (CVD). Primary IO is associated with mutations in the HFE gene. To which extent HFE gene mutations and metabolic alterations contribute to the presence of atherogenic lipoprotein modifications in primary IO remains undetermined. The present study aimed to assess small, dense low-density lipoprotein (LDL) levels, chemical composition of LDL and high-density lipoprotein (HDL) particles, and HDL functionality in IO patients. Eighteen male patients with primary IO and 16 sex- and age-matched controls were recruited. HFE mutations (C282Y, H63D and S65C), measures of insulin sensitivity and secretion (calculated from the oral glucose tolerance test), chemical composition and distribution profile of LDL and HDL subfractions (isolated by gradient density ultracentrifugation) and HDL functionality (as cholesterol efflux and antioxidative activity) were studied. IO patients compared with controls exhibited insulin resistance (HOMA-IR (homoeostasis model assessment-estimated insulin resistance): +93%, P< 0.001). Metabolic profiles differed across HFE genotypes. C282Y homozygotes (n=7) presented a reduced ß-cell function and insulin secretion compared with non-C282Y patients (n=11) (-58% and -73%, respectively, P< 0.05). In addition, C282Y homozygotes featured a predominance of large, buoyant LDL particles (C282Y: 43±5; non-C282Y: 25±8; controls: 32±7%; P< 0.001), whereas non-C282Y patients presented higher amounts of small, dense LDL (C282Y: 23±5; non-C282Y: 39±10; controls: 26±4%; P< 0.01). HDL particles were altered in C282Y homozygotes. However, HDL functionality was conserved. In conclusion, metabolic alterations and HFE gene mutations are involved in the presence of atherogenic lipoprotein modifications in primary IO. To what extent such alterations could account for an increase in CVD risk remains to be determined.

Erythropoiesis-driven regulation of hepcidin in human red cell disorders is better reflected through concentrations of soluble transferrin receptor rather than growth differentiation factor 15.

Growth differentiation factor 15 (GDF-15) is a bone marrow-derived cytokine whose ability to suppress iron regulator hepcidin in vitro and increased concentrations found in patients with ineffective erythropoiesis (IE)suggest that hepcidin deficiency mediated by GDF-15 may be the pathophysiological explanation for nontransfusional iron overload. We aimed to compare GDF-15 production in anemic states with different types of erythropoietic dysfunction. Complete blood counts, biochemical markers of iron status, plasma hepcidin, GDF-15, and known hepcidin regulators [interleukin-6 and erythropoietin (EPO)] were measured in 87 patients with red cell disorders comprising IE and hemolytic states: thalassemia, sickle cell anemia, and cobalamin deficiency. Healthy volunteers were also evaluated for comparison. Neither overall increased EPO,nor variable GDF-15 concentrations correlated with circulating hepcidin concentrations (P = 0.265 and P = 0.872). Relative hepcidin deficiency was found in disorders presenting with concurrent elevation of GDF-15 and soluble transferrin receptor (sTfR), a biomarker of erythropoiesis, and sTfR had the strongest correlation with hepcidin (r(s) = 0.584, P < 0.0001). Our data show that high concentrations of GDF-15 in vivo are not necessarily associated with pathological hepcidin reduction, and hepcidin deficiency was only found when associated with sTfR overproduction. sTfR elevation may be a necessary common denominator of erythropoiesis-driven mechanisms to favor iron absorption in anemic states and appears a suitable target for investigative approaches to iron disorders.

Inflammation is not the cause of an elevated serum ferritin in non-alcoholic fatty liver disease.

BACKGROUND: In non-alcoholic fatty liver disease (NALFD), it has often been assumed that an elevation in serum ferritin is likely related to inflammation rather than iron overload. MATERIAL AND METHODS: Patients referred with NAFLD were entered into a clinical study of phlebotomy therapy. A liver biopsy with liver iron concentration was done at entry and 6 months after phlebotomy (n = 56) until the patient had a low serum ferritin or developed anemia. Serum ferritin was compared to liver iron concentration, ESR, CRP, BMI and grade of inflammation on liver biopsy. RESULTS: Iron removed by phlebotomy in NAFLD correlated with the decrease in serum ferritin (r = 0.57, p = 0.0014) and liver iron concentration (r = 0.57, p = 0.0013). There was no significant correlations between serum ferritin and ESR, CRP or grade of liver inflammation. CONCLUSIONS: Serum ferritin is related to liver iron storage in NAFLD and decreasing body iron stores by phlebotomy is reflected by an appropriate decrease in serum ferritin. Inflammation is not the cause of the elevated serum ferritin in fatty liver disease.