Elevated Transferrin Saturation Research Articles

SLC40A1-related hemochromatosis associated with a p.Y333H mutation in mainland China: a pedigree report and literature review

BackgroundHaemochromatosis is a genetic disease characterized by the excessive deposition of iron in various tissues and organs, eventually results in organ damage including cirrhosis, diabetes, cardiomyopathy, etc. SLC40A1-related haemochromatosis is associated with gain-of-function mutations in the SLC40A1 gene, which encodes ferroportin. While sporadic reports of this condition exist in mainland China, the understanding of the phenotype and genetic pattern associated with the SLC40A1 p.Y333H mutation remains incomplete.Case presentationWe report a pedigree with heterozygous p.Y333H mutation in Chinese Han population. The proband is a 64-year-old man complaining of persistent abnormality of liver enzyme levels for 1 year, with a history of knee joint pain, diabetes and skin pigmentation. He displayed markedly elevated serum ferritin level and transferrin saturation. Magnetic resonance imaging showed iron deposition in the liver, spleen, and pancreas, along with cirrhosis and splenomegaly. Whole exome sequencing identified a heterozygous allelic variant c.997T > C (p.Y333H). Genetic screening of family members identified four first-degree relatives and three second-degree relatives having the same mutation. Additional cases with this mutation from two published studies were included. Among the probands and screened relatives, all eight males aged over 30 y had ferritin level > 1000 µg/L, transferrin saturation > 90%. Four patients with organ damage in the present study received therapeutic phlebotomy, alleviating clinical symptoms and improving in transferrin saturation and serum ferritin.ConclusionsThis study reports the largest pedigree with heterozygous SLC40A1 p.Y333H mutation in the Chinese population to date. In Chinese families, males over 30 years old with hemochromatosis due to SLC40A1 p.Y333H mutation exhibit severe iron overload phenotypes.

Environmental cadmium exposure perturbs systemic iron homeostasis via hemolysis and inflammation, leading to hepatic ferroptosis in common carp (Cyprinus carpio L.)

Cadmium (Cd) pollution is considered a pressing challenge to eco-environment and public health worldwide. Although it has been well-documented that Cd exhibits various adverse effects on aquatic animals, it is still largely unknown whether and how Cd at environmentally relevant concentrations affects iron metabolism. Here, we studied the effects of environmental Cd exposure (5 and 50 μg/L) on iron homeostasis and possible mechanisms in common carp. The data revealed that Cd elevated serum iron, transferrin saturation and iron deposition in livers and spleens, leading to the disruption of systemic iron homeostasis. Mechanistic investigations substantiated that Cd drove hemolysis by compromising the osmotic fragility and inducing defective morphology of erythrocytes. Cd concurrently exacerbated hepatic inflammatory responses, resulting in the activation of IL6-Stat3 signaling and subsequent hepcidin transcription. Notably, Cd elicited ferroptosis through increased iron burden and oxidative stress in livers. Taken together, our findings provide evidence and mechanistic insight that environmental Cd exposure could undermine iron homeostasis via erythrotoxicity and hepatotoxicity. Further investigation and ecological risk assessment of Cd and other pollutants on metabolism-related effects is warranted, especially under the realistic exposure scenarios.

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.

Clinical and Laboratory Characteristics of Individuals Aged ≤17 Years With Homeostatic Iron Regulator (HFE) p.C282Y Homozygosity, a Common Hemochromatosis Genotype.

Background Characteristics of cohorts of individuals aged ≤17 years with homeostatic iron regulator (HFE) p.C282Y (rs1800562) homozygosity, a common hemochromatosis genotype, have not been reported. Methodology We retrospectively tabulated characteristics of white individuals aged ≤17 years with p.C282Y homozygosity. Individuals were not recruited for this study. We defined transferrin saturation (TS) >45%, serum ferritin (SF) >300 µg/L (M) and >200 µg/L (F) as elevated and liver iron grade 3 or 4, hepatic iron index >1.9 µmol Fe/g dry weight liver/y, and phlebotomy-mobilized iron >1.0 g (M) and >0.3 g (F) as increased. Results There were nine males and six females with a mean age of 12 ± 4 years (range = 5-17 years). The mean age of 10 probands (13 ± 3 years) was greater than that of five individuals discovered in family studies (9 ± 4 years) (p = 0.0403). Presenting manifestations of probands included fatigue/lethargy (5), elevated TS (2), and polycystic ovary syndrome, amenorrhea, and diabetes (2). In 15 individuals, the mean TS was 65 ± 23%. TS was elevated in 11(73.3%) individuals aged 5-17 years. In 14 individuals, the mean SF was 262 ± 289 µg/L. SF was elevated and liver and phlebotomy-mobilized iron were increased in two male and three female probands aged 13-16 years (5/14 individuals, 35.7%). No individual had advanced hepatic fibrosis, arthropathy, hypogonadism, cardiomyopathy, or hyperpigmentation. Conclusions We conclude that five individuals aged 13-16 years (5/14 individuals, 35.7%) had increased liver and phlebotomy-mobilized iron.

Myelodysplastic Syndromes Benefit from Iron-Restricted Bone Marrow Transplant in Preclinical Mouse Model

Background: Hematopoietic stem cell transplantation (HSCT) remains the only fully curative therapy for diseases such as b-thalassemia, sickle cell disease, MDS and AML and represents a relevant procedure for gene therapy .Tissue iron overload and non-transferrin bound iron (NTBI) have emerged as adverse prognostic factors for post-transplant survival. Recently, we showed that - in line with observations in transplanted individuals - preparatory chemotherapy conditioning with a combination of busulfan and fludarabine in wild-type mice resulted in elevated serum iron and transferrin (Tf) saturation and elicited NTBI formation. Tf saturation and NTBI levels increased proportionally with conditioning intensity. Interestingly, we found that pre-conditioning TMPRSS6 silencing through a GalNAc-conjugated siRNA - by increasing hepcidin levels - reduced the peri-transplant elevation of Tf saturation and limited the appearance of NTBI. These results proved that NTBI formation is induced by conditioning chemotherapy in the peri-trasplant period independently of the presence of pre-existing iron overload. Aims & Methods: Here we asked whether these observations hold true in conditions hallmarked by pre-existing iron overload and elevated NTBI and how iron restriction impacts on bone marrow transplant (BMT) outcome. To this aim, we applied the GalNAc TMPRSS6 siRNA as iron restriction strategy in a mouse model of myelodysplastic syndromes (MDS) and assessed its ability to reduce conditioning-elicited NTBI formation as well as its potential benefit on BMT. After TMPRSS6 siRNA administration, CD45.2 + MDS mice received conditioning chemotherapy and transplant of CD45.1 + wild-type bone marrow cells. Systemic iron parameters, engraftment and chimerism were then analyzed. Results: Importantly, conditioning exacerbated the elevated systemic iron levels in MDS mice, which was prevented by pre-conditioning TMPRSS6 silencing. Similar to our observation in wild-type mice, recipient CD45.2 + MDS mice showed a superior blood chimerism, resulting from increased bone marrow and spleen engraftment of CD45.1 + donor cells. Multilineage engraftment in bone marrow, spleen and peripheral blood was superior in iron-restricted recipient MDS mice compared to controls. Finally, donor chimerism of hematopoietic stem and progenitor cells (HSPCs) was higher in iron-restricted versus control MDS mice undergoing BMT. Conclusion: These findings demonstrate that pre-transplant conditioning profoundly alters iron homeostasis and restricting iron improves BMT outcome by increasing engraftment efficiency. Overall, these data suggest that conditioning-elicited NTBI is a critical mediator of peri-transplant toxicity and adversely impacts transplant outcome. Specifically, our observations prove that iron restriction improves donor HSPC engraftment in the recipient bone marrow, likely resulting in more efficient reconstitution of the HSPC pool and improved multilineage engraftment. Lastly, our results indicate that the peri-transplant application of novel iron restriction strategies aimed at reducing conditioning-induced NTBI - by positively affecting BMT outcome - is of potential benefit for patients undergoing BMT or gene therapy, presenting either with or without pre-transplant iron overload.

Combination Therapy with Luspatercept and the Ferroportin Inhibitor Vamifeport Is Superior to Either Drug Alone in Improving Anemia and Reducing Myeloid Skewing in MDS

Background: Patients with myelodysplastic syndromes (MDS) are prone to develop iron overload as a consequence of ineffective erythropoiesis and chronic transfusion therapy. Although iron overload is a common feature in MDS, it has remained unclear whether and how iron excess is detrimental for MDS pathophysiology. Recently, we have shown that iron restriction by the oral ferroportin (FPN) inhibitor vamifeport improves anemia and reduces myeloid skewing, being of benefit for MDS as single treatment. Luspatercept is a recombinant fusion protein acting as TGF-β superfamily ligands trap which has recently gained FDA approval for the treatment of anemia in transfusion-dependent low-risk MDS patients. Luspatercept promotes erythropoietin (EPO)-independent maturation of late-stage erythroid cells, resulting in increased hemoglobin and red blood cells (RBCs) count. However, this drug - due to a lack of improvement in myeloid skewing and AML evolution - is considered a non-disease-modifying therapy. Aims: In this study we investigated the effect of a combined therapy using luspatercept and the FPN inhibitor vamifeport in a preclinical MDS mouse model, with the hypothesis that both drugs could have additive effects with further benefit for the disease. Methods: To this end, we administered the FPN inhibitor vamifeport in NUP98-HOXD13 MDS mice for 3 months (0.5 mg/ml into drinking water), combined with luspatercept for the last 2 months (5 mg/kg twice a week, subcutaneous injection), starting at 3 months of age. Mice receiving the combined treatment were compared to those untreated or receiving single treatments. Results: At steady-state MDS mice develop anemia, neutropenia and lymphopenia, together with an iron overload phenotype, hallmarked by inappropriately low hepcidin levels, elevated serum iron and transferrin saturation, non-transferrin-bound iron (NTBI) formation and tissue iron deposition. Vamifeport administration in MDS mice reduced serum iron and NTBI formation and prevented tissue iron loading, either as a single or combined treatment with luspatercept. Luspatercept and vamifeport, as single-agent treatment, ameliorated anemia and the maturation of bone marrow and splenic RBCs in MDS mice. The combined therapy further improved anemia compared to the treatments with either drugs alone, as suggested by the higher hemoglobin levels, hematocrit and RBC count, and the decreased number of early erythroid precursors, sign of more effective erythropoiesis. Importantly, vamifeport, but not luspatercept, significantly altered myeloid skewing in MDS, revealing a major role of the iron status in myeloid expansion. Myeloid bias, monitored as percentage of CD11b + Gr1 + myeloid cells in the bone marrow was attenuated by iron restriction in vamifeport-treated MDS mice compared to control and luspatercept-treated MDS animals. The combined treatment merkedly reduced myeloid skewing in MDS mice, similarly to the single vamifeport treatment. Furthermore, the number of immature cKit + myeloid blasts in the peripheral blood of MDS animals were decreased by vamifeport alone and in combination with luspatercept, but not by luspatercept alone. Finally, splenomegaly was reduced in MDS mice treated with vamifeport alone or in combination with luspatercept, confirming that iron restriction improves ineffective erythropoiesis and limits myeloid skewing. Overall, the combination therapy with vamifeport and luspatercept showed superior effects in improving anemia and myeloid bias as compared to single treatments. Conclusion: In conclusion, our results show that iron restriction by vamifeport enhances the erythroid maturation action of luspatercept, likely by improving iron utilization in erythroid cells and ameliorating their survival. Furthermore, vamifeport improves the myeloid skewing in the MDS model, suggesting disease-modifying activity as single agent as well as combined therapy with luspatercept. Together, these data prove that combo therapies aimed at restricting iron and boosting erythroid maturation may offer additive beneficial effects in MDS and provide pre-clinical evidence for combining iron restriction and TFG-β superfamily ligand-trap approaches as more effective therapeutic strategies for the treatment of MDS.

FRI429 Association Between Nonalcoholic Fatty Liver Disease And Fib-4 In Patients With Hypogonadism

Abstract Disclosure: C.M. Godar: None. K.F. Brown: None. A.J. Spiro: None. N.O. Vietor: None. T.D. Hoang: None. M.K. Shakir: None. Introduction: Recent studies have reported a strong bidirectional association between non-alcoholic fatty liver disease (NAFLD) and hypogonadism in both genders. Men with hypogonadism may have higher noninvasive indices of NAFLD via hepatic steatosis index (HSI, reference range <36) and hepatic fibrosis via FIB-4 (reference range <1.3). However, there is limited clinical data on the association between serum testosterone concentrations and NAFLD in men. We report here HSI and FIB-4 in 3 men with hypogonadism. Case #1: 56-year-old male with a 20-year history of idiopathic hypogonadism, hypertension on telmisartan and amlodipine, and obstructive sleep apnea with regular CPAP use. Pituitary MRI is normal. He uses 3 pumps of topical testosterone gel daily. Vital signs: BP 139/83mmHg, HR 59bpm and BMI 36.2. Examination of heart and lungs is normal, testes are 15cc bilaterally. Serum testosterone is 400-500 ng/dL, alanine aminotransferase (ALT) 88 U/L (0-50), aspartate aminotransferase (AST) 71 U/L (17-59), alkaline phosphatase (ALP) 78 U/L (38-126), iron saturation 43.1% (20-55), ferritin 452 ng/mL (30-400). Calculated FIB-4: 2.3, HSI: 46. Case #2: 71-year-old male with 46XX phenotype with hypogonadism and gynecomastia on 2 pumps of transdermal testosterone gel daily. Vital signs: BP 150/79 mmHg, HR 67/min, BMI 36.8. Examination of heart and lungs is normal, and testes are 5cc bilaterally. Serum testosterone is 416 ng/dL, ferritin 509 ng/mL, iron saturation 41.3%, ALT 19 U/L, AST 22 U/L, ALP 136 U/L. Liver ultrasound demonstrated diffuse hepatic steatosis with borderline hepatomegaly. Calculated FIB-4: 1.38, HSI: 48.4. Case #3: 48-year-old male with central hypogonadism currently taking testosterone 100 mg IM every week. Evaluation for central hypogonadism was unrevealing for pituitary lesion. Vital signs of BP 130/91, HR 76/min, BMI 27.2. Examination of heart and lungs is normal, and testes are 20cc bilaterally. ALT 201U/L, AST 80U/L, ALP 136U/L, serum testosterone 241 ng/dL. Liver ultrasound is consistent with hepatic steatosis. Calculated FIB-4: 1.22, HSI 59.2. Conclusion: Patients with a combination of hypogonadism, high BMI, mild or moderate elevations of AST/ALT/ALP, elevated serum ferritin or transferrin saturation should undergo screening for NAFLD. In this series, all 3 patients had high HSI, an early indicator of fibrosis although only 1 patient had a high FIB-4 level. As fibrosis is the strongest predictor for long-term clinical outcomes among patients with NAFLD there is growing interest in employing non-invasive methods such as HSI, FIB-4, NFS and APRI for risk stratification. In conclusion, it is recommended that high risk patients with hypogonadism need to be screened for NAFLD and hepatic fibrosis with these simple tools. Presentation: Friday, June 16, 2023

Screening for Hereditary Hemochromatosis in Newly Referred Diabetes Mellitus

AimsHereditary hemochromatosis (HH) is the most common inherited disease in European populations. It is particularly common in people of Irish heritage, approximately 2% of whom will be at risk of iron overload as a result of human homoeostatic iron regulator protein (HFE) gene mutations. We aimed to evaluate the utility of screening for HH in newly referred patients with DM of Irish heritage in a prospective study. MethodsOf 575 patients newly referred between March 2018 and March 2021, 556 attended for blood testing, to include fasting transferrin saturations, prior to their first clinic visit. Patients with elevated transferrin saturations were further screened for hereditary hemochromatosis (HH) with HFE gene analysis. ResultsTransferrin saturations were elevated in 13 of 556 patients (2.3%), 3 of whom had a preexisting diagnosis of HH. Of the remaining 10 patients, 7 had HFE gene mutations suggestive of HH (2 C282Y homozygous, 3 C282Y/H63D compound heterozygous, and 2 H63D homozygous), 1 was a HH carrier (C282Y heterozygous), and 2 had normal genetics. ConclusionsThe prevalence of HH of 1.8% in this screened DM population is lower than the reported incidence of HH in the Irish population, suggesting a limited utility of routine screening for HH in newly referred patients with DM.

Ferroportin inhibitor vamifeport ameliorates ineffective erythropoiesis in a mouse model of β-thalassemia with blood transfusions.

β-thalassemia is an inherited anemia characterized by ineffective erythropoiesis. Blood transfusions are required for survival in transfusion-dependent β-thalassemia and are also occasionally needed in patients with non-transfusion-dependent β-thalassemia. Patients with transfusion-dependent b-thalassemia often have elevated transferrin saturation (TSAT) and non-transferrin-bound iron (NTBI) levels, which can lead to organ iron overload, oxidative stress, and vascular damage. Vamifeport is an oral ferroportin inhibitor that was previously shown to ameliorate anemia, ineffective erythropoiesis, and dysregulated iron homeostasis in the Hbbth3/+ mouse model of β-thalassemia, under non-transfused conditions. Our study aimed to assess the effects of oral vamifeport on iron-related parameters (including plasma NTBI levels) and ineffective erythropoiesis following blood transfusions in Hbbth3/+ mice. A single dose of vamifeport prevented the transient transfusion-mediated NTBI increase in Hbbth3/+ mice. Compared with vehicle treatment, vamifeport significantly increased hemoglobin levels and red blood cell counts in transfused mice. Vamifeport treatment also significantly improved ineffective erythropoiesis in the spleens of Hbbth3/+ mice, with additive effects observed when treatment was combined with repeated transfusions. Vamifeport corrected leukocyte counts and significantly improved iron-related parameters (serum transferrin, TSAT and erythropoietin levels) versus vehicle treatment in Hbbth3/+ mice, irrespective of transfusion status. In summary, vamifeport prevented transfusion-mediated NTBI formation in Hbbth3/+ mice. When given alone or combined with blood transfusions, vamifeport also ameliorated anemia, ineffective erythropoiesis, and dysregulated iron homeostasis. Administering vamifeport together with repeated blood transfusions additively ameliorated anemia and ineffective erythropoiesis in this mouse model, providing preclinical proof-of-concept for the efficacy of combining vamifeport with blood transfusions in β-thalassemia.

Vascular Aging and Damage in Patients with Iron Metabolism Disorders.

Vascular aging is a physiological, multifactorial process that involves every type of vessel, from large arteries to microcirculation. This manifests itself as impaired vasomotor function, altered secretory phenotype, deteriorated intercellular transport function, structural remodeling, and aggravated barrier function between the blood and the vascular smooth muscle layer. Iron disorders, particularly iron overload, may lead to oxidative stress and, among other effects, vascular aging. The elevated transferrin saturation and serum iron levels observed in iron overload lead to the formation of a non-transferrin-bound iron (NTBI) fraction with high pro-oxidant activity. NTBI can induce the production of reactive oxygen species (ROS), which induce lipid peroxidation and mediate iron-related damage as the elements of oxidative stress in many tissues, including heart and vessels' mitochondria. However, the available data make it difficult to precisely determine the impact of iron metabolism disorders on vascular aging; therefore, the relationship requires further investigation. Our study aims to present the current state of knowledge on vascular aging in patients with deteriorated iron metabolism.

Genetic Iron Overload Aggravates and Pharmacological Iron Restriction Improves MDS Pathophysiology in a Preclinical Mouse Model

Background: Patients with myelodysplastic syndromes (MDS) are prone to develop iron overload as a consequence of ineffective erythropoiesis and chronic transfusion therapy. Although iron overload is a common feature in MDS, it remains unclear whether and how iron excess is detrimental for MDS pathophysiology. Aims: This study aimed at characterizing altered iron homeostasis in a preclinical MDS mouse model, understanding the molecular mechanisms underlying iron toxicity and unraveling the potential therapeutic value of pharmacologic iron restriction in this disease condition. Methods: To this end, we took advantage of complementary approaches and analyzed the effect of iron overload obtained through genetic activation of the iron exporter ferroportin (FPNC326S), and iron restriction achieved through the administration of the FPN inhibitor vamifeport in NUP98-HOXD13 MDS mice, starting at 3 or 5 months of age. Results: At steady-state MDS mice develop an iron overload phenotype, hallmarked by low hepcidin levels, elevated serum iron and transferrin saturation, non-transferrin-bound iron (NTBI) formation and tissue iron deposition. This is associated with anemia and low WBCs in the peripheral blood. FPNC326S MDS mice show an aggravated iron phenotype, with further elevated NTBI and tissue iron accumulation and still inappropriately low hepcidin levels. Vamifeport administration in MDS mice reduced serum iron (194.8 vs 141.8 mg/dl; P<0.05) and NTBI formation (0.62 vs 0 μM; P<0.05) and prevented tissue iron loading. While iron excess in FPNC326S MDS mice did not improve erythropoiesis and hematologic parameters in the peripheral blood, iron restriction by vamifeport significantly ameliorated anemia (Hb 9.5 vs 11.4 g/dl; RBC 5.4 vs 6.9x106 cells/ml; P<0.05) and maturation of bone marrow as well as splenic RBCs in MDS mice. The improved ineffective erythropoiesis was associated with reduced oxidative stress and apoptosis in erythroid progenitors. Importantly, we observed a major role of the iron status in myeloid expansion in MDS. The number of immature myeloid blasts and myeloid progenitors in the bone marrow of MDS mice were aggravated by iron overload in FPNC326S MDS mice and attenuated by iron restriction in vamifeport-treated MDS mice compared to control MDS animals. Myeloid bias, monitored as percentage bone marrow myeloid cells, was exacerbated by iron overload (54.3 vs 43.1% bone marrow mononuclear cells - BMNCs) and alleviated by iron restriction (67.5 vs 74.8% BMNCs; P<0.05). This was associated with increased and reduced inflammatory activation of bone marrow macrophages in FPNC326S MDS and vamifeport-treated MDS mice, respectively. This observation demonstrates a role for NTBI in driving the reported pro-inflammatory activation of MDS monocytes/macrophages (Fuster JJ et al, Science 2017; Jaiswal S et al, NEJM 2017; Cull AH et al, Exp Hematol 2017) and suggests that this iron-driven mechanism contributes to myeloid expansion. Overall, these alterations translated into a faster and delayed transition to AML in iron-overloaded and iron-restricted MDS mice, respectively. Finally, iron overload aggravated and iron restriction alleviated ROS formation, DNA damage and pyroptotic cell death in HSPCs. By reducing the intracellular labile iron pool, vamifeport improved HSPC quality and survival, partially rescuing the stem cell pool size (0.16 vs 0.38% Lin-BMNCs; P<0.05) in MDS mice. The ameliorated HSPC pool, reduced myeloid bias and inflammation, and attenuated ineffective erythropoiesis resulted in improved hematologic parameters for more than 3 months, and a significant survival increment in iron-restricted compared to control MDS mice (>45 days; P=0.037). We further demonstrate that a subgroup of mice can benefit from late iron restriction by vamifeport administration at 5 months of age, resulting in improved anemia and prolonged survival. Conclusion: Our results show for the first time in a preclinical mouse model of MDS that iron excess driven by ineffective erythropoiesis has pathological implication in transfusion-independent MDS. These effects are likely aggravated by transfusions causing additional iron overload. Finally, iron restriction achieved through pharmacologic FPN inhibition by the oral FPN inhibitor vamifeport significantly improves MDS pathophysiology, uncovering the therapeutic potential of early prevention of NTBI formation in MDS.

Iron accelerates Fusobacterium nucleatum-induced CCL8 expression in macrophages and is associated with colorectal cancer progression.

Accumulating evidence suggests that high levels of Fusobacterium nucleatum in colorectal tumor tissues can be associated with poor prognosis in patients with colorectal cancer (CRC); however, data regarding distinct prognostic subgroups in F. nucleatum-positive CRC remain limited. Herein, we demonstrate that high-iron status was associated with a worse prognosis in patients with CRC with F. nucleatum. Patients with CRC presenting elevated serum transferrin saturation exhibited preferential iron deposition in macrophages in the tumor microenvironment. In addition, F. nucleatum induced CCL8 expression in macrophages via the TLR4/NF-κB signaling pathway, which was inhibited by iron deficiency. Mechanistically, iron attenuated the inhibitory phosphorylation of NF-κB p65 by activating serine/threonine phosphatases, augmenting tumor-promoting chemokine production in macrophages. Our observations indicate a key role for iron in modulating the NF-κB signaling pathway and suggest its prognostic potential as a determining factor for interpatient heterogeneity in F. nucleatum-positive CRC.

Recommendations of 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.

Iron overload phenotypes and HFE genotypes in white hemochromatosis and iron overload screening study participants without HFE p.C282Y/p.C282Y.

BackgroundScreening program participants with iron overload (IO) phenotypes without HFE p.C282Y/p.C282Y are incompletely characterized.MethodsWe studied white participants who had IO phenotypes without p.C282Y/p.C282Y in post-screening clinical examinations (CE). We defined IO phenotypes as a) elevated serum ferritin (SF) and transferrin saturation (TS) at screening and CE, and b) absence of IO treatment, anemia, transfusion >10 units, alcohol intake >30 g/d, hepatitis B or C, and pregnancy. We defined IO-related disease as elevated alanine or aspartate aminotransferase (ALT/AST) or swelling/tenderness of 2nd/3rd metacarpophalangeal (MCP) joints. All participants had HFE p.C282Y and p.H63D genotyping.ResultsThere were 32 men and 26 women (mean age 54±16 y). Median food/supplemental iron intakes were 14.3/0.0 mg/d. Relative risks of HFE genotypes were 12.9 (p.C282Y/p.H63D), 3.0 (p.H63D/p.H63D), 1.9 (p.C282Y/wt), 0.9 (p.H63D/wt), and 0.5 (wt/wt) compared to 42,640 white screening participants without IO phenotypes or p.C282Y/p.C282Y. Regression on SF revealed positive associations: MCV (p = 0.0006; β coefficient = 0.4531); swelling/tenderness of MCP joints (p = 0.0033; β = 0.3455); and p.H63D/wt (p = 0.0015; β = 0.4146). IO-related disease (18 elevated ALT/AST, one swelling/tenderness of MCP joints) occurred in 19 participants (7 men, 12 women). Median MCV was higher in participants with IO-related disease (97 fL vs. 94 fL; p = 0.0007). Logistic regression on IO-related disease revealed a significant association with diabetes (p = 0.0416; odds ratio 18.9 (95% confidence interval 1.0, 341.1)).ConclusionsIn the present 58 screening program participants who had IO phenotypes without HFE p.C282Y/p.C282Y, relative risks of HFE genotypes p.C282Y/p.H63D, p.H63D/p.H63D, and p.C282Y/wt were significantly higher than in 42,640 white screening participants with neither IO phenotypes nor p.C282Y/p.C282Y. SF was significantly associated with MCV, swelling/tenderness of 2nd/3rd MCP joints, and p.H63D/wt. IO-related disease was significantly associated with MCV and diabetes.

NTBI levels in C282Y homozygotes after therapeutic phlebotomy.

C282Y homozygotes exposed to sustained elevated transferrin saturation (TS) may develop worsening clinical symptoms. This might be related to the appearance of non‐transferrin bound iron (NTBI) when TS≥50% and labile plasma iron (LPI) when TS levels reach 75–80%. In this study, NTBI levels were examined in 219 randomly selected untreated and treated C282Y homozygotes. Overall, 161 of 219 had TS ≥ 50%, 124 of whom had detectable NTBI (≥0.47 µM, 1.81 µM [0.92–2.46 µM]) with a median serum ferritin 320 µg/L (226–442 µg/L). Ninety of 219 homozygotes had TS ≥ 75%, and all had detectable NTBI (2.21 µM [1.53–2.59 µM] with a median ferritin 338 µg/L [230–447 µg/L]). Of 125 homozygotes who last had phlebotomy ≥12 months ago (42 months [25–74 months], 92 had TS levels ≥ 50%, and 70 of these had NTBI ≥ 0.47 µM (2.06 µM [1.23–2.61µM]). Twenty‐six of these 70 had a normal ferritin. Fifty‐five of 125 had TS ≥ 75%, and NTBI was detected in all of these (2.32 µM [1.57–2.77 µM]) with a median ferritin 344 µg/L (255–418 µg/L). Eighteen of these 55 had a normal ferritin. In summary, NTBI is frequently found in C282Y homozygotes with TS ≥ 50%. Furthermore, C282Y homozygotes in the maintenance phase often have TS ≥ 50% together with a normal ferritin. Therefore, monitoring the TS level during the maintenance phase is recommended as an accessible clinical marker of the presence of NTBI.

Transferrin saturation as a surrogate marker for assessment of labile nontransferrin bound iron in chronic liver disease.

Increased transferrin saturation (TS) and ferritin are common in hereditary hemochromatosis (HH) but also in chronic liver diseases (CLD). Nontransferrin bound iron (NTBI) is believed to be associated with iron-induced cell damage. We aimed to evaluate NTBI in CLD and their relationship with liver damage. Two groups of patients were studied. Group 1 (G1): 94 CLD patients from an Outpatient Hepatology Unit. Group 2 (G2): 36 healthy individuals form a Medical Checkup Clinic. Transferrin iron-binding capacity, TS, ferritin, AST, ALT, and red cell count were performed using standard tests. NTBI was assessed as enhanced labile plasma iron (eLPi). Levels of eLPi less than 0.4 µmol/l were considered within the normal range. Prevalence of increased iron tests (elevated TS and ferritin) was 14% in G1 and 5.5% in G2 ( P = 0.19). Positive NTBI was found in 12 patients (11 in G1 and 1 in G2). Positivity to NTBI was associated with increased iron tests ( P = 0.03), cirrhosis ( P = 0.03) and AST index (ASTI) ( P = 0.03). NTBI was associated with TS of more than 70% ( P = 0.002) but not to elevated ferritin ( P = 0.74). Variables strongly associated with a positive NTBI in univariate analysis (TS > 70%, cirrhosis and ASTI) were submitted to binary regression analysis. TS of more than 70% was the only independent predictive factor ( P = 0.049; odds ratio, 6.8). NTBI was associated with TS in CLD, but not with ferritin. NTBI testing could be useful for CLD patients with increased iron tests. Alternatively, a TS of more than 70% can be used as a surrogate marker.

Elevated transferrin saturation in individuals with alcohol use disorder: Association with HFE polymorphism and alcohol withdrawal severity.

Iron loading has been consistently reported in those with alcohol use disorder (AUD), but its effect on the clinical course of the disease is not yet fully understood. Here, we conducted a cohort study to examine whether peripheral iron measures, genetic variation in HFE rs1799945 and their interaction differed between 594 inpatient participants with alcohol use disorder (AUD) undergoing detoxification and 472 healthy controls (HC). We also assessed whether HFE rs1799945 was associated with elevated peripheral iron and can serve as a predictor of withdrawal severity. AUD patients showed significantly higher serum transferrin saturation than HC. Within the AUD group, transferrin saturation significantly predicted withdrawal symptoms (CIWA-Ar) and cumulative dose of benzodiazepine treatment during the first week of detoxification, which is an indicator of withdrawal severity. HFE rs1799945 minor allele carriers showed elevated transferrin saturation compared to non-carriers, both in AUD and healthy controls. Exploratory analyses indicated that, within the AUD cohort, HFE rs1799945 predicted CIWA withdrawal scores, and this relationship was significantly mediated by transferrin saturation. We provide evidence that serum transferrin saturation predicts alcohol withdrawal severity in AUD. Moreover, our findings replicated previous studies on elevated serum transferrin saturation in AUD and an involvement of HFE rs1799945 in serum transferrin saturation levels in both AUD and healthy controls. Future studies may use transferrin saturation measures as predictors for treatment or potentially treat iron overload to ameliorate withdrawal symptoms.

Annals for Educators - February 2022.

Annals for Educators - February 2022.

The PIEZO1 gene mutation (c.2005G&gt;T) causes iron overload cardiomyopathy: a case report

Abstract Background: Cardiomyopathy has a variety of etiologies. Here, we report a case of iron overload cardiomyopathy (IOC) in combination with hereditary stomatocytosis (HST) due to a rare mutation in the PIEZO1 gene. Case summary: A 31-year-old man presented to the clinic with a new onset of fatigue and abdominal distension. He had a history of 9-year cholelithiasis, 4-year hemolytic anemia, 7-month diabetes mellitus (DM), and 6-month low sex drive. The specific features of bronze skin, liver palms, yellow eyes, DM, and cardiomyopathy raised our suspicion of hemochromatosis, which was confirmed by an elevated serum ferritin concentration and high transferrin saturation. Echocardiography and cardiovascular magnetic resonance (CMR) imaging demonstrated dilation of all cardiac cavities with a left ventricular ejection fraction of 30%. CMR T2∗ mapping showed myocardial, hepatic, and pancreatic siderosis. Next-generation sequencing identified one missense variant in the PIEZO1 gene (c.2005G&gt;T), which conferred HST and hyperferritinemia. We screened his close family members and identified his son as a heterozygous carrier of this variant, who had intermittent jaundice. Conclusion: In this case, the PIEZO1 c.2005G&gt;T mutation conferred HST and IOC, complicated with cholelithiasis, DM, and low sex drive. Bronze skin, liver cirrhosis, cardiomyopathy, and DM are red flags, while magnetic resonance imaging T2∗ mapping, blood iron metabolism markers, and gene testing are valuable in the diagnosis.

Megaloblastic anemia-related iron overload and erythroid regulators: a case report

BackgroundIn ineffective erythropoiesis, hepcidin synthesis is suppressed by erythroid regulators, namely erythroferrone and growth differentiation factor-15. For the first time, the hypothesis that iron overload in megaloblastic anemia may be related to ineffective erythropoiesis is explored by describing the kinetics of hepcidin, erythroferrone, and growth differentiation factor-15 levels in a patient diagnosed with megaloblastic anemia associated with iron overload.Case presentationAn 81-year-old Caucasian male was admitted for fatigue. He had type-2 diabetes previously treated with metformin, ischemic cardiac insufficiency, and stage-3 chronic kidney disease. Vitiligo was observed on both hands. Biological tests revealed normocytic non-regenerative anemia associated with hemolysis, thrombocytopenia, and elevated sideremia, ferritin, and transferrin saturation levels. Megaloblastic anemia was confirmed with undetectable blood vitamin B12 and typical cytological findings like hyper-segmented neutrophils in blood and megaloblasts in bone marrow. The patient received vitamin B12 supplementation. At 3 months, biological parameters reached normal values. Hepcidin kinetics from diagnosis to 3 months inversely correlated with those of erythroferrone and growth differentiation factor-15.ConclusionsThis case suggests that iron-overload mechanisms of dyserythropoietic anemias may apply to megaloblastic anemias.