How we manage patients with hereditary haemochromatosis

Hereditary hemochromatosis caused by a C282Y/H63D mutation in the HFE gene: A case report

Hereditary hemochromatosis (HH) is a disease characterized by disordered iron metabolism. It often involves mutations of the HFE gene, which encodes the homeostatic iron regulator protein (HFE), as well as mutations affecting hepcidin antimicrobial peptide, hemojuvelin, or transferrin receptor 2. Historically, HH has been observed primarily in European and European diaspora populations, while classical HH is rare in Asian populations, including in China. In this article, we report a rare case of HH in a Chinese man that could be attributed to a heterozygous C282Y/H63D HFE mutation. Based on clinical examination, liver biopsy, and genetic testing results, the patient was diagnosed with HH. Clinical signs and symptoms and serum iron-related test results were recorded for a period of two years after the patient began treatment. Over this observation period, the patient was subjected to 25 phlebotomies (accounting for a total blood loss of 10.2 L). His serum ferritin levels decreased from 1550 μg/L to 454 μg/L, his serum iron concentration decreased from 40 μmol/L to 24.6 μmol/L, and his transferrin saturation decreased from 97.5% to 55.1%. Early diagnosis is essential for patients with HH to obtain good outcomes. Regular phlebotomy after diagnosis can improve HH symptoms and delay HH disease progression.

Haemochromatosis in children: A national retrospective cohort promoted by the A.I.E.O.P. (Associazione Italiana Emato-Oncologia Pediatrica) study group

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.

Rusfertide for the treatment of iron overload in HFE-related haemochromatosis: an open-label, multicentre, proof-of-concept phase 2 trial

BACKGROUND

Hereditary haemochromatosis protein (HFE)-related haemochromatosis, an inherited iron overload disorder caused by insufficient hepcidin production, results in excessive iron absorption and tissue and organ injury, and is treated with first-line therapeutic phlebotomy. We aimed to investigate the efficacy and safety of rusfertide, a peptidic mimetic of hepcidin, in patients with HFE-related haemochromatosis.

METHODS

This open-label, multicentre, proof-of-concept phase 2 trial was done across nine academic and community centres in the USA and Canada. Adults (aged ≥18 years) with HFE-related haemochromatosis on a stable therapeutic phlebotomy regimen (maintenance phase) for at least 6 months before screening and who had a phlebotomy frequency of at least 0·25 per month (eg, at least three phlebotomies in 12 months or at least four phlebotomies in 15 months) and less than one phlebotomy per month, with serum ferritin of less than 300 ng/mL and haemoglobin of more than 11·5 g/dL, were eligible. Patients initiated 24 weeks of subcutaneous rusfertide treatment within 7 days of a scheduled phlebotomy at 10 mg once weekly. Rusfertide doses and dosing schedules could be adjusted to maintain serum transferrin iron saturation (TSAT) at less than 40%. During rusfertide treatment, investigators were to consider the need for phlebotomy when the serum ferritin and TSAT values exceeded the patient's individual pre-phlebotomy serum ferritin and TSAT values. No primary endpoint or testing hierarchy was prespecified. Prespecified efficacy endpoints included the change in the frequency of phlebotomies; the proportion of patients achieving phlebotomy independence; change in serum iron, TSAT, serum transferrin, serum ferritin, and liver iron concentration (LIC) as measured by MRI; and treatment-emergent adverse events (TEAEs). The key efficacy analyses for phlebotomy rate and LIC were conducted by use of paired t tests in the intention-to-treat population, defined as all patients who received any study drug and who had pretreatment and at least one post-dose measurement. We included all participants who received at least one dose of rusfertide in the safety analyses. This trial is closed and completed and is registered with ClinicalTrials.gov, NCT04202965.

FINDINGS

Between March 11, 2020, and April 23, 2021, 28 patients were screened and 16 (ten [63%] men and six [38%] women) were enrolled. 16 were included in analyses of phlebotomy endpoints and 14 for the LIC endpoint. 12 (75%) patients completed 24 weeks of treatment. The mean number of phlebotomies was significantly reduced during the 24-week rusfertide treatment (0·06 phlebotomies [95% CI -0·07 to 0·20]) compared with 24 weeks pre-study (2·31 phlebotomies [95% CI 1·77 to 2·85]; p<0·0001). 15 (94%) of 16 patients were phlebotomy-free during the treatment period. Mean LIC in the 14 patients in the intention-to-treat population was 1·4 mg iron per g dry liver weight (95% CI 1·0 to 1·8) at screening and 1·1 mg iron per g dry liver weight (95% CI 0·9 to 1·3) at the end of treatment (p=0·068). Mean TSAT was 45·3% (95% CI 33·2 to 57·3) at screening, 36·7% (24·2 to 49·2) after the pretreatment phlebotomy, 21·8% (15·8 to 27·9) 24 h after the first dose of rusfertide, 40·4% (27·1 to 53·8) at the end of treatment, and 32·6% (25·0 to 40·1) over the treatment duration. Mean serum iron was 24·6 μmol/L (95% CI 18·6 to 30·6), 20·1 μmol/L (14·8 to 25·3), 11·9 μmol/L (9·2 to 14·7), 22·5 μmol/L (15·9 to 29·1), and 19·0 μmol/L (15·3 to 22·6) at these same timepoints, respectively. Mean serum ferritin was 83·3 μg/L (52·2 to 114.4), 65·5 μg/L (32·1 to 98·9), 62·8 μg/L (33·8 to 91·9), 150·0 μg/L (86·6 to 213.3), and 94·3 μg/L (54·9 to 133.6) at these same timepoints, respectively. There were only minor changes in serum transferrin concentration. 12 (75%) patients had at least one TEAE, the most common of which was injection site pain (five [31%] patients). All TEAEs were mild or moderate in severity, except for a serious adverse event of pancreatic adenocarcinoma, which was considered severe and unrelated to treatment and was pre-existing and diagnosed 21 days after starting rusfertide treatment.

INTERPRETATION

Rusfertide prevents iron re-accumulation in the absence of phlebotomies and could be a viable therapeutic option for selected patients with haemochromatosis.

FUNDING

Protagonist Therapeutics.

Maternal and prenatal outcomes of hemochromatosis in pregnancy: A population-based study

BACKGROUND

This retrospective study investigated the impact of hemochromatosis on maternal and perinatal outcomes among delivery hospitalizations in the United States between 2010 and 2019, revealing notable trends and associations.

METHODS

Utilizing data from over 36 million delivery hospitalizations, we conducted a comprehensive analysis, focusing on maternal complications, perinatal outcomes, and healthcare utilization among women with hemochromatosis compared to those without.

RESULTS

Women with hemochromatosis exhibited a longer length of hospital stay (3.27 ± 0.20 days vs. 2.64 ± 0.04 days) and higher total hospital charges ($21,789.66 ± $1124.41 vs. $17,751.63 ± $97.71) compared to those without the condition. There was a significant increase in the prevalence of hemochromatosis among delivery hospitalizations over the studied period, from 1.91 per 100,000 hospitalizations to 8.65 cases per 100,000 hospitalizations. Hemochromatosis patients demonstrated a higher prevalence of hypertensive disorders of pregnancy (aOR: 1.50, 95 % CI: 1.03-2.19) and VTE(aOR: 20.35, 95 % CI: 5.05-82.05).There were no statistically significant differences in rates of peripartum hemorrhage, C-section, preterm birth, fetal growth restriction, large for gestational age infants, and fetal death between the two groups.

CONCLUSIONS

Our findings underscore higher hypertensive disorders of pregnancy and VTE among women with hemochromatosis, despite unaffected perinatal outcomes. An increasing trend in hemochromatosis prevalence highlights the need for targeted interventions and cost-effective management strategies. Future research is needed to explore potential racial disparities and understand the rising incidence of hemochromatosis among pregnant women.

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.

Interpreting Iron Homeostasis in Congenital and Acquired Disorders

Mammalian cells require iron to satisfy their metabolic needs and to accomplish specialized functions, such as hematopoiesis, mitochondrial biogenesis, energy metabolism, or oxygen transport. Iron homeostasis is balanced by the interplay of proteins responsible for iron import, storage, and export. A misbalance of iron homeostasis may cause either iron deficiencies or iron overload diseases. The clinical work-up of iron dysregulation is highly important, as severe symptoms and pathologies may arise. Treating iron overload or iron deficiency is important to avoid cellular damage and severe symptoms and improve patient outcomes. The impressive progress made in the past years in understanding mechanisms that maintain iron homeostasis has already changed clinical practice for treating iron-related diseases and is expected to improve patient management even further in the future.

Perinatal exposure to a glyphosate pesticide formulation induces offspring liver damage

The present study investigated the effects of perinatal exposure to glyphosate-based herbicide (GBH) in offspring's liver. Pregnant Wistar rats were exposed to GBH (70 mg glyphosate/Kg body weight/day) in drinking water from gestation day 5 to postnatal day 15. The perinatal exposure to GBH increased ⁴⁵Ca²⁺ influx in offspring's liver. Pharmacological tools indicated a role played by oxidative stress, phospholipase C (PLC) and Akt pathways, as well as voltage-dependent Ca²⁺ channel modulation on GBH-induced Ca²⁺ influx in offspring's liver. In addition, changes in the enzymatic antioxidant defense system, decreased GSH content, lipid peroxidation and protein carbonylation suggest a connection between GBH-induced hepatotoxic mechanism and redox imbalance. The perinatal exposure to GBH also increased the enzymatic activities of transaminases and gamma-glutamyl transferase in offspring's liver and blood, suggesting a pesticide-induced liver injury. Moreover, we detected increased iron levels in liver, blood and bone marrow of GBH-exposed rats, which were accompanied by increased transferrin saturation and decreased transferrin levels in blood. The levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were increased in the liver of rats perinatally exposed to GBH, which were associated with. Increased phospho-p65NFκB immunocontent. Therefore, we propose that excessive amounts of iron in offspring's liver, blood and bone marrow induced by perinatal exposure to GBH may account for iron-driven hepatotoxicity, which was associated with Ca²⁺ influx, oxidative damage and inflammation. Further studies will clarify whether these events can ultimately impact on liver function.

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.

Juvenile Hemochromatosis in an Asymptomatic Patient-Importance of Early Diagnosis

Juvenile hemochromatosis is a rare inherited disorder of iron regulation leading to iron overload, which usually presents before the age of 30. One of the most serious clinical characteristics associated with early-onset iron overload is liver disease with eventual cirrhosis, often associated with a reduced life expectancy even after treatment. This case report summarizes an asymptomatic pediatric patient with persistently elevated transaminase levels, which led to a diagnosis of juvenile hemochromatosis relatively early in the course of his disease. The aim of this case report is to increase awareness and stress the importance of early diagnosis and treatment, as it is vital to prevent life-threatening complications and optimize patient outcomes. Consideration should be taken to recognize potential manifestations despite the rarity of the condition. Patients with signs of hepatocellular injury without explanation should prompt evaluation including consideration for iron overload after other common causes are ruled out.

Runx3 regulates iron metabolism via modulation of BMP signalling

Objectives

Runx3, a member of the Runx family of transcription factors, has been studied as a tumour suppressor and key player of organ development. In a previous study, we reported differentiation failure and excessive angiogenesis in the liver of Runx3 knock‐out (KO) mice. Here, we examined a function of the Runx3 in liver, especially in iron metabolism.

Methods

We performed histological and immunohistological analyses of the Runx3 KO mouse liver. RNA‐sequencing analyses were performed on primary hepatocytes isolated from Runx3 conditional KO (cKO) mice. The effect of Runx3 knock‐down (KD) was also investigated using siRNA‐mediated KD in functional human hepatocytes and human hepatocellular carcinoma cells.

Result

We observed an iron‐overloaded liver with decreased expression of hepcidin in Runx3 KO mice. Expression of BMP6, a regulator of hepcidin transcription, and activity of the BMP pathway were decreased in the liver tissue of Runx3 KO mice. Transcriptome analysis on primary hepatocytes isolated from Runx3 cKO mice also revealed that iron‐induced increase in BMP6 was mediated by Runx3. Similar results were observed in Runx3 knock‐down experiments using HepaRG cells and HepG2 cells. Finally, we showed that Runx3 enhanced the activity of the BMP6 promoter by responding to iron stimuli in the hepatocytes.

Conclusion

In conclusion, we suggest that Runx3 plays important roles in iron metabolism of the liver through regulation of BMP signalling.

The impact of blood donation on blood counts and ferritin levels: A multi-center study from the Eastern Mediterranean region

Regular donation of whole blood may lead to iron deficiency. In this study, we aimed to assess the impact of frequent whole blood donation on hematological parameters. Whole blood donors were enrolled from four blood banks located in Saudi Arabia, United Arab Emirates (UAE), Libya and Oman, between 2016 and 2017. SPSS version 21.0 was used to generate descriptive and inferential statistics. A total number of 3096 blood donors were screened (males 93.8 %, females; 6.2 %), with a mean donor age of 35.29 ± 9.31 years. For male blood donors, the majority (1073) had 1-3 previous donations. Increased frequency of donations was significantly associated with increases in age and weight, decreases in Hemoglobin (Hb) and ferritin measures, and increases in Red Blood Cells (RBC) counts. A General Linear Model (GLM) adjusted for age and weight indicated negative impacts on White Blood Cells (WBC) counts and ferritin. A weak correlation between the Hb and ferritin levels was observed (r = 0.160, P > 0.001). For female donors, the majority (63 out of 114) were first time donors. Increased frequency of donations was significantly associated with an increase in age and a decrease in HCT readings. A GLM adjusted for age and weight indicated a negative impact on ferritin. A strong correlation was observed between the Hb and ferritin levels for the most frequent female donors (r = 0.636, P > 0.001). In conclusion, regular whole blood donation impacts hematological parameters in particular the levels of ferritin in the serum.

Comparing Care of the Primary and Secondary Hemochromatosis Patients

Hemochromatosis is an imbalance of excessive serum iron and is a life-threatening condition if left untreated. Due to different causes, primary and secondary hemochromatosis have different patient care considerations for the infusion nurse. Understanding the pathophysiology and how the body absorbs iron is imperative for providing the highest quality care. Since primary (hereditary) hemochromatosis originates from a gene mutation, and secondary (acquired) from excessive intake, the treatment and education must be adjusted accordingly to deliver successful outcomes for both diagnoses.

A predictive model for estimating the number of erythrocytapheresis or phlebotomy treatments for patients with naïve hereditary hemochromatosis

Background and Aims

Standard treatment for naïve hereditary hemochromatosis patients consists of phlebotomy or a personalized erythrocytapheresis. Erythrocytapheresis is more efficient, but infrequently used because of perceived costs and specialized equipment being needed. The main aim of our study was to develop a model that predicts the number of initial treatment procedures for both treatment methods. This information may help the clinician to select the optimal treatment modality for the individual patient.

Methods

We analyzed retrospective data of 125 newly diagnosed patients (C282Y homozygous), treated either with phlebotomy (n = 54) or erythrocytapheresis (n = 71) until serum ferritin (SF) reached levels ≤100 μg/L. To estimate the required number of treatment procedures multiple linear regression analysis was used for each treatment method separately.

Results

The linear regression model with the best predictive quality (R² = 0.74 and 0.73 for erythrocytapheresis and phlebotomy respectively) included initial SF, initial hemoglobin (Hb) level, age, and BMI, where initial SF was independently related to the total number of treatment procedures for both treatment methods. The prediction error expressed in RMSPE and RMSDR was lower for erythrocytapheresis than for phlebotomy (3.8 and 4.1 vs 7.0 and 8.0 respectively),

Conclusions

Although the prediction error of the developed model was relatively large, the model may help the clinician to choose the most optimal treatment method for an individual patient. Generally erythrocytapheresis halves the number of treatment procedures for all patients, where the largest reduction (between 55% and 64%) is reached in patients with an initial Hb level ≥ 9 mmol/L (14.5 g/dL).

ClinicalTrials.gov number NCT00202436.

Aspartate/asparagine-β-hydroxylase: a high-throughput mass spectrometric assay for discovery of small molecule inhibitors

The human 2-oxoglutarate dependent oxygenase aspartate/asparagine-β-hydroxylase (AspH) catalyses the hydroxylation of Asp/Asn-residues in epidermal growth factor-like domains (EGFDs). AspH is upregulated on the surface of malign cancer cells; increased AspH levels correlate with tumour invasiveness. Due to a lack of efficient assays to monitor the activity of isolated AspH, there are few reports of studies aimed at identifying small-molecule AspH inhibitors. Recently, it was reported that AspH substrates have a non-canonical EGFD disulfide pattern. Here we report that a stable synthetic thioether mimic of AspH substrates can be employed in solid phase extraction mass spectrometry based high-throughput AspH inhibition assays which are of excellent robustness, as indicated by high Z'-factors and good signal-to-noise/background ratios. The AspH inhibition assay was applied to screen approximately 1500 bioactive small-molecules, including natural products and active pharmaceutical ingredients of approved human therapeutics. Potent AspH inhibitors were identified from both compound classes. Our AspH inhibition assay should enable the development of potent and selective small-molecule AspH inhibitors and contribute towards the development of safer inhibitors for other 2OG oxygenases, e.g. screens of the hypoxia-inducible factor prolyl-hydroxylase inhibitors revealed that vadadustat inhibits AspH with moderate potency.

A case report of hereditary hemochromatosis caused by mutation of SLC40A1 gene

RATIONALE

Hereditary hemochromatosis (HH) is a frequent autosomal recessive disease. The pathogenesis of disease is excessive intestinal absorption of dietary iron, resulting in pathologically high iron storage in tissues and organs. As a systemic disease, it has several manifestations including cirrhosis, diabetes mellitus, cardiomyopathy, joint disease. However, a proportion of patients are asymptomatic.

PATIENT CONCERNS

A 34-year-old man who had abnormal liver function for 9 months without specific symptoms. He underwent various tests, including liver biopsy and genetic testing, which eventually ruled out common liver diseases and identified iron metabolic abnormalities. In addition, we confirmed the pathogenic genes by sequencing the genes of him and his families.

DIAGNOSIS

Combined with the symptoms, auxiliary examinations and sequencing results, the patient was diagnosed as HH.

INTERVENTIONS

The patient was given a low iron diet and phlebotomy therapy interval 2 weeks until the ferritin is <100 mg/L.

OUTCOMES

The patient' condition is stable during the follow-up period.

LESSONS

When clinicians are confronted with unexplained liver dysfunction, the possibility of the HH should be considered. Liver biopsy and gene sequencing are helpful in diagnosis. Phlebotomy treatment is the most economical and practical treatment for HH at present, but it should vary from person to person.

The Clinically Used Iron Chelator Deferasirox Is an Inhibitor of Epigenetic JumonjiC Domain-Containing Histone Demethylases

Fe(II)- and 2-oxoglutarate (2OG)-dependent JumonjiC domain-containing histone demethylases (JmjC KDMs) are "epigenetic eraser" enzymes involved in the regulation of gene expression and are emerging drug targets in oncology. We screened a set of clinically used iron chelators and report that they potently inhibit JMJD2A (KDM4A) in vitro. Mode of action investigations revealed that one compound, deferasirox, is a bona fide active site-binding inhibitor as shown by kinetic and spectroscopic studies. Synthesis of derivatives with improved cell permeability resulted in significant upregulation of histone trimethylation and potent cancer cell growth inhibition. Deferasirox was also found to inhibit human 2OG-dependent hypoxia inducible factor prolyl hydroxylase activity. Therapeutic effects of clinically used deferasirox may thus involve transcriptional regulation through 2OG oxygenase inhibition. Deferasirox might provide a useful starting point for the development of novel anticancer drugs targeting 2OG oxygenases and a valuable tool compound for investigations of KDM function.

Oxidative Stress in β-Thalassemia

Cell oxidative status, which represents the balance between oxidants and antioxidants, is involved in normal functions. Under pathological conditions, there is a shift toward the oxidants, leading to oxidative stress, which is cytotoxic, causing oxidation of cellular components that result in cell death and organ damage. Thalassemia is a hereditary hemolytic anemia caused by mutations in globin genes that cause reduced or complete absence of specific globin chains (commonly, α or β). Although oxidative stress is not the primary etiology of thalassemia, it mediates several of its pathologies. The main causes of oxidative stress in thalassemia are the degradation of the unstable hemoglobin and iron overload-both stimulate the production of excess free radicals. The symptoms aggravated by oxidative stress include increased hemolysis, ineffective erythropoiesis and functional failure of vital organs such as the heart and liver. The oxidative status of each patient is affected by multiple internal and external factors, including genetic makeup, health conditions, nutrition, physical activity, age, and the environment (e.g., air pollution, radiation). In addition, oxidative stress is influenced by the clinical manifestations of the disease (unpaired globin chains, iron overload, anemia, etc.). Application of personalized (theranostics) medicine principles, including diagnostic tests for selecting targeted therapy, is therefore important for optimal treatment of the oxidative stress of these patients. We summarize the role of oxidative stress and the current and potential antioxidative therapeutics in β-thalassemia and describe some methodologies, mostly cellular, that might be helpful for application of a theranostics approach to therapy.

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.

A novel SLC40A1 p.Y333H mutation with gain of function of ferroportin: A recurrent cause of haemochromatosis in China

BACKGROUND & AIMS

Haemochromatosis type 4, also known as ferroportin disease, is an autosomal dominant genetic disorder caused by pathogenic mutations in the SLC40A1 gene, which encodes ferroportin 1 (FPN1). We have identified a novel SLC40A1 p.Y333H mutation in our previous study. In the present study, we tried to investigate the frequency and pathogenicity of the SLC40A1 p.Y333H mutation in haemochromatosis in China.

METHODS

Patients were analysed for SLC40A1 p.Y333H as well as mutations in the other classic haemochromatosis-related genes by Sanger sequencing. To analyse iron export capacity of the SLC40A1 p.Y333H mutant, the 293T cells were transfected with the SLC40A1 p.Y333H construct and then treated with hepcidin after exposure to ferric ammonium citrate. Cellular localization of mutant FPN1, expression of FPN1 and intracellular ferritin were analysed by immunofluorescence and Western blotting.

RESULTS

Of 22 unrelated cases with primary iron overload, three cases (3/22, 13.6%) harboured the SLC40A1 p.Y333H, with no missense mutations identified in any other classical haemochromatosis-related genes including HFE, HJV, HAMP and TFR2. Pedigree analysis showed that three probands and the son of one proband had haemochromatosis of stage 3, while the son of another proband with age of 16 showed elevated transferrin saturation but normal serum ferritin level. In vitro studies showed the mutant p.Y333H ferroportin was resistant to hepcidin, affecting the subsequent internalization and degradation of FPN1, and was associated with ferroportin gain of function.

CONCLUSIONS

The SLC40A1 p.Y333H mutation is associated with gain of function of ferroportin, representing one of the major aetiological factors of haemochromatosis in China.

Tuning the Anti(myco)bacterial Activity of 3-Hydroxy-4-pyridinone Chelators through Fluorophores

Controlling the sources of Fe available to pathogens is one of the possible strategies that can be successfully used by novel antibacterial drugs. We focused our interest on the design of chelators to address Mycobacterium avium infections. Taking into account the molecular structure of mycobacterial siderophores and considering that new chelators must be able to compete for Fe(III), we selected ligands of the 3-hydroxy-4-pyridinone class to achieve our purpose. After choosing the type of chelating unit it was also our objective to design chelators that could be monitored inside the cell and for that reason we designed chelators that could be functionalized with fluorophores. We didn’t realize at the time that the incorporation a fluorophore, to allow spectroscopic detection, would be so relevant for the antimycobacterial effect or to determine the affinity of the chelators towards biological membranes. From a biophysical perspective, this is a fascinating illustration of the fact that functionalization of a molecule with a particular label may lead to a change in its membrane permeation properties and result in a dramatic change in biological activity. For that reason we believe it is interesting to give a critical account of our entire work in this area and justify the statement “to label means to change”. New perspectives regarding combined therapeutic approaches and the use of rhodamine B conjugates to target closely related problems such as bacterial resistance and biofilm production are also discussed.

Food deprivation increases hepatic hepcidin expression and can overcome the effect of Hfe deletion in male mice

Iron-loading disorders, such as hereditary hemochromatosis, are associated with inappropriately low expression of the iron regulatory hormone, hepcidin. A recent study has demonstrated that food deprivation can increase hepcidin production in mice. We have examined this effect in more detail to determine whether the pathway(s) that are responsible might provide novel targets for pharmaceutical intervention in disorders of iron homeostasis. C57BL/6 mice were deprived of food for 5, 10, 16, or 24 h before euthanasia, then blood and tissue samples were collected for analysis. The effect of food deprivation was also examined in Hfe-/- mice, a model of hereditary hemochromatosis, as well as mice that were maintained on an iron-deficient diet or injected with erythropoietin. Food deprivation increased the hepatic expression of the gene that encodes hepcidin, hepcidin antimicrobial peptide 1 ( Hamp1), with maximal expression observed after 16 h, and was able to overcome the reduction in Hamp1 expression associated with Hfe deficiency. Food deprivation also increased Hamp1 expression in response to stimuli that more strongly suppress the gene, such as iron deficiency and erythropoietin treatment, but the effects were not significant. These results indicate that Hamp1 induction by food deprivation is independent of HFE and suggest that targeting the pathway regulated by food deprivation could have clinical benefit in iron-loading conditions.-Mirciov, C. S. G., Wilkins, S. J., Anderson, G. J., Frazer, D. M. Food deprivation increases hepatic hepcidin expression and can overcome the effect of Hfe deletion in male mice.

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.

Pathophysiology and treatment of patients with beta-thalassemia - an update

Thalassemia (thal) is an autosomal recessive, hereditary, chronic hemolytic anemia due to a partial or complete deficiency in the synthesis of α-globin chains (α-thal) or β-globin chains (β-thal) that compose the major adult hemoglobin (α ₂β _2). It is caused by one or more mutations in the corresponding genes. The unpaired globin chains are unstable; they precipitate intracellularly, resulting in hemolysis, premature destruction of red blood cell [RBC] precursors in the bone marrow, and a short life-span of mature RBCs in the circulation. The state of anemia is treated by frequent RBC transfusions. This therapy results in the accumulation of iron (iron overload), a condition that is exacerbated by the breakdown products of hemoglobin (heme and iron) and the increased iron uptake for the chronic accelerated, but ineffective, RBC production. Iron catalyzes the generation of reactive oxygen species, which in excess are toxic, causing damage to vital organs such as the heart and liver and the endocrine system. Herein, we review recent findings regarding the pathophysiology underlying the major symptoms of β-thal and potential therapeutic modalities for the amelioration of its complications, as well as new modalities that may provide a cure for the disease.

Excess iron: considerations related to development and early growth

What effects might arise from early life exposures to high iron? This review considers the specific effects of high iron on the brain, stem cells, and the process of erythropoiesis and identifies gaps in our knowledge of what molecular damage may be incurred by oxidative stress that is imparted by high iron status in early life. Specific areas to enhance research on this topic include the following: longitudinal behavioral studies of children to test associations between iron exposures and mood, emotion, cognition, and memory; animal studies to determine epigenetic changes that reprogram brain development and metabolic changes in early life that could be followed through the life course; and the establishment of human epigenetic markers of iron exposures and oxidative stress that could be monitored for early origins of adult chronic diseases. In addition, efforts to understand how iron exposure influences stem cell biology could be enhanced by establishing platforms to collect biological specimens, including umbilical cord blood and amniotic fluid, to be made available to the research community. At the molecular level, there is a need to better understand stress erythropoiesis and changes in iron metabolism during pregnancy and development, especially with respect to regulatory control under high iron conditions that might promote ineffective erythropoiesis and iron-loading anemia. These investigations should focus not only on factors such as hepcidin and erythroferrone but should also include newly identified interactions between transferrin receptor-2 and the erythropoietin receptor. Finally, despite our understanding that several key micronutrients (e.g., vitamin A, copper, manganese, and zinc) support iron's function in erythropoiesis, how these nutrients interact remains, to our knowledge, unknown. It is necessary to consider many factors when formulating recommendations on iron supplementation.

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.

The mechanisms of systemic iron homeostasis and etiology, diagnosis, and treatment of hereditary hemochromatosis

Hereditary hemochromatosis (HH) is a group of genetic iron overload disorders that manifest with various symptoms, including hepatic dysfunction, diabetes, and cardiomyopathy. Classic HH type 1, which is common in Caucasians, is caused by bi-allelic mutations of HFE. Severe types of HH are caused by either bi-allelic mutations of HFE2 that encodes hemojuvelin (type 2A) or HAMP that encodes hepcidin (type 2B). HH type 3, which is of intermediate severity, is caused by bi-allelic mutations of TFR2 that encodes transferrin receptor 2. Mutations of SLC40A1 that encodes ferroportin, the only cellular iron exporter, causes either HH type 4A (loss-of-function mutations) or HH type 4B (gain-of-function mutations). Studies on these gene products uncovered a part of the mechanisms of the systemic iron regulation; HFE, hemojuvelin, and TFR2 are involved in iron sensing and stimulating hepcidin expression, and hepcidin downregulates the expression of ferroportin of the target cells. Phlebotomy is the standard treatment for HH, and early initiation of the treatment is essential for preventing irreversible organ damage. However, because of the rarity and difficulty in making the genetic diagnosis, a large proportion of patients with non-HFE HH might have been undiagnosed; therefore, awareness of this disorder is important.