Hepatic Iron Loading Research Articles

Relationship Between Hepatic Iron Concentration and Glycemic Metabolism, Prediabetes, and Type 2 Diabetes: A Systematic Review.

Emerging research has suggested a potential link between high iron levels, indicated by serum ferritin levels, and the development of type 2 diabetes (T2D). However, the role of hepatic iron concentration (HIC) on T2D development and progression is not well understood. This study aims to systematically review the literature on HIC and/or the degree of hepatic iron overload (HIO) in individuals with prediabetes and/or diagnosed T2D, and to analyze associations between HIC and markers of glucose metabolism. The databases Medline, PubMed, Embase, CINAHL, and Web of Knowledge were searched for studies published in English from 1999 to March 2024. This review followed the Preferred Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Data were extracted following the established eligibility criteria. Study characteristics and biomarkers related to prediabetes, T2D, and HIO were extracted. The risk of bias was analyzed using the Newcastle-Ottawa Scale. Data were stratified by the exposure and analyzed in subgroups according to the outcome. Data regarding the HIC values in controls, individuals with prediabetes, and individuals with T2D and the association estimates between HIC or HIO and markers of glycemic metabolism, prediabetes, or T2D were extracted. A total of 12 studies were identified, and data from 4110 individuals were analyzed. HIO was not consistently observed in prediabetic/T2D populations; however, elevated HIC was frequently observed in prediabetic and T2D individuals, and was associated with the disruption of certain glycemic markers in some cases. The extent of iron overload, as indicated by hepatic iron load, varied among the prediabetic and T2D populations studied. Further research is needed to understand the distribution and regulation of iron in T2D pathology.

Extrahepatic Iron Loading Associates With the Propensity to Develop Advanced Hepatic Fibrosis in Hemochromatosis

Hemostatic iron regulator-hemochromatosis can result in progressive iron-loading and advanced hepatic fibrosis in some individuals. We studied total body and hepatic iron loading to determine whether the distribution of iron-loading influences the risk of advanced fibrosis. One hundred thirty-eight men and 66 women with hemochromatosis who underwent liver biopsy for staging of hepatic fibrosis had evaluation of hepatic iron concentration (HIC), hepatic iron index (HIC/age), total body iron stores (mobilizable iron), and mobilizable iron/HIC ratio (a marker of total body iron relative to hepatic iron). The potential impact of liver volume on mobilizable iron stores was assessed using magnetic resonance imaging in a separate cohort of 19 newly diagnosed individuals with hemochromatosis. Of 204 biopsied subjects, 41 had advanced fibrosis and exhibited 60% greater accumulation of mobilizable iron relative to HIC (mean 0.070 ± 0.008 g Fe/[μmol Fe/g]) compared with 163 subjects with low-grade fibrosis (mean 0.044 ± 0.002 g Fe/[μmol Fe/g], P < .0001). Linear regression modeling confirmed a discrete advanced hepatic fibrosis phenotype associated with greater mobilizable iron stores relative to HIC. The ratios of the upper to lower 95% limits of the distributions of liver volumes and the mobilizable iron/HIC ratios were 2.7 (95% confidence interval 2.3-3.0) and 9.7 (95% confidence interval 8.0-11.7), respectively, indicating that the distribution of liver volumes is not sufficiently wide to explain the variability in mobilizable iron/HIC ratios, suggesting that significant extrahepatic iron loading is present in those with advanced hepatic fibrosis. Advanced hepatic fibrosis develops in hemostatic iron regulator-hemochromatosis individuals who also have excessive extrahepatic mobilizable iron stores.

Magnetic resonance imaging assessment of the changes of cardiac and hepatic iron load in thalassemia patients before and after hematopoietic stem cell transplantation

To investigate the value of T2* technique on 3.0 T magnetic resonance imaging (MRI) in evaluating the changes of cardiac and hepatic iron load before and after hematopoietic stem cell transplantation (HSCT) in patients with thalassemia (TM), the 141 TM patients were divided into 6 group for subgroup analysis: 6, 12, 18, 24 and > 24 months group, according to the postoperative interval. The T2* values of heart and liver (H-T2*, L-T2*) were quantified in TM patients before and after HSCT using 3.0 T MRI T2* technology, and the corresponding serum ferritin (SF) was collected at the same time, and the changes of the three before and after HSCT were compared. The overall H-T2* (P = 0.001) and L-T2* (P = 0.041) of patients after HSCT were higher than those before HSCT (mean relative changes = 19.63%, 7.19%). The H-T2* (P < 0.001) and L-T2* (P < 0.001) > 24 months after HSCT were significantly higher than those before HSCT (mean relative changes = 69.19%, 93.73%). The SF of 6 months (P < 0.001), 12 months (P = 0.008), 18 months (P = 0.002) and > 24 months (P = 0.001) were significantly higher than those before HSCT (mean relative changes = 57.93%, 73.84%, 128.51%, 85.47%). There was no significant improvement in cardiac and liver iron content in TM patients within 24 months after HSCT, while the reduction of cardiac and liver iron content in patients is obvious when > 24 months after HSCT.

Evaluation of the efficacy of signal-averaged electrocardiogram testing in the cardiac assessment of beta-thalassemia major patients

BackgroundMore than 70% of thalassemia’s major mortality is due to the cardiac complications of this syndrome, mostly consequent to myocardial Iron overload; therefore, evaluation of such complications is of utmost importance. T2*MRI is used to assess hepatic and myocardial Iron load in thalassemia patients, which is not always available. Signal-Averaged Electrocardiography is a rather easy method of evaluating major thalassemia patients regarding their risk for sudden cardiac death.Methods and materialsIn this cross-sectional study, 48 patients with thalassemia major underwent evaluation with electrocardiography, signal-averaged electrocardiography, echocardiography, T2*MRI, and ferritin level. The association of the existence of ventricular late potentials in SAECG and other cardiac variables was evaluated. Moreover, the association between myocardial and hepatic Iron load and cardiac characteristics was assessed.Results48 patients with a mean age of 30.31 ± 7.22 years old entered the study. 27 (56.3%) of the patients had ventricular late potentials, which were associated with myocardial dry Iron weight (P = 0.011). Nonspecific ST-T changes and premature atrial and ventricular contractions were seen more frequently in patients with late potentials (P = 0.002, 0.031, and 0.031, respectively). Patients with higher myocardial and hepatic Iron loads had longer QTc in their 12-lead surface electrocardiograms.ConclusionPatients with ventricular late potentials assessed by SAECG had a higher myocardial Iron load. Higher myocardial Iron load is associated with higher cardiac complications in patients with beta-thalassemia major; therefore, SAECG can be used as a screening test for cardiac complications in beta-thalassemia major patients.

TMPRSS6 Inhibition with a Monoclonal Antibody Improves Red Blood Cell Health and Reduces Hepatic Iron Loading in Mouse Models of Iron Overload Diseases

Beta-thalassemia is a genetic disorder arising from loss of function mutations in the beta-globin gene, leading to ineffective erythropoiesis and organ iron overload. The latter contributes to liver fibrosis, type-2 diabetes, cancer, and cardiac toxicities. The major cause of increased iron loading is the reduced hepcidin levels because of the ineffective erythropoiesis. Iron is regulated by the hormone hepcidin. The BMP6-HJV signaling axis induces hepcidin expression via SMAD1/5 activation and the serine-protease TMPRSS6 is a negative regulator of HJV. Individuals with loss-of-function mutations in the TMPRSS6 gene have high levels of circulating hepcidin resulting in iron-restricted/iron-deficiency anemia. Thus, blocking TMPRSS6 may be a viable strategy to elevate hepcidin and reduce iron levels in beta-thalassemia or hereditary hemochromatosis. We generated a monoclonal antibody (REGN7999) that inhibits TMPRSS6 activity hence preventing HJV cleavage. This in turn accentuates BMP6-HJV signaling, consequently increasing serum hepcidin. In the Hbbth3/+ mouse model of beta-thalassemia, treatment with REGN7999 (10 mg/kg, s.c., weekly for 8 weeks) led to a significant reduction in liver iron (~50% reduction compared to the isotype treated group) and improved red blood cell health as determined by Annexin V staining, intracellular oxidative stress, and measurement of red blood cell turnover. This effect on red blood cells was reflected by a longer running distance of Hbbth3/+ mice during forced exercise and a reduction in serum lactate production. Our data shows, that targeting TMPRSS6 has significant advantages over current treatments, such as Luspatercept, an ACVR2b receptor trap or iron chelation. These therapeutics target either red blood cell formation (Luspatercept) or iron loading (iron chelators), but not both. Hence, blockade of TMPRSS6 seems a good addition to current therapeutics. In addition, we tested REGN7999 in HFE-/-mice, a mouse model of hereditary hemochromatosis. After 8 weeks treatment, liver iron from HFE-/- mice was significantly reduced in these animals. Taken together, inhibition of TMPRSS6 is an advantageous strategy in different iron overload diseases.

Quantitative T2* MRI for bone marrow iron overload: normal reference values and assessment in thalassemia major patients.

We evaluated the feasibility and reproducibility of bone marrow T2* values and established the lower limit of normal in a cohort of healthy subjects. We investigated the clinical correlates of bone marrow T2* values in patients with thalassemia major (TM). Thirty healthy subjects and 274 consecutive TM patients (38.96 ± 8.49years, 151 females) underwent MRI at 1.5T. An axial slice in the upper abdomen was acquired by a T2* gradient-echo multiecho sequence and the T2* value was calculated in a circular region of interest defined in the visible body of the first or second lumbar vertebra. In patients, also liver and heart T2* values were assessed. In healthy subjects bone marrow T2* values were independent of age and gender. The lower limit of normal for bone marrow T2* was 13ms. In both healthy subjects and 30 randomly selected patients, the coefficient of variation for inter-operator-reproducibility was < 10%. TM patients exhibited significantly lower bone marrow T2* values than healthy subjects (7.47 ± 5.18ms vs. 17.08 ± 1.89ms; p < 0.0001). A pathological bone marrow T2* was detected in 82.8% of TM patients. In TM, the female sex was associated with reduced bone marrow T2* values. Bone marrow T2* values were inversely correlated with mean serum ferritin levels (R = -0.431; P < 0.0001) and hepatic iron load (R = -0.215; P < 0.0001). A serum ferritin level > 536ng/ml predicted the presence of a pathological bone marrow T2*. A positive correlation was found between bone marrow and heart T2* values (R = 0.143; P = 0.018). A normal bone marrow T2* showed a negative predictive value of 100% for cardiac iron. Bone marrow T2* measurements can be easily obtained using the same sequences acquired for liver iron quantification and may bring new insights into the pathophysiology of iron deposition; hence, they should be incorporated into clinical practice.

The role of MRI-R2* in the detection of subclinical pancreatic iron loading among transfusion-dependent sickle cell disease patients and correlation with hepatic and cardiac iron loading

ObjectivesPancreatic reserve could be preserved by early assessment of pancreatic iron overload among transfusion-dependent sickle cell disease (SCD) patients. This study aimed to measure pancreatic iron load and correlate its value with patients’ laboratory and radiological markers of iron overload.Materials and methodsSixty-six SCD children and young adults underwent MRI T2* relaxometry using a simple mathematical spreadsheet and laboratory assessment.ResultsThe results indicated moderate-to-severe hepatic iron overload among 65.2% of studied cases. None had cardiac iron overload. Normal-to-mild iron overload was present in the pancreas in 86% of cases, and 50% had elevated serum ferritin > 2500 ug/L. There was no significant correlation between pancreatic R2* level, serum ferritin, and hepatic iron overload. Patients with higher levels of hemolysis markers and lower pre-transfusion hemoglobin levels showed moderate-to-severe pancreatic iron overload.ConclusionChronically transfused patients with SCD have a high frequency of iron overload complications including pancreatic iron deposition, thereby necessitating proper monitoring of the body’s overall iron balance as well as detection of extrahepatic iron depositions.

Intestinal Dmt1 is Required for Iron Loading in Mice Modeling β‐Thalassemia Intermedia

β‐thalassemia intermedia (βTI) is characterized by chronic anemia, ineffective erythropoiesis, and excessive intestinal iron absorption leading to systemic iron overload. Divalent metal‐ion transporter 1 (DMT1), the main intestinal iron transporter, may mediate excessive iron absorption in Th3/+ mice, which model βTI.ObjectiveTo determine if intestinal DMT1 is required for iron‐loading in beta‐thalassemia, and if so, to utilize a ginger nanoparticle‐derived lipid vector (GDLVs) siRNA delivery system to normalize iron absorption in Th3/+ mice.HypothesisDMT1 mediates excessive iron absorption in βTI mice and decreasing DMT1 expression by GDLVs‐siRNA will prevent iron accumulation in these mice.MethodsTh3/+ mice were crossed with mice lacking intestinal DMT1 generating double KOs. Also, weanling mice were gavaged daily for 16 days with GDLVs carrying functional DMT1 siRNA, and iron absorption and iron loading were assessed.ResultsLiver, spleen, kidney, heart, and duodenum non‐heme iron levels were decreased in Th3/+ mice lacking intestinal DMT1. Serum non‐heme iron content, serum ferritin levels, and transferrin saturation also decreased in Th3/+ mice lacking intestinal DMT1. Splenomegaly was alleviated in the double KO mice. Oral gavage of GDLVs carrying DMT1 siRNA blunted intestinal DMT1 expression and mitigated hepatic and splenic iron loading. Serum non‐heme iron levels, serum ferritin, and transferrin saturation also decreased in Th3/+ mice receiving GDLVs with DMT1 siRNA.ConclusionIntestinal DMT1 is required for iron‐loading in Th3/+ mice, and in vivo DMT1 knock down is an effective approach to blunt iron loading in mice modeling βTI.

Frequency, Pattern, and Associations of Renal Iron Accumulation in Sickle Beta-Thalassemia

▪Background: Chronically transfused homozygous sickle cell disease (HbSS) patients were shown to have higher kidney iron deposition than thalassemia major patients, not associated to total body iron and mainly caused by chronic hemolysis. Kidney iron deposition has not been explored in sickle beta-thalassemia (Sβ-thal), resulting from the inheritance of both sickle cell and beta-thalssemia genes.Aim: This multi center study aimed to study frequency, pattern, and associations of renal iron accumulation in sickle beta-thalassemia.Methods: Thirty-three Sβ-thal patients (36.49±14.72 years; 13 females) consecutively enrolled in the Extension-Myocardial Iron Overload in Thalassemia (E-MIOT) network were considered. Moreover, 20 healthy subjects, 14 HbSS patients and 71 thalassemia major (TM) patients were included as comparison groups. Hepatic, cardiac, pancreatic, and renal iron overload was quantified by the gradient-echo T2* technique. In each kidney T2* was measured in anterior, posterolateral, and posteromedial parenchymal regions and the global T2* value was calculated as the average of the two kidneys T2* values.Results. Global renal T2* were significantly higher in healthy subjects versus both Sβ-thal patients (49.68±10.09 ms vs 43.19±8.07 ms; P=0.013) and HbSS patients (49.68±10.09 ms vs 26.21±17.07 ms; P<0.0001).Sβ-thal patients showed comparable age, sex, frequency of regular transfusion, hematochemical parameters, and hepatic, cardiac and pancreatic iron load than HbSS patients, but they had a significant lower frequency of renal iron overload (global renal T2*<31 ms) (9.1% vs 57.1%; P=0.001).Regularly transfused patients (16 Sβ-thal and 10 HbSS) were compared with TM patients, homogeneous for age and sex, but TM started regular transfusions significantly earlier and they were more frequently chelated. No significant difference was detected in terms of hepatic and cardiac iron levels, but TM patients had significantly lower pancreas T2* values than both the other two groups and significantly higher global renal T2* values than HbSS patients (42.87±9.43 ms vs 24.39±15.74 ms; P=0.001).In Sβ-thal patients no significant difference was detected between T2* values in left and right kidneys, and global renal T2* values were not associated to age, gender, splenectomy, and they were comparable between regularly transfused and non transfused patients.No correlation was detected between renal T2* values and serum ferritin levels or iron load in the other organs.Global renal T2* values were not associated with serum creatinine levels but showed a significant inverse correlation with serum lactate dehydrogenase (Figure 1).Conclusion. Renal iron deposition is not common in Sβ-thal patients, with a prevalence significantly lower compared to that of HbSS patients, but with a similar underlying mechanism due to the chronic hemolysis. [Display omitted] DisclosuresPepe: Bayer S.p.A.: Other: no profit support; Chiesi Farmaceutici S.p.A: Other: no profit support. Maggio: Novartis: Membership on an entity's Board of Directors or advisory committees; Celgene Corp: Membership on an entity's Board of Directors or advisory committees; Bluebird Bio: Membership on an entity's Board of Directors or advisory committees.

ROLE OF CARDIOVASCULAR MAGNETIC RESONANCE IMAGING IN ASSESSMENT OF MYOCARDIAL IRON OVERLOAD IN THALASSEMIA PATIENTS

Background: Thalassemia major anemia patients require repeated blood transfusions, which improves their survival and quality of life, however it leads to iron overload and cellular damage. Serum ferritin and liver biopsy were used classically to measure iron overload and to monitor patient response to chelation therapy. Magnetic resonance imaging (MRI T2*) has proven to be a non-invasive, effective technique in detecting and quantifying myocardial and hepatic iron overload and in adjustment of iron chelation therapy.Aim of Work: To assess myocardial siderosis among our patients using MRI T2* technique and to correlate it with hepatic iron load and left ventricular ejection fraction (LVEF).Patients and methods: Our study included 42 cases of regularly transfused patients. Hepatic and myocardial iron overload were measured by multi-breath-hold MRI T2* technique and a cine view sequence was used to assess left ventricular function (EF).Results: Myocardial and hepatic iron overload were inter-correlated to each other and correlated to left ventricular function (LVEF). There was insignificant correlation between cardiac and hepatic T2* value results (k = 0.014, P > 0.05). However, there was a progressive and significant decline in left ventricular ejection fraction (r = 0·61, P < 0·001) in patients with low cardiac T2* values (T2* < 20 ms).Conclusion: MRI T2* technique is a precise, reproducible, and non-invasive technique for measuring tissue iron concentration and sparing the patients from an invasive biopsy technique. It also benefits in early detection of cardiac dysfunction and provides a follow up tool helping in chelation therapy adjustment.

Albuminuria Is Associated with Hepatic Iron Load in Patients with Non-Alcoholic Fatty Liver Disease and Metabolic Syndrome.

Background: Increased albuminuria is associated with increased serum ferritin, insulin resistance, and non-alcoholic fatty liver disease (NAFLD). Liver iron accumulation is also related to hyperferritinemia, insulin resistance, and NAFLD; however, there is no evidence on its relationship with albuminuria. Aims: To assess the relationship between hepatic iron load and urine albumin-to-creatinine ratio (UACR) in patients with metabolic syndrome (MetS) and NAFLD. Methods: In total, 75 MetS and NAFLD patients (aged 40–60 years, BMI 27–40 kg/m2) were selected from a cohort according to available data on hepatic iron load (HepFe) by magnetic resonance imaging (MRI). Subjects underwent anthropometric measurements, biochemistry testing, and liver MRI. Increased albuminuria was defined by UACR. Results: UACR correlated with NAFLD, HepFe, triglycerides, serum ferritin, fasting insulin, insulin resistance (calculated using the homeostatic model assessment for insulin resistance—HOMA-IR- formula), and platelets (p < 0.05). Multiple regression analysis adjusted for gender, age, eGFR, HbA1c, T2DM, and stages of NAFLD, found that HepFe (p = 0.02), serum ferritin (p = 0.04), fasting insulin (p = 0.049), and platelets (p = 0.009) were associated with UACR (R2 = 0.370; p = 0.007). UACR, liver fat accumulation, serum ferritin, and HOMA-IR increased across stages of HepFe (p < 0.05). Patients with severe NAFLD presented higher HepFe, fasting insulin, HOMA-IR, and systolic blood pressure as compared to patients in NAFLD stage 1 (p < 0.05). Conclusion: Hepatic iron load, serum ferritin, fasting insulin, and platelets were independently associated with albuminuria. In the context of MetS, increased stages of NAFLD presented higher levels of HepFe. Higher levels of HepFe were accompanied by increased serum ferritin, insulin resistance, and UACR. The association between iron accumulation, MetS, and NAFLD may represent a risk factor for the development of increased albuminuria.

Tissue-Specific Regulation of Ferroportin in Wild-Type and Hjv-/- Mice Following Dietary Iron Manipulations.

Hepcidin is a liver‐derived peptide hormone that limits iron egress from tissues to the bloodstream. It operates by binding to the iron exporter ferroportin, which blocks iron transport and tags ferroportin for degradation. Genetic hepcidin inactivation leads to hereditary hemochromatosis, a disease of iron overload. We used wild‐type and Hjv‐/‐ mice, a model of hemochromatosis, to examine the expression of ferroportin and other proteins of iron metabolism in hepcidin target tissues. The animals were previously subjected to dietary iron manipulations. In Hjv‐/‐ mice, hepcidin messenger RNA correlated significantly with hepatic iron load (r = 0.8211, P < 0.001), but was substantially lower compared with wild‐type controls. Duodenal ferroportin and divalent metal transporter 1 (DMT1), as well as splenic and hepatic ferroportin, were overexpressed in these animals. A high‐iron diet (2% carbonyl iron) suppressed duodenal DMT1 levels in both wild‐type and Hjv‐/‐ mice; however, it did not affect duodenal ferroportin expression in Hjv‐/‐ mice, and only reduced it in wild‐type mice. In contrast, the high‐iron diet decreased splenic ferroportin exclusively in Hjv‐/‐ mice, whereas it induced hepatic ferroportin exclusively in wild‐type mice. Conclusion: Our data show that dietary iron differentially affects ferroportin expression in mouse tissues and are consistent with hepcidin‐dependent and hepcidin‐independent mechanisms for ferroportin regulation. In the Hjv‐/‐ mouse model of hemochromatosis, duodenal ferroportin remains unresponsive to iron but DMT1 is appropriately iron‐regulated.

British Society for Haematology guidelines for the management of adult myelodysplastic syndromes.

British Society for Haematology guidelines for the management of adult myelodysplastic syndromes.

Iron Binding to Specific Lobes of Transferrin Differentially Affects Erythropoiesis and Hepcidin Signaling

Introduction: Transferrin (Tf) plays a role in iron homeostasis as both an iron cargo molecule and as a signaling molecule. Tf is comprised of two homologous lobes (N and C), each of which can bind one iron molecule. As such Tf circulates as four forms: diferric, monoferric C, monoferric N and apo. Upon iron binding, clefts in each lobe close resulting in a conformational shift in the structure of the molecule and altering its affinity for the transferrin receptors. The most abundant molecules in the circulation at normal transferrin saturations are the monoferric forms. The relative abundance of circulating monoferric N in healthy individuals is greater than C, and greater with increased iron status. The N and C lobes differ in several physical properties, including binding affinities for iron. Whether these differences have functional consequences has been a subject of controversy. In vitro data suggest that iron is released initially from the C-lobe during delivery from diferric Tf to the erythron. These observations led to the proposal that iron occupancy of the N lobe might serve as an indicator of erythroid iron sufficiency, and as a signal to regulate dietary iron absorption. We thus hypothesized that iron homeostasis would be influenced by the presence of iron on the transferrin C-lobe vs the N-lobe.Methods: To test this hypothesis, we generated mice producing exclusively monoferric N or C transferrins by mutating two essential tyrosines in the iron binding site of each of the lobes to phenylalanine (Y114 and Y207 in the N-blocked (N-bl) mouse and Y448 and Y537 in the C-blocked (C-bl) mouse). Heterozygous mice were crossed and offspring analyzed for hematological parameters, tissue iron concentrations, and expression by RT-PCR of selected genes relevant to iron homeostasis.Results: The N-bl and C-bl Tf mutant mice each demonstrate hepatic iron loading; however, N-bl mice demonstrated higher non-heme liver iron concentrations than C-bl Tf mutant mice (1542 +/- 89.48 vs 1089 +/- 110.6 ug Fe/g dry weight, respectively; p <0.0001) compared to wild-type (261.8 +/- 22.17 ug Fe/g dry weight; p < 0.0001) at 2 months of age. Liver hepcidin (Hamp1) expression was decreased in both Tf mutants and was significantly lower in the N-bl mutant mice compared to wild-type (1.18 +/- 0.15). Bmp6 expression was not different across strains. Bone marrow Erfe expression was increased ~4-fold in each strain relative to wild-type (p < 0.05). Both strains demonstrate a mild microcytic anemia with hemoglobin concentrations of 12.11 +/- 0.17 and 12.87 +/- 0.24 and MCV values of 42.42 +/- 0.15 and 40.24 +/- 0.13 for N-bl and C-bl mice, respectively, compared to wild type hemoglobin concentrations of 14.98 +/- 0.11 and MCV values of 53.16 +/- 0.11 (p < 0.01 across all categories). Red blood counts are significantly higher in C-bl mutant mice (9.98 +/- 0.12) than in N-bl mutant mice (9.16 +/- 0.09; p <0.001) or controls (8.91 +/- 0.06; p < 0.0001). In contrast, serum erythropoietin (Epo) is significantly higher in N-bl (503 +/- 50.18; p < 0.0001) compared to C-bl (273 +/- 29.5) and wild-type mice (221.6 +/- 10.61; p < 0.0001), resulting in a RBC:Epo ratio of 0.019 +/- 0.003 for N-bl mice, 0.04 +/- 0.003 for C-bl mice and 0.04 +/- 0.001 for wild-type mice (p <0.0001 for N-bl compared to C-bl and wt).Conclusions: N-bl and C-bl Tf mutant mice demonstrate a hemochromatosis phenotype consistent with decreased hepcidin signaling; however, severity differs. Both mouse models demonstrate iron restrictive erythropoiesis; however, erythrocyte count is suppressed relative to erythropoietin levels only in the N-bl mutant mice. The N and C lobes of transferrin thus demonstrate functionally distinct properties. We speculate that iron bound to the N-lobe of transferrin augments the signaling properties of transferrin which regulate hepcidin expression and erythropoiesis. DisclosuresRivella:Ionis Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees, Research Funding. Fleming:Protagonist Therapeutics: Membership on an entity's Board of Directors or advisory committees.

Magnetic resonance quantitative susceptibility mapping in the evaluation of hepatic fibrosis in chronic liver disease: a feasibility study.

Noninvasive methods for the early diagnosis and staging of hepatic fibrosis are needed. The present study aimed to investigate the alteration of magnetic susceptibility in the liver of patients with various fibrosis stages and to evaluate the feasibility of using susceptibility to stage hepatic fibrosis. A total of 30 consecutive patients with chronic liver diseases (CLDs) underwent magnetic resonance imaging (MRI) and liver biopsy evaluation of hepatic fibrosis, necroinflammatory activity, iron load, and steatosis. Quantitative susceptibility mapping (QSM), R2* and proton density fat fraction (PDFF) images were postprocessed from the same gradient-echo data for quantitative tissue characterization using region of interest (ROI) analysis. The differences for MRI measurements between cohorts of non-significant (Ishak-F <3) and significant fibrosis (Ishak-F ≥3) and the correlation of MRI measurements with fibrosis stages and necroinflammatory activity grades were tested. Receiver operating characteristic (ROC) analysis was also performed. There was a significant difference in liver susceptibility between the cohorts of significant and non-significant fibrosis (Z=-2.880, P=0.004). A moderate negative correlation between the stages of liver fibrosis and liver susceptibility was observed (r=-0.471, P=0.015). Liver magnetic susceptibility differentiated non-significant from significant hepatic fibrosis with an area under the receiver operating curve (AUC) of 0.836 (P=0.004). A highly sensitive diagnostic performance with an AUC of 0.933 was obtained using magnetic susceptibility and PDFF together (P<0.001). A noninvasive liver QSM-based evaluation promises an accurate assessment of significant fibrosis in patients with CLDs.

Modulating NF-κB, MAPK, and PI3K/AKT signaling by ergothioneine attenuates iron overload-induced hepatocellular injury in rats.

The liver is highly susceptible to iron overload-evoked oxidative injury. Ergothioneine is a thio-histidine amino acid that has exhibited strong antioxidant and metal chelating activities. Thisstudy aimed at exploring the potential modulating effects of ergothioneine on iron-triggered liver injury. The results showed that ergothioneine inhibited iron-evoked inflammation and apoptosis as demonstrated by a significant reduction in tumor necrosis factor-α and interleukin-6 levels and in caspase-3 activity. Ergothioneine significantly improved liver cell survival as indicated by modulating phosphatidylinositol 3-kinase/protein kinase B signaling. Consistent with reduced necrotic cell death, ergothioneine diminished the iron-evoked histopathological changes and decreased serum activity of the liver enzymes. Mechanistically, ergothioneine reduced nuclear translocation of nuclear factor kappa B p65 and modulated p38 mitogen-activated protein kinase/c-Fos signaling. In addition, it enhanced the liver tissue antioxidant potential and curbed hepatic iron load. Together, these results point out the modulatory effects of ergothioneine on iron-evoked liver cell injury that are possibly mediated via anti-inflammatory, antioxidant, and possible iron chelation capabilities.

Role of Cardiovascular Magnetic Resonance Imaging in Assessment of Myocardial Iron Overload in Thalassemic Patients

Background: Thalassemia major anemia patients require repeated blood transfusions, which improves their survival and quality of life, however it leads to iron overload and cellular damage. Serum ferritin and liver biopsy were used classically to measure iron overload and to monitor patient response to chelation therapy. Magnetic resonance imaging (MRI T2*) has proven to be a non-invasive, effective technique in detecting and quantifying iron in the heart and liver and in adjustment of iron chelation therapy. Objective: To assess myocardial siderosis among our patients using MRI T2* technique and correlate it with hepatic iron load and left ventricular ejection fraction (LVEF). Patients and methods: Our study included 42 cases of monthly transfused patients. Hepatic and myocardial iron overload were measured by multi-breath-hold MRI T2* technique and a cine view sequence was used to assess left ventricular function (EF). Results: Myocardial and hepatic iron overload were inter-correlated to each other and correlated to left ventricular function (LVEF). There was insignificant correlation between cardiac and hepatic T2* value results (k = 0.014, P > 0.05). However, there was a progressive and significant decline in left ventricular ejection fraction (r = 0·61, P < 0·001) in patients with low cardiac T2* values (T2* < 20 ms). Conclusion: MRI T2* technique is a precise, reproducible, and non-invasive technique for measuring tissue iron concentration and sparing the patients from an invasive biopsy technique. It also benefits in early detection of cardiac dysfunction and provides a follow up tool helping in chelation therapy adjustment.

Sympathetic Overactivation in Patients With Essential Hypertension and Hepatic Iron Overload.

Iron overload has been recently shown to be associated with a hyperadrenergic state in genetic hemochromatosis. Whether this is also the case in essential hypertension, characterized by sympathetic activation and frequently by body iron overload, is unknown. In 17 healthy normotensive controls (age 52.3±3.2 years, mean±SE), in 21 age-matched patients with hypertension with iron overload (HT+), defined by serum ferritin levels, and in 28 hypertensives without this condition, we measured efferent postganglionic muscle sympathetic nerve traffic (microneurography), heart rate and blood pressure variability (power spectral analysis), serum ferritin, and metabolic variables. Muscle sympathetic nerve traffic was significantly (P<0.02 at least) greater in HT+ than in patients with hypertension without iron overload and normotensive subjects both when expressed as bursts incidence over time (41.8±1.4 versus 31.5±1.4 and 23.6±0.9 bursts/min) and as bursts corrected for heart rate (55.3±1.8 versus 42.3±1.2 and 31.7±1.2 bursts/100 heartbeats). In HT+, low-frequency systolic blood pressure variability was significantly reduced. In HT+, but not in the other 2 groups, muscle sympathetic nerve traffic was significantly related to serum ferritin (r=0.51, P<0.03), transferrin saturation (r=0.47, P<0.03), and hepatic iron load (r=0.76, P<0.0001, magnetic resonance imaging), as well as to homeostatic model assessment index values (r=0.46, P<0.05). These data provide the first evidence that in HT+ elevated serum ferritin is associated with a hyperadrenergic state of greater magnitude than the one seen in patients with hypertension without iron overload. They also show that the potentiation of the sympathetic activation detected in HT+ is related to elevated serum ferritin and to the associated metabolic alterations, possibly participating in the increased cardiovascular risk characterizing iron overload.

Hepatic and cardiac iron load as determined by MRI T2* in patients with congenital dyserythropoietic anemia type I.

Iron overload comprises one of the main complications of congenital dyserythropoietic anemia type I (CDA-I). When analyzing magnetic resonance imaging T2* (MRI T2*) results in CDA patients, two previous studies reported discordant results regarding iron load in these patients. To further understand iron loading pattern in this group of patients, we analyzed MRI T2* findings in 46 CDA-I patients. Mild to moderate hepatic iron overload was detected in 28/46 (60.8%) patients. A significant correlation was found between serum ferritin and liver iron concentration (LIC). A significant correlation (p value = 0.02) was also found between the patient's age and LIC, reflecting increased iron loading over time, even in the absence of transfusion therapy. Notably, no cardiac iron overload was detected in any patient. Transfusion-naive patients had better LIC and better cardiac T2* values. These results demonstrate that a high percentage of CDA-I patients have liver iron concentration above the normal values, risking them with significant morbidity and mortality, and emphasize the importance of periodic MRI T2* studies for direct assessment of tissue iron concentration in these patients, taking age and transfusional burden into consideration.

Hepatic Iron Overload in Transfusion Dependent Chronic Hemolytic Anemic Patients: Where Does MRI R2* Relaxometry Stand?

Abstract Background: Hepatic iron overload in pediatric population with repeated blood transfusion is an important morbidity warranting the evolution of a noninvasive method of liver iron quantification. MR T2*/R2* relaxometry technique has shown promising results in this domain. Aim of Study: To show the value of MR T2*/R2* relax-ometry technique, in assessment of hepatic iron overload in a sample pediatric patient population at our hospital on repeated blood transfusions therapy for thalassemia and sickle cell anemia. Patients and Methods: A total of 44 patients, mean age 11.14±3.38 (range: 6-17 years old) patients with thalassemia and sickle cell anemia who had received more than 20 blood transfusions and on chelation therapy at the time of the examination, underwent MRI T2*/R2* relaxometry study. The corresponding iron overload was calculated for each patient, then correlation between R2* and serum ferritin level was done by using Pearson's correlation coefficient. Results: Serum ferritin levels ranged between 56.7 and 11524ng/mL (mean 3605.8ng/mL). R2* values ranged between 77.1 and 11426Hz (mean 2361Hz). Based on the calculated Liver Iron Concentrations (LIC) values which ranged between 0.47 and 42.55mg/g (mean 11.38mg/g) 9 patients (20.45%) showed normal hepatic iron load, 10 patients (22.73%) showed mild iron overload, 13 patients (29.55%) showed moderate overload and 12 patients (27.27%) showed severe overload. The correlation between R2* and serum ferritin was a weak positive one with a Pearson's coefficient of 0.49 (p=0.000645). The correlation between LIC and serum ferritin was a moderate positive one with a Pearson's correlation of 0.5 (p=0.000494). Conclusion: Quantification of liver iron deposition in children with chronic hemolytic anemia receiving multiple blood transfusions is empirical for chelation therapy monitor-ing. R2* relaxometry shows promising results as an effective quantitative tool for estimation of hepatic iron overload when compared to serum ferritin levels, therefore providing a safer alternative in contrast to tissue biopsy.