[Research advances in the pathogenesis and treatment of neurodegeneration with brain iron accumulation].

Neurodegeneration with brain iron accumulation (NBIA) is a group of rare neurogenetic degenerative diseases caused by genetic mutations and characterized by iron deposition in the central nervous system, especially in the basal ganglia, with an overall incidence rate of 2/1 000 000-3/1 000 000. Major clinical manifestations are extrapyramidal symptoms. This disease is presently classified into 14 different subtypes based on different pathogenic genes, and its pathogenesis and treatment remain unclear. This article summarizes the research advances in the pathogenesis and treatment of NBIA, so as to help pediatricians understand this disease and provide a reference for subsequent research on treatment.

Palliative care in 9 children with neurodegeneration with brain iron accumulation.

AIM: Evaluation of pediatric palliative home care of families with children suffering from neurodegeneration with brain iron accumulation (NBIA) and their parents. MATERIAL AND METHODS: The children were treated at home by a multidisciplinary team. Densitometry was used to evaluate the condition of the skeletal system. Botulinum toxin was injected into the muscles in doses between 22 and 50 units/kg. The quality of palliative care was assessed on the basis of a specially designed questionnaire for parents. RESULTS: The observations were performed on a group of 9 patients with NBIA. On admission, the median age of patients was 9 years (7-14). The average time of palliative home care was 1569 days (34 days-17 years). The median age at death (6 patients) was 11 years (7-15). The botulinum toxin injections gave the following results: reduction of spasticity and dystonia, reduction of spine and chest deformation, relief of pain and suffering, facilitation of rehabilitation and nursing, prevention of permanent contractures, and reduction of excessive salivation. Bone mineral density and bone strength index were reduced. Two patients experienced pathological fracture of the femur. The body mass index at admission varied between 9.8 and 14.9. In 7 cases, introduction of a ketogenic diet resulted in the increase of body mass and height. The ketogenic diet did not worsen the neurological symptoms. The parents positively evaluated the quality of care. CONCLUSION: Palliative home care is the optimal form of treatment for children with NBIA.

Hyperferritinemia in Nonalcoholic Fatty Liver Disease: Iron Accumulation or Inflammation?

Hyperferritinemia, observed in inflammation, iron overload as well as in combination of both, is found in ∼30% of nonalcoholic fatty liver disease (NAFLD) patients. The authors summarized the evidence regarding the potential cause of hyperferritinemia in NAFLD, as this may affect the indicated therapy. A systematic literature search was conducted in EMBASE, PubMed, MEDLINE, and the Cochrane library. In the majority of NAFLD patients, hyperferritinemia is due to inflammation without hepatic iron overload. In a smaller group, a dysmetabolic iron overload syndrome (DIOS) is found, showing hyperferritinemia in combination with mild iron accumulation in the reticuloendothelial cells. The smallest group consists of NAFLD patients with hemochromatosis. Phlebotomy is only effective with hepatocellular iron overload and should not be the treatment when hyperferritinemia is related to inflammation, whether or not combined with DIOS. Treatment with lifestyle changes is to date probably the more effective way until new medication is becoming available.

Diagnostics and Treatments of Iron-Related CNS Diseases.

Iron has been proposed to be responsible for neuronal loss in several diseases of the central nervous system, including Alzheimer's disease (AD), Parkinson's disease (PD), stroke, Friedreich's ataxia (FRDA), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS). In many diseases, abnormal accumulation of brain iron in disease-affected area has been observed, without clear knowledge of the contribution of iron overload to pathogenesis. Recent evidences implicate that key proteins involved in the disease pathogenesis may also participate in cellular iron metabolism, suggesting that the imbalance of brain iron homeostasis is associated with the diseases. Considering the complicated regulation of iron homeostasis within the brain, a thorough understanding of the molecular events leading to this phenotype is still to be investigated. However, current understanding has already provided the basis for the diagnosis and treatment of iron-related CNS diseases, which will be reviewed here.

Hepcidin in the diagnosis of iron disorders.

The discovery of the iron-regulatory hormone hepcidin in 2001 has revolutionized our understanding of iron disorders, and its measurement should advance diagnosis/treatment of these conditions. Although several assays have been developed, a gold standard is still lacking, and efforts toward harmonization are ongoing. Nevertheless, promising applications can already be glimpsed, ranging from the use of hepcidin levels for diagnosing iron-refractory iron deficiency anemia to global health applications such as guiding safe iron supplementation in developing countries with high infection burden.

A new model of an arteriovenous fistula in chronic kidney disease in the mouse: beneficial effects of upregulated heme oxygenase-1.

The arteriovenous fistula (AVF) is the preferred hemodialysis vascular access, but it is complicated by high failure rates and attendant morbidity. This study provides the first description of a murine AVF model that recapitulates two salient features of hemodialysis AVFs, namely, anastomosis of end-vein to side-artery to create the AVF and the presence of chronic kidney disease (CKD). CKD reduced AVF blood flow, observed as early as 3 days after AVF creation, and increased neointimal hyperplasia, venous wall thickness, thrombus formation, and vasculopathic gene expression in the AVF. These adverse effects of CKD could not be ascribed to preexisting alterations in blood pressure or vascular reactivity in this CKD model. In addition to vasculopathic genes, CKD induced potentially vasoprotective genes in the AVF such as heme oxygenase-1 (HO-1) and HO-2. To determine whether prior HO-1 upregulation may protect in this model, we upregulated HO-1 by adeno-associated viral gene delivery, achieving marked venous induction of the HO-1 protein and HO activity. Such HO-1 upregulation improved AVF blood flow and decreased venous wall thickness in the AVF. Finally, we demonstrate that the administration of carbon monoxide, a product of HO, acutely increased AVF blood flow. This study thus demonstrates: 1) the feasibility of a clinically relevant murine AVF model created in the presence of CKD and involving an end-vein to side-artery anastomosis; 2) the exacerbatory effect of CKD on clinically relevant features of this model; and 3) the beneficial effects in this model conferred by HO-1 upregulation by adeno-associated viral gene delivery.

Astrocyte Dysfunction in Developmental Neurometabolic Diseases.

Astrocytes play crucial roles in maintaining brain homeostasis and in orchestrating neural development, all through tightly coordinated steps that cooperate to maintain the balance needed for normal development. Here, we review the alterations in astrocyte functions that contribute to a variety of developmental neurometabolic disorders and provide additional data on the predominant role of astrocyte dysfunction in the neurometabolic neurodegenerative disease glutaric acidemia type I. Finally, we describe some of the therapeutical approaches directed to neurometabolic diseases and discuss if astrocytes can be possible therapeutic targets for treating these disorders.

[GENETICALLY DETERMINED DISEASES ASSOCIATED WITH PATHOLOGICAL BRAIN IRON ACCUMULATION AND NEURODEGENERATION]. / GENETIKAILAG MEGHÁTAROZOTT, AGYI VASFELHALMOZÓDÁSSAL ÉS NEURODEGENERÁCIÓVAL JÁRÓ KÓRKÉPEK.

The rare, genetically determined group of diseases characterized by pathological accumulation of iron in the central nervous system and progressive, typically movement disorder's symptoms are called NBIA (neurodegeneration with brain iron accumulation). By the rapid development of molecular genetics, it has become apparent that different mutations in numerous genes can lead to pathological cerebral iron accumulation. Simultaneously, it has also been recognized that the age of onset, the symptoms and the prognosis of NBIA disorders are much more diverse than it was previously perceived. To our knowledge, a review article on the most recent clinical data of NBIA has not been published in Hungarian. In the first part of this publication, we survey the general clinical characteristics and the diagnostic algorithm of NBIA diseases and address some considerations for differential diagnostics. In the second part of this review, the particular NBIA disorders are presented in details. The purpose of this article is to provide a clinical overview that may be useful for neurologists, pediatricians and any other medical practitioners interested in this field.

[Iron's ups and downs]. / Le fer dans tous ses états.

Iron is an essential trace metal whose extracellular concentration and stores are efficiently regulated. Systemic iron homeostasis assures a stable milieu in which each cell regulates its iron uptake to meet its own requirements. The system is challenged by variable availability of iron in the diet, by occasional iron losses through bleeding and by the fluctuations in the iron request by iron requiring processes such as erythropoiesis, growth, pregnancy and lactation; but also by pathologic processes involving aberrant iron retention leading to tissue iron overload and finally to end organ damage. A low serum ferritin is 100% specific for iron deficiency ; conversely hyperferritinemia is not a reliable sign of iron overload. Iron deficiency is a pan-ethnic disorder more prevalent in western and ageing people. Anemia represents the end stage of iron deficiency. During inflammatory states, iron becomes unavailable for erythropoiesis although adequate stores are present. This phenomenon is called functional iron deficiency and is characteristic of anemia of chronic disorders. Hyperferritinemia may exist in the presence or in the absence of iron overload. A cut off value of > 45% for transferrine saturation has been suggested to discriminate both settings. All the acquired conditions associated with hyperferritinemia must be excluded before performing genetic testing. Perfect understanding of iron homeostasis regulation as well as an adequate use of analyses exploring iron metabolism are mandatory for proper clinical management of iron deficiency and overload states.

[Management of renal anemia in 2013]. / Prise en charge de l'anémie rénale en 2013.

Anemia occurs frequently in patients with chronic kidney disease (CKD), especially in the later stages, and the main etiologies are decreased production of erythropoietin (EPO) as well as iron and vitamin deficiencies. For these reasons, it is essential to detect anemia in patients with CKD and to investigate the etiology. If anemia (Hb < 100 g/l) persists after substitution of deficiencies, treatment with recombinant human erythropoietin (rHuEPO) should be considered. New guidelines (KDIGO - August 2012) have just been published by the National Kidney Foundation (NKF) for the management of anemia in patients with renal failure. This article reviews the principles and innovations in management in 2013.

Iron deficiency syndromes and iron-restricted erythropoiesis (CME).

The relationships between erythropoietin (EPO), iron, and erythropoiesis and the presence of iron-restricted erythropoiesis have important implications in anemia management. Iron-restricted erythropoiesis occurs in the presence of one or more iron deficiency syndromes: absolute iron deficiency, functional iron deficiency, and/or iron sequestration. Absolute iron deficiency is a common nutritional deficiency in women's health, pediatrics, and the elderly and is therefore an important public health problem. Functional iron deficiency occurs in patients with significant EPO-mediated erythropoiesis or therapy with erythropoiesis-stimulating agents, even when storage iron is present. Iron sequestration mediated by hepcidin is an underappreciated but common cause of iron-restricted erythropoiesis in patients with chronic inflammatory disease. The challenge for treating and laboratory-based physicians is to understand the contributory role(s) of each of these syndromes, so that the potential value of emerging and innovative pharmacologic strategies can be considered as options in patient blood management.

Hepatitis C, porphyria cutanea tarda and liver iron: an update.

Porphyria cutanea tarda (PCT) is the most common form of porphyria across the world. Unlike other forms of porphyria, which are inborn errors of metabolism, PCT is usually an acquired liver disease caused by exogenous factors, chief among which are excess alcohol intake, iron overload, chronic hepatitis C, oestrogen therapy and cigarette smoking. The pathogenesis of PCT is complex and varied, but hereditary or acquired factors that lead to hepatic iron loading and increased oxidative stress are of central importance. Iron loading is usually only mild or moderate in degree [less than that associated with full-blown haemochromatosis (HFE)] and is usually acquired and/or mutations in HFE. Among acquired factors are excessive alcohol intake and chronic hepatitis C infection, which, like mutations in HFE, decrease hepcidin production by hepatocytes. The decrease in hepcidin leads to increased iron absorption from the gut. In the liver, iron loading and increased oxidative stress leads to the formation of non-porphyrin inhibitor(s) of uroporphyrinogen decarboxylase and to oxidation of porphyrinogens to porphyrins. The treatment of choice of active PCT is iron reduction by phlebotomy and maintenance of a mildly iron-reduced state without anaemia. Low-dose antimalarials (cinchona alkaloids) are also useful as additional therapy or as alternative therapy for active PCT in those without haemochromatosis or chronic hepatitis C. In this review, we provide an update of PCT with special emphasis upon the important role often played by the hepatitis C virus.

Management strategies of iron accumulation in a captive population of black rhinoceroses (Diceros bicornis minor).

During routine health screens for black rhinoceroses (Diceros bicornis minor) in a captive setting, serum iron and ferritin were analyzed as well as total iron binding capacity and total iron saturation. Trends for ferritin and percent iron saturation showed steady increases since 2003 in four of four animals (three males; one female) with two animals (one male; one female) consistently showing higher elevations over conspecifics. The historical diet had been comprised of a commercial or in-house complete pelleted feed; several species of fresh browse, Bermuda grass, alfalfa and timothy hays, as well as enrichment and training items (apples, carrots, sweet potatoes, and a small amount of leafy greens and vegetables). In 2009, one of the three male rhinoceroses showed a threefold increase in ferritin and concurrently exhibited clinical signs of lethargy, decreased appetite, and disinterest in training. The lone female showed a twofold increase; she also became reproductively acyclic in the prior year. The male was immobilized for examination and phlebotomy. During the same time period, a new version of the complete pelleted feed, with a reduced amount of iron, was introduced. Subsequent to the diet change, the male's ferritin levels have consistently declined, and the female started cycling again. Even with these corrective steps to reduce iron levels, levels of iron saturation remained high, and ferritin levels were still above 1,500 ng/ml. Therapeutic phlebotomy was instituted via a rigorous training program that allowed phlebotomies over a 30-min time frame. This was possible because of a long-term training program for the animals, consistent training personnel, routine collection of samples on a monthly basis, and general comfort level of the animals in the restraint chute. The results of this integrated approach showed some significant improvements and an overall positive impact on the animals.

Serum ferritin: Past, present and future.

BACKGROUND: Serum ferritin was discovered in the 1930s, and was developed as a clinical test in the 1970s. Many diseases are associated with iron overload or iron deficiency. Serum ferritin is widely used in diagnosing and monitoring these diseases. SCOPE OF REVIEW: In this chapter, we discuss the role of serum ferritin in physiological and pathological processes and its use as a clinical tool. MAJOR CONCLUSIONS: Although many aspects of the fundamental biology of serum ferritin remain surprisingly unclear, a growing number of roles have been attributed to extracellular ferritin, including newly described roles in iron delivery, angiogenesis, inflammation, immunity, signaling and cancer. GENERAL SIGNIFICANCE: Serum ferritin remains a clinically useful tool. Further studies on the biology of this protein may provide new biological insights.

A diagnostic approach to hyperferritinemia with a non-elevated transferrin saturation.

Elevated serum ferritin concentrations are common in clinical practice. In this review, we provide an approach to interpreting the serum ferritin elevation in relationship to other clinical parameters including the patient history, transferrin saturation, serum concentrations of alanine, and aspartate aminotransferases (ALT, AST), testing for HFE mutations, liver imaging, liver biopsy, and liver iron concentration. We used observations from a large series of patients with hepatic iron overload documented by liver iron concentration measurement from two referral practices as a gold standard to guide the interpretation of the predictive values of non-invasive iron tests. Three case studies illustrate common problems in interpreting iron blood tests.

Ferritin L-subunit gene mutation and hereditary hyperferritinaemia cataract syndrome (HHCS): a case report and literature review.

ABSTRACTObjectives: Hereditary hyperferritinaemia cataract syndrome (HHCS) is an autosomal dominant disease characterized by high serum ferritin levels and juvenile bilateral cataracts. It is often caused by mutations in the iron response element (IRE) of the ferritin L-subunit (FTL) gene. Here, we report a 73-year-old woman who presented to clinic with persistently elevated serum ferritin and family history of juvenile bilateral cataracts in four generations.Methods: Exome sequencing was used to identify the mutation of the FTL gene. Moreover, Sanger sequencing was performed to validate the mutation in the proband. We also reviewed the FLT gene mutations in published HHCS cases to provide experience for accurate diagnosis of similar patients.Results: A heterozygous mutation at position +33 (c.-167C > T, chr19:49468598) of the FTL gene was identified in the patient.Discussion: HHCS should be considered in the differential diagnosis of hyperferritinemia, especially in the presence of normal serum iron concentration and transferrin saturation.Conclusion: For patients with unexplained hyperferritinemia and bilateral cataracts who have experienced early vision loss, the establishment of genetic counseling is essential to diagnose other family members who are at risk in time.Abbreviations: FTL: ferritin L-subunit; HHCS: hereditary hyperferritinaemia cataract syndrome; IDT: integrated DNA technologies; IRE: iron response element; IRP: iron regulatory proteins; MRI: magnetic resonance imaging; SNV: single nucleotide variant; UTR: untranslated region.

Genetic iron chelation protects against proteasome inhibition-induced dopamine neuron degeneration.

Impairment of the ubiquitin proteasome system (UPS) and iron accumulation in the substantia nigra (SN) have both been implicated in the pathogenesis of Parkinson's disease (PD). We previously reported that chemical iron chelation can protect against proteasome inhibitor lactacystin-induced dopamine (DA) neurodegeneration in vivo. Here, we tested potential neuroprotection via genetic expression of the iron chelator human ferritin heavy chain (H-ferritin). We found that overexpression of H-ferritin in DA neurons significantly reduced lactacystin-induced nigral DA neuron loss and striatal DA depletion. Overexpression of H-ferritin also attenuated elevated levels of total and ferrous iron as well as the divalent metal ion transporter 1 (DMT1) in the SN following lactacystin treatment. In addition, overexpression of H-ferritin alleviated the inhibitory effects of lactacystin on proteasome activity in the nigral tissues. These results suggest that H-ferritin exerts neuroprotection possibly by modulating iron homeostasis and restoring proteasome activity.