Benefits and risks of iron therapy for chronic anaemias

Metals on the Menu-Analyzing the Presence, Importance, and Consequences

Metals are integral components of the natural environment, and their presence in the food supply is inevitable and complex. While essential metals such as sodium, potassium, magnesium, calcium, iron, zinc, and copper are crucial for various physiological functions and must be consumed through the diet, others, like lead, mercury, and cadmium, are toxic even at low concentrations and pose serious health risks. This study comprehensively analyzes the presence, importance, and consequences of metals in the food chain. We explore the pathways through which metals enter the food supply, their distribution across different food types, and the associated health implications. By examining current regulatory standards for maximum allowable levels of various metals, we highlight the importance of ensuring food safety and protecting public health. Furthermore, this research underscores the need for continuous monitoring and management of metal content in food, especially as global agricultural and food production practices evolve. Our findings aim to inform dietary recommendations, food fortification strategies, and regulatory policies, ultimately contributing to safer and more nutritionally balanced diets.

Sucrosomial® Iron Supplementation in Mice: Effects on Blood Parameters, Hepcidin, and Inflammation

Sucrosomial^® Iron is a recently developed formulation to treat iron deficiency based on ferric pyrophosphate covered by a matrix of phospholipids plus sucrose esters of fatty acids. Previous data indicated that Sucrosomial^® Iron is efficiently absorbed by iron-deficient subjects, even at low dosage, and without side effects. Its structural properties may suggest that it is absorbed by an intestinal pathway which is different to the one used by ionic iron. Although, studies in vitro showed that Sucrosomial^® Iron is readily absorbed, no animal models have been established to study this important aspect. To this aim, we induced iron deficient anemia in mice by feeding them with a low-iron diet, and then we treated them with either Sucrosomial^® Iron or sulfate iron by gavage for up to two weeks. Both iron formulations corrected anemia and restored iron stores in a two-week period, but with different kinetics. Ferrous Sulfate was more efficient during the first week and Sucrosomial^® Iron in the second week. Of note, when given at the same concentrations, Ferrous Sulfate induced the expression of hepcidin and four different inflammatory markers (Socs3, Saa1, IL6 and CRP), while Sucrosomial^® Iron did not. We conclude that anemic mice are interesting models to study the absorption of oral iron, and that Sucrosomial^® Iron is to be preferred over Ferrous Sulfate because of similar absorption but without inducing an inflammatory response.

Emergency Medicine Evaluation and Management of Anemia

Anemia is a common condition and is diagnosed on laboratory assessment. It is defined by abnormally low hemoglobin concentration or decreased red blood cells. Several classification systems exist. Laboratory markers provide important information. Acute anemia presents with symptoms owing to acute blood loss; chronic anemia may present with worsening fatigue, dyspnea, lightheadedness, or chest pain. Specific treatments depend on the underlying anemia and etiology. Iron is an alternative treatment for patients with microcytic anemia owing to iron deficiency. Hyperbaric oxygen is an option for alternative rescue therapy. Most patients with chronic anemia may be discharged with follow-up if hemodynamically stable.

Iron Metabolism and Infection

The review highlights the intrinsic problems in the acquisition of ferric iron (FeIII) by pathogenic microorganisms, and bacteria in particular, during their infection of animals. Acquisition of iron from host sources, such as ferritin, transferrin, and heme compounds, is discussed. Acquisition can be by direct contact, via a surface receptor protein of the bacterium, with one of the iron-containing compounds, but more frequently iron is acquired by the production of a siderophore. Over 500 different siderophores are now known; they work by having a superior binding power to that of the host iron-containing materials. They literally strip the iron out of these molecules. They are low-molecular-weight (< 1,000 Da) compounds that are produced in response to iron deprivation, which is a primary host defense mechanism against infections. The iron–siderophore complex is small enough to be taken up into the bacterial cells, usually via an active transport process; the iron is removed from the siderophore, normally by a reductive process, and is then incorporated into the various apoproteins of the bacterial cell or is stored within the bacteria in the form of bacterioferritin. To combat the effectiveness of the siderophores, animals may synthesize specific proteins to bind and nullify their action. The role of one such protein, siderocalin (= lipocalin 2), is discussed. However, these countermeasures have, in turn, been thwarted by at least one bacterium, Salmonella, glycosylating its siderophore (enterobactin/enterochelin) so that binding of the modified siderophore (now termed salmochelin) with lipocalin can no longer occur.

Spectroscopic, potentiometric and theoretical studies of novel imino-phenolate chelators for Fe(III)

The present study was targeted to explore the binding properties of two strong chelators for Fe(III) based on tripodal-iminophenolate moiety. Complexation behavior of the tripodal systems cis-cis cyclohexane-1,3,5-tricarboxylic acid tris-({2-[(2-hydroxy-benzylidene)-amino]-ethyl}-amide (CYCOENSAL, L(1)) and cis-cis cyclohexane-1,3,5-tricarboxylic acid tris-({3-[(2-hydroxy-benzylidene)-amino]-propyl}-amide (CYCOPNSAL, L(2)) is described. Three protonation constants obtained are assigned for three hydroxyl groups of aromatic ring were employed for the evaluation of the formation constants of the metal complexes. Both ligands liberate three protons each forming monomeric complexes of type FeLH3, FeLH2, FeLH and FeL (L=L(1) and L(2)). The first species FeLH3 depicted at low pH, where the ligands were coordinated through three imine nitrogen and other species form subsequently from FeLH3 in steps upon deprotonation and coordination of the phenolic oxygen giving encapsulated tris(phenolate) complexes. The probable structures of the metal complexes formed in solution were proposed through molecular modeling calculations. L(2) was observed to be highly selective towards Fe(III) as compared to L(1).

Out of balance--systemic iron homeostasis in iron-related disorders

Iron is an essential element in our daily diet. Most iron is required for the de novo synthesis of red blood cells, where it plays a critical role in oxygen binding to hemoglobin. Thus, iron deficiency causes anemia, a major public health burden worldwide. On the other extreme, iron accumulation in critical organs such as liver, heart, and pancreas causes organ dysfunction due to the generation of oxidative stress. Therefore, systemic iron levels must be tightly balanced. Here we focus on the regulatory role of the hepcidin/ferroportin circuitry as the major regulator of systemic iron homeostasis. We discuss how regulatory cues (e.g., iron, inflammation, or hypoxia) affect the hepcidin response and how impairment of the hepcidin/ferroportin regulatory system causes disorders of iron metabolism.

Isocitrate ameliorates anemia by suppressing the erythroid iron restriction response

The unique sensitivity of early red cell progenitors to iron deprivation, known as the erythroid iron restriction response, serves as a basis for human anemias globally. This response impairs erythropoietin-driven erythropoiesis and underlies erythropoietic repression in iron deficiency anemia. Mechanistically, the erythroid iron restriction response results from inactivation of aconitase enzymes and can be suppressed by providing the aconitase product isocitrate. Recent studies have implicated the erythroid iron restriction response in anemia of chronic disease and inflammation (ACDI), offering new therapeutic avenues for a major clinical problem; however, inflammatory signals may also directly repress erythropoiesis in ACDI. Here, we show that suppression of the erythroid iron restriction response by isocitrate administration corrected anemia and erythropoietic defects in rats with ACDI. In vitro studies demonstrated that erythroid repression by inflammatory signaling is potently modulated by the erythroid iron restriction response in a kinase-dependent pathway involving induction of the erythroid-inhibitory transcription factor PU.1. These results reveal the integration of iron and inflammatory inputs in a therapeutically tractable erythropoietic regulatory circuit.

Antioxidant, tautomerism and antibacterial studies of Fe(III)-1,2,4-triazole based complexes

New Fe(III) complexes have been synthesized by the reactions of ferric nitrate with Schiff base derived from 3-substituted phenyl-4-amino-5-hydrazino-1,2,4-triazole and indoline-2,3-dione. All these complexes are soluble in DMF and DMSO; low molar conductance values indicate that they are non-electrolytes. Elemental analyses suggest that the complexes have 1:1 stoichiometry of the type [FeLn(H2O)(OH)]·xH2O. Structural and spectroscopic properties have been studied on the basis of elemental analyses, infrared spectra, (1)H and (13)H NMR spectra, electronic spectra, magnetic measurements and FAB mass spectra. FT-IR, (1)H and (13)H NMR studies reveal that the ligand (Ln) exists in the tautomeric enol form in both the states with intramolecular hydrogen bonding. Magnetic moment and reflectance spectral studies reveal that an octahedral geometry has been assigned to all the prepared complexes. FRAP values indicate that all the compounds have a ferric reducing antioxidant power. The compounds 2 and 3 showed relatively high antioxidant activity while compound 1 and 4 shows poor antioxidant power. Also good antimicrobial activities of the complexes against Staphylococcus aureus, Bacillus subtilis, Serratia marcescens, Pseudomonas aeruginosa and Escherichia coli have been found compared to its free ligands.

Effect of intravenous vitamin C on cytokine activation and oxidative stress in end-stage renal disease patients receiving intravenous iron sucrose

Reticuloendothelial blockade in hemodialysis patients prevents optimal intravenous (IV) iron utilization. Vitamin C has emerged as a potential therapy to improve anemia treatment by enhancing iron mobilization. However, Vitamin C can act as a pro-oxidant in the presence of iron. This was a prospective, open-label, crossover study. Thirteen patients with end-stage renal disease on hemodialysis and four healthy controls were assigned to receive 100 mg of IV iron sucrose (IS) or 100 mg of IV IS co-administered with 300 mg of IV Vitamin C (IS + C) in random sequence. Serum samples for IL-1, IL-6, TNF-α and IL-10 and non-transferrin bound iron were obtained at baseline, 45 min and 105 min post study medication administration. Peripheral blood mononuclear cells were isolated at the same time points and stained with fluorescent probes to identify intracellular reactive oxygen species and mitochondrial membrane potential (Δψm) by flow cytometry. Lipid peroxidation was assessed by plasma F2-isoprosatane concentration. Both IS and IS + C were associated with increased plasma F2-isoprostanes concentrations post-infusion. Maximal plasma F2-isoprostane concentrations after IS + C were significantly elevated from baseline (234 ± 0.04 vs. 0.198 ± 0.028 ng/mL, p = 0.02). After IS + C, IL-1, IL-6, IL-10, and TNF-alpha were significantly elevated compared to baseline. After IS alone only IL-6 was noted to be elevated. Intracellular production of H(2)O(2) and loss of mitochondrial membrane potential (Δψm) was observed after IS while IS + C was associated with increased O (2) (·-) production. Both IS and IS + C induced serum cytokine activation accompanied by lipid peroxidation, however, IS + C induced higher plasma concentrations of F2-isoprostanes, IL-1, IL-10, and TNF-α post-infusion. Long-term safety studies of IV iron co-administered with Vitamin C are warranted.

Improving hepatitis B vaccine efficacy in end-stage renal diseases patients and role of adjuvants

Hepatitis B virus (HBV) infection is a serious global health problem.The prevalence of viral hepatitis is higher in dialysis patients than in the general population because of the opportunity for exposure during the dialysis procedure. Immunization is the most effective way to prevent transmission of hepatitis B virus (HBV) and hence the development of acute or chronic hepatitis B. It is well established that patients with end-stage renal disease including dialysis-dependent patients, have an impaired immune response to hepatitis B vaccine. End stage renal diseases (ESRD) patients have lower seroconversion rates compared with the subjects with intact renal function. Moreover, even after the completion of vaccination schedule anti-hepatitis B (anti-HBs) titers of responder dialysis, patients are low and decline logarithmically with time. The impaired efficacy of HBV vaccine in patients with ESRD has been attributed to numerous factors such as immune compromise because of uremia and some other factors. One approach to improve the immunogenicity of existing HBV vaccines is adjuvantation, and it's very important to find more effective adjutants for improving HBV vaccine efficacy. In this paper we have a brief review on recently known new ways for improving HBV vaccine efficacy.

Iron levels in polarized macrophages: regulation of immunity and autoimmunity

Although the hallmark of autoimmune diseases remains the generation of autoantigen-specific lynfocytic cell response, growing evidence is showing a key role for macrophages in a number of autoimmune diseases. Macrophages are characterized by phenotypical and functional heterogeneity. Different immunological signals, coming from systemic blood circulation or from microenvironment, polarize macrophages to classical (M1) or alternative (M2) phenotypes. Iron accumulation in M1 macrophages is a well known bacteriostatic mechanism and one of the mechanisms at the basis of anemia associated to chronic inflammation. Moreover, some recent data suggest that iron accumulation in macrophages can directly activate macrophages to pro-inflammatory M1 phenotype, highlighting a putative role of macrophage iron retention in the pathogenesis of chronic inflammatory and autoimmune diseases. Conversely, iron content is low in M2 macrophages, principally due to increased iron release, and increased availability of iron in the extracellular milieu supported by M2 macrophages could influence the growth rate of adjacent cell and thus play an important role in tumor growth and tissue remodeling. In this review we summarize the molecular mechanisms sustaining differential iron metabolism in polarized macrophages, discuss the relevance of this metabolic signature in chronic inflammatory and autoimmune diseases, and finally focus on potential therapeutic implications rising from a better understanding of underlying molecular mechanisms.

Effects of intravenous iron saccharate on improving severe anemia in rheumatoid arthritis patients

Anemia in rheumatoid arthritis (RA) is multifactorial. Iron deficiency, either definite or relative (defect in iron utilization), exists in RA patients with anemia. Intravenous iron therapy is indicated in severe and symptomatic cases or those with conditions precluding use of oral iron, but its safety and long-term efficacy have not been well-established. Forty severe anemic (hemoglobin < 9 g/dL) RA patients with or without demonstrable bone marrow iron stain were enrolled in this study. Fractionated administration of intravenous iron saccharate was undertaken and the median follow-up time was 1 year. All patients exhibited significant elevations of hemoglobin 3 months after treatment, which were more pronounced in the nonstainable iron marrow subjects {median (interquartile range): 3.8 (2.9-4.8) g/dL versus 2.9 (2.0-3.0) g/dL, p < 0.01}. Thereafter, hemoglobin remained at a plateau level that lasted during the observation period. Throughout the whole course, none of the cases exhibited side effects or flare up of disease activities. The use of intravenous iron saccharate, preferably administrated in a fractionated way, is effective in the correction of severe anemia in RA patients, especially those with nonstainable iron marrow.

Hepatitis B virus infection and related factors in hemodialysis patients in China - systematic review and meta-analysis

AIMS

To provide a comprehensive and reliable tabulation of available data on the epidemiological characteristics and risk factors for hepatitis B virus (HBV) infection in maintenance hemodialysis (HD) patients in China and help to inform prevention programs and guide future research.

METHODS

A systematic review was constructed based on the computerized literature database. Confidence intervals (95% CI) of infection rates were calculated using the approximate normal distribution model. Odds ratios (OR) and 95% CI were calculated by fixed or random effects models. Hepatitis B surface antigen positivity (HBsAg (+)) was set as the sign of HBV infection.

RESULTS

Fifty studies met our inclusion criteria. The pooled prevalence of HBV infection among HD patients in China was 11.9%. Blood transfusion was correlated with an increase in HBV infection (p = 0.05). HD patients with a long-term history were more likely to be infected than those with a short-term history. The levels of alanine aminotransferase were higher in the HBsAg (+) patients (p < 0.001). Large doses of HBV vaccine (80 μg/dose) increased the seroconversion rate. The response rate of intradermal injection of HBV vaccine was higher than that of intramuscular injection.

CONCLUSION

Hepatitis B is still one of the main complications in HD patients in China, and the frequency of blood transfusion and duration of HD were the risk factors. Large doses and intradermal injection of HBV vaccine were recommended to prevent HBV infection in HD patients. The findings of this meta-analysis have implications for optimal prevention and treatment of Hepatitis B in HD patients.

Effects of cellular iron deficiency on the formation of vascular endothelial growth factor and angiogenesis. Iron deficiency and angiogenesis

Background

Young women diagnosed with breast cancer are known to have a higher mortality rate from the disease than older patients. Specific risk factors leading to this poorer outcome have not been identified. In the present study, we hypothesized that iron deficiency, a common ailment in young women, contributes to the poor outcome by promoting the hypoxia inducible factor-1α (HIF-1α and vascular endothelial growth factor (VEGF) formation. This hypothesis was tested in an in vitro cell culture model system.

Results

Human breast cancer MDA-MB-231 cells were transfected with transferrin receptor-1 (TfR1) shRNA to constitutively impair iron uptake. Cellular iron status was determined by a set of iron proteins and angiogenesis was evaluated by levels of VEGF in cells as well as by a mouse xenograft model. Significant decreases in ferritin with concomitant increases in VEGF were observed in TfR1 knockdown MDA-MB-231 cells when compared to the parental cells. TfR1 shRNA transfectants also evoked a stronger angiogenic response after the cells were injected subcutaneously into nude mice. The molecular mechanism appears that cellular iron deficiency elevates VEGF formation by stabilizing HIF-1α. This mechanism is also true in human breast cancer MCF-7 and liver cancer HepG2 cells.

Conclusions

Cellular iron deficiency increased HIF-1α, VEGF, and angiogenesis, suggesting that systemic iron deficiency might play an important part in the tumor angiogenesis and recurrence in this young age group of breast cancer patients.

Iron-induced expression of bone morphogenic protein 6 in intestinal cells is the main regulator of hepatic hepcidin expression in vivo

BACKGROUND & AIMS

Recent studies identified bone morphogenic protein 6 (BMP6) as a key regulator of hepatic hepcidin expression and iron metabolism, but the cellular source of BMP6 and the reason for its specific effect on hepatocytes are unknown.

METHODS

BMP and hepcidin expression upon iron sensing were analyzed in vivo in BMP6(-/-) and BMP6(+/+) mice and ex vivo in tissue and in vitro in cells of the liver and the small intestine.

RESULTS

BMP6(-/-) mice developed severe hepatic iron accumulation and reduced hepcidin expression with increasing age. This phenotype could be triggered in younger BMP6(-/-) mice by dietary or parenteral iron application. Furthermore, both treatments induced a marked up-regulation of BMP6 expression in the small intestine of BMP6(+/+) mice. Ex vivo treatment of intestinal tissue of BMP6(+/+) mice with iron sulfate or holo-transferrin confirmed epithelial cells as an inducible source of BMP6. In contrast, iron overload did not promote a striking induction of BMP6 expression in hepatocytes or macrophages. Furthermore, iron-supplemented diet induced a compensatory up-regulation of BMP2, BMP4, and BMP9 in the small intestine of BMP6(-/-) mice that was apparently not sufficient to assure iron homeostasis. As a potential explanation, analysis of hepatocytes revealed an expression pattern of BMP receptor subunits preferentially used by BMP6, and treatment of hepatocytes with different recombinant BMPs identified BMP6 as the most potent stimulator of hepcidin expression.

CONCLUSIONS

Epithelial cells of the small intestine are the predominant cellular source of BMP6 upon iron sensing. Our findings reveal a previously unknown mechanism in which the small intestine controls iron homeostasis.

Serum hepcidin concentration in chronic haemodialysis patients: associations and effects of dialysis, iron and erythropoietin therapy

BACKGROUND

Hepcidin, a liver-derived peptide induced by iron overload and inflammation, is a major regulator of iron homeostasis. As hepcidin decreases gastrointestinal iron absorption and recirculation from monocytes, over-expression is associated with the development of anaemia.

METHODS

We studied the associations between circulating hepcidin levels and various laboratory parameters related to anaemia and/or inflammation in 20 patients on chronic haemodialysis. Furthermore, we determined the impact of dialysis and iron and/or erythropoietin (rhEpo) supplementation therapy on hepcidin serum concentrations. The patients were withheld from iron and rhEpo for 2 weeks before study entry. Hepcidin was measured by liquid chromatography-mass spectrometry (LC-MS/MS); serum iron and haematological parameters, cytokines and pro-hepcidin by commercially available enzyme-linked immunosorbent assays (ELISA) or standard automated methods.

RESULTS

While hepcidin levels at baseline were not correlated to pro-hepcidin, interleukin-6 or transforming growth factor-beta concentrations, we found significant associations with reticulocyte count (r = -0.55; P = 0.015), serum iron (r = 0.7; P = 0.004) and ferritin levels (r = 0.63; P = 0.004) and transferrin saturation (r = 0.69, P = 0.001). Dialysis using either a high or a low flux biocompatible dialyser resulted in a significant decrease of hepcidin concentrations, which returned to pre-dialysis values before the next dialysis session. When studying the effects of anaemia treatment, we observed a significant reduction of hepcidin levels following administration of rhEpo but not iron.

CONCLUSIONS

Hepcidin levels in stable haemodialysis patients appear to reflect systemic iron load, but not inflammation. Due to the negative association between reticulocyte counts and hepcidin, the reduction of circulating hepcidin concentrations by dialysis and/or rhEpo treatment may positively affect erythropoiesis.

Intravenous iron attenuates postvaccination anti-HBsAg titres after quadruple hepatitis B vaccination in dialysis patients with erythropoietin therapy

BACKGROUND

Anaemia in patients with end-stage renal disease (ESRD) is commonly treated with recombinant human erythropoietin (rHuEPO), often in combination with an adjuvant iron supplement. There is much evidence that rHuEPO can influence the immune response by its effect on lymphocytes. Also, iron catalyses the formation of radicals and increases the risk of major infections by negatively affecting the immune system. The relationship between antibodies to hepatitis B surface antigen (anti-HBsAg) responsiveness after hepatitis B vaccination and rHuEPO/adjuvant iron supplementation has not been reported before.

AIM

To determine the effects of subcutaneous erythropoietin and intravenous (i.v.) iron therapy on the responsiveness of anti-HBsAg after quadruple hepatitis B vaccination among ESRD patients.

METHODS

Retrospective medical records were reviewed in a hospital with a tertiary teaching facility. Eighty-three ESRD patients, including 51 who underwent haemodialysis and 32 who underwent peritoneal dialysis therapy, received a quadruple recombinant hepatitis B vaccine. We investigated anti-HBsAg titres in those patients who either received rHuEPO alone (n = 50) or rHuEPO in combination with i.v. iron (n = 33).

RESULTS

We found that the postvaccination anti-HBsAg titre was significantly lower in the rHuEPO plus i.v. iron group when compared with the group with rHuEPO alone (p < 0.05). The increment of anti-HBsAg between the initial month and the seventh month was positively correlated with therapeutic rHuEPO dosages in the group with rHuEPO alone (r = 0.303, p = 0.033). This relationship was not present in the rHuEPO with i.v. iron group (r = -0.289, p = 0.229).

CONCLUSIONS

The levels of anti-HBsAg after hepatitis B vaccination are positively correlated with the dose of rHuEPO treatment during the vaccinated period among ESRD patients without i.v. iron supplementation. Also, i.v. iron negatively impacts the responsiveness of anti-HBsAg titre after hepatitis B vaccination in ESRD patients who have undergone rHuEPO therapy.

Does iron have a role in breast cancer?

Oestrogen and family history are two of the most important risk factors for breast cancer. However, these risk factors cannot explain the differences in the incidence and recurrence of breast cancer between premenopausal and postmenopausal women. In this paper I propose that, in premenopausal women, an iron deficiency caused by menstruation stabilises hypoxia inducible factor-1alpha, which increases the formation of vascular endothelial growth factor. This mechanism results in premenopausal women being more susceptible to angiogenesis and, consequently, leads to a high recurrence of breast cancer. Conversely, increased concentrations of iron in postmenopausal women, as a result of menstrual cessation, contribute to a high incidence of breast cancer via oxidative-stress pathways. Although the focus of this Personal View is on iron, this by no means negates the roles of other known risk factors in breast-cancer development. Characterisation of the role of iron in breast cancer could potentially benefit patients by decreasing recurrence and incidence and increasing overall survival.

Intravenous Iron Therapy: A Summary of Treatment Options and Review of Guidelines

Iron replacement for iron-deficiency anemia has historically been accomplished with the use of oral iron therapy. Although oral iron is appropriate for most iron-deficiency anemia patients, many patients do not respond to or may be intolerant of oral iron, or may experience bleeding of sufficient magnitude to require higher iron doses than that achievable with oral iron. Intravenous iron therapy is a useful option for these latter patients. Three intravenous iron products are recommended: low-molecular weight iron dextran (INFeD), ferric gluconate (Ferrlecit), and iron sucrose (Venofer). These intravenous iron products have superior safety profiles compared to high-molecular weight iron dextran. The Food and Drug Administration's approval of erythropoietic-stimulating agents to treat certain types of anemia has increased usage of intravenous iron for functional iron deficiency. This review summarizes the current status of intravenous iron products and discusses their advantages and disadvantages in treating both absolute and functional iron deficiency.

Synthesis of 5-dialkyl(aryl)aminomethyl-8-hydroxyquinoline dansylates as selective fluorescent sensors for Fe3+

A series of 5-dialkyl(aryl)aminomethyl-8-hydroxyquinoline dansylates were synthesized and their fluoroionophoric properties toward representative alkali ions, alkaline earth ions and transition metal ions were investigated. Among the selected ions, Fe3+ caused considerable quenching of the fluorescence, while Cr3+ caused quenching to some extent. The absence of any significant fluorescence quenching effects of the other ions examined, especially Fe2+, renders these compounds highly useful Fe3+-selective fluorescent sensors.

Iron therapy for renal anemia: how much needed, how much harmful?

Iron deficiency is the most common cause of hyporesponsiveness to erythropoiesis-stimulating agents (ESAs) in end-stage renal disease (ESRD) patients. Iron deficiency can easily be corrected by intravenous iron administration, which is more effective than oral iron supplementation, at least in adult patients with chronic kidney disease (CKD). Iron status can be monitored by different parameters such as ferritin, transferrin saturation, percentage of hypochromic red blood cells, and/or the reticulocyte hemoglobin content, but an increased erythropoietic response to iron supplementation is the most widely accepted reference standard of iron-deficient erythropoiesis. Parenteral iron therapy is not without acute and chronic adverse events. While provocative animal and in vitro studies suggest induction of inflammation, oxidative stress, and kidney damage by available parenteral iron preparations, several recent clinical studies showed the opposite effects as long as intravenous iron was adequately dosed. Thus, within the recommended international guidelines, parenteral iron administration is safe. Intravenous iron therapy should be withheld during acute infection but not during inflammation. The integration of ESA and intravenous iron therapy into anemia management allowed attainment of target hemoglobin values in the majority of pediatric and adult CKD and ESRD patients.

Molecular and clinical aspects of iron homeostasis: From anemia to hemochromatosis

The discovery in recent years of a plethora of new genes whose products are implicated in iron homeostasis has led to rapid expansion of our knowledge in the field of iron metabolism and its underlying complex regulation in both health and disease. Abnormalities of iron metabolism are among the most common disorders encountered in practical medicine and may have significant negative impact on physical condition and life expectancy. Basic insights into the principles of iron homeostasis and the pathophysiological and clinical consequences of iron overload, iron deficiency and misdistribution are thus of crucial importance in modern medicine. This review summarizes our current understanding of human iron metabolism and focuses on the clinically relevant features of hereditary and secondary hemochromatosis, iron deficiency anemia, anemia of chronic disease and anemia of critical illness. The interconnections between iron metabolism and immunity are also addressed, in as much as they may affect the risk and course of infections and malignancies.