Optimizing the diagnosis and the treatment of iron overload diseases

Acetylated oligopeptide and N-acetylcysteine protect against iron overload-induced dentate gyrus hippocampal degeneration through upregulation of Nestin and Nrf2/HO-1 and downregulation of MMP-9/TIMP-1 and GFAP

Iron accumulation in the brain causes oxidative stress, blood-brain barrier (BBB) breakdown, and neurodegeneration. We examined the preventive effects of acetylated oligopeptides (AOP) from whey protein on iron-induced hippocampal damage compared to N-acetyl cysteine (NAC). This 5-week study used 40 male albino rats. At the start, all rats received 150 mg/kg/day of oral NAC for a week. The 40 animals were then randomly divided into four groups: Group I (control) received a normal diet; Group II (iron overload) received 60 mg/kg/day intraperitoneal iron dextran 5 days a week for 4 weeks; Group III (NAC group) received 150 mg/kg/day NAC and iron dextran; and Group IV (AOP group) received 150 mg/kg/day AOP and iron dextran. Enzyme-linked immunosorbent assay, spectrophotometry, and qRT-PCR were used to measure MMP-9, tissue inhibitor metalloproteinase-1 (TIMP-1), MDA, reduced glutathione (GSH) levels, and nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) gene expression. Histopathological and immunohistochemical detection of nestin, claudin, caspase, and GFAP was also done. MMP-9, TIMP-1, MDA, caspase, and GFAP rose in the iron overload group, while GSH, Nrf2, HO-1, nestin, and claudin decreased. The NAC and AOP administrations improved iron overload-induced biochemical and histological alterations. We found that AOP and NAC can protect the brain hippocampus from iron overload, improve BBB disruption, and provide neuroprotection with mostly no significant difference from healthy controls.

Hyperferritinemia and liver iron content determined with MRI: Reintroduction of the liver iron index

BACKGROUND

Hyperferritinemia is found in around 12 % of the general population. Analyzing the cause can be difficult. In case of doubt about the presence of major iron overload most guidelines advice to perform a MRI as a reliable non-invasive marker to measure liver iron concentration (LIC). In general, a LIC of ≥ 36 µmol/g dw is considered the be elevated however in hyperferritinemia associated with, for example, obesity or alcohol (over)consumption the LIC can be ≥ 36 µmol/g dw in abscence of major iron overload. So, unfortunately a clear cut-off value to differentiate iron overload from normal iron content is lacking. Previously the liver iron index (LII) (LIC measured in liver biopsy (LIC-b)/age (years)), was introduced to differentiate between patients with major (LII ≥ 2) and minor or no iron overload (LII < 2). Based on the good correlation between the LIC-b and LIC determined with MRI (LIC-MRI), our goal was to investigate whether a LII_MRI ≥ 2 is a good indicator of major iron overload, reflected by a significantly higher amount of iron needed to be mobilized to reach iron depletion.

METHODS

We compared the amount of mobilized iron to reach depletion and inflammation-related characteristics in two groups: LII-MRI ≥ 2 versus LII-MRI <2 in 92 hyperferritinemia patients who underwent HFE genotyping and MRI-LIC determination.

RESULTS

Significantly more iron needed to be mobilized to reach iron depletion in the LII ≥ 2 group (mean 4741, SD ± 4135 mg) versus the LII-MRI <2 group (mean 1340, SD ± 533 mg), P < 0.001. Furthermore, hyperferritinemia in LII-MRI < 2 patients was more often related to components of the metabolic syndrome while hyperferritinemia in LII-MRI ≥ 2 patients was more often related to HFE mutations. ROC curve analysis showed good performance of LII =2 as cut-off value. However the calculations showed that the optimal cut-off for the LII = 3.4.

CONCLUSION

The LII-MRI with a cut-off value of 2 is an effective method to differentiate major from minor iron overload in patients with hyperferritinemia. But the LII-MRI = 3.4 seems a more promising diagnostic test for major iron overload.

The effect of chronic intermittent hypobaric hypoxia improving liver damage in metabolic syndrome rats through ferritinophagy

Studies have confirmed that hepatic iron overload is one of the important factors causing liver damage in the metabolic syndrome (MS). As a special form of autophagy, ferritinophagy is involved in the regulation of iron metabolism. Our previous studies have shown that chronic intermittent hypobaric hypoxia (CIHH) can improve the iron metabolism disorder. The aim of this study was to investigate how CIHH improves liver damage through ferritinophagy in MS rats. Male Sprague-Dawley rats aged 8-10 weeks were randomly divided into four groups: control (CON), CIHH (exposed to hypoxia at a simulated altitude of 5000 m for 28 days, 6 h daily), MS model (induced by a 16-week high-fat diet and 10% fructose water feeding), and MS + CIHH (exposed to CIHH after a 16-week MS inducement) groups. Liver index, liver function, iron content, tissue morphology, oxidative stress, ferritinophagy, ferroptosis, and iron metabolism-related protein expression were measured, and the ferritinophagy flux in the liver was further analyzed. Compared with CON rats, MS rats had an increased liver index, damaged liver tissue and function, increased iron content and iron deposition, disrupted iron metabolism, significantly increased oxidative stress indicators in the liver, significantly upregulated expression of ferroptosis-related proteins, and downregulated expression of nuclear receptor coactivator 4 (NCOA4) and ferritinophagy flux. After CIHH treatment, the degree of liver damage and various abnormal indicators in MS rats were significantly improved. CIHH may improve liver damage by promoting NCOA4-mediated ferritinophagy, reducing iron overload and oxidative stress, and thereby alleviating ferroptosis in MS rats.

Guideline Review: European Association for the Study of Liver (EASL) Clinical Practice Guidelines on Haemochromatosis

The European Association for the Study of the Liver (EASL) has recently (June 2022) produced new clinical practice guidelines for the investigation and management of haemochromatosis, to replace the previous document published in 2010. Here, we provide an overview of the principal changes recommended for the investigation and management of haemochromatosis arising from these guidelines and highlight particular areas where evidence is lacking and where future focus on specific research would improve patient treatment and outcomes. The guideline provides several important new recommendations that will have a meaningful impact on patient management. Specifically, the use of hepatic elastography as a non-invasive assessment of fibrosis, erythrocytapheresis as an alternative treatment modality to classical phlebotomy, surveillance for hepatocellular carcinoma, dietary recommendations in patients with haemochromatosis and guidance on controversial topics including the management of P.C282Y/p.H63D compound heterozygotes, which have been a source of controversy within the field. It is anticipated that the new guidance will affect the management of haemochromatosis patients commonly seen in gastroenterology, liver and related clinics (e.g. haematology and rheumatology) and with this publication we intend to highlight these changes so as to empower clinicians with the confidence to bring these improvements to their translational practice in the treatment of these patients.

Iron metabolism and cardiovascular disease: Basic to translational purviews and therapeutical approach

Iron interactions with the cardiovascular system were proposed about half a century ago, yet a clear-cut understanding of this micronutrient and its intricacies with acute and chronic events is still lacking. In chronic heart failure, patients with decreased iron stores appear to benefit from intravenous administration of metallic formulations, whereas acute diseases (e.g., myocardial infarction, stroke) are barely studied in randomized controlled trials in humans. However, proof-of-concept studies have indicated that the dual redox characteristics of iron could be involved in atherosclerosis, necrosis, and ferroptosis. To this end, we sought to review the currently available body of literature pertaining to these temporal profiles of heart diseases, as well as the pathophysiologic mechanism by which iron enacts, underlining key points related to treatment options.

EASL Clinical Practice Guidelines on haemochromatosis

Haemochromatosis is characterised by elevated transferrin saturation (TSAT) and progressive iron loading that mainly affects the liver. Early diagnosis and treatment by phlebotomy can prevent cirrhosis, hepatocellular carcinoma, diabetes, arthropathy and other complications. In patients homozygous for p.Cys282Tyr in HFE, provisional iron overload based on serum iron parameters (TSAT >45% and ferritin >200 μg/L in females and TSAT >50% and ferritin >300 μg/L in males and postmenopausal women) is sufficient to diagnose haemochromatosis. In patients with high TSAT and elevated ferritin but other HFE genotypes, diagnosis requires the presence of hepatic iron overload on MRI or liver biopsy. The stage of liver fibrosis and other end-organ damage should be carefully assessed at diagnosis because they determine disease management. Patients with advanced fibrosis should be included in a screening programme for hepatocellular carcinoma. Treatment targets for phlebotomy are ferritin <50 μg/L during the induction phase and <100 μg/L during the maintenance phase.

HFE hemochromatosis: an overview about therapeutic recommendations

Hemochromatosis is currently characterized by the iron overload caused by hepcidin deficiency. Large advances in the knowledge on the hemochromatosis pathophysiology have occurred due to a better understanding of the protein of the iron metabolism, the genetic basis of hemochromatosis and of other iron overload diseases or conditions which can lead to this phenotype. In the present review, the main aims are to show updates on hemochromatosis and to report a practical set of therapeutic recommendations for the human factors engineering protein (HFE) hemochromatosis for the p.Cys282Tyr (C282Y/C282Y) homozygous genotype, elaborated by the Haemochromatosis International Taskforce.

MRI-based R2* mapping in patients with suspected or known iron overload

PURPOSE

R2* relaxometry is a quantitative method for assessment of iron overload. The purpose is to analyze the cross-sectional relationships between R2* in organs across patients with primary and secondary iron overload. Secondary analyses were conducted to analyze R2* according to treatment regimen.

METHODS

This is a retrospective, cross-sectional, institutional review board-approved study of eighty-one adult patients with known or suspected iron overload. R2* was measured by segmenting the liver, spleen, bone marrow, pancreas, renal cortex, renal medulla, and myocardium using breath-hold multi-echo gradient-recalled echo imaging at 1.5 T. Phlebotomy, transfusion, and chelation therapy were documented. Analyses included correlation, Kruskal-Wallis, and post hoc Dunn tests. p < 0.01 was considered significant.

RESULTS

Correlations between liver R2* and that of the spleen, bone marrow, pancreas, and heart were respectively 0.49, 0.33, 0.27, and 0.34. R2* differed between patients with primary and secondary overload in the liver (p < 0.001), spleen (p < 0.001), bone marrow (p < 0.01), renal cortex (p < 0.001), and renal medulla (p < 0.001). Liver, spleen, and bone marrow R2* were higher in thalassemia than in hereditary hemochromatosis (all p < 0.01). Renal cortex R2* was higher in sickle cell disease than in hereditary hemochromatosis (p < 0.001) and in thalassemia (p < 0.001). Overall, there was a trend toward lower liver R2* in patients assigned to phlebotomy and higher liver R2* in patients assigned to transfusion and chelation therapy.

CONCLUSION

R2* relaxometry revealed differences in degree or distribution of iron overload between organs, underlying etiologies, and treatment.

In vitro identification and characterisation of iron chelating catechol-containing natural products and derivatives

Iron is an essential component for multiple biological processes. Its regulation within the body is thus tightly controlled. Dysregulation of iron levels within the body can result in several disorders associated with either excess iron accumulation, including haemochromatosis and thalassaemia, or iron deficiency. In cases of excess body iron, therapy involves depleting body iron levels either by venesection, typically for haemochromatosis, or using iron chelators for thalassemia. However, the current chelation options for people with iron overload are limited, with only three iron chelators approved for clinical use. This presents an opportunity for improved therapeutics to be identified and developed. The aim of this study was to examine multiple compounds from within the Davis open access natural product-based library (512 compounds) for their ability to chelate iron. In silico analysis of this library initially identified nine catechol-containing compounds and two closely related compounds. These compounds were subsequently screened using an in vitro DNA breakage assay and their ability to chelate biological iron was also examined in an iron-loaded hepatocyte cellular assay. Toxicity was assessed in hepatocyte and breast cancer cell lines. One compound, RAD362 [N-(3-aminopropyl)-3,4-dihydroxybenzamide] was able to protect against DNA damage, likely through the prevention of free radicals generated via the Fenton reaction; RAD362 treatment resulted in decreased ferritin protein levels in iron-loaded hepatocytes. Lastly, RAD362 resulted in significantly less cell death than the commonly used iron chelator deferoxamine. This is the first study to identify compound RAD362 as an iron chelator and potential therapeutic.

Amlodipine as adjuvant therapy to current chelating agents for reducing iron overload in thalassaemia major: a systematic review, meta-analysis and simulation of future studies

BACKGROUND AND OBJECTIVES

Iron overload in thalassaemia is a crucial prognostic factor and a major cause of death due to heart failure or arrhythmia. Therefore, previous research has recommended amlodipine as an auxiliary treatment to current chelating agents for reducing iron overload in thalassaemia patients.

MATERIALS AND METHODS

A systematic review and meta-analysis of the results of three randomized clinical trials evaluating the use of amlodipine in thalassaemia patients through 12 databases were carried out.

RESULTS

Our final cohort included 130 patients. Insignificant difference in decreasing liver iron concentrations was found between amlodipine and control groups {weighted mean difference = -0·2, [95% confidence interval = (-0·55-0·15), P = 0·26]}. As regards serum ferritin, our analysis also showed no significant difference in serum ferritin between amlodipine and control groups {weighted mean difference [95% confidence interval = -0·16 (-0·51-0·19), P = 0·36]}. Similarly, there was insignificant difference in cardiac T2* between amlodipine and control groups {weighted mean difference [95% confidence interval = 0·34 (-0·01-0·69), P = 0·06]}.

CONCLUSIONS

Despite the growing evidence supporting the role of amlodipine in reducing iron overload in thalassaemia patients, our meta-analysis did not find that evidence collectively significant. The results of our simulation suggest that when more data are available, a meta-analysis with more randomized clinical trials could provide more conclusive insights.

An efficient machine learning-based approach for screening individuals at risk of hereditary haemochromatosis

Hereditary haemochromatosis (HH) is an autosomal recessive disease, where HFE C282Y homozygosity accounts for 80–85% of clinical cases among the Caucasian population. HH is characterised by the accumulation of iron, which, if untreated, can lead to the development of liver cirrhosis and liver cancer. Since iron overload is preventable and treatable if diagnosed early, high-risk individuals can be identified through effective screening employing artificial intelligence-based approaches. However, such tools expose novel challenges associated with the handling and integration of large heterogeneous datasets. We have developed an efficient computational model to screen individuals for HH using the family study data of the Hemochromatosis and Iron Overload Screening (HEIRS) cohort. This dataset, consisting of 254 cases and 701 controls, contains variables extracted from questionnaires and laboratory blood tests. The final model was trained on an extreme gradient boosting classifier using the most relevant risk factors: HFE C282Y homozygosity, age, mean corpuscular volume, iron level, serum ferritin level, transferrin saturation, and unsaturated iron-binding capacity. Hyperparameter optimisation was carried out with multiple runs, resulting in 0.94 ± 0.02 area under the receiving operating characteristic curve (AUCROC) for tenfold stratified cross-validation, demonstrating its outperformance when compared to the iron overload screening (IRON) tool.

Atypical juvenile hereditary hemochromatosis onset with positive pancreatic islet autoantibodies diabetes caused by novel mutations in HAMP and overall clinical management

Background

Atypical clinical symptoms of juvenile hereditary hemochromatosis (JHH) often leads to misdiagnosis and underdiagnosis bringing ominous outcomes, even death.

Methods

The whole exome was sequenced and interpreted. A literature review assisted to analyze and verify the phenotype–genotype relationships. We revealed the entire process of diagnosis, treatments, and outcome of two diabetic onset of JHH families to provide new insights for genotype–phenotype relation with novel compound heterozygous mutations in the hepcidin antimicrobial peptide (HAMP, OMIM: 606464).

Results

Two probands were diagnosed and treated as type 1 diabetes initially because of specific symptoms and positive islet autoantibodies. Poor control of hyperglycemia and progressive symptoms occurred. Sequencing informed that the compound heterozygous and homozygous mutations c.166C>G and c.223C>T in HAMP caused type 1 diabetic‐onset JHH. The two patients accessed irregular phlebotomy treatments, and then, experienced poor prognosis. We summarized the process of overall clinical management of reported 26 cases comparing to our novel atypical diabetic onsets Juvenile Hereditary Hemochromatosis cases.

Conclusion

It was first reported that positive pancreatic islet autoantibodies diabetes onset of JHH resulted from loss‐of‐function mutations of HAMP, of which the atypical JHH should be differentially diagnosed with type 1 diabetes at the onset. Early administration of phlebotomy and vital organs protection and surveillance might be important for the treatment of atypical JHH.

Novel mutations in the bone morphogenetic protein 6 gene in patients with iron overload and non-homozygous genotype for the HFE p.Cys282Tyr mutation

BACKGROUND

Five main genes are associated with hemochromatosis; however, current studies show that, in addition to these genes, others may be associated with primary iron overload (IO). One of these is the bone morphogenetic protein 6 (BMP6), which encodes a protein that modulates hepcidin synthesis and, consequently, iron homeostasis.

AIM

To identify BMP6 gene pathogenic variants in patients with IO and non-homozygous genotype for the HFE p.Cys282Tyr mutation.

MATERIALS AND METHODS

Fifty-three patients with primary IO and non-homozygous genotype for the HFE p.Cys282Tyr were selected. Subsequent bidirectional DNA sequencing of BMP6 exons was performed.

RESULTS

Two novel variants were found. One at homozygous state p.Gln158Ter (c.472C>T) was pathogenic, the other one at heterozygous state p.Val394Met (c.1180G>A) was of uncertain significance (VUS); the third variant at heterozygous state p.Arg257His (c.770G>A) has already been described and associated with IO. No BMP6 pathogenic variants that would explain iron overload phenotypes were detected in 94% of the studied patients.

CONCLUSION

Identification of the BMP6 pathogenic variants in Brazilian patients with primary IO might contribute to the genetic understanding of this phenotype.

Influence of mitochondrial and systemic iron levels in heart failure pathology

Iron deficiency or overload poses an increasingly complex issue in cardiovascular disease, especially heart failure. The potential benefits and side effects of iron supplementation are still a matter of concern, even though current guidelines suggest therapeutic management of iron deficiency. In this review, we sought to examine the iron metabolism and to identify the rationale behind iron supplementation and iron chelation. Cardiovascular disease is increasingly linked with iron dysmetabolism, with an increased proportion of heart failure patients being affected by decreased plasma iron levels and in turn, by the decreased quality of life. Multiple studies have concluded on a benefit of iron administration, even if just for symptomatic relief. However, new studies field evidence for negative effects of dysregulated non-bound iron and its reactive oxygen species production, with concern to heart diseases. The molecular targets of iron usage, such as the mitochondria, are prone to deleterious effects of the polyvalent metal, added by the scarcely described processes of iron elimination. Iron supplementation and iron chelation show promise of therapeutic benefit in heart failure, with the extent and mechanisms of both prospects not being entirely understood. It may be that a state of decreased systemic and increased mitochondrial iron levels proves to be a useful frame for future advancements in understanding the interconnection of heart failure and iron metabolism.

Therapeutic Advances in Regulating the Hepcidin/Ferroportin Axis

The interaction between hepcidin and ferroportin is the key mechanism involved in regulation of systemic iron homeostasis. This axis can be affected by multiple stimuli including plasma iron levels, inflammation and erythropoietic demand. Genetic defects or prolonged inflammatory stimuli results in dysregulation of this axis, which can lead to several disorders including hereditary hemochromatosis and anaemia of chronic disease. An imbalance in iron homeostasis is increasingly being associated with worse disease outcomes in many clinical conditions including multiple cancers and neurological disorders. Currently, there are limited treatment options for regulating iron levels in patients and thus significant efforts are being made to uncover approaches to regulate hepcidin and ferroportin expression. These approaches either target these molecules directly or regulatory steps which mediate hepcidin or ferroportin expression. This review examines the current status of hepcidin and ferroportin agonists and antagonists, as well as inducers and inhibitors of these proteins and their regulatory pathways.

Treatment of iron overload syndrome: a general review

SUMMARY INTRODUCTION Iron overload is a broad syndrome with a large spectrum of causative etiologies that lead to iron deposition. When iron exceeds defenses, it causes oxidative damage and tissular disfunction. Treatment may prevent organ dysfunction, leading to greater life expectancy. METHODS Literature from the last five years was reviewed through the use of the PubMed database in search of treatment strategies. DISCUSSION Different pharmacological and non-pharmacological strategies are available for the treatment of iron overload and must be used according to etiology and patient compliance. Therapeutic phlebotomy is the basis for the treatment of hereditary hemochromatosis. Transfusional overload patients and those who cannot tolerate phlebotomy need iron chelators. CONCLUSION Advances in the understanding of iron overload have lead to great advances in therapies and new pharmacological targets. Research has lead to better compliance with the use of oral chelators and less toxic drugs.

ACG Clinical Guideline: Hereditary Hemochromatosis

Hereditary hemochromatosis (HH) is one of the most common genetic disorders among persons of northern European descent. There have been recent advances in the diagnosis, management, and treatment of HH. The availability of molecular diagnostic testing for HH has made possible confirmation of the diagnosis for most patients. Several genotype-phenotype correlation studies have clarified the differences in clinical features between patients with the C282Y homozygous genotypes and other HFE mutation patterns. The increasing use of noninvasive tests such as MRI T2* has made quantification of hepatic iron deposition easier and eliminated the need for liver biopsy in most patients. Serum ferritin of <1,000 ng/mL at diagnosis remains an important diagnostic test to identify patients with a low risk of advanced hepatic fibrosis and should be used routinely as part of the initial diagnostic evaluation. Genetic testing for other types of HH is available but is expensive and generally not useful in most clinical settings. Serum ferritin may be elevated among patients with nonalcoholic fatty liver disease and in those with alcoholic liver disease. These diagnoses are more common than HH among patients with elevated serum ferritin who are not C282Y homozygotes or C282Y/H63D compound heterozygotes. A secondary cause for liver disease should be excluded among patients with suspected iron overload who are not C282Y homozygotes. Phlebotomy remains the mainstay of therapy, but emerging novel therapies such as new chelating agents may have a role for selected patients.

[Cardiac involvement in storage diseases : Role of genetic diagnostics]

In clinical practice cardiac involvement in patients with storage disorders is often diagnosed at a late and advanced stage of the disease with pronounced organ damage. As the currently available targeted therapies can only stop the progress of the disease, a timely diagnosis is of particular relevance. Genetic testing has become increasingly more important in cases of suspected cardiac manifestation in storage disorders. Thereby, diagnostic genetic testing can help to confirm the diagnosis and may also be relevant for therapeutic decision making. In relatives of affected patients predictive genetic testing provides the opportunity for an early therapeutic intervention.

New Perspectives in Iron Chelation Therapy for the Treatment of Neurodegenerative Diseases

Iron chelation has been introduced as a new therapeutic concept for the treatment of neurodegenerative diseases with features of iron overload. At difference with iron chelators used in systemic diseases, effective chelators for the treatment of neurodegenerative diseases must cross the blood–brain barrier. Given the promissory but still inconclusive results obtained in clinical trials of iron chelation therapy, it is reasonable to postulate that new compounds with properties that extend beyond chelation should significantly improve these results. Desirable properties of a new generation of chelators include mitochondrial destination, the center of iron-reactive oxygen species interaction, and the ability to quench free radicals produced by the Fenton reaction. In addition, these chelators should have moderate iron binding affinity, sufficient to chelate excessive increments of the labile iron pool, estimated in the micromolar range, but not high enough to disrupt physiological iron homeostasis. Moreover, candidate chelators should have selectivity for the targeted neuronal type, to lessen unwanted secondary effects during long-term treatment. Here, on the basis of a number of clinical trials, we discuss critically the current situation of iron chelation therapy for the treatment of neurodegenerative diseases with an iron accumulation component. The list includes Parkinson’s disease, Friedreich’s ataxia, pantothenate kinase-associated neurodegeneration, Huntington disease and Alzheimer’s disease. We also review the upsurge of new multifunctional iron chelators that in the future may replace the conventional types as therapeutic agents for the treatment of neurodegenerative diseases.

Increased transferrin saturation is associated with subgingival microbiota dysbiosis and severe periodontitis in genetic haemochromatosis

Genetic haemochromatosis (GH) is responsible for iron overload. Increased transferrin saturation (TSAT) has been associated with severe periodontitis, which is a chronic inflammatory disease affecting tissues surrounding the teeth and is related to dysbiosis of the subgingival microbiota. Because iron is essential for bacterial pathogens, alterations in iron homeostasis can drive dysbiosis. To unravel the relationships between serum iron biomarkers and the subgingival microbiota, we analysed samples from 66 GH patients. The co-occurrence analysis of the microbiota showed very different patterns according to TSAT. Healthy and periopathogenic bacterial clusters were found to compete in patients with normal TSAT (≤45%). However, significant correlations were found between TSAT and the proportions of Porphyromonas and Treponema, which are two genera that contain well-known periopathogenic species. In patients with high TSAT, the bacterial clusters exhibited no mutual exclusion. Increased iron bioavailability worsened periodontitis and promoted periopathogenic bacteria, such as Treponema. The radical changes in host-bacteria relationships and bacterial co-occurrence patterns according to the TSAT level also suggested a shift in the bacterial iron supply from transferrin to NTBI when TSAT exceeded 45%. Taken together, these results indicate that iron bioavailability in biological fluids is part of the equilibrium between the host and its microbiota.

Monitoring Iron Overload: Relationship between R2* Relaxometry of the Liver and Serum Ferritin under Different Therapies

Objective:

The objective of this study was to evaluate the relationship between hepatic magnetic resonance imaging (MRI) with R2* relaxometry and serum ferritin in therapy monitoring of patients with iron overload. Further, a possible influence of the chosen therapy (phlebotomy or chelation) was assessed.

Materials and Methods:

We retrospectively evaluated 42 patients with baseline and follow-up R2* relaxometry and determination of serum ferritin before and during therapeutic phlebotomy or iron chelation therapy or watchful waiting, respectively. Linear regression analysis was used to analyze the correlation between changes of R2* and serum ferritin. Regression lines for different groups were compared with analysis of covariance.

Results:

We found a moderate positive statistical correlation (r = 0.509) between serum ferritin and R2*, a moderate positive correlation between absolute R2* changes and serum ferritin changes (r = 0.497), and a strong correlation for percentage changes (r = 0.712). The correlation analysis between relative changes of R2* and serum ferritin for the different therapies resulted in a strong correlation between phlebotomy and chelation (r = 0.855/0.727) and a moderate for no applied therapy (r = 0.536). In 22/92 paired examinations, a discordance of R2* and ferritin was found, particularly involving patients under chelation.

Conclusions:

Despite the good correlation between serum ferritin and R2* relaxometry in monitoring iron overload, treatment response may be misinterpreted when only serum ferritin is considered. Although ferritin is an acceptable and far cheaper tool for monitoring, MRI should be performed for confirmation, especially in case of unexpected ferritin changes, particularly under chelation therapy.

Haemochromatosis

Haemochromatosis is defined as systemic iron overload of genetic origin, caused by a reduction in the concentration of the iron regulatory hormone hepcidin, or a reduction in hepcidin-ferroportin binding. Hepcidin regulates the activity of ferroportin, which is the only identified cellular iron exporter. The most common form of haemochromatosis is due to homozygous mutations (specifically, the C282Y mutation) in HFE, which encodes hereditary haemochromatosis protein. Non-HFE forms of haemochromatosis due to mutations in HAMP, HJV or TFR2 are much rarer. Mutations in SLC40A1 (also known as FPN1; encoding ferroportin) that prevent hepcidin-ferroportin binding also cause haemochromatosis. Cellular iron excess in HFE and non-HFE forms of haemochromatosis is caused by increased concentrations of plasma iron, which can lead to the accumulation of iron in parenchymal cells, particularly hepatocytes, pancreatic cells and cardiomyocytes. Diagnosis is noninvasive and includes clinical examination, assessment of plasma iron parameters, imaging and genetic testing. The mainstay therapy is phlebotomy, although iron chelation can be used in some patients. Hepcidin supplementation might be an innovative future approach.

Therapeutic recommendations in HFE hemochromatosis for p.Cys282Tyr (C282Y/C282Y) homozygous genotype

Although guidelines are available for hereditary hemochromatosis, a high percentage of the recommendations within them are not shared between the different guidelines. Our main aim is to provide an objective, simple, brief, and practical set of recommendations about therapeutic aspects of HFE hemochromatosis for p.Cys282Tyr (C282Y/C282Y) homozygous genotype, based on the published scientific studies and guidelines, in a form that is reasonably comprehensible to patients and people without medical training. This final version was approved at the Hemochromatosis International meeting on 12th May 2017 in Los Angeles.

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.

Electronic supplementary material

The online version of this article (doi: 10.1186/s12881-017-0513-5) contains supplementary material, which is available to authorized users.

Dual action of vitamin C in iron supplement therapeutics for iron deficiency anemia: prevention of liver damage induced by iron overload

Vitamin C, an excellent reducing agent, aids in increasing absorbable ferrous iron in iron deficiency anemia.

Pathogenesis, Diagnostics, and Treatment of Hereditary Haemochromatosis: A 150 Year-Long Understanding of an Iron Overload Disorder

Haemochromatosis is an iron overload disorder that can be inherited or acquired and when diagnosis is delayed, disease progression and death can occur. Iron overload was first described by the French internist Armand Trousseau in 1865 in an article on diabetes in which alterations in skin pigmentations were reported. Some years later, the German pathologist Friedrich Daniel von Recklinghausen coined the term ‘haemochromatosis’ for a metabolic disorder characterised by excess deposition of iron in the tissue. This disorder affects 1 in 200 subjects of Caucasians of Northern European descent. The systemic excess iron build-up condition quickly gained an intense clinical interest. Haemochromatosis can lead to severe pathological symptoms in multiple organs, including the liver, bones, spleen, heart, pancreas, joints, and reproductive organs. With the progress of the disease, hepatic damage predominates. Polymorphisms in several independent genes can lead to haemochromatosis. However, the most widely known haemochromatosis-associated and studied ones are genetic variants in the HFE gene, located on the short arm of human chromosome 6. Early detection and phlebotomy prior to the onset of fibrosis/cirrhosis can reduce morbidity and normalise life expectancy. Consequently, phlebotomy has been accepted for decades as a standard treatment for the reduction of iron load. Nowadays, other methods, such as erythrocytapheresis, therapeutic application of iron chelators and proton pump inhibitors, or hepcidin-targeted therapy, are discussed as alternative personalised treatments of hereditary haemochromatosis. This review focusses on the pathogenesis, diagnosis, and therapy of haemochromatosis.

Genetic hemochromatosis: Pathophysiology, diagnostic and therapeutic management

The term hemochromatosis (HC) corresponds to several diseases characterized by systemic iron overload of genetic origin and affecting both the quality of life and life expectancy. Major improvement in the knowledge of iron metabolism permits to divide these diseases into two main pathophysiological categories. For most HC forms (types 1, 2, 3 and 4B HC) iron overload is related to cellular hepcidin deprivation which causes an increase of plasma iron concentration and the appearance of plasma non-transferrin bound iron. In contrast, iron excess in type 4A ferroportin disease is related to decreased cellular iron export. Whatever the HC type, the diagnosis rests on a non-invasive strategy, combining clinical, biological and imaging data. The mainstay of the treatment remains venesection therapy with the perspective of hepcidin supplementation for hepcidin deprivation-related HC. Prevention of HC is critical at the family level and, for type 1 HC, remains a major goal, although still debated, at the population level.

The Construction and Characterization of Mitochondrial Ferritin Overexpressing Mice

Mitochondrial ferritin (FtMt) is a H-ferritin-like protein which localizes to mitochondria. Previous studies have shown that this protein can protect mitochondria from iron-induced oxidative damage, while FtMt overexpression in cultured cells decreases cytosolic iron availability and protects against oxidative damage. To investigate the in vivo role of FtMt, we established FtMt overexpressing mice by pro-nucleus microinjection and examined the characteristics of the animals. We first confirmed that the protein levels of FtMt in the transgenic mice were increased compared to wild-type mice. Interestingly, we found no significant differences in the body weights or organ to body weight ratios between wild type and transgenic mice. To determine the effects of FtMt overexpression on baseline murine iron metabolism and hematological indices, we measured serum, heart, liver, spleen, kidney, testis, and brain iron concentrations, liver hepcidin expression and red blood cell parameters. There were no significant differences between wild type and transgenic mice. In conclusion, our results suggest that FtMt overexpressing mice have no significant defects and the overexpression of FtMt does not affect the regulation of iron metabolism significantly in transgenic mice.

Iron for Africa-Report of an Expert Workshop

Scientific experts from nine countries gathered to share their views and experience around iron interventions in Africa. Inappropriate eating habits, infections and parasitism are responsible for significant prevalence of iron deficiency, but reliable and country-comparable prevalence estimates are lacking: improvements in biomarkers and cut-offs values adapted to context of use are needed. Benefits of iron interventions on growth and development are indisputable and outweigh risks, which exist in populations with a high infectious burden. Indeed, pathogen growth may increase with enhanced available iron, calling for caution and preventive measures where malaria or other infections are prevalent. Most African countries programmatically fortify flour and supplement pregnant women, while iron deficiency in young children is rather addressed at individual level. Coverage and efficacy could improve through increased access for target populations, raised awareness and lower cost. More bioavailable iron forms, helping to decrease iron dose, or prebiotics, which both may lower risk of infections are attractive opportunities for Africa. Fortifying specific food products could be a relevant route, adapted to local context and needs of population groups while providing education and training. More globally, partnerships involving various stakeholders are encouraged, that could tackle all aspects of the issue.

Pathophysiological consequences and benefits of HFE mutations: 20 years of research

Mutations in the HFE (hemochromatosis) gene cause hereditary hemochromatosis, an iron overload disorder that is hallmarked by excessive accumulation of iron in parenchymal organs. The HFE mutation p.Cys282Tyr is pathologically most relevant and occurs in the Caucasian population with a carrier frequency of up to 1 in 8 in specific European regions. Despite this high prevalence, the mutation causes a clinically relevant phenotype only in a minority of cases. In this review, we summarize historical facts and recent research findings about hereditary hemochromatosis, and outline the pathological consequences of the associated gene defects. In addition, we discuss potential advantages of HFE mutations in asymptomatic carriers.

Hypobaric Hypoxia Regulates Brain Iron Homeostasis in Rats

Disruption of iron homeostasis in brain has been found to be closely involved in several neurodegenerative diseases. Recent studies have reported that appropriate intermittent hypobaric hypoxia played a protective role in brain injury caused by acute hypoxia. However, the mechanisms of this protective effect have not been fully understood. In this study, Sprague-Dawley (SD) rat models were developed by hypobaric hypoxia treatment in an altitude chamber, and the iron level and iron related protein levels were determined in rat brain after 4 weeks of treatment. We found that the iron levels significantly decreased in the cortex and hippocampus of rat brain as compared to that of the control rats without hypobaric hypoxia treatment. The expression levels of iron storage protein L-ferritin and iron transport proteins, including transferrin receptor-1 (TfR1), divalent metal transporter 1 (DMT1), and ferroportin1 (FPN1), were also altered. Further studies found that the iron regulatory protein 2 (IRP2) played a dominant regulatory role in the changes of iron hemostasis, whereas iron regulatory protein 1 (IRP1) mainly acted as cis-aconitase. These results, for the first time, showed the alteration of iron metabolism during hypobaric hypoxia in rat models, which link the potential neuroprotective role of hypobaric hypoxia treatment to the decreased iron level in brain. This may provide insight into the treatment of iron-overloaded neurodegenerative diseases. J. Cell. Biochem. 118: 1596-1605, 2017. © 2016 Wiley Periodicals, Inc.

How we manage patients with hereditary haemochromatosis

A number of disorders cause iron overload: some are of genetic origin, such as hereditary haemochromatosis, while others are acquired, for instance due to repeated transfusions. This article reviews the treatment options for hereditary haemochromatosis, with special attention to the use of erythrocytapheresis. In general, therapy is based on the removal of excess body iron, for which ferritin levels are used to monitor the effectiveness of treatment. For many decades phlebotomy has been widely accepted as the standard treatment. Recent publications suggest that erythrocytapheresis, as a more individualized treatment, can provide a good balance between effectiveness, tolerability and costs. Other treatments like oral chelators and proton pomp inhibitors, which are used in selected patients, create the possibility to further individualize treatment of hereditary haemochromatosis. In the future, hepcidin-targeted therapy could provide a more fundamental approach to treatment.