Iron homoeostasis in rheumatic disease

Restless leg syndrome in systemic lupus erythematosus: Associations with disease activity, quality of life and depression

OBJECTIVES

The aim of this study was to determine the prevalence of restless leg syndrome (RLS) among patients with SLE, describe their clinical characteristics, examine its impact on health-related quality of life (HRQoL), and evaluate its association with depression.

METHODS

A total of 124 SLE patients were recruited, with data on demographics, and clinical features collected. RLS diagnosis was based on the international RLS study group criteria, while depression was assessed by the patient health questionnaire. HRQoL was assessed by a disease-specific validated questionnaire, the LupusQoL, pain intensity was examined through the pain visual analogue scale, and disease activity was evaluated via the patient global assessment. These variables were compared between SLE patients with RLS and without RLS using t-tests or Wilcoxon and the chi-square test of independence for categorical variables. A p-value ≤0.05 was considered statistically significant.

RESULTS

Among the SLE patients (mean age 48, 87.1 % women), 32 % had RLS. The SLE patients with RLS were found to have a longer delay in diagnosis (1 vs 0.5 years; p = 0.019) and were less likely to be employed (65 % vs 45 %, p = 0.040) compared to non-RLS patients. In addition, RLS patients were more likely to have coexisting Major Depressive Disorder (MDD) (p = 0.019), higher levels of pain (p = 0.006) and disease activity based on patient global assessment (p = 0.014). Further, most of the domains of LupusQoL were significantly lower in the RLS patients group suggesting a worse HRQoL.

CONCLUSION

RLS was present in one-third of the SLE cohort, significantly impairing HRQoL and correlating with depression, higher pain, and increased disease activity. These findings underscore the importance of early RLS detection and management in SLE patients.

Assessing causal association of circulating micronutrients and systemic lupus erythematosus susceptibility: a Mendelian randomization study

Background

Previous studies showed the conflicting associations between circulating micronutrient levels and systemic lupus erythematosus (SLE). Therefore, we aimed to clarify the causal association between circulating micronutrient levels and the risk of SLE by two-sample Mendelian randomization (MR) analysis.

Methods

56 single nucleotide polymorphisms (SNPs) significantly associated with 14 circulating micronutrients (vitamin A, B6, B9, B12, C, D and E, phosphorus, calcium, magnesium, copper, iron, zinc, and selenium) in published genome-wide association studies (GWAS) were used as instrumental variables (IVs). And summary statistics related to SLE were obtained from the IEU OpenGWAS database. We used the MR Steiger test to estimate the possible causal direction between circulating micronutrients and SLE. In the MR analysis, inverse variance weighting (IVW) method and the Wald ratio was as the main methods., Moreover, the MR-Pleiotropy residuals and outliers method (MR-PRESSO), Cochrane's Q-test, MR-Egger intercept method and leave-one-out analyses were applied as sensitivity analyses. Additionally, we conducted a retrospective analysis involving the 20,045 participants from the Third National Health and Nutritional Examination Survey (NHANES III). Weight variables were provided in the NHANES data files. Univariate and multivariate logistic regression analyses were performed to determine the associations between circulating micronutrients and SLE.

Results

The MR estimates obtained from the IVW method revealed potential negative correlations between circulating calcium (OR: 0.06, 95% CI: 0.01-0.49, P = 0.009), iron levels (OR: 0.63, 95% CI: 0.43-0.92, P = 0.016) and the risk of SLE. The results remained robust, even under various pairs of sensitivity analyses. Our retrospective analysis demonstrated that the levels of vitamin D, serum total calcium, and serum iron were significantly lower in SLE patients (N = 40) when compared to the control group (N = 20,005). Multivariate logistic regression analysis further established that increased levels of vitamin D and serum total calcium served as protective factors against SLE.

Conclusion

Our results provided genetic evidence supporting the potential protective role of increasing circulating calcium in the risk of SLE. Maintaining adequate levels of calcium may help reduce the risk of SLE.

Heterogeneous ferroptosis susceptibility of macrophages caused by focal iron overload exacerbates rheumatoid arthritis

Focal iron overload is frequently observed in patients with rheumatoid arthritis (RA), yet its functional significance remains elusive. Herein, we report that iron deposition in lesion aggravates arthritis by inducing macrophage ferroptosis. We show that excessive iron in synovial fluid positively correlates with RA disease severity as does lipid hyperoxidation of focal monocyte/macrophages. Further study reveals high susceptibility to iron induced ferroptosis of the anti-inflammatory macrophages M2, while pro-inflammatory M1 are less affected. Distinct glutathione peroxidase 4 (GPX4) degradation depending on p62/SQSTM1 in the two cell types make great contribution mechanically. Of note, ferroptosis inhibitor liproxstatin-1 (LPX-1) can alleviate the progression of K/BxN serum-transfer induced arthritis (STIA) mice accompanied with increasing M2 macrophages proportion. We thus propose that the heterogeneous ferroptosis susceptibility of macrophage subtypes as well as consequent inflammation and immune disorders are potential biomarkers and therapeutic targets in RA.

Cardiorenal syndrome and iron supplementation-more benefits than risks: a narrative review

Intravenous iron administration has emerged as a crucial intervention for managing patients with cardiorenal syndrome (CRS) and iron deficiency, with or without the presence of anemia. Multiple studies have demonstrated the benefits of intravenous iron supplementation in improving anemia, symptoms, and functional capacity in patients with HF and iron deficiency. Furthermore, iron supplementation has been associated with a reduction in hospitalizations for HF exacerbation and the improvement of patients' quality of life and clinical outcomes. In addition to its effects on HF management, emerging evidence suggests a potential positive impact on kidney function in patients with CRS. Studies have shown an increase in estimated glomerular filtration rate and improvements in renal function markers in patients receiving intravenous iron therapy, highlighting the potential of this intervention in patients with CRS. This paper reviews the existing literature on the impact of intravenous iron therapy in these patient populations and explores its effects on various clinical outcomes. Future research endeavors are eagerly awaited to further improve our understanding of its clinical implications and optimize patient outcomes.

Identification of Immune Infiltration and Iron Metabolism-Related Subgroups in Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a prevalent neurodevelopmental disorder with a broad spectrum of symptoms and prognoses. Effective therapy requires understanding this variability. ASD children's cognitive and immunological development may depend on iron homoeostasis. This study employs a machine learning model that focuses on iron metabolism hub genes to identify ASD subgroups and describe immune infiltration patterns. A total of 97 control and 148 ASD samples were obtained from the GEO database. Differentially expressed genes (DEGs) and an iron metabolism gene collection achieved the intersection of 25 genes. Unsupervised cluster analysis determined molecular subgroups in individuals with ASD based on 25 genes related to iron metabolism. We assessed gene ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, gene set variation analysis (GSVA), and immune infiltration analysis to compare iron metabolism subtype effects. We employed machine learning to identify subtype-predicting hub genes and utilized both training and validation sets to assess gene subtype prediction accuracy. ASD can be classified into two iron-metabolizing molecular clusters. Metabolic enrichment pathways differed between clusters. Immune infiltration showed that clusters differed immunologically. Cluster 2 had better immunological scores and more immune cells, indicating a stronger immune response. Machine learning screening identified SELENBP1 and CAND1 as important genes in ASD's iron metabolism signaling pathway. These genes express in the brain and have AUC values over 0.8, implying significant predictive power. The present study introduces iron metabolism signaling pathway indicators to predict ASD subtypes. ASD is linked to immune cell infiltration and iron metabolism disorders.

Ferroptosis as an emerging target in rheumatoid arthritis

Rheumatoid arthritis (RA) is an autoimmune disease of unknown etiology. Due to the rise in the incidence rate of RA and the limitations of existing therapies, the search for new treatment strategies for RA has become a global focus. Ferroptosis is a novel programmed cell death characterized by iron-dependent lipid peroxidation, with distinct differences from apoptosis, autophagy, and necrosis. Under the conditions of iron accumulation and the glutathione peroxidase 4 (GPX4) activity loss, the lethal accumulation of lipid peroxide is the direct cause of ferroptosis. Ferroptosis mediates inflammation, oxidative stress, and lipid oxidative damage processes, and also participates in the occurrence and pathological progression of inflammatory joint diseases including RA. This review provides insight into the role and mechanism of ferroptosis in RA and discusses the potential and challenges of ferroptosis as a new therapeutic strategy for RA, with an effort to provide new targets for RA prevention and treatment.

Polydatin ameliorates inflammation and oxidative stress associated with MSU-induced gouty arthritis in mice by regulating PPAR-γ and ferritin activation

AIMS

Polygonum cuspidatum Sieb. et Zucc is one of the commonly used herbs for the treatment of gouty arthritis, and polydatin is one of its main effective components. This study evaluated the therapeutic potential of polydatin for the treatment of gout.

MAIN METHODS

The ankle joint of C57BL/6 mice were injected with MSU suspensions to simulate human gouty arthritis, and oral treatment with polydatin (25, 50, and 100 mg/kg body weight) was performed at 1 h after MSU crystal injection. The effect of polydatin on model mice was evaluated by measuring ankle swelling, gait, histopathological analysis, proinflammatory cytokine expression, as well as the contents of NO, MDA and GSH. The targets of polydatin were explored by Real-Time PCR and IHC.

KEY FINDINGS

Treatment with polydatin inhibited ankle swelling, improved abnormal gait, and reduced ankle lesions dose-dependently. Moreover, polydatin decreased pro-inflammatory cytokine expression, and promoted expression of anti-inflammatory cytokine. In addition, polydatin inhibited MSU-induced oxidative stress by decreasing oxidative product (NO, MDA) generation and promote the antioxidant (GSH). Further, we found that polydatin reduced inflammation by decreasing the expression of NLRP3 inflammasome component via activating PPAR-γ. Moreover, polydatin can protect against iron overload and attenuate oxidative stress by promoting the activation of ferritin.

SIGNIFICANCE

Our findings indicates that polydatin ameliorates MSU-induced inflammation and oxidative stress by regulating PPAR-γ and ferritin activation in gouty arthritis model mice, and this research result suggests that polydatin has therapeutic potential for the treatment of gout in humans through multiple targets.

Dysregulated Iron Homeostasis as Common Disease Etiology and Promising Therapeutic Target

Iron is irreplaceably required for animal and human cells as it provides the activity center for a wide variety of essential enzymes needed for energy production, nucleic acid synthesis, carbon metabolism and cellular defense. However, iron is toxic when present in excess and its uptake and storage must, therefore, be tightly regulated to avoid damage. A growing body of evidence indicates that iron dysregulation leading to excess quantities of free reactive iron is responsible for a wide range of otherwise discrete diseases. Iron excess can promote proliferative diseases such as infections and cancer by supplying iron to pathogens or cancer cells. Toxicity from reactive iron plays roles in the pathogenesis of various metabolic, neurological and inflammatory diseases. Interestingly, a common underlying aspect of these conditions is availability of excess reactive iron. This underpinning aspect provides a potential new therapeutic avenue. Existing hematologically used iron chelators to take up excess iron have shown serious limitations for use but new purpose-designed chelators in development show promise for suppressing microbial pathogen and cancer cell growth, and also for relieving iron-induced toxicity in neurological and other diseases. Hepcidin and hepcidin agonists are also showing promise for relieving iron dysregulation. Harnessing iron-driven reactive oxygen species (ROS) generation with ferroptosis has shown promise for selective destruction of cancer cells. We review biological iron requirements, iron regulation and the nature of iron dysregulation in various diseases. Current results pertaining to potential new therapies are also reviewed.

Elevated transferrin receptor impairs T cell metabolism and function in systemic lupus erythematosus

T cells in systemic lupus erythematosus (SLE) exhibit multiple metabolic abnormalities. Excess iron can impair mitochondria and may contribute to SLE. To gain insights into this potential role of iron in SLE, we performed a CRISPR screen of iron handling genes on T cells. Transferrin receptor (CD71) was identified as differentially critical for TH1 and inhibitory for induced regulatory T cells (iTregs). Activated T cells induced CD71 and iron uptake, which was exaggerated in SLE-prone T cells. Cell surface CD71 was enhanced in SLE-prone T cells by increased endosomal recycling. Blocking CD71 reduced intracellular iron and mTORC1 signaling, which inhibited TH1 and TH17 cells yet enhanced iTregs. In vivo treatment reduced kidney pathology and increased CD4 T cell production of IL-10 in SLE-prone mice. Disease severity correlated with CD71 expression on TH17 cells from patients with SLE, and blocking CD71 in vitro enhanced IL-10 secretion. T cell iron uptake via CD71 thus contributes to T cell dysfunction and can be targeted to limit SLE-associated pathology.

New Insights into the Regulatory Role of Ferroptosis in Ankylosing Spondylitis via Consensus Clustering of Ferroptosis-Related Genes and Weighted Gene Co-Expression Network Analysis

Background: The pathogenesis of ankylosing spondylitis (AS) remains undetermined. Ferroptosis is a newly discovered form of regulated cell death involved in multiple autoimmune diseases. Currently, there are no reports on the connection between ferroptosis and AS. Methods: AS samples from the Gene Expression Omnibus were divided into two subgroups using consensus clustering of ferroptosis-related genes (FRGs). Weighted gene co-expression network analysis (WGCNA) of the intergroup differentially expressed genes (DEGs) and protein–protein interaction (PPI) analysis of the key module were used to screen out hub genes. A multifactor regulatory network was then constructed based on hub genes. Results: The 52 AS patients in dataset GSE73754 were divided into cluster 1 (n = 24) and cluster 2 (n = 28). DEGs were mainly enriched in pathways related to mitochondria, ubiquitin, and neurodegeneration. Candidate hub genes, screened by PPI and WGCNA, were intersected. Subsequently, 12 overlapping genes were identified as definitive hub genes. A multifactor interaction network with 45 nodes and 150 edges was generated, comprising the 12 hub genes and 32 non-coding RNAs. Conclusions: AS can be divided into two subtypes according to FRG expression. Ferroptosis might play a regulatory role in AS. Tailoring treatment according to the ferroptosis status of AS patients can be a promising direction.

Management of iron deficiency in chronic heart failure

Iron deficiency is frequent in patients with chronic heart failure (CHF) with a prevalence of 50%, and its frequency varies depending on the study groups. The presence of iron deficiency limits erythropoiesis, leading to the development of anemia over time in patients with CHF, regardless of gender, race, and left ventricular ejection fraction (LVEF). Observational studies demonstrate a higher prevalence of iron deficiency in women and in patients with higher NYHA (New York Heart Association) functional class, decreased LVEF, increased brain natriuretic peptide (NT-proBNP), or increased high-sensitivity C-reactive protein. Iron deficiency and anemia in patients with CHF are independently associated with a decreased exercise capacity, hospitalizations for CHF, an increase in overall mortality and mortality from cardiovascular diseases. The clinical significance of iron deficiency requires the need to diagnose iron metabolism in all patients with CHF. Current guidelines for the diagnosis and treatment of CHF indicate the need to determine the level of ferritin and saturation of transferrin in all patients with a suspected diagnosis of heart failure. The use of oral iron therapy in patients with CHF demonstrates its low efficacy in correcting this condition according to the clinical trials. At the same time the use of intravenous iron therapy is safe and improves symptoms, exercise capacity and quality of life in patients with heart failure with reduced ejection fraction and iron deficiency, which has been shown both in international placebo-controlled trials and meta-analyses. The use of iron carboxymaltose should improve CHF symptoms, exercise capacity and quality of life in patients with CHF and LVEF45%. Intravenous iron therapy has also been shown to reduce readmissions for CHF in patients with an LVEF50% who have recently been hospitalized for worsening CHF.

PCBP1 is associated with rheumatoid arthritis by affecting RNA products of genes involved in immune response in Th1 cells

Rheumatoid arthritis (RA) is an autoimmune disease characterized by persistent synovitis, in which T helper 1 (Th1) can promote the development of a pro-inflammatory microenvironment. Poly(rC)-binding protein 1 (PCBP1) has been identified as a promising biomarker of RA, while its molecular mechanisms in RA development are unknown. As a canonical RNA binding protein, we propose that PCBP1 could play roles in RA by affecting both expression and alternative splicing levels in Th1 cells. Here, microarray datasets (GSE15573 and GSE23561), including 102 peripheral blood mononuclear cell samples from 39 RA patients and 63 controls, were used to evaluate the PCBP1 expression changes in RA patients. High throughput sequencing data (GSE84702) of iron driven pathogenesis in Th1 cells were downloaded and reanalyzed, including two Pcbp1 deficiency samples and two control samples in Th1 cells. In addition, CLIP-seq data of PCBP1 in Jurkat T cells was also analyzed to investigate the regulatory mechanisms of PCBP1. We found PCBP1 were down-regulated in RA specimens compared with control. The result of differentially expressed genes (DEGs) showed that Pcbp1 silencing in Th1 cells affected the expression of genes involved in immune response pathway. Alternative splicing analysis also revealed that PCBP1-regulated alternative splicing genes (RASGs) were enriched in TNF-a/NF-κB signaling pathway, T cell activation, T cell differentiation and T cell differentiation associated immune response pathways, which were highly associated with RA. DEGs and RASGs by Pcbp1 deficiency in mice were validated in PBMCs specimens of RA patients by RT-qPCR. Investigation of the CLIP-seq data revealed PCBP1 preferred to bind to 3'UTR and intron regions. PCBP1-bound genes were also significantly associated with RASGs, identifying 102 overlapped genes of these two gene sets. These genes were significantly enriched in several immune response related pathways, including myeloid cell differentiation and positive regulation of NF-κB transcription factor activity. Two RA-related genes, PML and IRAK1, were screened from the above immune related pathways. These results together support our hypothesis that PCBP1 can regulate the expression of genes involved in immune response pathway, and can bind to and regulate the alternative splicing of immune response related genes in immune T cells, and ultimately participate in the molecular mechanism of RA, providing new research ideas and directions for clinical diagnosis and treatment.

A Practical Perspective of the Hematologic Manifestations of Systemic Lupus Erythematosus

Systemic lupus erythematosus (SLE) is a chronic inflammatory disease with an unknown etiology that can affect any organ or system of the human body. Hematological, renal, or central nervous system manifestations in these patients result in great morbidity because high doses of glucocorticoids, cytotoxic medications, or biological drugs are required to control these manifestations. It is noteworthy that hematological involvement predominates during the first years of the disease and tends to last over time, with the premise that it may be the initial manifestation of the disease. Clear examples of this are the cases of hemolytic anemia and immune thrombocytopenia that can be initially classified as idiopathic or primary to be later classified as secondary when associated with infections, medications, neoplasms, or autoimmune diseases. The spectrum of hematologic manifestations in SLE is very broad, including lymphopenia, anemia, thrombocytopenia, or pancytopenia. In some cases, lymphadenopathy and splenomegaly are also identified. The vast majority of these manifestations denote high disease activity. However, many of these alterations have a multifactorial cause that must be taken into account to adopt a more complete therapeutic approach. The objective of this review is to characterize in detail the hematological manifestations of SLE to offer clinicians a practical vision of its diagnosis and treatment.

Iron deprivation restrains the differentiation and pathogenicity of T helper 17 cell

Iron plays a critical role in immune responses. However, its role in T helper cell differentiation and function remains poorly understood. In this study, it is shown that the restraint of iron availability through blocking CD71-mediated iron endocytosis impaired the differentiation and pathogenicity of T_H 17 cells. Administrations of anti-CD71 mAb could relieve the development of experimental autoimmune encephalomyelitis (EAE). Mechanistically, the iron deficiency due to the blocking of CD71 enhanced IL-2 expression, which further restrained the differentiation of T_H 17 cells. Meanwhile, CD71 blockade impaired histone modifications of Il17 gene and reduced the recruitment of RORγt to Il17a locus. In sum, the findings reveal that iron plays a pivotal role in regulating T_H 17 cell differentiation and function in autoimmune diseases.

Genetically Predicted Serum Iron Status Is Associated with Altered Risk of Systemic Lupus Erythematosus among European Populations

BACKGROUND

Observational epidemiological studies have reported an inconsistent relation between iron status and risk of systemic lupus erythematosus (SLE). Moreover, it remains uncertain whether the observed association is causal or due to confounding or reverse causality.

OBJECTIVES

We aimed to investigate the association between serum iron status and risk of SLE using a 2-sample Mendelian randomization (MR) approach.

METHODS

Genetic instruments for iron status including serum iron, log-transformed ferritin, transferrin saturation, and transferrin were identified from a large-scale genome-wide association study (GWAS) performed by the Genetics of Iron Status Consortium among 48,972 individuals of European ancestry (55% female). Three independent single nucleotide polymorphisms (rs1800562, rs1799945, and rs855791) concordantly related with 4 iron status biomarkers were selected as instrumental variables. Summary statistics of SLE were obtained from a publicly available GWAS of 4036 patients with SLE and 6959 controls of European descent. The MR study was conducted using the inverse-variance weighted (IVW) method, supplemented with MR-Egger regression and simple- and weighted-median methods. Leave-one-out analysis was further performed to test the robustness of our findings. ORs with 95% CIs were calculated.

RESULTS

Genetically predicted iron status was associated with altered risk of SLE, with ORs of 0.79 (95% CI: 0.66, 0.94), 0.54 (95% CI: 0.34, 0.85), 0.82 (95% CI: 0.71, 0.94), and 1.36 (95% CI: 1.06, 1.76) per 1-SD increase in iron, log-transformed ferritin, transferrin saturation, and transferrin using the IVW method, respectively. MR-Egger regression did not indicate potential pleiotropic bias. Sensitivity analyses produced similar findings, suggesting the robustness of the association.

CONCLUSIONS

Our study suggested that high iron status may be associated with a reduced risk of SLE among European populations. Further studies are warranted to elucidate the mechanism underlying the protective role of iron against susceptibility to SLE.

Trace elements in patients with aortic valve sclerosis

Background:

Aortic valve sclerosis (AVSc) is defined as the thickening and calcification of aortic valve cusps, in the absence of obstruction of ventricular outflow. AVSc is linked with a clear imbalance in some trace elements.

Aims:

The objective of this study was to investigate the relationship between AVSc and serum levels of iron (Fe), zinc (Zn), selenium (Se), and copper (Cu). Additionally, this research aimed to explore the clinical significance of human serum zinc, selenium, copper, and iron concentrations as a potential new biomarker for AVSc patients and to clarify the pathophysiological role in individuals at risk of developing AVSc.

Patients and methods:

The study included 40 subjects with AVSc (25% male and 75% female) who were compared with a healthy control group with the same gender ratio. AVSc was based on comprehensive echocardiographic assessments. Blood samples were taken and Zn and Cu concentrations were determined through the use of atomic absorption spectroscopy. Se was measured using an inductively coupled plasma mass spectrometry device and Fe was measured using a Beckman Coulter instrument.

Results:

There was a significant difference in the prevalence of diabetes, blood pressure levels, and body mass index between the patients and the healthy subjects (p < 0.05). The differences between the serum Fe, Se, and Cu levels of the AVSc patients and the healthy subjects (p > 0.05) were recorded. The serum Zn of AVSc patients when compared was significantly lower compared with that of the control group (p < 0.01).

Conclusion:

Patients with AVSc had an imbalance in some of the trace elements in their blood. The patient group’s valves had higher serum Cu levels and lower serum Se, Zn, and Fe concentrations compared with the healthy group’s valves. In the valve patients as compared, AVSc had a high prevalence of obesity, hypertension, and diabetes.

A mini-review on ion fluxes that regulate NLRP3 inflammasome activation

The activation of NLR family pyrin domain containing 3 (NLRP3) inflammasome can be induced by a wide spectrum of activators. This is unlikely achieved by the binding of different activators directly to the NLRP3 protein itself, as the activators found so far show different forms of chemical structures. Previous studies have shown that these activators can induce potassium ion (K+) and chloride ion (Cl-) efflux, calcium (Ca2+) and other ion mobilization, mitochondrial dysfunction, and lysosomal disruption, all of which are believed to cause NLRP3 inflammasome activation; how these events are induced by the activators and how they coordinate with each other in inducing the NLRP3 inflammasome activation are not fully understood. Increasing evidence suggests that the coordinated change of intracellular ion concentrations may be a common mechanism for the NLRP3 activation by different activators. In this mini-review, we present a brief summary of the current knowledge about how different ionic flows (including K+, sodium ion, Ca2+, magnesium ion, manganese ion, zinc ion, iron ion, and Cl-) are involved in regulating the NLRP3 inflammasome activation in macrophages.

Serum CRP, MDA, Vitamin C, and Trace Elements in Bangladeshi Patients with Rheumatoid Arthritis

Rheumatoid arthritis (RA) is an autoimmune disorder that is a painful health crisis. This study aimed to assess the serum C-reactive protein (CRP), malondialdehyde (MDA), non-enzymatic antioxidant (vitamin C), and trace elements (Zn, Cu, Mn, and Fe) in RA patients, and thereby correlate these parameters with the association of RA. This study included 20 Bangladeshi RA patients and 20 normal healthy volunteers as control subjects. CRP level was determined using a laboratory-based latex agglutination-enhanced immunoassay. The lipid peroxidation level was determined by measurement of the serum level of MDA. Non-enzymatic antioxidant vitamin C was assessed by UV spectrophotometric method. Trace elements were determined by atomic absorption spectroscopy (AAS). Our study observed significantly higher concentrations of CRP (p < 0.001) and MDA (p < 0.001), and significantly lower concentrations of vitamin C (p < 0.001) in the RA patient. The mean values of Zn, Cu, Mn, and Fe were 6.62 ± 0.34, 1.42 ± 0.17, 7.51 ± 0.23, and 29.25 ± 0.41 ppm for the RA patients respectively and 13.57 ± 9.13, 1.15 ± 0.17, 1.59 ± 0.18, and 62.47 ± 5.25 ppm for the control subjects, consequently. There was a significant difference (p < 0.05) in the trace element levels between the RA patients and control subjects. Our study suggests that a higher concentration of CRP and MDA, lower levels of vitamin C, and altered trace elements may be linked to RA.

Iron deficiency negatively regulates protein methylation via the downregulation of protein arginine methyltransferase

Iron is an essential trace metal for all biological processes and plays a role in almost every aspect of body growth. Previously, we found that iron-depletion downregulated the expression of proteins, arginine methyltransferase-1 and 3 (PRMT1 and PRMT3), by an iron-specific chelator, deferoxamine (DFO), in rat liver FAO cell line using DNA microarray analysis (unpublished data). However, regulatory mechanisms underlying the association between iron deficiency and PRMT expression are unclear in vitro and in vivo. In the present study, we revealed that the treatment of cells with two iron-specific chelators, DFO and deferasirox (DFX), downregulated the gene and protein expression of PRMT1 and 3 as compared with the untreated cells. Subsequently, DFO and DFX treatments decreased protein methylation. Importantly, these effects were attenuated by a holo-transferrin treatment. Furthermore, weanling Wistar-strain rats were fed a control diet or an iron-deficient diet for 4 weeks. Dietary iron deficiency was found to decrease the concentration of hemoglobin and liver iron while increasing the heart weight. PRMT and protein methylation levels were also significantly reduced in the iron-deficient group as compared to the control group. To our knowledge, this is the first study to demonstrate that PRMT levels and protein methylation are reduced in iron-deficient models, in vitro and in vivo.

Ideal food pyramid for patients with rheumatoid arthritis: A narrative review

Emerging literature suggests that diet plays an important modulatory role in rheumatoid arthritis (RA) because diet is an environmental factor that affects inflammation, antigen presentation, antioxidant defense mechanisms and gut microbiota. Patients with RA frequently ask their doctors about which diets to follow, and even in the absence of advice from their physicians, many patients are undertaking various dietary interventions. Given this background, the aim of this review is to evaluate the evidence to date regarding the ideal dietary approach for management of RA in order to reduce the counteracting inflammation, and to construct a food pyramid for patients with RA. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains, preferably gluten free), together with fruits and vegetables (5 portions; among which fruit, berries and citrus fruit are to be preferred, and among the vegetables, green leafy ones.), light yogurt (125 ml), skim milk (200 ml), 1 glass (125 ml) of wine and extra virgin olive oil; weekly, fish (3 portions), white meat (3 portions), legumes (2 portions) eggs (2 portions), seasoned cheeses (2 portions), and red or processed meats (once a week). At the top of the pyramid, there are two pennants: one green means that subjects with RA need some personalized supplementation (vitamin D and omega 3) and one red means that there are some foods that are banned (salt and sugar). The food pyramid allows patients to easily figure out what to eat.

Δ9 -Tetrahydrocannabinolic acid alleviates collagen-induced arthritis: Role of PPARγ and CB1 receptors

BACKGROUND AND PURPOSE

Δ⁹ -Tetrahydrocannabinolic acid (Δ⁹ -THCA-A), the precursor of Δ⁹ -THC, is a non-psychotropic phytocannabinoid that shows PPARγ agonist activity. Here, we investigated the ability of Δ⁹ -THCA-A to modulate the classic cannabinoid CB₁ and CB₂ receptors and evaluated its anti-arthritis activity in vitro and in vivo.

EXPERIMENTAL APPROACH

Cannabinoid receptors binding and intrinsic activity, as well as their downstream signalling, were analysed in vitro and in silico. The anti-arthritis properties of Δ⁹ -THCA-A were studied in human chondrocytes and in the murine model of collagen-induced arthritis (CIA). Plasma disease biomarkers were identified by LC-MS/MS based on proteomic and elisa assays.

KEY RESULTS

Functional and docking analyses showed that Δ⁹ -THCA-A can act as an orthosteric CB₁ receptor agonist and also as a positive allosteric modulator in the presence of CP-55,940. Also, Δ⁹ -THCA-A seemed to be an inverse agonist for CB₂ receptors. In vivo, Δ⁹ -THCA-A reduced arthritis in CIA mice, preventing the infiltration of inflammatory cells, synovium hyperplasia, and cartilage damage. Furthermore, Δ⁹ -THCA-A inhibited expression of inflammatory and catabolic genes on knee joints. The anti-arthritic effect of Δ⁹ -THCA-A was blocked by either SR141716 or T0070907. Analysis of plasma biomarkers, and determination of cytokines and anti-collagen antibodies confirmed that Δ⁹ -THCA-A mediated its activity mainly through PPARγ and CB₁ receptor pathways.

CONCLUSION AND IMPLICATIONS

Δ⁹ -THCA-A modulates CB₁ receptors through the orthosteric and allosteric binding sites. In addition, Δ⁹ -THCA-A exerts anti-arthritis activity through CB₁ receptors and PPARγ pathways, highlighting its potential for the treatment of chronic inflammatory diseases such as rheumatoid arthritis.

Causal associations of iron status with gout and rheumatoid arthritis, but not with inflammatory bowel disease

BACKGROUND & AIMS

We conducted a two-sample Mendelian randomization study to assess the associations of iron homeostasis with the risk of gout, rheumatoid arthritis and inflammatory bowel disease.

METHODS

Single-nucleotide polymorphisms for iron status were selected at the genome-wide significance level from a large genome-wide association study of 48 972 European-descent individuals. Summary-level data for gout, rheumatoid arthritis and inflammatory bowel disease were obtained from The Global Urate Genetics Consortium and two large genome-wide association studies, respectively. Inverse-variance weighted method with random-effects and sensitivity analyses were performed.

RESULTS

Genetic predisposition to high iron status was causally associated with higher odds of gout, lower odds of rheumatoid arthritis, but not associated with inflammatory bowel disease. The odds ratios of gout were 1.35 (95% confidence interval (CI), 1.00, 1.81; p = 0.047), 2.07 (95% CI, 1.23, 3.50; p = 0.006), 1.27 (95% CI, 1.07, 1.50; p = 0.007) and 0.69 (95% CI, 0.54, 0.90; p = 0.005) per one standard deviation increment of serum iron, ferritin, transferrin saturation, and transferrin levels, respectively. For rheumatoid arthritis, the corresponding odds ratios were 0.79 (95% CI, 0.65, 0.94; p = 0.010), 0.59 (95% CI, 0.40, 0.86; p = 0.007), 0.84 (95% CI, 0.75, 0.94; p = 0.003) and 1.28 (95% CI, 1.06, 1.55; p = 0.012).

CONCLUSIONS

Based on consistent findings for four iron biomarkers, genetically high iron status was positively associated with gout and inversely associated with rheumatoid arthritis. There was limited MR evidence supporting a causal association between iron status and inflammatory bowel disease.

Zinc and iron complexes of oleanolic acid, (OA) attenuate allergic airway inflammation in rats

Oleanolic acid (OA) is a hydroxyl pentacyclic triterpene acid (HTAs) used in various ailments. Inflammatory diseases may be profoundly influenced by iron (Fe) and zinc (Zn) status. We studied the anti-asthmatic effects of two metal complexes (Fe and Zn) of OA in the ovalbumin (OVA)-induced rat model. Delayed type hypersensitivity (DTH) was measured. Total and differential leucocyte count was done in blood as well as bronchoalveolar lavage fluid (BALF). The mRNA expression levels of pro-inflammatory cytokines were measured in lung tissue by reverse transcription polymerase chain reaction. The levels of cyclooxygenase-2 (COX-2), immunoglobulin E (IgE) and 5-lipoxygenase (5-LOX) were estimated by enzyme linked immunosorbent assay. Splenocyte proliferation was performed through BrdU uptake method and nitric oxide levels were measured by colorimetric assay kit. The acute toxicity study was also done for the complexes. The asthmatic group developed allergic airway inflammation shown by increased DTH and inflammatory markers in blood and BALF. OA + Fe and OA + Zn displayed significant decrease in DTH, NO, expression of IL-4, 5, 13, 17, toll-like receptor-2, nuclear factor-kappa B and tumor necrosis factor-α; serum IgE, COX-2, and 5-LOX. The metal complexes also attenuated OVA-stimulated splenocyte proliferation. While no hepatotoxic or nephrotoxic potential was shown by OA + Fe and OA + Zn. Our findings indicate that both OA + Fe and OA + Zn possess significant anti-asthmatic effect which may be ascribed to its immunomodulatory and anti-inflammatory features.

Rusty Microglia: Trainers of Innate Immunity in Alzheimer's Disease

Alzheimer's disease, the most common form of dementia, is marked by progressive cognitive and functional impairment believed to reflect synaptic and neuronal loss. Recent preclinical data suggests that lipopolysaccharide (LPS)-activated microglia may contribute to the elimination of viable neurons and synapses by promoting a neurotoxic astrocytic phenotype, defined as A1. The innate immune cells, including microglia and astrocytes, can either facilitate or inhibit neuroinflammation in response to peripherally applied inflammatory stimuli, such as LPS. Depending on previous antigen encounters, these cells can assume activated (trained) or silenced (tolerized) phenotypes, augmenting or lowering inflammation. Iron, reactive oxygen species (ROS), and LPS, the cell wall component of gram-negative bacteria, are microglial activators, but only the latter can trigger immune tolerization. In Alzheimer's disease, tolerization may be impaired as elevated LPS levels, reported in this condition, fail to lower neuroinflammation. Iron is closely linked to immunity as it plays a key role in immune cells proliferation and maturation, but it is also indispensable to pathogens and malignancies which compete for its capture. Danger signals, including LPS, induce intracellular iron sequestration in innate immune cells to withhold it from pathogens. However, excess cytosolic iron increases the risk of inflammasomes' activation, microglial training and neuroinflammation. Moreover, it was suggested that free iron can awaken the dormant central nervous system (CNS) LPS-shedding microbes, engendering prolonged neuroinflammation that may override immune tolerization, triggering autoimmunity. In this review, we focus on iron-related innate immune pathology in Alzheimer's disease and discuss potential immunotherapeutic agents for microglial de-escalation along with possible delivery vehicles for these compounds.

No effects without causes: the Iron Dysregulation and Dormant Microbes hypothesis for chronic, inflammatory diseases

Since the successful conquest of many acute, communicable (infectious) diseases through the use of vaccines and antibiotics, the currently most prevalent diseases are chronic and progressive in nature, and are all accompanied by inflammation. These diseases include neurodegenerative (e.g. Alzheimer's, Parkinson's), vascular (e.g. atherosclerosis, pre-eclampsia, type 2 diabetes) and autoimmune (e.g. rheumatoid arthritis and multiple sclerosis) diseases that may appear to have little in common. In fact they all share significant features, in particular chronic inflammation and its attendant inflammatory cytokines. Such effects do not happen without underlying and initially 'external' causes, and it is of interest to seek these causes. Taking a systems approach, we argue that these causes include (i) stress-induced iron dysregulation, and (ii) its ability to awaken dormant, non-replicating microbes with which the host has become infected. Other external causes may be dietary. Such microbes are capable of shedding small, but functionally significant amounts of highly inflammagenic molecules such as lipopolysaccharide and lipoteichoic acid. Sequelae include significant coagulopathies, not least the recently discovered amyloidogenic clotting of blood, leading to cell death and the release of further inflammagens. The extensive evidence discussed here implies, as was found with ulcers, that almost all chronic, infectious diseases do in fact harbour a microbial component. What differs is simply the microbes and the anatomical location from and at which they exert damage. This analysis offers novel avenues for diagnosis and treatment.

Iron Drives T Helper Cell Pathogenicity by Promoting RNA-Binding Protein PCBP1-Mediated Proinflammatory Cytokine Production

Iron deposition is frequently observed in human autoinflammatory diseases, but its functional significance is largely unknown. Here we showed that iron promoted proinflammatory cytokine expression in T cells, including GM-CSF and IL-2, via regulating the stability of an RNA-binding protein PCBP1. Iron depletion or Pcbp1 deficiency in T cells inhibited GM-CSF production by attenuating Csf2 3' untranslated region (UTR) activity and messenger RNA stability. Pcbp1 deficiency or iron uptake blockade in autoreactive T cells abolished their capacity to induce experimental autoimmune encephalomyelitis, an animal model for multiple sclerosis. Mechanistically, intracellular iron protected PCBP1 protein from caspase-mediated proteolysis, and PCBP1 promoted messenger RNA stability of Csf2 and Il2 by recognizing UC-rich elements in the 3' UTRs. Our study suggests that iron accumulation can precipitate autoimmune diseases by promoting proinflammatory cytokine production. RNA-binding protein-mediated iron sensing may represent a simple yet effective means to adjust the inflammatory response to tissue homeostatic alterations.

Role of Diet in Influencing Rheumatoid Arthritis Disease Activity

BACKGROUND

Patients with Rheumatoid Arthritis (RA) frequently ask their doctors about which diets to follow, and even in the absence of advice from their physicians, many patients are undertaking various dietary interventions.

DISCUSSION

However, the role of dietary modifications in RA is not well understood. Several studies have tried to address these gaps in our understanding. Intestinal microbial modifications are being studied for the prevention and management of RA. Some benefits of vegan diet may be explained by antioxidant constituents, lactobacilli and fibre, and by potential changes in intestinal flora. Similarly, Mediterranean diet shows anti-inflammatory effects due to protective properties of omega-3 polyunsaturated fatty acids and vitamins, but also by influencing the gut microbiome. Gluten-free and elemental diets have been associated with some benefits in RA though the existing evidence is limited. Long-term intake of fish and other sources of long-chain polyunsaturated fatty acids are protective for development of RA. The benefits of fasting, anti-oxidant supplementation, flavanoids, and probiotics in RA are not clear. Vitamin D has been shown to influence autoimmunity and specifically decrease RA disease activity. The role of supplements such as fish oils and vitamin D should be explored in future trials to gain new insights in disease pathogenesis and develop RA-specific dietary recommendations.

CONCLUSION

Specifically more research is needed to explore the association of diet and the gut microbiome and how this can influence RA disease activity.

Intravenous Ferric Carboxymaltose in Patients with Type 2 Diabetes Mellitus and Iron Deficiency: CLEVER Trial Study Design and Protocol

INTRODUCTION

HbA1c is the gold standard for glycemic control in pre-diabetes and diabetes. However, its validity has been questioned, especially in the presence of imbalanced iron homeostasis. The CLEVER trial aims to evaluate the relationship between iron deficiency and HbA1c (a biomarker for the diagnosis and therapeutic monitoring of type 2 diabetes) in a randomized, placebo-controlled, multicenter clinical trial.

METHODS

The CLEVER (intravenous ferric CarboxymaLtosE for improVement of mEtabolic parameters in type 2 diabetes patients with iRon deficiency) trial is a randomized, single-blind, proof-of-concept study with two treatment arms. 140 men and women diagnosed with type 2 diabetes and iron deficiency will receive either placebo or ferric carboxymaltose (500 or 1000 mg) as intravenous infusions. The primary outcome measure is the change in HbA1c level between baseline and after 12 weeks of treatment. Secondary endpoints include change of iron status and metabolic markers as well as treatment safety and tolerability. Furthermore, the potential clinical improvement in quality of life and the reliability of HbA1c measurement in patients with type 2 diabetes and iron deficiency will be investigated.

RESULTS

Both excessive iron and iron deficiency are associated with metabolic disorders; excessive iron is a risk factor for the development of diabetes, whereas iron deficiency is associated with obesity and insulin resistance. It has been suggested that iron increases insulin secretion in pancreatic beta-cells. CLEVER is the first study to investigate the hypothesis that intravenous substitution with ferric carboxymaltose reduces HbA1c levels in patients with type 2 diabetes and iron deficiency, thereby improving metabolic status and quality of life.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov (NCT01513369).

FUNDING

GWT-TUD GmbH acts as sponsor of the clinical trial. Financial support is provided by Vifor Pharma.

Iron deficiency in heart failure: Efficacy and safety of intravenous iron therapy

AIM

To discuss the pathophysiology of iron metabolism in chronic heart failure (CHF) and the current knowledge of the efficacy of intravenous (IV) iron therapy in patients with CHF and identify points of controversy as well as highlight areas for future research.

DISCUSSION

Iron deficiency is a recognized complication of many chronic conditions. Numerous studies have reported that iron deficiency is highly prevalent in patients with CHF and is associated with exercise intolerance, reduced quality of life, and increased risk of hospitalization and mortality. Several small studies have demonstrated IV iron to be associated with improvements in symptoms, exercise capacity, quality of life, renal function, New York Heart Association (NYHA) functional class and left ventricular ejection fraction (LVEF), and reduction in NT-pro-brain natriuretic peptide (NT-proBNP) in patients with CHF and iron deficiency. Two larger-scale trials confirming these results (FAIR-HF and CONFIRM-HF) have led to guideline recommendations that IV iron therapy should be considered in patients with CHF with reduced ejection fraction and iron deficiency (serum ferritin <100 μg/L, or ferritin between 100 and 299 μg/L with transferrin saturation <20%) to provide symptomatic relief and improve exercise capacity and quality of life.

CONCLUSION

Intravenous iron therapy improves symptoms, exercise capacity, and quality of life, at least in the short-to-intermediate time. However, there are still currently no standardized criteria used to define iron deficiency and the underlying mechanism of iron deficiency in CHF remains incompletely understood. Further work is required to improve the ability to identify iron deficiency in patients with CHF and evaluate the effect of iron repletion on hard endpoints including hospitalization and mortality.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

Urinary biomarkers in childhood lupus nephritis

Juvenile-onset systemic lupus erythematosus (JSLE) is a rare, severe multisystem autoimmune disease affecting the kidney (Lupus Nephritis, LN) in up to 80% of children. LN is more severe in children than adults, with potential for irreversible kidney damage requiring dialysis or transplant. Renal biopsy is currently the gold standard for diagnosing and monitoring LN, however, it is invasive and associated with complications. Urine biomarkers have been shown to be better than serum biomarkers in differentiating renal disease from other organ manifestations. Over the past decade, there have been an increasing number of studies investigating specific candidate biomarkers implicated in the pathogenesis of LN or screening for urinary biomarkers using hypothesis free methods. In this review, developments in urine biomarkers for LN will be reviewed, highlighting those that are of relevance to children and have gone through validation in independent international patient cohorts, bringing them close to clinical translation.

Activation of the NLRP3 inflammasome by cellular labile iron

Cellular labile iron, which contains chelatable redox-active Fe(2+), has been implicated in iron-mediated cellular toxicity leading to multiple organ dysfunction. Iron homeostasis is controlled by monocytes/macrophages through their iron recycling and storage capacities. Furthermore, iron sequestration by monocytes/macrophages is regulated by pro-inflammatory cytokines including interleukin-1, highlighting the importance of these cells in the crosstalk between inflammation and iron homeostasis. However, a role for cellular labile iron in monocyte/macrophage-mediated inflammatory responses has not been defined. Here we describe how cellular labile iron activates the NLRP3 inflammasome in human monocytes. Stimulation of lipopolysaccharide-primed peripheral blood mononuclear cells with ferric ammonium citrate increases the level of cellular Fe(2+) levels in monocytes and induces production of interleukin-1β in a dose-dependent manner. This ferric ammonium citrate-induced interleukin-1β production is dependent on caspase-1 and is significantly inhibited by an Fe(2+)-specific chelator. Ferric ammonium citrate consistently induced interleukin-1β secretion in THP1 cells, but not in NLRP3-deficient THP1 cells, indicating a requirement for the NLRP3 inflammasome. Additionally, activation of the inflammasome is mediated by potassium efflux, reactive oxygen species-mediated mitochondrial dysfunction, and lysosomal membrane permeabilization. Thus, these results suggest that monocytes/macrophages not only sequestrate iron during inflammation, but also mediate inflammation in response to cellular labile iron, which provides novel insights into the role of iron in chronic inflammation.

Appraising the Role of Iron in Brain Aging and Cognition: Promises and Limitations of MRI Methods

Age-related increase in frailty is accompanied by a fundamental shift in cellular iron homeostasis. By promoting oxidative stress, the intracellular accumulation of non-heme iron outside of binding complexes contributes to chronic inflammation and interferes with normal brain metabolism. In the absence of direct non-invasive biomarkers of brain oxidative stress, iron accumulation estimated in vivo may serve as its proxy indicator. Hence, developing reliable in vivo measurements of brain iron content via magnetic resonance imaging (MRI) is of significant interest in human neuroscience. To date, by estimating brain iron content through various MRI methods, significant age differences and age-related increases in iron content of the basal ganglia have been revealed across multiple samples. Less consistent are the findings that pertain to the relationship between elevated brain iron content and systemic indices of vascular and metabolic dysfunction. Only a handful of cross-sectional investigations have linked high iron content in various brain regions and poor performance on assorted cognitive tests. The even fewer longitudinal studies indicate that iron accumulation may precede shrinkage of the basal ganglia and thus predict poor maintenance of cognitive functions. This rapidly developing field will benefit from introduction of higher-field MRI scanners, improvement in iron-sensitive and -specific acquisition sequences and post-processing analytic and computational methods, as well as accumulation of data from long-term longitudinal investigations. This review describes the potential advantages and promises of MRI-based assessment of brain iron, summarizes recent findings and highlights the limitations of the current methodology.

Beneficial effects of long-term intravenous iron therapy with ferric carboxymaltose in patients with symptomatic heart failure and iron deficiency†

Aim

The aim of this study was to evaluate the benefits and safety of long-term i.v. iron therapy in iron-deficient patients with heart failure (HF).

Methods and results

CONFIRM-HF was a multi-centre, double-blind, placebo-controlled trial that enrolled 304 ambulatory symptomatic HF patients with left ventricular ejection fraction ≤45%, elevated natriuretic peptides, and iron deficiency (ferritin <100 ng/mL or 100–300 ng/mL if transferrin saturation <20%). Patients were randomized 1 : 1 to treatment with i.v. iron, as ferric carboxymaltose (FCM, n = 152) or placebo (saline, n = 152) for 52 weeks. The primary end-point was the change in 6-min-walk-test (6MWT) distance from baseline to Week 24. Secondary end-points included changes in New York Heart Association (NYHA) class, Patient Global Assessment (PGA), 6MWT distance, health-related quality of life (QoL), Fatigue Score at Weeks 6, 12, 24, 36, and 52 and the effect of FCM on the rate of hospitalization for worsening HF. Treatment with FCM significantly prolonged 6MWT distance at Week 24 (difference FCM vs. placebo: 33 ± 11 m, P = 0.002). The treatment effect of FCM was consistent in all subgroups and was sustained to Week 52 (difference FCM vs. placebo: 36 ± 11 m, P < 0.001). Throughout the study, an improvement in NYHA class, PGA, QoL, and Fatigue Score in patients treated with FCM was detected with statistical significance observed from Week 24 onwards. Treatment with FCM was associated with a significant reduction in the risk of hospitalizations for worsening HF [hazard ratio (95% confidence interval): 0.39 (0.19–0.82), P = 0.009]. The number of deaths (FCM: 12, placebo: 14 deaths) and the incidence of adverse events were comparable between both groups.

Conclusion

Treatment of symptomatic, iron-deficient HF patients with FCM over a 1-year period resulted in sustainable improvement in functional capacity, symptoms, and QoL and may be associated with risk reduction of hospitalization for worsening HF (ClinicalTrials.gov number NCT01453608).

[Perioperative anemia management: a systematic review and meta-analysis]

Anemia is a risk factor for increased postoperative morbidity and mortality. International guidelines, therefore, recommend preoperative diagnostic work up and causal treatment of anemia. Iron therapy, however, is suspected to negatively affect disease progression in patients with cancer-associated anemia. The objective of our systematic review was to assess the efficacy and safety of perioperative diagnosis and causal therapy of anemia, and to determine the effect of iron supplement on disease progression of cancer.We systematically searched multiple electronic databases. Two persons independently reviewed abstracts and full-text articles. We rated the risk of bias using the Cochrane Risk of Bias Tool and assessed the quality of the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation). Meta-Analyses were performed using the DerSimonian&Laird random effects method. Results indicate that preoperative therapy of anemia could reduce the need for blood transfusions (relative risk: 0,78; 95% confidence interval 0,61-1,02; number needed to treat: 6) For other patient-relevant outcomes the number of events were too small to detect clinically relevant differences. We could not find any evidence that iron supplements have an influence on the progression of tumors.

Iron deficiency and heart failure: diagnostic dilemmas and therapeutic perspectives

Iron is a micronutrient essential for cellular energy and metabolism, necessary for maintaining body homoeostasis. Iron deficiency is an important co-morbidity in patients with heart failure (HF). A major factor in the pathogenesis of anaemia, it is also a separate condition with serious clinical consequences (e.g. impaired exercise capacity) and poor prognosis in HF patients. Experimental evidence suggests that iron therapy in iron-deficient animals may activate molecular pathways that can be cardio-protective. Clinical studies have demonstrated favourable effects of i.v. iron on the functional status, quality of life, and exercise capacity in HF patients. It is hypothesized that i.v. iron supplementation may become a novel therapy in HF patients with iron deficiency.

Inflammation associated anemia and ferritin as disease markers in SLE

Introduction

In a recent screening to detect biomarkers in systemic lupus erythematosus (SLE), expression of the iron storage protein, ferritin, was increased. Given that proteins that regulate the storage, transfer and release of iron play an important role in inflammation, this study aims to determine the serum and urine levels of ferritin and of the iron transfer protein, transferrin, in lupus patients and to correlate these levels with disease activity, inflammatory cytokine levels and markers of anemia.

Methods

A protein array was utilized to measure ferritin expression in the urine and serum of SLE patients and healthy controls. To confirm these results as well as the role of the iron transfer pathway in SLE, ELISAs were performed to measure ferritin and transferrin levels in inactive or active SLE patients and healthy controls. The relationship between ferritin/transferrin levels and inflammatory markers and anemia was next analyzed.

Results

Protein array results showed elevated ferritin levels in the serum and urine of lupus patients as compared to controls, which were further validated by ELISA. Increased ferritin levels correlated with measures of disease activity and anemia as well as inflammatory cytokine titers. Though active SLE patients had elevated urine transferrin, serum transferrin was reduced.

Conclusion

Urine ferritin and transferrin levels are elevated significantly in SLE patients and correlate with disease activity, bolstering previous reports. Most importantly, these changes correlated with the inflammatory state of the patients and anemia of chronic disease. Taken together, altered iron handling, inflammation and anemia of chronic disease constitute an ominous triad in SLE.

Immunostimulation in the era of the metagenome

Microbes are increasingly being implicated in autoimmune disease. This calls for a re-evaluation of how these chronic inflammatory illnesses are routinely treated. The standard of care for autoimmune disease remains the use of medications that slow the immune response, while treatments aimed at eradicating microbes seek the exact opposite-stimulation of the innate immune response. Immunostimulation is complicated by a cascade of sequelae, including exacerbated inflammation, which occurs in response to microbial death. Over the past 8 years, we have collaborated with American and international clinical professionals to research a model-based treatment for inflammatory disease. This intervention, designed to stimulate the innate immune response, has required a reevaluation of disease progression and amelioration. Paramount is the inherent conflict between palliation and microbicidal efficacy. Increased microbicidal activity was experienced as immunopathology-a temporary worsening of symptoms. Further studies are needed, but they will require careful planning to manage this immunopathology.

Intralysosomal iron induces lysosomal membrane permeabilization and cathepsin D-mediated cell death in trabecular meshwork cells exposed to oxidative stress

PURPOSE

To investigate the role of intralysosomal redox-active iron in oxidative stress-induced damage in trabecular meshwork (TM) cells.

METHODS

Chronic oxidative stress was applied using the hyperoxic model; acute oxidative stress was applied with H(2)O(2). Microarray analysis was performed using microarrays. mRNA and protein levels were quantified by real-time PCR and Western blot analysis, respectively. Redox-active iron was monitored using calcein-AM. Apoptosis was quantified using double staining. DNA damage was evaluated by single-cell gel electrophoresis assay. Lysosomal permeabilization was monitored using uptake and acridine orange relocation techniques. Intracellular ROS production was quantified using H(2)DCFDA. Cytosolic translocation of cathepsins was visualized with pepstatin-A-BODIPY-FL. Chemical inhibition of cathepsins was achieved with leupeptin and pepstatin A. Silencing of cathepsin expression was accomplished with miRNA sequences. Lysosomal iron chelation was achieved with desferrioxamine.

RESULTS

Chronically stressed TM cells showed elevated levels of redox-active iron and altered expression of genes involved in intracellular iron homeostasis. Although iron increased ROS production and lipofuscin levels and sensitized TM cells to H(2)O(2), intralysosomal iron chelation completely protected the cells against H(2)O(2)-induced cell death and apoptosis. The protective effect of desferrioxamine was mediated by the prevention of lysosomal ROS generation and the rupture of lysosomal membrane, with the subsequent release of cathepsin D into the cytosol.

CONCLUSIONS

These results indicate that the generation of intralysosomal ROS induces lysosomal membrane permeabilization and the release of cathepsin D into the cytosol, leading to TM cell death. Here, the authors propose a mechanism by which oxidative stress might contribute to the decrease in cellularity reported in the TM tissue with both aging and disease.

Iron deficiency: an ominous sign in patients with systolic chronic heart failure

AIMS

Beyond erythropoiesis, iron is involved in numerous biological processes crucial for maintenance of homeostasis. Patients with chronic heart failure (CHF) are prone to develop iron deficiency (ID), and iron supplementation improves their functional status and quality of life. We sought to examine the relationship between ID and survival in patients with systolic CHF.

METHODS AND RESULTS

In a prospective observational study, we evaluated 546 patients with stable systolic CHF [age: 55 +/- 11 (mean +/- standard deviation) years, males: 88%, left ventricular ejection fraction: 26 +/- 7%, New York Heart Association (NYHA) class (I/II/III/IV): 57/221/226/42]. Iron deficiency was defined as: ferritin <100 microg/L, or 100-300 microg/L with transferrin saturation <20%. The prevalence of ID was 37 +/- 4% [+/-95% confidence intervals (CI)] in the entire CHF population (32 +/- 4 vs. 57 +/- 10%-in subjects without vs. with anaemia defined as haemoglobin level <12 g/dL in women and <13 g/dL in men, P < 0.001). In a multiple logistic model, ID was more prevalent in women, those in the advanced NYHA class, with higher plasma N-terminal pro-type B natriuretic peptide and higher serum high-sensitivity C-reactive protein (all P < 0.05). At the end of follow-up (mean duration: 731 +/- 350 days), there were 153 (28%) deaths and 30 (6%) heart transplantations (HTX). In multivariable models, ID (but not anaemia) was related to an increased risk of death or HTX (adjusted hazard ratio 1.58, 95% CI 1.14-2.17, P < 0.01).

CONCLUSION

In patients with systolic CHF, ID is common and constitutes a strong, independent predictor of unfavourable outcome. Iron supplementation may be considered as a therapeutic approach in these patients to improve prognosis.