Iron and the Pathophysiology of Diabetes.

High iron is a risk factor for type 2 diabetes mellitus (T2DM) and affects most of its cardinal features: decreased insulin secretion, insulin resistance, and increased hepatic gluconeogenesis. This is true across the normal range of tissue iron levels and in pathologic iron overload. Because of iron's central role in metabolic processes (e.g., fuel oxidation) and metabolic regulation (e.g., hypoxia sensing), iron levels participate in determining metabolic rates, gluconeogenesis, fuel choice, insulin action, and adipocyte phenotype. The risk of diabetes related to iron is evident in most or all tissues that determine diabetes phenotypes, with the adipocyte, beta cell, and liver playing central roles. Molecular mechanisms for these effects are diverse, although there may be integrative pathways at play. Elucidating these pathways has implications not only for diabetes prevention and treatment, but also for the pathogenesis of other diseases that are, like T2DM, associated with aging, nutrition, and iron.

Hemochromatosis drives acute lethal intestinal responses to hyperyersiniabactin-producing Yersinia pseudotuberculosis.

Hemachromatosis (iron-overload) increases host susceptibility to siderophilic bacterial infections that cause serious complications, but the underlying mechanisms remain elusive. The present study demonstrates that oral infection with hyperyersiniabactin (Ybt) producing Yersinia pseudotuberculosis Δfur mutant (termed Δfur) results in severe systemic infection and acute mortality to hemochromatotic mice due to rapid disruption of the intestinal barrier. Transcriptome analysis of Δfur-infected intestine revealed up-regulation in cytokine-cytokine receptor interactions, the complement and coagulation cascade, the NF-κB signaling pathway, and chemokine signaling pathways, and down-regulation in cell-adhesion molecules and Toll-like receptor signaling pathways. Further studies indicate that dysregulated interleukin (IL)-1ß signaling triggered in hemachromatotic mice infected with Δfur damages the intestinal barrier by activation of myosin light-chain kinases (MLCK) and excessive neutrophilia. Inhibiting MLCK activity or depleting neutrophil infiltration reduces barrier disruption, largely ameliorates immunopathology, and substantially rescues hemochromatotic mice from lethal Δfur infection. Moreover, early intervention of IL-1ß overproduction can completely rescue hemochromatotic mice from the lethal infection.

Differences in bone microarchitecture between genetic and secondary iron-overload mouse models suggest a role for hepcidin deficiency in iron-related osteoporosis.

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

Adverse effects of therapeutic phlebotomies: Prospective study of 587 procedures.

BACKGROUND: Therapeutic phlebotomy (TP), a widely used medical procedure, can be performed on diverse patients with iron overload or polyglobulia. However, its adverse events are not well known as most of the information on phlebotomy is derived from healthy blood donors (0.1%-5.3%). In contrast, TP is applicable to a broader, more complex population with comorbidities and old age. To ascertain the incidence of adverse events in phlebotomies, we conducted a prospective study on patients who attended our Unit. STUDY DESIGN AND METHODS: We prospectively gathered data from patients referred to our Unit for TP. Data regarding demographics, health status, and adverse events within at least 24 h of phlebotomy were gathered via a structured questionnaire during each visit. RESULTS: Between August 2021 and September 2022, 189 patients underwent 587 procedures. Most patients were men, over 60 (57.3%) had comorbidities, and 93% underwent at least two procedures during the study period. Twenty patients (10.8%) presented 25 adverse events (4.3% of phlebotomies), usually vasovagal reactions, none of which were clinically relevant, and all were managed by nursing staff on site, with full patient recovery. DISCUSSION: The rate of adverse events (<5%) in patients undergoing TP was low and comparable to that seen in healthy blood donors. Consequently, even old patients and those with some comorbidities can safely undergo TP when the process is carefully managed.

Hereditary hemochromatosis with homozygous C282Y HFE mutation: possible clinical model to assess effects of elevated reactive oxygen species on the development of cardiovascular disease.

Hereditary hemochromatosis with the homozygous C282Y HFE mutation (HH-282H) is a genetic condition which causes iron overload (IO) and elevated reactive oxygen species (ROS) secondary to the IO. Interestingly, even after successful iron removal therapy, HH-282H subjects demonstrate chronically elevated ROS. Raised ROS are also associated with the development of multiple cardiovascular diseases and HH-282H subjects may be at risk to develop these complications. In this narrative review, we consider HH-282H subjects as a clinical model for assessing the contribution of elevated ROS to the development of cardiovascular diseases in subjects with fewer confounding clinical risk factors as compared to other disease conditions with high ROS. We identify HH-282H subjects as a potentially unique clinical model to assess the impact of chronically elevated ROS on the development of cardiovascular disease and to serve as a clinical model to detect effective interventions for anti-ROS therapy.

The clinical management of porphyria cutanea tarda: An update.

Porphyria cutanea tarda (PCT) is the commonest of the porphyrias (Semin Liver Dis 1998;18:67). It often occurs secondary to an underlying internal disorder, has significant impacts on liver health and longevity, and is a treatable disease. Thus, for the clinician, recognising the disease to make the correct diagnosis, identifying causative underlying diseases, and treating the porphyria and its complications, are crucial. Although reviews on the management of PCT have been written, there have recently been significant advances in the understanding of the factors predisposing to the disease, and of its wider health impacts. This review aims to help the clinician to diagnose and manage patients with PCT, with an emphasis on the impact of recent advances on clinical management.

Iron overload disorders: Growth and gonadal dysfunction in childhood and adolescence.

Hemochromatosis (HC) is characterized by the progressive accumulation of iron in the body, resulting in organ damage. Endocrine complications are particularly common, especially when the condition manifests in childhood or adolescence, when HC can adversely affect linear growth or pubertal development, with significant repercussions on quality of life even into adulthood. Therefore, a timely and accurate diagnosis of these disorders is mandatory, but sometimes complex for hematologists without endocrinological support. This is a narrative review focused on puberty and growth disorders during infancy and adolescence aiming to offer guidance for diagnosis, treatment, and proper follow-up. Additionally, it aims to highlight gaps in the existing literature and emphasizes the importance of collaboration among specialists, which is essential in the era of precision medicine.

Novel mutation of transferrin receptor 2 causing hereditary hemochromatosis type 3 in a Japanese patient.

Hereditary hemochromatosis (HH) is recognized as a progressive iron-storage disorder, and leading to severe organ impairments, including liver cirrhosis. Hereditary hemochromatosis type 3 arises from mutations in the transferrin receptor 2 (TFR2) gene. However, HH type 3 is rare in Asia, and information regarding genetic mutations and associated phenotypes remains limited. Here, we reported the case of a Japanese patient with HH type 3, with a novel homozygous mutation of the TFR2 gene. A 69-year-old woman presented to our hospital with hand joint pain and was referred due to liver impairment. Viral hepatitis and autoimmune liver diseases were ruled out. However, the transferrin saturation was 92.2%, and the serum ferritin level was 1611.8 ng/mL. Additionally, abdominal computed tomography showed diffuse increased density of the liver parenchyma. Abdominal magnetic resonance imaging also suggested iron deposition. There is no history of prior treatments involving blood transfusions or iron agents. Her parents were involved in a consanguineous marriage, prompting genetic testing. She had a homozygous novel mutation, c.1337G>A (p.G446E), in the TFR2 gene. Serum hepcidin-25 level was decreased to 2.9 ng/mL. According to the American Society of Medical Genetics and Genomics guideline, the mutation was classified as likely pathogenic, leading to the diagnosis of HH type 3. Following phlebotomy, her arthritis resolved, and serum transaminase levels were normalized. This case marks the first demonstration of homozygous mutation, c.1337G>A (p.G446E), in the TFR2 gene in patients with HH type 3.

Clinical characteristics and outcomes of acute liver failure in neonates: a retrospective cohort in China.

Neonatal acute liver failure (NALF), as a rare disease with high mortality, has limited relevant literature reports in China. We attempted to analyze a NALF cohort to improve the prognosis of this disease. We included all patients diagnosed with NALF at our institution between 2016 and 2021 and retrospectively reviewed their electronic records. NALF was defined as an INR ≥ 2.0 due to liver disease 28 days after birth. Comparisons were made according to etiology and outcome. The Kaplan-Meier method was used to estimate survival. Fifty-eight patients were included in this study. Etiologies included hypoxic/ischemic injury (29.3%), infection (27.6%), gestational alloimmune liver disease with neonatal hemochromatosis (GALD-NH) (10.3%), inherited metabolic diseases (5.2%), hemophagocytic lymphohistiocytosis (1.7%), other etiologies (12.1%), and unidentified causes (13.8%). Enteroviruses constituted 87.5% of the viral infections, whereas herpes simplex virus accounted for no infections. The median INR was significantly lower in the infection group than in the GALD-NH group (P < 0.05 for multiple comparisons). At the last follow-up, none of the patients had undergone liver transplantation, and the overall mortality rate was 50%. Liver function completely recovered in 31% of the patients, all of whom survived. The overall median survival time was 48 days; 26 days for hypoxic/ischemic injury and 43 days for GALD-NH. The incidence of cholestasis was significantly greater among surviving patients (P = 0.018).   Conclusion: Hypoxic/ischemic injury and infection are the predominant etiologies of NALF in China. The overall prognosis of NALF is poor, but its short-term prognosis is determined by the etiology. What is Known: • Neonatal acute liver failure (NALF) is a rare disorder with limited cohort studies, especially in China. • Gestational alloimmune liver disease, viral infections (especially herpes simplex virus), metabolic diseases and ischemic insults are common etiologies of NALF, which are significantly different from other populations. • There are no reliable biochemical markers to predict the outcome of NALF. What is New: • In this first report on a Chinese NALF cohort, we demonstrate that hypoxic/ischemic injury and infection (excluding herpes simplex virus) are the predominant etiologies of NALF. • The overall prognosis of NALF is poor, and its etiology determines the short-term outcome.

Eicosanoids and Oxylipin Signature in Hereditary Hemochromatosis Patients Are Similar to Dysmetabolic Iron Overload Syndrome Patients but Are Impacted by Dietary Iron Absorption.

INTRODUCTION: Oxylipins are mediators of oxidative stress. To characterize the underlying inflammatory processes and phenotype effect of iron metabolism disorders, we investigated the oxylipin profile in hereditary hemochromatosis (HH) and dysmetabolic iron overload syndrome (DIOS) patients. METHODS: An LC-MS/MS-based method was performed to quantify plasma oxylipins in 20 HH and 20 DIOS patients in fasting conditions and 3 h after an iron-rich meal in HH patients. RESULTS: Principal component analysis showed no separation between HH and DIOS, suggesting that the clinical phenotype has no direct impact on oxylipin metabolism. 20-HETE was higher in DIOS and correlated with hypertension (p = 0.03). Different oxylipin signatures were observed in HH before and after the iron-rich meal. Discriminant oxylipins include epoxy fatty acids derived from docosahexaenoic acid and arachidonic acid as well as 13-HODE and 9-HODE. Mediation analysis found no major contribution of dietary iron absorption for 16/22 oxylipins significantly affected by the meal. DISCUSSION: The oxylipin profiles of HH and DIOS seemed similar except for 20-HETE, possibly reflecting different hypertension prevalence between the two groups. Oxylipins were significantly affected by the iron-rich meal, but the specific contribution of iron was not clear. Although iron may contribute to oxidative stress and inflammation in HH and DIOS, this does not seem to directly affect oxylipin metabolism.

The relationship between liver stiffness by two-dimensional shear wave elastography and iron overload status in transfusion-dependent patients.

Increased liver stiffness (LS) can be result of increased liver iron concentration (LIC) which may not yet be reflected in the liver fibrotic status. The objective of our study was to examine relationship between hemochromatosis, LS, and serum ferritin level in transfusion-dependent patients. We recruited all 70 transfusion-dependent patients, whose median age was 15, referred for evaluating LIC status by magnetic resonance imaging (MRI) followed by two-dimensional ultrasonography shear wave elastography (2D-SWE). Thalassemia beta affected the majority of the patients. The optimal cut point for prediction of severe hemochromatosis using median SWE (kPa) and SWV (m/s) was ≥ 7.0 kPa and ≥ 1.54 m/s, respectively, with sensitivity of 0.76 (95% confidence interval [CI] 0.55, 0.91) and, specificity of 0.69 (95%CI 0.53, 0.82). When combing the optimal cut point of SWE (kPa) at ≥ 7.0 and serum ferritin ≥ 4123 ng/mL, the sensitivity increased to 0.84 (95%CI 0.64, 0.95) with specificity of 0.67 (95%CI 0.50, 0.80), positive predictive value (PPV) of 0.60 (95%CI 0.42, 0.76), and negative predictive value (NPV) of 0.88 (95%CI 0.71, 0.96). Simultaneous tests of 2D-SWE and serum ferritin for prediction of severe hemochromatosis showed the highest sensitivity of 84% (95%CI 0.64-0.95), as compared to 2D-SWE alone at 76% (95%CI 0.55, 0.91) or serum ferritin alone at 44% (95%CI 0.24-0.65). We recommend measuring both 2D-SWE and serum ferritin in short interval follow up patients. Adding 2D-SWE to management guideline will help in deciding for aggressive adjustment of iron chelating medication and increased awareness of patients having severe hemochromatosis.

Copper, Iron, Cadmium, and Arsenic, All Generated in the Universe: Elucidating Their Environmental Impact Risk on Human Health Including Clinical Liver Injury.

Humans are continuously exposed to various heavy metals including copper, iron, cadmium, and arsenic, which were specifically selected for the current analysis because they are among the most frequently encountered environmental mankind and industrial pollutants potentially causing human health hazards and liver injury. So far, these issues were poorly assessed and remained a matter of debate, also due to inconsistent results. The aim of the actual report is to thoroughly analyze the positive as well as negative effects of these four heavy metals on human health. Copper and iron are correctly viewed as pollutant elements essential for maintaining human health because they are part of important enzymes and metabolic pathways. Healthy individuals are prepared through various genetically based mechanisms to maintain cellular copper and iron homeostasis, thereby circumventing or reducing hazardous liver and organ injury due to excessive amounts of these metals continuously entering the human body. In a few humans with gene aberration, however, liver and organ injury may develop because excessively accumulated copper can lead to Wilson disease and substantial iron deposition to hemochromatosis. At the molecular level, toxicities of some heavy metals are traced back to the Haber Weiss and Fenton reactions involving reactive oxygen species formed in the course of oxidative stress. On the other hand, cellular homeostasis for cadmium and arsenic cannot be provided, causing their life-long excessive deposition in the liver and other organs. Consequently, cadmium and arsenic represent health hazards leading to higher disability-adjusted life years and increased mortality rates due to cancer and non-cancer diseases. For unknown reasons, however, liver injury in humans exposed to cadmium and arsenic is rarely observed. In sum, copper and iron are good for the human health of most individuals except for those with Wilson disease or hemochromatosis at risk of liver injury through radical formation, while cadmium and arsenic lack any beneficial effects but rather are potentially hazardous to human health with a focus on increased disability potential and risk for cancer. Primary efforts should focus on reducing the industrial emission of hazardous heavy metals.

Hemochromatosis: Ferroptosis, ROS, Gut Microbiome, and Clinical Challenges with Alcohol as Confounding Variable.

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

Might nontransferrin-bound iron in blood plasma and sera be a nonproteinaceous high-molecular-mass FeIII aggregate?

The HFE (Homeostatic Fe regulator) gene is commonly mutated in hereditary hemochromatosis. Blood of (HFE)(-/-) mice and of humans with hemochromatosis contains toxic nontransferrin-bound iron (NTBI) which accumulates in organs. However, the chemical composition of NTBI is uncertain. To investigate, HFE(-/-) mice were fed iron-deficient diets supplemented with increasing amounts of iron, with the expectation that NTBI levels would increase. Blood plasma was filtered to obtain retentate and flow-through solution fractions. Liquid chromatography detected by inductively coupled plasma mass spectrometry of flow-through solutions exhibited low-molecular-mass iron peaks that did not increase intensity with increasing dietary iron. Retentates yielded peaks due to transferrin (TFN) and ferritin, but much iron in these samples adsorbed onto the column. Retentates treated with the chelator deferoxamine (DFO) yielded a peak that comigrated with the Fe-DFO complex and originated from iron that adhered to the column in the absence of DFO. Additionally, plasma from younger and older 57Fe-enriched HFE mice were separately pooled and concentrated by ultrafiltration. After removing contributions from contaminating blood and TFN, Mössbauer spectra were dominated by features due to magnetically interacting FeIII aggregates, with greater intensity in the spectrum from the older mice. Similar features were generated by adding 57FeIII to "pseudo plasma". Aggregation was unaffected by albumin or citrate at physiological concentrations, but DFO or high citrate concentrations converted aggregated FeIII into high-spin FeIII complexes. FeIII aggregates were retained by the cutoff membrane and adhered to the column, similar to the behavior of NTBI. A model is proposed in which FeII entering blood is oxidized, and if apo-TFN is unavailable, the resulting FeIII ions coalesce into FeIII aggregates, a.k.a. NTBI.

Physiopathological changes of ferritin mRNA density and distribution in hippocampal astrocytes in the mouse brain.

Astrocytes are thought to play a crucial role in brain iron homeostasis. How they accomplish this regulation in vivo is unclear. In a recent transcriptomic analysis, we showed that polysomal Ftl1 and Fth1 mRNAs, encoding the ferritin light (Ftl) and heavy (Fth) chains that assemble into ferritin, a critical complex for iron storage and reduction, are enriched in perisynaptic astrocytic processes as compared to astrocytic soma. These data suggested that ferritin translation plays a specific role at the perisynaptic astrocytic interface and is tighly regulated by local translation. Here, we used our recently described AstroDot 3D in situ methodology to study the density and localization of ferritin mRNAs in astrocytes in the hippocampus in three different contexts in which local or systemic iron overload has been documented: aging, the hepcidin knock-out mouse model of hemochromatosis and the APP/PS1dE9 mouse model of Alzheimer's disease (AD). Our results showed that in wild type mice, Fth1 mRNA density was higher than Ftl1 and that both mRNAs were mostly distributed in astrocyte fine processes. Aging and absence of hepcidin caused an increased Fth1/Ftl1 ratio in astrocytes and in the case of aging, led to a redistribution of Fth1 mRNAs in astrocytic fine processes. In contrast, in AD mice, we observed a lower Fth1/Ftl1 ratio. Fth1 mRNAs became more somatic and Ftl1 mRNAs redistributed in large processes of astrocytes proximal to Amyloid beta (Aß) deposits. Hence, we propose that regulation of ferritin mRNA density and distribution in astrocytes contribute to iron homeostasis in physiology and pathophysiology.

Predisposing factors for advanced liver fibrosis in patients with sickle cell disease.

Sickle cell disease (SCD) is one of the most common monogenic disorders worldwide and liver complications are common in this group of patients. Our study aims to highlight the prevalence of chronic liver complications and the main predisposing factors for advanced liver fibrosis in SCD patients. For this purpose, 219 patients from eight Thalassemia and Sickle Cell Units across Greece enrolled in our study and history of liver related disease complications was recorded, as well as a full laboratory and imaging analysis concerning their liver function. 13.6% of the patients had advanced liver fibrosis. The presence of liver fibrosis was significantly correlated with advanced age, male gender, cholelithiasis and higher LDH, γ-GT, INR, direct and indirect bilirubin levels. These patients had exhibited significantly more episodes of liver crises and acute intrahepatic cholestasis. No correlation was observed with right heart failure or previous viral hepatitis. Patients with advanced liver fibrosis were receiving a more intensive transfusion therapy for a longer period of time and had higher Liver Iron Concentration levels. Our study shows that liver complications and cirrhosis is a significant cause of morbidity in patients with SCD and it is primarily associated with intravascular hemolysis and vaso-occlusive phenomena and secondarily with iron overload.

Analysis of Hand Joint Space Morphology in Women and Men with Hereditary Hemochromatosis.

Hereditary hemochromatosis (HH) causes unbalanced iron deposition in many organs including the joints leading to severe cartilage loss and bone damage in the metacarpophalangeal joints (MCPJ). High-resolution peripheral quantitative computed tomography (HR-pQCT) and its joint space width (JSW) quantification algorithm quantifies in vivo 3D joint morphology. We therefore aimed to (i) determine feasibility and performance of the JSW algorithm in HH, (ii) quantify joint space morphology, and (iii) investigate the relationship between morphological and clinical parameters in HH. Here, we performed an exploratory study on 24 HH patients and sex- and age-matched controls using HR-pQCT imaging of MCPJ. Mineralized bone structure was automatically segmented from the grayscale image data and periosteal surface bone masks and joint space masks were generated. Mean, minimal, and maximal joint space width (JSW; JSW.MIN; JSW.MAX), JSW heterogeneity (JSW.SD), JSW asymmetry (JSW.AS), and joint space volume (JSV) were computed. Demographics and, for HH patients, disease-specific parameters were recorded. Segmentation of JS was very good with 79.7% of MCPJs successfully segmented at first attempt and 20.3% requiring semi-manual correction. HH men showed larger JSV at all MCPs (+ 25.4% < JSV < + 41.8%, p < 0.05), larger JSW.MAX at MCP 3-4 (+ 14%, 0.006 < p < 0.062), and wider JSW (+ 13%, p = 0.043) at MCP 4 relative to HH women. Compared to controls, both HH men and HH women showed larger JSW.AS and smaller JSW.MIN at all MCP levels, reaching significance for HH men at MCP 2 and 3 (JSW.AS: + 323% < JSW.AS < + 359%, 0.020 < p < 0.043; JSW.MIN: - 216% < JSW.MIN < - 225%, p < 0.043), and for women at MCP 3 (JSW.AS: + 180%, p = 0.025; JSW.MIN: - 41.8%, p = 0.022). Time since HH diagnosis was correlated positively with MCP 4 JSW.AS and JSW.SD (0.463 < ρ < 0.499, p < 0.040), and the number of phlebotomies since diagnosis was correlated with JSW.SD at all MCPs (0.432 < ρ < 0.535, p < 0.050). HR-pQCT-based JSW quantification in MCPJ of HH patients is feasible, performs well even in narrow JS, and allows to define the microstructural joint burden of HH.

Oral Non-absorbable Polymer-Deferoxamine Conjugates for Reducing Dietary Iron Absorption.

Hereditary hemochromatosis (HH) is a non-transfusional genetic iron overload (IO) disease wherein patients are not able to regulate dietary iron absorption, which ultimately leads to excess cellular iron accumulation. Preventative measures for HH mainly include phlebotomy and asking patients to minimize dietary iron intake. To investigate alternative iron reduction strategies, we report on prophylactic non-absorbable polymer-deferoxamine (DFO) conjugates capable of chelating and reducing excessive gut uptake of dietary iron. Three different sizes of the conjugates (56 nm, 256 nm, and 7.4 µm) were prepared, and their physicochemical properties, transit times in the gut under fed/fasted conditions, acute safety, and efficacy at reducing iron absorption in a dietary iron-overload mouse model were investigated. The conjugates were synthesized through reverse phase water-in-oil (w/o) emulsions, followed by conjugation of DFO to the resulting polymer scaffolds. In vitro studies using Caco-2 transwell assays showed that the conjugates could not permeate across the monolayer, were poorly endocytosed, and did not induce cellular toxicity. In vivo mouse studies via oral gavage demonstrated that polymer-DFO conjugates remained in the gastrointestinal (GI) tract for up to 12 h and significantly prevented escalation of serum ferritin levels and excess liver iron accumulation. Ex vivo images of the duodenum suggest that nanometer-sized conjugates (56 and 246 nm) perform better at chelating dietary iron based on longer retention times (i.e., entrapment in the villi of the duodenum) and an overall slower transit from the GI tract compared to larger micron-sized (7.4 µm) conjugates. Overall, nanometer-sized polymer-DFO conjugates were orally non-absorbable, appeared safe, and were more efficacious at reducing dietary iron absorption when taken with non-heme containing food.

Early adaptive responses in the skeletal muscle of young mice with hereditary hemochromatosis.

BACKGROUND: Hereditary hemochromatosis (HH) is characterized by iron overload that can cause multiple organ dysfunction primarily due to uncontrolled iron-mediated oxidative stress. Although HH leads to muscular weakness, disorder, and fatigue, the mechanism by which HH affects skeletal muscle physiology is largely unknown. METHODS: Using Hfe knockout mice (6-7 months old), a well-defined mouse model of HH, we examined iron status in the skeletal muscle, as well as other organs. As mitochondria are key organelle for muscular function, this study also explored how molecular markers for mitochondrial function and related systems are regulated in the HH skeletal muscle using western blots. RESULTS: Although iron overload was evident at the systemic level, only mild iron overload was observed in the skeletal muscle of HH. Of note, mitochondrial electron transport chain complex I was upregulated in the HH skeletal muscle, which was accompanied by enhanced autophagy. However, these molecular changes were not associated with oxidative stress, suggesting altered mitochondrial metabolism in the muscle in response to iron overload. CONCLUSIONS: These early adaptive responses may be important for supporting mitochondrial health before fully developing skeletal muscle dysfunction in HH. More studies are needed to determine the role of autophagy in the HH-related muscle mitochondrial dysfunction.

Risk of Hepatocellular Carcinoma in Patients with Various HFE Genotypes.

BACKGROUND AND AIMS: Hereditary hemochromatosis (HH) is associated with increased risk of hepatocellular carcinoma (HCC). However, HCC risk factors within this population and across various HFE genotypes remain unclear. METHODS: We conducted a retrospective cohort study of patients with ≥ 1 HFE genotype test in the Veterans Health Administration. We followed patients until HCC, death, or 6/30/19. We calculated incidence rates (IRs) and used Cox proportional hazards models to estimate HCC risk. In patients with type-1 HH genotypes (C282Y/C282Y or C282Y/H63D), we examined risk factors for HCC. RESULTS: We identified 5225 patients: 260 were C282Y/C282Y; 227 were C282Y/H63D; 436 were H63D heterozygous; 535 had other HFE mutations; 3767 without mutation. IR for C282Y/C282Y homozygotes (5.59/1000 PYs) and C282Y/H63D compound heterozygotes (4.12/1000 PYs) were significantly higher than controls (0.92/1000 PYs) with adjusted hazard ratio (adj HR), 95% CI 8.80, 4.17-18.54; and 5.25, 2.24-12.32, respectively. HCC risk was higher in H63D heterozygote than controls (adj HR = 2.82, 95% CI 1.21-6.58); cases were related to non-alcoholic fatty liver disease. Among patients with HH, age ≥ 65 (adj HR = 2.2, 95% CI 0.47-10.27), diabetes (adj HR 3.74, 95% CI 1.25-11.20) and high baseline aspartate-aminotransferase to platelet ratio-index (APRI, adj HR = 3.91, 95% CI 1.29-11.89) had higher risk. Among patients with high baseline ferritin, persistent ferritin > 250 ng/mL had higher risk. CONCLUSION: HCC risk was high in C282Y homozygous and C282Y/H63D patients. These HFE genotypes, older age, diabetes, high APRI/ferritin levels were associated with increased risk. While H63D heterozygous genotype was associated with HCC risk, this association might be due to metabolic factors.