Iron deficiency is associated with poor prognosis in idiopathic sudden sensorineural hearing loss.

OBJECTIVE: The effects of iron deficiency on the prognosis of idiopathic sudden sensorineural hearing loss are unclear. This study aimed to investigate the association between serum iron levels and idiopathic sudden sensorineural hearing loss prognosis and its usefulness as an independent prognostic marker for idiopathic sudden sensorineural hearing loss. METHODS: The audiological and haematological data, including hearing recovery and serum iron levels, of 103 patients with idiopathic sudden sensorineural hearing loss evaluated between 2015 and 2018 were retrospectively analysed. RESULTS: The overall complete recovery rate was 16.5 per cent. Initial higher hearing threshold was associated with poor idiopathic sudden sensorineural hearing loss prognosis. Serum iron levels were significantly higher in the complete recovery group than in the non-complete recovery group (p < 0.05). CONCLUSION: The possibility of complete recovery from idiopathic sudden sensorineural hearing loss was significantly lower with lower serum iron levels, suggesting that the serum iron level might be a novel prognostic marker for idiopathic sudden sensorineural hearing loss.

Abnormal iron status is associated with an increased risk of mortality in patients on peritoneal dialysis.

BACKGROUND AND AIMS: Iron deficiency is prevalent, but there is limited data about the relationship between iron status and poor outcomes in chronic kidney disease patients undergoing peritoneal dialysis (PD). We aimed to investigate the association between iron status and mortality in PD patients. METHODS AND RESULTS: This retrospective study was conducted on incident PD patients from January 2006 to December 2016 and followed up until December 2018. Patients were categorized into four groups according to baseline serum transferrin saturation (percent) and ferritin levels (ng/ml): reference (20-30%, 100-500 ng/ml), absolute iron deficiency (<20%, <100 ng/ml), function iron deficiency (FID) (<20%, >100 ng/ml), and high iron (>30%, >500 ng/ml). Among the 1173 patients, 77.5% had iron deficiency. During a median follow-up period of 43.7 months, compared with the reference group, the FID group was associated with increased risk for all-cause [adjusted hazard ratio (aHR) 1.87, 95% confidence interval (95% CI) 1.05-3.31, P = 0.032], but not cardiovascular (CV) mortality. Additionally, the high iron group had a more than four-fold increased risk of both all-cause and CV mortality [aHR 4.32 (95% CI 1.90-9.81), P < 0.001; aHR 4.41 (95% CI 1.47-13.27), P = 0.008; respectively]. CONCLUSION: FID and high iron predict worse prognosis of patients on PD.

Clinical features and blood iron metabolism markers in children with beta-propeller protein associated neurodegeneration.

BACKGROUND: Neurodegeneration with brain iron accumulation constitutes a group of rare progressive movement disorders sharing intellectual disability and neuroimaging findings as common denominators. Beta-propeller protein-associated neurodegeneration (BPAN) represents approximately 7% of the cases, and its first signs are typically epilepsy and developmental delay. We aimed to describe in detail the phenotype of BPAN with a special focus on iron metabolism. MATERIAL AND METHODS: We present a cohort of paediatric patients with pathogenic variants of WD-Repeat Domain 45 gene (WDR45). The diagnosis was established by targeted panel sequencing of genes associated with epileptic encephalopathies (n = 9) or by Sanger sequencing of WDR45 (n = 1). Data on clinical characteristics, molecular-genetic findings and other performed investigations were gathered from all participating centres. Markers of iron metabolism were analysed in 6 patients. RESULTS: Ten children (3 males, 7 females, median age 8.4 years) from five centres (Prague, Berlin, Vogtareuth, Tubingen and Cologne) were enrolled in the study. All patients manifested first symptoms (e.g. epilepsy, developmental delay) between 2 and 31 months (median 16 months). Seven patients were seizure-free (6 on antiepileptic medication, one drug-free) at the time of data collection. Neurological findings were non-specific with deep tendon hyperreflexia (n = 4) and orofacial dystonia (n = 3) being the most common. Soluble transferrin receptor/log ferritin ratio was elevated in 5/6 examined subjects; other parameters of iron metabolism were normal. CONCLUSION: Severity of epilepsy often gradually decreases in BPAN patients. Elevation of soluble transferrin receptor/log ferritin ratio could be another biochemical marker of the disease and should be explored by further studies.

Iron deficiency during first-line chemotherapy in metastatic cancers: a prospective epidemiological study.

PURPOSE: Anemia is common in oncology and negatively impacts quality of life. However, there is lack of knowledge about iron deficiency (ID) epidemiology. The aim of this study was to prospectively assess iron status in patients with locally advanced or metastatic cancer beginning chemotherapy. METHODS: In this prospective, multicenter cohort study, anemia and ID were evaluated in patients with locally advanced or metastatic solid tumors and lymphoma before starting chemotherapy. Blood samples were collected at inclusion (W0), 6 weeks (W6), and 12 weeks (W12). Prevalence was evaluated in the general population, according to tumor location and was correlated with tumor response. RESULTS: One hundred twenty-nine patients were enrolled between 2013 and 2015; 119 had solid tumors and 10 lymphomas. At W0, there were no significant difference between locations with a prevalence around 50-60% (range 47.2-70.4%) and only a trend for colorectal cancer (70.4%, P = 0.069) due to a higher prevalence of absolute ID (18.5%). Prevalence of ID+ decreased between W0 and W6 and remained stable until W12 due to the proportion of patients with ID and without anemia. However, anemia prevalence increased during W0 and W6 and remained stable to W6 from W12 due to patients with anemia but without ID. A significant correlation between tumor response and ID prevalence was found (P = 0.036). CONCLUSIONS: We confirm the high prevalence of ID and anemia in cancer patients. ID status is correlated to tumor response providing a strong rationale for iron monitoring during cancer management.

[Severe hypocupremia and familial amyloid polyneuropathy]. / Hipocupremia severa y polineuropatía amiloidótica familiar por transtiretina.

INTRODUCTION: Introduction: we report a patient with transthyretin familial amyloid polyneuropathy (TTR-FAP) and severe hypocupremia. Case report: a 79-year-old male with TTR-FAP and severe malnutrition. Laboratory tests showed low serum copper (Cu) and ceruloplasmin levels, as well as low urinary Cu levels. The patient reported neither digestive symptoms nor previous gastrointestinal surgery. Liver function tests, iron metabolism, hemoglobin, leukocytes and zinc were normal. Discussion: Cu is a trace element. It is part of the cuproenzymes involved in several physiological functions. Hypocupremia can be related to genetic or acquired etiologies, including low intake, bariatric surgery, increased losses, etc. Primary clinical manifestations include hematological (anemia and leukopenia) and neurological (myelopathy, peripheral neuropathy) features. Treatment is empirical. In severe cases it may be initiated with endovenose administration, followed by oral supplementation.

INTRODUCCIÓN: Introducción: presentamos el caso de un paciente con antecedentes de polineuropatía amiloidótica familiar por transtiretina (TTR-FAP) diagnosticado de hipocupremia severa. Caso clínico: varón de 79 años afecto de TTR-FAP. Visto en consulta de nutrición por desnutrición severa. En el estudio analítico presenta cifras de cobre (Cu) sérico y ceruloplasmina bajas, con Cu en orina también bajo. No tiene clínica digestiva ni antecedentes de cirugía gastrointestinal. Las pruebas de función hepática, la ferrocinética, las cifras de Hb y leucocitos y los niveles de zinc (Zn) no presentan alteraciones relevantes. Discusión: el Cu es un oligoelemento que participa como componente de las cuproenzimas en múltiples funciones fisiológicas. Los niveles séricos bajos pueden relacionarse con causas genéticas o adquiridas, como la baja ingesta, la cirugía bariátrica, el aumento de las pérdidas, etc. Las principales manifestaciones clínicas son hematológicas (anemia, leucopenia) o neurológicas (mielopatía, neuropatía periférica). El tratamiento tiene base empírica. En los casos severos puede iniciarse con administración intravenosa, seguido de mantenimiento por vía oral.

Hyperferritinaemia: An Iron Sword of Autoimmunity.

BACKGROUND: Ferritin is a molecule that plays many roles being the storage for iron, signalling molecule, and modulator of the immune response. METHODS: Different electronic databases were searched in a non-systematic way to find out the literature of interest. RESULTS: The level of ferritin rises in many inflammatory conditions including autoimmune disorders. However, in four inflammatory diseases (i.e., adult-onset Still's diseases, macrophage activation syndrome, catastrophic antiphospholipid syndrome, and sepsis), high levels of ferritin are observed suggesting it as a remarkable biomarker and pathological involvement in these diseases. Acting as an acute phase reactant, ferritin is also involved in the cytokine-associated modulator of the immune response as well as a regulator of cytokine synthesis and release which are responsible for the inflammatory storm. CONCLUSION: This review article presents updated information on the role of ferritin in inflammatory and autoimmune diseases with an emphasis on hyperferritinaemic syndrome.

Unclassifiable non-CML classical myeloproliferative diseases with microcytosis: findings indicating diagnosis of polycythemia vera masked by iron deficiency

Background/aim: Polycythemia Vera (PV) is a myeloproliferative disorder characterized by overproduction of morphologically normal red blood cells (RBCs), granulocytes, and platelets, a phenotype that is caused by a mutation (V617F) in Janus kinase 2 (JAK2). However, JAK2 V617F is also found in approximately 50% of patients with essential thrombocytosis and primary myelofibrosis, rendering its presence nonspecific as a diagnostic test. An increased red cell mass is a major criterion for the diagnosis of PV according to World Health Organization (WHO) 2016 criteria. High hemoglobin (Hgb) or Hematocrit (Hct) are universally used as indicators of an increased red cell mass for the diagnosis of PV. However, conditions such as iron deficiency (ID) with decreased mean cell volume may mask the diagnosis due to nonelevated Hct level. The aim of this study was to investigate the clinical characteristics of the patients with unclassifiable non-CML classical myeloproliferative disease with microcytosis (MPD/M) and nonelevated Hgb and Hct levels at diagnosis and to determine if some of these cases could be real PV cases masked due to ID-related microcytosis. Materials and methods: There were 23 MPD/M cases among 208 non-CML classical MPD cases (11%). Among 22 patients who had adequate test results related to the cause of microcytosis, ID and beta-thalassemia trait (TT) were the apparent causes of microcytosis in 15 and 1 cases, respectively. Results: Clinicopathological correlations revealed consistently positive JAK2 V617F mutation status (20/20, 100%), frequently elevated RBC count (17/23, 73.9%), and PV-compatible bone marrow findings (10/12, 83.3%). These findings are compatible with PV instead of essential thrombocytopenia or primary myelofibrosis. In spite of frequent cytoreductive treatment, 3 patients developed increased Hgb/Htc levels during median 58.2 (279­63) months' follow-up. Conclusion: These data show that the majority of MPD/M cases are PV patients masked due to ID-related microcytosis.

Treatment options for anemia in the elderly.

Anemia in elderly (AE), though often mild, is quite common and independently associated with important clinical outcomes, including decreased quality of life, risk of falls and fractures, cognitive decline, increased length of hospital stay, and even mortality. AE is generally overlooked, and hence undertreated, especially when comorbidities distract the attention of physicians and caregivers. This also partially reflects difficulties in dissecting the cause(s) of AE, which is typically multifactorial, as well as our limited diagnostic approach often categorizing AE as apparently "unexplained". Therapeutic approaches have been traditionally limited to transfusions, or supplementation with hematinics, including group B vitamins and iron. The latter has been largely underutilized, because of missing diagnosis of iron deficiency using inappropriate laboratory thresholds, as well as complex schedule and adverse effects associated with traditional preparations. After decades of stagnation, new oral and intravenous iron preparations look promising, particularly in the elderly. Moreover, a number of innovative anti-anemic drugs, like hepcidin modulators, Hypoxia Inducible Factor (HIF) stabilizers, and activin type II receptor agonists are entering the clinical arena and may substantially improve our therapeutic armamentarium to AE in the near future.

The Influence of Cardiovascular Medications on Iron Metabolism in Patients with Heart Failure.

Background and objectives: The etiology of anemia associated with heart failure is not fully understood, but there are data suggesting the involvement of multiple mechanisms, including various drug therapies used in patients with heart failure. Our primary objective was to evaluate the impact of beta blockers, angiotensin-converting enzyme inhibitors, and calcium-channel blockers on iron metabolism in patients with heart failure. Materials and Methods: This was a prospective observational study that included patients diagnosed with heart failure and iron deficiency (defined by ferritin <100 µg/L, or 100-300 µg/L with transferrin saturation <20%). Patients with anemia secondary to a known cause were excluded. Results: We found a statistically significant correlation between beta-blocker treatment and ferritin values (p = 0.02). Iron, hemoglobin, and hematocrit levels were significantly lower in the patients using calcium-channel blockers than those who were not. We also found a statistically significant indirect correlation (p = 0.04) between the use of angiotensin-converting enzyme inhibitors and hematocrit levels. Conclusion: The contribution of our study arises from the additional data regarding the drug-induced etiology of iron deficiency. Practitioners should be aware of the potential impact of therapeutic recommendations and this should imply a close monitoring of the biochemical parameters of iron deficiency in this category of patients.

Do Transferrin Levels Predict Haemodialysis Adequacy in Patients with End-Stage Renal Disease?

BACKGROUND: Since haemodialysis is a lifesaving therapy, adequate control measures are necessary to evaluate its adequacy and to constantly adjust the dose to reduce hospitalisation and prolong patient survival. Malnutrition is common in haemodialysis patients and closely related to morbidity and mortality. Patients undergoing haemodialysis have a high prevalence of protein-energy malnutrition and inflammation, along with abnormal iron status. The haemodialysis dose delivered is an important predictor of patient outcome. AIM: To evaluate through haemodialysis adequacy, which parameter(s), if any, better predict Kt/V, among those used to assess nutritional status, inflammation response, and iron status. METHODS: We retrospectively studied 78 patients undergoing haemodialysis due to end-stage renal disease. As parameters of nutritional status, geriatric nutritional risk index (GNRI), transferrin levels, lymphocyte count, and albumin concentration were analysed. As signs of inflammation, C reactive protein (CRP) levels and ferritin concentrations were studied as well. Iron status was evaluated by both transferrin and ferritin levels, as well as by haemoglobin (Hb) concentration. RESULTS: The core finding of our retrospective study is that transferrin levels predict the adequacy of haemodialysis expressed as Kt/V; the latter is the only predictor (P = 0.001) when adjusting for CRP concentrations, a solid marker of inflammation, and for ferritin levels considered an iron-storage protein, but also a parameter of inflammatory response. DISCUSSION AND CONCLUSION: In keeping with the results of this study, we underline that the use of transferrin levels to assess haemodialysis quality combine into a single test the evaluation of the three most important factors of protein-energy wasting.

Iron Deficiency and Obesity - Are we Diagnosing with Appropriate Indicators?

INTRODUCTION: We aim to define the iron deficiency prevalence and eventual differences between obese patients with and without metabolic syndrome. MATERIAL AND METHODS: Analysis of patients evaluated at multidisciplinary consultation of obesity in our institution between 2013 and 2015 (n = 260). Iron deficiency: ferritin levels < 15 ng/mL. EXCLUSION CRITERIA: prior bariatric surgery; lack of ferritin or hemoglobin determinations. RESULTS: We analyzed data from 215 patients (84.2% female) with a mean age of 42.0 ± 10.3 years. The median body mass index was 42.5 (40.0 - 46.8) kg/m2 and 52.1% had metabolic syndrome. Iron deficiency was present in 7.0%, with no differences between genders or between patients with or without metabolic syndrome. Hypertension was associated with lower prevalence of iron deficiency. Type 2 diabetes and hypertension patients had higher levels of ferritin. The multivariate analysis showed that metabolic syndrome and increasing body mass index were predictive of higher risk of iron deficiency while hypertension predicted lower odds of iron deficiency. DISCUSSION: The prevalence of iron deficiency was similar in other published studies. Iron deficiency may be underdiagnosed if based only on ferritin concentrations. In our study, diabetes and hypertension appear to contribute to the increase in ferritin levels described in obesity. CONCLUSION: Ferritin may not be a reliable index for evaluating iron stores in obese patients, particularly when associated with comorbidities such as type 2 diabetes and hypertension. Further studies are needed to guide the diagnosis and iron supplementation in these patients.

Introdução: Os objetivos foram a determinação da prevalência de défice de ferro e de eventuais diferenças entre os doentes obesos com e sem síndrome metabólica. Material e Métodos: Análise dos doentes observados na consulta multidisciplinar de obesidade na nossa instituição entre 2013 e 2015 (n = 260). Défice de ferro: ferritina < 15 ng/mL. Critérios de exclusão: cirurgia bariátrica prévia, ausência de doseamentos de ferritina e de hemoglobina. Resultados: Avaliaram-se 215 doentes (84,2% mulheres) com uma idade média de 42,0 ± 10,3 anos. O índice de massa corporal mediano foi 42,5 (40,0 - 46,8) kg/m2 e 52,1% apresentavam síndrome metabólica. O défice de ferro estava presente em 7,0% sem diferenças entre os géneros e entre os doentes com e sem síndrome metabólica. A hipertensão associou-se a menor prevalência de défice de ferro. Doentes com diabetes tipo 2 e hipertensão apresentaram valores mais elevados de ferritina. Na análise multivariada, a síndrome metabólica e o índice de massa corporal constituíram fatores preditivos de défice de ferro, enquanto a hipertensão se associou a um menor risco. Discussão: A prevalência de défice de ferro foi similar a estudos previamente publicados. O défice de ferro pode ser subdiagnosticado se baseado apenas nas concentrações de ferritina. No nosso estudo, a diabetes e a hipertensão parecem contribuir para os níveis elevados de ferritina descritos na obesidade. Conclusão: A ferritina poderá não ser um índice fiável para avaliação de reservas de ferro na obesidade, particularmente quando associada a diabetes tipo 2 e hipertensão. São necessários mais estudos de forma a orientar o diagnóstico e a suplementação com ferro nestes doentes.

Phenotypic heterogeneity in seven Italian cases of aceruloplasminemia.

INTRODUCTION: Aceruloplasminemia is an ultra-rare hereditary disorder characterized by iron-restricted microcytic anemia and tissue iron overload associated with diabetes, retinal and progressive neurological degeneration. We describe genotypes and phenotypes at diagnosis, and disease evolution of seven Italian patients. METHODS: Anagraphical, biochemical, genetic, clinical and instrumental data were collected at diagnosis and during a long-term follow-up. Mutations, ferroxidase activity and Western Blot analysis of ceruloplasmin were performed according to standard protocols. RESULTS: Three mutations were already described (p.Phe217Ser, deletions of exon 11 and 12), p.Ile991Thr is a very rare variant, p.Cys338Ser and IVS6+1G > A were novel mutations. In silico analyses suggested they were highly likely or likely to be damaging. At diagnosis, 100% had microcytosis, 86% had mild-moderate anemia, low serum iron and high serum ferritin. Four (57%) had type 1 diabetes or glucose intolerance, 3/7 had neurological manifestations, and only one had early diabetic retinopathy. All but one underwent iron chelation therapy requiring temporary discontinuation because of anemia worsening. At the end of follow-up, three patients aggravated and 2 developed neurological symptoms; only two patients were free of neurological manifestations and showed mild or absent brain iron. CONCLUSION: Aceruloplasminemia phenotypes ranged from classical characterized by progressive neurologic derangement to milder in which signs of systemic iron overload prevailed over brain iron accumulation. Within this large heterogeneity, microcytosis with or without anemia, low serum iron and high serum ferritin were the early hallmarks of the disease. Therapeutic approaches other than iron chelation should be explored to reduce morbidity and improve life expectancy.

Hepatic iron is the major determinant of serum ferritin in NAFLD patients.

BACKGROUND AND AIMS: Elevated serum ferritin is common in NAFLD, and is associated with more advanced disease and increased mortality. Hyperferritinaemia in NAFLD is often attributed to inflammation, while in other conditions ferritin closely reflects body iron stores. The aim of this study was to clarify the underlying cause of hyperferritinaemia in NAFLD. METHODS: Ferritin levels were examined with markers of iron status, inflammation and liver injury across the clinical spectrum of NAFLD using blood, tissue and magnetic resonance (MR) imaging. A separate larger group of NAFLD patients with hepatic iron staining and quantification were used for validation. RESULTS: Serum ferritin correlated closely with the iron regulatory hormone hepcidin, and liver iron levels determined by MR. Furthermore, ferritin levels reflected lower serum adiponectin, a marker of insulin resistance, and liver fat, but not cytokine or CRP levels. Ferritin levels differed according to fibrosis stage, increasing from early to moderate disease, and declining in cirrhosis. A similar pattern was found in the validation cohort of NAFLD patients, where ferritin levels were highest in those with macrophage iron deposition. Multivariate analysis revealed liver iron and hepcidin levels as the major determinants of serum ferritin. CONCLUSIONS: While hyperferritinaemia is associated with markers of liver injury and insulin resistance, serum hepcidin and hepatic iron are the strongest predictors of ferritin levels. These findings highlight the role of disordered iron homeostasis in the pathogenesis of NAFLD, suggesting that therapies aimed at correcting iron metabolism may be beneficial.

Ferritin light chain gene mutations in two Brazilian families with hereditary hyperferritinemia-cataract syndrome / Mutações no gene da cadeia leve da ferritina em duas famílias brasileiras com síndrome hereditária hiperferritinemia-catarata

ABSTRACT Hereditary hyperferritinemia-cataract syndrome is an autosomal dominant genetic disorder associated with mutations in the 5'UTR region of the ferritin light chain gene. These mutations cause the ferritin levels to increase even in the absence of iron overload. Patients also develop bilateral cataract early due to accumulation of ferritin in the lens, and many are misdiagnosed as having hemochromatosis and thus not properly treated. The first cases were described in 1995 and several mutations have already been identified. However, this syndrome is still a poorly understood. We report two cases of unrelated Brazilian families with clinical suspicion of the syndrome, which were treated in our department. For the definitive diagnosis, the affected patients, their parents and siblings were submitted to Sanger sequencing of the 5'UTR region for detection of the ferritin light gene mutation. Single nucleotide polymorphism-like mutations were found in the affected patients, previously described. The test assisted in making the accurate diagnosis of the disease, and its description is important so that the test can be incorporated into clinical practice.

RESUMO A síndrome hereditária hiperferritinemia-catarata é uma doença genética autossômica dominante associada a mutações na região 5'UTR do gene da cadeia leve da ferritina. Estas mutações elevam os níveis de ferritina, mesmo na ausência de sobrecarga de ferro. Os pacientes também desenvolvem catarata bilateral precocemente, devido ao acúmulo de ferritina no cristalino, e muitos são erroneamente diagnosticados como portadores de hemocromatose, sendo tratados de maneira inadequada. Os primeiros casos foram descritos em 1995, e diversas mutações já foram identificadas. Entretanto, essa síndrome ainda é pouco conhecida. Relatamos dois casos de famílias brasileiras, não relacionadas, com suspeita clínica da síndrome, que foram atendidas em nosso serviço. Para o diagnóstico definitivo, os pacientes afetados, seus pais e irmãos foram submetidos à pesquisa de mutação do gene ferritina, por sequenciamento de Sanger da região 5'UTR. Foram encontradas mutações do tipo polimorfismo de nucleotídeo único nos pacientes afetados, já descritas anteriormente. O teste auxiliou no diagnóstico preciso da doença e é importante ser divulgado, para ser incorporado na prática clínica.

Diagnosis of hyperferritinemia in routine clinical practice.

The discovery of hyperferritinemia is often fortuitous, revealed in results from a laboratory screening or follow-up test. The aim of the diagnostic procedure is therefore to identify its cause and to identify or rule out hepatic iron overload, in a three-stage process. In the first step, clinical findings and several simple laboratory tests are sufficient to detect four of the most frequent causes of high ferritin concentrations: alcoholism, inflammatory syndrome, cytolysis, and metabolic syndrome. None of these causes is associated with substantial hepatic iron overload. If transferrin saturation is high (> 50%), hereditary hemochromatosis will be considered in priority. In the second phase, rarer diseases will be sought. Among them, only chronic hematologic diseases (acquired or congenital) and excessive iron intake or infusions (patients on chronic dialysis and high-level athletes) are at risk of iron overload. In the third stage, if a doubt persists about the cause or if the ferritin concentration is very high or continues to rise, it is essential to verify the hepatic iron concentration to rule out overload. The principal examination to guide diagnosis and treatment is hepatic MRI to assess its iron concentration. It is essential to remember that more than 40% of patients with hyperferritinemia have several causes simultaneously present.

The dynamics of hepcidin-ferroportin internalization and consequences of a novel ferroportin disease mutation.

The hepcidin-ferroportin axis underlies the pathophysiology of many iron-associated disorders and is a key target for the development of therapeutics for treating iron-associated disorders. The aims of this study were to investigate the dynamics of hepcidin-mediated ferroportin internalization and the consequences of a novel disease-causing mutation on ferroportin function. Specific reagents for ferroportin are limited; we developed and characterized antibodies against the largest extracellular loop of ferroportin and developed a novel cell-based assay for studying hepcidin-ferroportin function. We show that hepcidin-mediated ferroportin internalization is a rapid process and could be induced using low concentrations of hepcidin. Targeted next-generation sequencing utilizing an iron metabolism gene panel developed in our group identified a novel ferroportin p.D84E variant in a patient with iron overload. Wild-type and mutant ferroportin constructs were generated, transfected into HEK293 cells and analysed using an all-in-one flow-cytometry-based assay to study the effects on hepcidin-mediated internalization and iron transport. Consistent with the classical phenotype of ferroportin disease, the p.D84E mutation results in an inability to transport iron and hepcidin insensitivity. These results validate a recently proposed 3D-structural model of ferroportin and highlight the significance of this variant in the structure and function of ferroportin. Our novel ferroportin antibody and assay will be valuable tools for investigating the regulation of hepcidin/ferroportin function and the development of novel approaches for the therapeutic modulation of iron homeostasis.

Ferritin light chain gene mutations in two Brazilian families with hereditary hyperferritinemia-cataract syndrome.

Hereditary hyperferritinemia-cataract syndrome is an autosomal dominant genetic disorder associated with mutations in the 5'UTR region of the ferritin light chain gene. These mutations cause the ferritin levels to increase even in the absence of iron overload. Patients also develop bilateral cataract early due to accumulation of ferritin in the lens, and many are misdiagnosed as having hemochromatosis and thus not properly treated. The first cases were described in 1995 and several mutations have already been identified. However, this syndrome is still a poorly understood. We report two cases of unrelated Brazilian families with clinical suspicion of the syndrome, which were treated in our department. For the definitive diagnosis, the affected patients, their parents and siblings were submitted to Sanger sequencing of the 5'UTR region for detection of the ferritin light gene mutation. Single nucleotide polymorphism-like mutations were found in the affected patients, previously described. The test assisted in making the accurate diagnosis of the disease, and its description is important so that the test can be incorporated into clinical practice.

The Effect of Iron Status on Risk of Coronary Artery Disease: A Mendelian Randomization Study-Brief Report.

OBJECTIVE: Iron status is a modifiable trait that has been implicated in cardiovascular disease. This study uses the Mendelian randomization technique to investigate whether there is any causal effect of iron status on risk of coronary artery disease (CAD). APPROACH AND RESULTS: A 2-sample Mendelian randomization approach is used to estimate the effect of iron status on CAD risk. Three loci (rs1800562 and rs1799945 in the HFE gene and rs855791 in TMPRSS6) that are each associated with serum iron, transferrin saturation, ferritin, and transferrin in a pattern suggestive of an association with systemic iron status are used as instruments. SNP (single-nucleotide polymorphism)-iron status association estimates are based on a genome-wide association study meta-analysis of 48 972 individuals. SNP-CAD estimates are derived by combining the results of a genome-wide association study meta-analysis of 60 801 CAD cases and 123 504 controls with those of a meta-analysis of 63 746 CAD cases and 130 681 controls obtained from Metabochip and genome-wide association studies. Combined Mendelian randomization estimates are obtained for each marker by pooling results across the 3 instruments. We find evidence of a protective effect of higher iron status on CAD risk (iron odds ratio, 0.94 per SD unit increase; 95% confidence interval, 0.88-1.00; P=0.039; transferrin saturation odds ratio, 0.95 per SD unit increase; 95% confidence interval, 0.91-0.99; P=0.027; log-transformed ferritin odds ratio, 0.85 per SD unit increase; 95% confidence interval, 0.73-0.98; P=0.024; and transferrin odds ratio, 1.08 per SD unit increase; 95% confidence interval, 1.01-1.16; P=0.034). CONCLUSIONS: This Mendelian randomization study supports the hypothesis that higher iron status reduces CAD risk. These findings may highlight a therapeutic target.

Ferric carboxymaltose in patients with restless legs syndrome and nonanemic iron deficiency: A randomized trial.

BACKGROUND: Compromised iron status is important in restless legs syndrome pathophysiology. We compared the efficacy and tolerability of ferric carboxymaltose (single intravenous dose) versus placebo for restless legs syndrome treatment in iron-deficient nonanemic patients. METHODS: Patients with moderate to severe restless legs syndrome and serum ferritin < 75 µg/L (or serum ferritin 75-300 µg/L and transferrin saturation < 20%) were randomized to ferric carboxymaltose (1000 mg iron) or placebo. Mean change difference between ferric carboxymaltose and placebo in International Restless Legs Syndrome Severity Scale score from baseline to week 4 was the primary end point; week 12 was a secondary end point. RESULTS: Ferric carboxymaltose treatment (n = 59) led to nonsignificant improvement over placebo (n = 51) in International Restless Legs Syndrome Severity Scale score at week 4 (difference [95% confidence interval], -2.5 [-5.93 to 1.02], P = 0.163), reaching significance by week 12 (-4.66 [-8.59 to -0.73], P = 0.021). CONCLUSIONS: In patients who responded to treatment, ferric carboxymaltose may require more time to stabilize restless legs syndrome than previously assumed. © 2017 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.