Serum ferritin iron in iron overload and liver damage: correlation to body iron stores and diagnostic relevance

Melatonin: a ferroptosis inhibitor with potential therapeutic efficacy for the post-COVID-19 trajectory of accelerated brain aging and neurodegeneration

The unprecedented pandemic of COVID-19 swept millions of lives in a short period, yet its menace continues among its survivors in the form of post-COVID syndrome. An exponentially growing number of COVID-19 survivors suffer from cognitive impairment, with compelling evidence of a trajectory of accelerated aging and neurodegeneration. The novel and enigmatic nature of this yet-to-unfold pathology demands extensive research seeking answers for both the molecular underpinnings and potential therapeutic targets. Ferroptosis, an iron-dependent cell death, is a strongly proposed underlying mechanism in post-COVID-19 aging and neurodegeneration discourse. COVID-19 incites neuroinflammation, iron dysregulation, reactive oxygen species (ROS) accumulation, antioxidant system repression, renin-angiotensin system (RAS) disruption, and clock gene alteration. These events pave the way for ferroptosis, which shows its signature in COVID-19, premature aging, and neurodegenerative disorders. In the search for a treatment, melatonin shines as a promising ferroptosis inhibitor with its repeatedly reported safety and tolerability. According to various studies, melatonin has proven efficacy in attenuating the severity of certain COVID-19 manifestations, validating its reputation as an anti-viral compound. Melatonin has well-documented anti-aging properties and combating neurodegenerative-related pathologies. Melatonin can block the leading events of ferroptosis since it is an efficient anti-inflammatory, iron chelator, antioxidant, angiotensin II antagonist, and clock gene regulator. Therefore, we propose ferroptosis as the culprit behind the post-COVID-19 trajectory of aging and neurodegeneration and melatonin, a well-fitting ferroptosis inhibitor, as a potential treatment.

Prognostic value of preoperative serum ferritin in hepatocellular carcinoma patients undergoing transarterial chemoembolization

The present study investigated the prognostic impact of preoperative serum ferritin (SF) levels on the survival of patients with hepatocellular carcinoma (HCC) undergoing transarterial chemoembolization (TACE). Clinicopathological characteristics and laboratory biomarkers of 223 patients with HCC who underwent TACE were retrospectively reviewed. The Kaplan-Meier method was used to calculate the overall survival (OS), and the log-rank test was used to evaluate statistical significance. Univariate and multivariate analyses were performed using Cox proportional hazards regression to evaluate the prognostic impact of SF in these patients. The present findings identified extrahepatic metastases [hazard ratio (HR)=0.490,95%; confidence interval (CI)=0.282-0.843; P=0.010)] and vascular invasion (HR=0.373; 95% CI=0.225-0.619; P<0.0001) as independent prognostic factors for OS. However, preoperative SF levels could not independently predict OS when compared with other prognostic factors (HR=0.810; 95% CI=0.539-1.216; P=0.309). In conclusion, preoperative SF level is an unreliable biochemical predictor of survival in patients with HCC undergoing TACE.

Sex difference in the association between blood alcohol concentration and serum ferritin

Introduction

The sex difference in alcohol use disorder (AUD) is ingrained in distinctive neurobiological responses between men and women, which necessitates further investigation for a more tailored management.

Methods

Minding the findings of iron dysregulation in AUD and the sex difference in iron homeostasis in multiple physiological and pathological settings, we examined the sex difference in the association between serum ferritin and blood alcohol concentration (BAC) in intoxicated males (n = 125) and females (n = 59). We included patients with both serum ferritin tested of any value and a BAC above the level of detection during the same hospital admission period. We investigated sex difference in the relationship between BAC, serum ferritin and liver enzymes in intoxicated critically ill and noncritically ill patients.

Results

We found a negative association between serum ferritin and BAC in critically ill, intoxicated females [R2 = 0.44, F(1,14) = 11.02, p = 0.005], with much attenuated serum ferritin in females compared to their male counterparts (194.5 ± 280.4 vs. 806.3 ± 3405.7 ng/L, p = 0.002). We found a positive association between serum ferritin and liver enzymes [alanine transaminase (ALT) and aspartate transferase (AST)] in critically ill intoxicated females [ALT: R2 = 0.48, F(1,10) = 9.1, p = 0.013; AST: R2 = 0.68, F(1,10) = 21.2, p = 0.001] and in noncritically ill intoxicated males [ALT: R2 = 0.1, F(1,83) = 9.4, p = 0.003; AST: R2 = 0.1, F(1,78) = 10.5, p = 0.002]. The effect of BAC on serum ferritin was not mediated by ALT [indirect effect: (B = 0.13, p = 0.1)]. We also found a significant effect of sex, anemia, intensive care unit (ICU) admission and mortality on serum ferritin.

Discussion

Our results suggest that high BAC in intoxicated female patients is associated with attenuated serum ferritin levels, questioning the role of low serum ferritin in female vulnerability to alcohol.

PSS functionalized and stabilized carbon nanodots for specific sensing of iron in biological medium

Carbon Quantum Dots (CQDs) are already emerged as an excellent sensing element for its exceptional behavior in fluorescence, biocompatibility, and water dispersibility. However, its poor stability, selectivity and reproducibility in complex medium still be a big problem for its practical application. To overcome this, in the work, we have developed a new type of carbon quantum dot-PSS fluorescent nanocomposites which has been used for specific Fe³⁺ detection. The polystyrene sulfonate (PSS) polymer not only stabilize the QDs but also produces specific sites for Fe³⁺ to make a co-ordinate complex via Fe³⁺-SO3. The detection limit is calculated as low as 1 ppm which is adequate for measuring Fe³⁺ in blood or water samples. The mechanism of the quenching is very specific towards the Fe³⁺ ion due to the presence of PSS which makes the sensor selective among other metal ions and possible interferences. The rapid process of sensing, simple instrumentation, and excellent performances in presence of 1 % BSA and serum samples indicates the possible application for diagnostic usage in near future.

Quantification of Liver Iron Overload with MRI: Review and Guidelines from the ESGAR and SAR

Accumulation of excess iron in the body, or systemic iron overload, results from a variety of causes. The concentration of iron in the liver is linearly related to the total body iron stores and, for this reason, quantification of liver iron concentration (LIC) is widely regarded as the best surrogate to assess total body iron. Historically assessed using biopsy, there is a clear need for noninvasive quantitative imaging biomarkers of LIC. MRI is highly sensitive to the presence of tissue iron and has been increasingly adopted as a noninvasive alternative to biopsy for detection, severity grading, and treatment monitoring in patients with known or suspected iron overload. Multiple MRI strategies have been developed in the past 2 decades, based on both gradient-echo and spin-echo imaging, including signal intensity ratio and relaxometry strategies. However, there is a general lack of consensus regarding the appropriate use of these methods. The overall goal of this article is to summarize the current state of the art in the clinical use of MRI to quantify liver iron content and to assess the overall level of evidence of these various methods. Based on this summary, expert consensus panel recommendations on best practices for MRI-based quantification of liver iron are provided.

Multicenter Reproducibility of Liver Iron Quantification with 1.5-T and 3.0-T MRI

Background MRI is a standard of care tool to measure liver iron concentration (LIC). Compared with regulatory-approved R2 MRI, R2* MRI has superior speed and is available in most MRI scanners; however, the cross-vendor reproducibility of R2*-based LIC estimation remains unknown. Purpose To evaluate the reproducibility of LIC via single-breath-hold R2* MRI at both 1.5 T and 3.0 T with use of a multicenter, multivendor study. Materials and Methods Four academic medical centers using MRI scanners from three different vendors (three 1.5-T scanners, one 2.89-T scanner, and two 3.0-T scanners) participated in this prospective cross-sectional study. Participants with known or suspected liver iron overload were recruited to undergo multiecho gradient-echo MRI for R2* mapping at 1.5 T and 3.0 T (2.89 T or 3.0 T) on the same day. R2* maps were reconstructed from the multiecho images and analyzed at a single center. Reference LIC measurements were obtained with a commercial R2 MRI method performed using standardized 1.5-T spin-echo imaging. R2*-versus-LIC calibrations were generated across centers and field strengths using linear regression and compared using F tests. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic performance of R2* MRI in the detection of clinically relevant LIC thresholds. Results A total of 207 participants (mean age, 38 years ± 20 [SD]; 117 male participants) were evaluated between March 2015 and September 2019. A linear relationship was confirmed between R2* and LIC. All calibrations within the same field strength were highly reproducible, showing no evidence of statistically significant center-specific differences (P > .43 across all comparisons). Calibrations for 1.5 T and 3.0 T were generated, as follows: for 1.5 T, LIC (in milligrams per gram [dry weight]) = -0.16 + 2.603 × 10-2 R2* (in seconds-1); for 2.89 T, LIC (in milligrams per gram) = -0.03 + 1.400 × 10-2 R2* (in seconds-1); for 3.0 T, LIC (in milligrams per gram) = -0.03 + 1.349 × 10-2 R2* (in seconds-1). Liver R2* had high diagnostic performance in the detection of clinically relevant LIC thresholds (area under the ROC curve, >0.98). Conclusion R2* MRI enabled accurate and reproducible quantification of liver iron overload over clinically relevant ranges of liver iron concentration (LIC). The data generated in this study provide the necessary calibrations for broad clinical dissemination of R2*-based LIC quantification. ClinicalTrials.gov registration no.: NCT02025543 © RSNA, 2022 Online supplemental material is available for this article.

Hereditary Hyperferritinemia

Ferritin is a ubiquitous protein that is present in most tissues as a cytosolic protein. The major and common role of ferritin is to bind Fe²⁺, oxidize it and sequester it in a safe form in the cell, and to release iron according to cellular needs. Ferritin is also present at a considerably low proportion in normal mammalian sera and is relatively iron poor compared to tissues. Serum ferritin might provide a useful and convenient method of assessing the status of iron storage, and its measurement has become a routine laboratory test. However, many additional factors, including inflammation, infection, metabolic abnormalities, and malignancy-all of which may elevate serum ferritin-complicate interpretation of this value. Despite this long history of clinical use, fundamental aspects of the biology of serum ferritin are still unclear. According to the high number of factors involved in regulation of ferritin synthesis, secretion, and uptake, and in its central role in iron metabolism, hyperferritinemia is a relatively common finding in clinical practice and is found in a large spectrum of conditions, both genetic and acquired, associated or not with iron overload. The diagnostic strategy to reveal the cause of hyperferritinemia includes family and personal medical history, biochemical and genetic tests, and evaluation of liver iron by direct or indirect methods. This review is focused on the forms of inherited hyperferritinemia with or without iron overload presenting with normal transferrin saturation, as well as a step-by-step approach to distinguish these forms to the acquired forms, common and rare, of isolated hyperferritinemia.

Brain iron assessment in patients with First-episode schizophrenia using quantitative susceptibility mapping

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Patients with first-episode schizophrenia had significantly decreased QSM values in the bilateral substantia nigra, left red nucleus and left thalamus.

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Patients with first-episode schizophrenia had significantly increased regional volumes in the bilateral putamen and bilateral substantia nigra.

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QSM provides superior sensitivity over R₂* mapping in the evaluation of schizophrenia-related iron alterations.

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QSM values in regions that showed intergroup differences did not exhibited significant correlations with PANSS scores.

Purpose

Decreased serum ferritin level was recently found in schizophrenia. Whether the brain iron concentration in schizophrenia exists abnormality is of research significance. Quantitative susceptibility mapping (QSM) was used in this study to assess brain iron changes in the grey matter nuclei of patients with first-episode schizophrenia.

Methods

The local ethics committee approved the study, and all subjects gave written informed consent. Thirty patients with first-episode schizophrenia and 30 age and gender-matched healthy controls were included in this study. QSM and effective transverse relaxation rate (R₂*) maps were reconstructed from a three-dimensional multi-echo gradient-echo sequence. The inter-group differences of regional QSM values, R₂* values and volumes were calculated in the grey matter nuclei, including bilateral caudate nucleus, putamen, globus pallidus, substantia nigra, red nucleus, and thalamus. The diagnostic performance of QSM and R₂* was evaluated using receiver operating characteristic curve. The correlations between regional iron variations and clinical PANSS (Positive and Negative Syndrome Scale) scores were assessed using partial correlation analysis.

Results

Compared to healthy controls, patients with first-episode schizophrenia had significantly decreased QSM values (less paramagnetic) in the bilateral substantia nigra, left red nucleus and left thalamus (p < 0.05, FDR correction). QSM proved more sensitive than R₂* regarding inter-group differences. The highest diagnostic performance for first-episode schizophrenia was observed in QSM value of the left substantia nigra (area under the curve, AUC = 0.718, p = 0.004). Regional volumes of bilateral putamen and bilateral substantia nigra were increased (p < 0.05, FDR correction) in first-episode schizophrenia. However, both QSM and R₂* values did not show significant correlations with PANSS scores (p > 0.05).

Conclusion

This study reveals decreased iron concentration in grey matter nuclei of patients with first-episode schizophrenia. QSM provides superior sensitivity over R₂* in the evaluation of schizophrenia-related brain iron changes. It demonstrated that QSM may be a potential biomarker for further understanding the pathophysiological mechanism of first-episode schizophrenia.

Serum or plasma ferritin concentration as an index of iron deficiency and overload

BACKGROUND

Reference standard indices of iron deficiency and iron overload are generally invasive, expensive, and can be unpleasant or occasionally risky. Ferritin is an iron storage protein and its concentration in the plasma or serum reflects iron stores; low ferritin indicates iron deficiency, while elevated ferritin reflects risk of iron overload. However, ferritin is also an acute-phase protein and its levels are elevated in inflammation and infection. The use of ferritin as a diagnostic test of iron deficiency and overload is a common clinical practice.

OBJECTIVES

To determine the diagnostic accuracy of ferritin concentrations (serum or plasma) for detecting iron deficiency and risk of iron overload in primary and secondary iron-loading syndromes.

SEARCH METHODS

We searched the following databases (10 June 2020): DARE (Cochrane Library) Issue 2 of 4 2015, HTA (Cochrane Library) Issue 4 of 4 2016, CENTRAL (Cochrane Library) Issue 6 of 12 2020, MEDLINE (OVID) 1946 to 9 June 2020, Embase (OVID) 1947 to week 23 2020, CINAHL (Ebsco) 1982 to June 2020, Web of Science (ISI) SCI, SSCI, CPCI-exp & CPCI-SSH to June 2020, POPLINE 16/8/18, Open Grey (10/6/20), TRoPHI (10/6/20), Bibliomap (10/6/20), IBECS (10/6/20), SCIELO (10/6/20), Global Index Medicus (10/6/20) AIM, IMSEAR, WPRIM, IMEMR, LILACS (10/6/20), PAHO (10/6/20), WHOLIS 10/6/20, IndMED (16/8/18) and Native Health Research Database (10/6/20). We also searched two trials registers and contacted relevant organisations for unpublished studies.

SELECTION CRITERIA

We included all study designs seeking to evaluate serum or plasma ferritin concentrations measured by any current or previously available quantitative assay as an index of iron status in individuals of any age, sex, clinical and physiological status from any country.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. We designed the data extraction form to record results for ferritin concentration as the index test, and bone marrow iron content for iron deficiency and liver iron content for iron overload as the reference standards. Two other authors further extracted and validated the number of true positive, true negative, false positive, false negative cases, and extracted or derived the sensitivity, specificity, positive and negative predictive values for each threshold presented for iron deficiency and iron overload in included studies. We assessed risk of bias and applicability using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. We used GRADE assessment to enable the quality of evidence and hence strength of evidence for our conclusions.

MAIN RESULTS

Our search was conducted initially in 2014 and updated in 2017, 2018 and 2020 (10 June). We identified 21,217 records and screened 14,244 records after duplicates were removed. We assessed 316 records in full text. We excluded 190 studies (193 records) with reasons and included 108 studies (111 records) in the qualitative and quantitative analysis. There were 11 studies (12 records) that we screened from the last search update and appeared eligible for a future analysis. We decided to enter these as awaiting classification. We stratified the analysis first by participant clinical status: apparently healthy and non-healthy populations. We then stratified by age and pregnancy status as: infants and children, adolescents, pregnant women, and adults. Iron deficiency We included 72 studies (75 records) involving 6059 participants. Apparently healthy populations Five studies screened for iron deficiency in people without apparent illness. In the general adult population, three studies reported sensitivities of 63% to 100% at the optimum cutoff for ferritin, with corresponding specificities of 92% to 98%, but the ferritin cutoffs varied between studies. One study in healthy children reported a sensitivity of 74% and a specificity of 77%. One study in pregnant women reported a sensitivity of 88% and a specificity of 100%. Overall confidence in these estimates was very low because of potential bias, indirectness, and sparse and heterogenous evidence. No studies screened for iron overload in apparently healthy people. People presenting for medical care There were 63 studies among adults presenting for medical care (5042 participants). For a sample of 1000 subjects with a 35% prevalence of iron deficiency (of the included studies in this category) and supposing a 85% specificity, there would be 315 iron-deficient subjects correctly classified as having iron deficiency and 35 iron-deficient subjects incorrectly classified as not having iron deficiency, leading to a 90% sensitivity. Thresholds proposed by the authors of the included studies ranged between 12 to 200 µg/L. The estimated diagnostic odds ratio was 50. Among non-healthy adults using a fixed threshold of 30 μg/L (nine studies, 512 participants, low-certainty evidence), the pooled estimate for sensitivity was 79% with a 95% confidence interval of (58%, 91%) and specificity of 98%, with a 95% confidence interval of (91%, 100%). The estimated diagnostic odds ratio was 140, a relatively highly informative test. Iron overload We included 36 studies (36 records) involving 1927 participants. All studies concerned non-healthy populations. There were no studies targeting either infants, children, or pregnant women. Among all populations (one threshold for males and females; 36 studies, 1927 participants, very low-certainty evidence): for a sample of 1000 subjects with a 42% prevalence of iron overload (of the included studies in this category) and supposing a 65% specificity, there would be 332 iron-overloaded subjects correctly classified as having iron overload and 85 iron-overloaded subjects incorrectly classified as not having iron overload, leading to a 80% sensitivity. The estimated diagnostic odds ratio was 8.

AUTHORS' CONCLUSIONS

At a threshold of 30 micrograms/L, there is low-certainty evidence that blood ferritin concentration is reasonably sensitive and a very specific test for iron deficiency in people presenting for medical care. There is very low certainty that high concentrations of ferritin provide a sensitive test for iron overload in people where this condition is suspected. There is insufficient evidence to know whether ferritin concentration performs similarly when screening asymptomatic people for iron deficiency or overload.

Re-examining ferritin-bound iron: current and developing clinical tools

Iron is a highly important metal ion cofactor within the human body, necessary for haemoglobin synthesis, and required by a wide range of enzymes for essential metabolic processes. Iron deficiency and overload both pose significant health concerns and are relatively common world-wide health hazards. Effective measurement of total iron stores is a primary tool for both identifying abnormal iron levels and tracking changes in clinical settings. Population based data is also essential for tracking nutritional trends. This review article provides an overview of the strengths and limitations associated with current techniques for diagnosing iron status, which sets a basis to discuss the potential of a new serum marker - ferritin-bound iron - and the improvement it could offer to iron assessment.

Complex confounder-corrected R2* mapping for liver iron quantification with MRI

OBJECTIVES

MRI-based R2* mapping may enable reliable and rapid quantification of liver iron concentration (LIC). However, the performance and reproducibility of R2* across acquisition protocols remain unknown. Therefore, the objective of this work was to evaluate the performance and reproducibility of complex confounder-corrected R2* across acquisition protocols, at both 1.5 T and 3.0 T.

METHODS

In this prospective study, 40 patients with suspected iron overload and 10 healthy controls were recruited with IRB approval and informed written consent and imaged at both 1.5 T and 3.0 T. For each subject, acquisitions included four different R2* mapping protocols at each field strength, and an FDA-approved R2-based method performed at 1.5 T as a reference for LIC. R2* maps were reconstructed from the complex data acquisitions including correction for noise effects and fat signal. For each subject, field strength, and R2* acquisition, R2* measurements were performed in each of the nine liver Couinaud segments and the spleen. R2* measurements were compared across protocols and field strength (1.5 T and 3.0 T), and R2* was calibrated to LIC for each acquisition and field strength.

RESULTS

R2* demonstrated high reproducibility across acquisition protocols (p > 0.05 for 96/108 pairwise comparisons across 2 field strengths and 9 liver segments, ICC > 0.91 for each field strength/segment combination) and high predictive ability (AUC > 0.95 for four clinically relevant LIC thresholds). Calibration of R2* to LIC was LIC = - 0.04 + 2.62 × 10^-2 R2* at 1.5 T and LIC = 0.00 + 1.41 × 10^-2 R2* at 3.0 T.

CONCLUSIONS

Complex confounder-corrected R2* mapping enables LIC quantification with high reproducibility across acquisition protocols, at both 1.5 T and 3.0 T.

KEY POINTS

• Confounder-corrected R2* of the liver provides reproducible R2* across acquisition protocols, including different spatial resolutions, echo times, and slice orientations, at both 1.5 T and 3.0 T. • For all acquisition protocols, high correlation with R2-based liver iron concentration (LIC) quantification was observed. • The calibration between confounder-corrected R2* and LIC, at both 1.5 T and 3.0 T, is determined in this study.

Ferritins in Kidney Disease

Ferritins are evolutionarily conserved proteins that regulate cellular iron metabolism. It is the only intracellular protein that is capable of storing large quantities of iron. Although the ratio of different subunits determines the iron content of each ferritin molecule, the exact mechanism that dictates organization of these subunits still is unclear. In this review, we address renal ferritin expression and its implication in kidney disease. Specifically, we address the role of ferritin subunits in preventing kidney injury and also promoting tolerance against infection-associated kidney injury. We describe functions for ferritin that are independent of its ability to ferroxidize and store iron. We further discuss the implications of ferritin in body fluids, including blood and urine, during inflammation and kidney disease. Although there are several in-depth review articles on ferritin in the context of iron metabolism, we chose to focus on the role of ferritin particularly in kidney health and disease and highlight unanswered questions in the field.

Transferrin and transferrin receptors update

In vertebrates, transferrin (Tf) safely delivers iron through circulation to cells. Tf-bound iron is incorporated through Tf receptor (TfR) 1-mediated endocytosis. TfR1 can mediate cellular uptake of both Tf and H-ferritin, an iron storage protein. New World arenaviruses, which cause hemorrhagic fever, and Plasmodium vivax use TfR1 for entry into host cells. Human TfR2, another receptor for Tf, is predominantly expressed in hepatocytes and erythroid precursors, and holo-Tf dramatically upregulates its expression. TfR2 forms a complex with hemochromatosis protein, HFE, and serves as a component of the iron sensing machinery in hepatocytes. Defects in TfR2 cause systemic iron overload, hemochromatosis, through down-regulation of hepcidin. In erythroid cells, TfR2 forms a complex with the erythropoietin receptor and regulates erythropoiesis. TfR2 facilitates iron transport from lysosomes to mitochondria in erythroblasts and dopaminergic neurons. Administration of apo-Tf, which scavenges free iron, has been explored for various clinical conditions including atransferrinemia, iron overload, and tissue ischemia. Apo-Tf has also been shown to ameliorate anemia in animal models of β-thalassemia. In this review, I provide an update and summary on our knowledge of mammalian Tf and its receptors.

Ferritin in serum and urine: A pilot study

Serum ferritin reflects total body iron stores, thus a low serum ferritin is used as a parameter of iron deficiency. In healthy adults in Japan, urine ferritin levels were about 5% of serum ferritin levels, with a correlation coefficient of 0.79. It is not known whether a low urine ferritin could serve as a non-invasive screen for iron deficiency. If so, this might be useful for neonates and young children, avoiding phlebotomy to screen for iron deficiency. However, for urinary ferritin screening to be feasible, ferritin must be measurable in the urine and correlate with serum ferritin. Testing should also clarify whether the iron content of ferritin in serum and urine are similar. In this pilot feasibility study we measured ferritin in paired serum and urine samples of healthy adult males, healthy term neonates, growing preterm neonates, and children who had very high serum ferritin levels from liver disorders or iron overload. We detected ferritin in every urine sample, and found a correlation with paired serum ferritin (Spearman correlation coefficient 0.78 of log₁₀-transformed values). These findings suggest merit in further studying urinary ferritin in select populations, as a potential non-invasive screen to assess iron stores.

Measurement of liver iron by magnetic resonance imaging in the UK Biobank population

The burden of liver disease continues to increase in the UK, with liver cirrhosis reported to be the third most common cause of premature death. Iron overload, a condition that impacts liver health, was traditionally associated with genetic disorders such as hereditary haemochromatosis, however, it is now increasingly associated with obesity, type-2 diabetes and non-alcoholic fatty liver disease. The aim of this study was to assess the prevalence of elevated levels of liver iron within the UK Biobank imaging study in a cohort of 9108 individuals. Magnetic resonance imaging (MRI) was undertaken at the UK Biobank imaging centre, acquiring a multi-echo spoiled gradient-echo single-breath-hold MRI sequence from the liver. All images were analysed for liver iron and fat (expressed as proton density fat fraction or PDFF) content using LiverMultiScan. Liver iron was measured in 97.3% of the cohort. The mean liver iron content was 1.32 ± 0.32 mg/g while the median was 1.25 mg/g (min: 0.85 max: 6.44 mg/g). Overall 4.82% of the population were defined as having elevated liver iron, above commonly accepted 1.8 mg/g threshold based on biochemical iron measurements in liver specimens obtained by biopsy. Further analysis using univariate models showed elevated liver iron to be related to male sex (p<10⁻¹⁶, r² = 0.008), increasing age (p<10⁻¹⁶, r² = 0.013), and red meat intake (p<10⁻¹⁶, r² = 0.008). Elevated liver fat (>5.6% PDFF) was associated with a slight increase in prevalence of elevated liver iron (4.4% vs 6.3%, p = 0.0007). This study shows that population studies including measurement of liver iron concentration are feasible, which may in future be used to better inform patient stratification and treatment.

Serum ferritin is not a reliable predictor to determine iron overload in thalassemia major patients post-hematopoietic stem cell transplantation

OBJECTIVE

Iron overload (IO) in transfusion-dependent anemia persists after hematopoietic stem cell transplantation (HSCT) and can cause long-term organ damage. In many studies, the diagnosis of IO before and after HSCT is based on serum ferritin (SF) levels rather than on assessment of liver iron concentration (LIC) by MRI or SQUID.

METHOD

In a retrospective multicenter study, we analyzed the concordance for indication of iron depletion therapy and correlation between LIC and SF of 36 thalassemia patients after HSCT. LIC was determined either by MRI-R2 (FerriScan®) or SQUID.

RESULTS

The concordance between LIC and SF varies over time after transplant (P = 0.011). The correlation between SF and LIC was strong in the first year (Spearman's rho 0.75; P < 0.001). In agreement, the concordance between SF and LIC concerning indication for treatment was close to 1 with an overall error rate ca. of 10%. In particular in the first year after HSCT, SF underestimates the degree of iron overload. However, in the longitudinal analysis since the second year post-HSCT onward no association was found between LIC and SF (P = 0.217). Furthermore, in the second year after HSCT, the overall error rate was 35%, whereas in the 3rd, 4th, and >4th year, it was 58%, 60%, and 25%, respectively.

CONCLUSIONS

Our data suggest serum ferritin is not a reliable predictor to determine iron overload in thalassemia patients after HSCT.

Eryptosis in Haemochromatosis: Implications for rheology

BACKGROUND

Haemochromatosis is an iron-storage disease with different genetic mutations, characterized by an increased intestinal absorption of iron, resulting in a deposition of excessive amounts of iron in parenchymal cells. When the iron is released in the blood, it is left in an unliganded form, where it can participate in Haber-Weiss and Fenton reactions, creating hydroxyl radicals. Erythrocytes (RBCs) are particularly vulnerable to hydroxyl radical damage, which can result in eryptosis (programmed cell death similar to apoptosis).

STUDY DESIGN AND METHODS

Here, we used flow cytometry to study the presence of eryptosis in the main genotypic variations of HFE (heterozygous and homozygous C282Y; H63D; C282Y/H63D). We also viewed RBCs from the different mutations using super-resolution Airyscan confocal microscopy.

RESULTS

Flow cytometry showed significant changes in membrane biochemistry, indicated by the presence of phosphatidylserine (PS) proteins on the outer leaflet of the membrane, as well as increased intracellular calpain. This was found in all of the studied mutations. Airyscan fluorescence revealed PS flip and also microparticles from RBCs. Such microparticles are known to be pro-inflammatory.

CONCLUSION

We conclude that RBC pathology is present in all the studied HFE mutations, even in low penetrance mutations, and this might affect rheology in these individuals.

Hemochromatosis: pathophysiology, evaluation, and management of hepatic iron overload with a focus on MRI

Hereditary hemochromatosis (HH) is an autosomal recessive disorder that occurs in approximately 1 in 200-250 individuals. Mutations in the HFE gene lead to excess iron absorption. Excess iron in the form of non-transferrin-bound iron (NTBI) causes injury and is readily uptaken by cardiomyocytes, pancreatic islet cells, and hepatocytes. Symptoms greatly vary among patients and include fatigue, abdominal pain, arthralgias, impotence, decreased libido, diabetes, and heart failure. Untreated hemochromatosis can lead to chronic liver disease, fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Many invasive and noninvasive diagnostic tests are available to aid in diagnosis and treatment. MRI has emerged as the reference standard imaging modality for the detection and quantification of hepatic iron deposition, as ultrasound (US) is unable to detect iron overload and computed tomography (CT) findings are nonspecific and influenced by multiple confounding variables. If caught and treated early, HH disease progression can significantly be altered. Area covered: The data on Hemochromatosis, iron overload, and MRI were gathered by searching PubMed. Expert commentary: MRI is a great tool for diagnosis and management of iron overload. It is safe, effective, and a standard protocol should be included in diagnostic algorithms of future treatment guidelines.

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.

Significance of serum ferritin as a prognostic factor in advanced hepatobiliary cancer patients treated with Korean medicine: a retrospective cohort study

Background

Advanced hepatobiliary cancers are highly lethal cancers that require precise prediction in clinical practice. Serum ferritin level increases in malignancy and high serum ferritin level is associated with poor survival in various cancers. This study aimed to identify whether serum ferritin could independently predict the overall survival (OS) of patients with advanced hepatobiliary cancers.

Methods

The retrospective cohort study was performed by reviewing medical records of patients with advanced hepatobiliary cancers from June 2006 to September 2016. The demographic and clinicopathological characteristics as well as the biochemical markers were evaluated at the initiation of Korean medicine (KM) treatment. The OS was calculated using Kaplan-Meier estimates. The Cox proportional hazard model was used to identify the independent prognostic significance of serum ferritin for survival.

Results

The median OS of all subjects was 5.1 months (range, 0.5–114.9 months). The median OS of group with low ferritin levels and that with high ferritin levels was 7.5 months (range, 0.7–114.9 months) and 2.8 months (range, 0.5–22.8 months), respectively (P < 0.001). The results of the univariate analysis showed that the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) (P = 0.002), tumor type (P = 0.001), prior treatment (P = 0.023), serum ferritin (P < 0.001), hemoglobin (P = 0.002), total bilirubin (P = 0.002), gamma-glutamyl transpeptidase (P = 0.007), albumin (P = 0.013), white blood cell (P = 0.002), and C-reactive protein (CRP) (P < 0.001) were significant factors for the patients’ survival outcome. On multivariate analysis controlling confounding factors, ferritin (P = 0.041), CRP (P = 0.010), ECOG-PS (P = 0.010), and tumor type (P = 0.018) were identified as independent prognostic factors for survival.

Conclusions

These results indicate that serum ferritin is a valid clinical biochemical marker to predict survival of patients with advanced hepatobiliary cancers.

Clinical and Laboratory Associations with Persistent Hyperferritinemia in 373 Black Hemochromatosis and Iron Overload Screening Study Participants

BACKGROUND

373 black participants had elevated screening and post-screening serum ferritin (SF) (> 300 μg/L men; > 200 μg/L women).

MATERIAL AND METHODS

We retrospectively studied SF and post-screening age; sex; body mass index; transferrin saturation (TS); ALT; AST; GGT; elevated C-reactive protein; ß-thalassemia; neutrophils; lymphocytes; monocytes; platelets; metacarpophalangeal joint hypertrophy; hepatomegaly; splenomegaly; diabetes; HFE H63D positivity; iron/alcohol intakes; and blood/erythrocyte transfusion units. Liver disease was defined as elevated ALT or AST. We computed correlations of SF and TS with: age; body mass index; ALT; AST; GGT; C-reactive protein; blood cell counts; and iron/alcohol. We compared participants with SF > 1,000 and ≤ 1,000 μg/L and performed regressions on SF.

RESULTS

There were 237 men (63.5%). Mean age was 55 ± 13 (SD) y. 143 participants had liver disease (62 hepatitis B or C). There were significant correlations of SF: TS, ALT, AST, GGT, and monocytes (positive); and SF and TS with platelets (negative). 22 participants with SF > 1,000 μg/L had significantly higher median TS, ALT, and AST, and prevalences of anemia and transfusion > 10 units; and lower median platelets. Regression on SF revealed significant associations: TS; male sex; age; GGT; transfusion units (positive); and splenomegaly (negative) (p < 0.0001, 0.0016, 0.0281, 0.0025, 0.0001, and 0.0096, respectively). Five men with SF > 1,000 μg/L and elevated TS had presumed primary iron overload (hemochromatosis). Four participants had transfusion iron overload.

CONCLUSION

Persistent hyperferritinemia in 373 black adults was associated with male sex, age, TS, GGT, and transfusion. 2.4% had primary iron overload (hemochromatosis) or transfusion iron overload.

Quantitative Susceptibility Mapping Reveals an Association between Brain Iron Load and Depression Severity

Previous studies have detected abnormal serum ferritin levels in patients with depression; however, the results have been inconsistent. This study used quantitative susceptibility mapping (QSM) for the first time to examine brain iron concentration in depressed patients and evaluated whether it is related to severity. We included three groups of age- and gender-matched participants: 30 patients with mild-moderate depression (MD), 14 patients with major depression disorder (MDD) and 20 control subjects. All participants underwent MR scans with a 3D gradient-echo sequence reconstructing for QSM and performed the 17-item Hamilton Depression Rating Scale (HDRS) test. In MDD, the susceptibility value in the bilateral putamen was significantly increased compared with MD or control subjects. In addition, a significant difference was also observed in the left thalamus in MDD patients compared with controls. However, the susceptibility values did not differ between MD patients and controls. The susceptibility values positively correlated with the severity of depression as indicated by the HDRS scores. Our results provide evidence that brain iron deposition may be associated with depression and may even be a biomarker for investigating the pathophysiological mechanism of depression.

Diabetes in HFE Hemochromatosis

Diabetes in whites of European descent with hemochromatosis was first attributed to pancreatic siderosis. Later observations revealed that the pathogenesis of diabetes in HFE hemochromatosis is multifactorial and its clinical manifestations are heterogeneous. Increased type 2 diabetes risk in HFE hemochromatosis is associated with one or more factors, including abnormal iron homeostasis and iron overload, decreased insulin secretion, cirrhosis, diabetes in first-degree relatives, increased body mass index, insulin resistance, and metabolic syndrome. In p.C282Y homozygotes, serum ferritin, usually elevated at hemochromatosis diagnosis, largely reflects body iron stores but not diabetes risk. In persons with diabetes type 2 without hemochromatosis diagnoses, serum ferritin levels are higher than those of persons without diabetes, but most values are within the reference range. Phlebotomy therapy to achieve iron depletion does not improve diabetes control in all persons with HFE hemochromatosis. The prevalence of type 2 diabetes diagnosed today in whites of European descent with and without HFE hemochromatosis is similar. Routine iron phenotyping or HFE genotyping of patients with type 2 diabetes is not recommended. Herein, we review diabetes in HFE hemochromatosis and the role of iron in diabetes pathogenesis in whites of European descent with and without HFE hemochromatosis.

Magnetic mapping of iron in rodent spleen

Evaluation of iron distribution and density in biological tissues is important to understand the pathogenesis of a variety of diseases and the fate of exogenously administered iron-based carriers and contrast agents. Iron distribution in tissues is typically characterized via histochemical (Perl's) stains or immunohistochemistry for ferritin, the major iron storage protein. A more accurate mapping of iron can be achieved via ultrastructural transmission electron microscopy (TEM) based techniques, which involve stringent sample preparation conditions. In this study, we elucidate the capability of magnetic force microscopy (MFM) as a label-free technique to map iron at the nanoscale level in rodent spleen tissue. We complemented and compared our MFM results with those obtained using Perl's staining and TEM. Our results show how MFM mapping corresponded to sizes of iron-rich lysosomes at a resolution comparable to that of TEM. In addition MFM is compatible with tissue sections commonly prepared for routine histology.

Ferritin and iron studies in anaemia and chronic disease

Anaemia is a condition in which the number of red cells necessary to meet the body's physiological requirements is insufficient. Iron deficiency anaemia and the anaemia of chronic disease are the two most common causes of anaemia worldwide;¹ iron homeostasis plays a pivotal role in the pathogenesis of both diseases. An understanding of how iron studies can be used to distinguish between these diseases is therefore essential not only for diagnosis but also in guiding management. This review will primarily focus on iron deficiency anaemia and anaemia of chronic disease; however, iron overload in anaemia will also be briefly discussed.

Prevalence and risk factors of iron overload after hematopoietic stem cell transplantation for childhood acute leukemia: a LEA study

Data on post-transplant iron overload (IO) are scarce in pediatrics. We conducted a prospective multicenter cohort study (Leucémie de l'Enfant et de l'Adolescent cohort) to determine the prevalence and risk factors of IO in 384 acute leukemia survivors transplanted during childhood. Prevalence of IO (ferritin level ⩾350 ng/mL) was 42.2% (95%CI 37.2-47.2%). Factors significantly associated with IO were: 1) in univariate analysis: older age at transplant (P<0.001), allogeneic versus autologous transplantation (P<0.001), radiation-based preparative regimen (P=0.035) and recent period of transplantation (P<0.001); 2) in multivariate analysis: older age at transplant in quartiles (Odds Ratio (OR)=7.64, 95% CI: 3.73-15.64 for age >12.7 years and OR=5.36, 95% CI: 2.63-10.95 for age from 8.2 to 12.7 years compared to age < 4.7 years), acute myeloid leukemia (OR=3.23, 95% CI: 1.47-7.13), allogeneic graft (OR=4.34, 95% CI: 2.07-9.12 for alternative donors and OR=2.53, 95% CI: 1.2-5.33 for siblings, compared to autologous graft) and radiation-based conditioning regimen (OR=2.45, 95% CI: 1.09-5.53). Graft-versus-host disease was an additional risk factor for allogeneic graft recipients. In conclusion, IO is a frequent complication in pediatric long-term survivors after transplantation for acute leukemia, more frequently observed in older children, those transplanted from alternative donors or with graft-versus-host disease.

Enhanced Electrochemical Sensing with Carbon Nanotubes Modified with Bismuth and Magnetic Nanoparticles in a Lab-on-a-Chip

Iron plays an especially important role in human physiological functions and pathological impairments. The superior properties of carbon nanotubes (CNTs) and their modification with bismuth and magnetic nanoparticles as developed in this work have led to an extraordinary and novel material to facilitate ultrasensitive detection in the nanomolar range. Here, we present the development of an electrochemical sensor for detection of ferrous (Fe2+) and ferric (Fe3+) iron by means of CNTs modified with bismuth and magnetic nanoparticles for higher sensitivity of detection. The sensor fabrication includes microfabrication methodologies, soft lithography, and electrodeposition. Cyclic voltammetry and differential pulse voltammetry are used for the electroanalytical studies and detection of the ions in samples. The sensor has a dynamic range of detection from 0.01 nm to 10 mm. The performance of the sensor with modified CNTs was explored for sensitivity and specificity. CNTs, modified with bismuth and magnetic nanoparticles by means of electrodeposition, enhanced the detection limit significantly down to 0.01 nm.

MRI-based quantitative susceptibility mapping (QSM) and R2* mapping of liver iron overload: Comparison with SQUID-based biomagnetic liver susceptometry

PURPOSE

We aimed to determine the agreement between quantitative susceptibility mapping (QSM)-based biomagnetic liver susceptometry (BLS) and confounder-corrected R2* mapping with superconducting quantum interference device (SQUID)-based biomagnetic liver susceptometry in patients with liver iron overload.

METHODS

Data were acquired from two healthy controls and 22 patients undergoing MRI and SQUID-BLS as part of routine monitoring for iron overload. Magnetic resonance imaging was performed on a 3T system using a three-dimensional multi-echo gradient-echo acquisition. Both magnetic susceptibility and R2* of the liver were estimated from this acquisition. Linear regression was used to compare estimates of QSM-BLS and R2* to SQUID-BLS.

RESULTS

Both QSM-BLS and confounder-corrected R2* were sensitive to the presence of iron in the liver. Linear regression between QSM-BLS and SQUID-BLS demonstrated the following relationship: QSM-BLS = (-0.22 ± 0.11) + (0.49 ± 0.05) · SQUID-BLS with r²  = 0.88. The coefficient of determination between liver R2* and SQUID-BLS was also r²  = 0.88.

CONCLUSION

We determined a strong correlation between both QSM-BLS and confounder-corrected R2* to SQUID-BLS. This study demonstrates the feasibility of QSM-BLS and confounder-corrected R2* for assessing liver iron overload, particularly when SQUID systems are not accessible. Magn Reson Med 78:264-270, 2017. © 2016 International Society for Magnetic Resonance in Medicine.

Risk Factors for Insulin Resistance, Metabolic Syndrome, and Diabetes in 248 HFE C282Y Homozygotes Identified by Population Screening in the HEIRS Study

BACKGROUND

We sought to identify risk factors for insulin resistance, metabolic syndrome (MetS), and diabetes mellitus in 248 non-Hispanic white HFE C282Y homozygotes identified by population screening.

METHODS

We analyzed observations obtained prospectively in a postscreening examination: age; sex; body mass index (BMI); systolic/diastolic blood pressure; metacarpophalangeal (MP) joint hypertrophy; hepatomegaly; complete blood counts; alanine/aspartate aminotransferase levels; elevated C-reactive protein (>0.5 mg/dL); transferrin saturation; serum ferritin; homeostasis model assessment-insulin resistance (HOMA-IR); and MetS.

RESULTS

Twenty-six participants (10.5%) had diabetes diagnoses. A significant trend across HOMA-IR quartiles was observed only for blood neutrophils. Logistic regression on HOMA-IR fourth quartile revealed positive associations: age (P = 0.0002); male sex (P = 0.0022); and BMI (P < 0.0001). HOMA-IR fourth quartile predicted MetS (P < 0.0001). Logistic regression on diabetes revealed positive associations: age (P = 0.0012); male sex (P = 0.0068); MP joint hypertrophy (P = 0.0167); neutrophils (P = 0.0342); and MetS (P = 0.0298). Serum ferritin did not predict HOMA-IR fourth quartile, MetS, or diabetes.

CONCLUSIONS

In screening C282Y homozygotes, age, male sex, and BMI predicted HOMA-IR fourth quartile. HOMA-IR fourth quartile alone predicted MetS. Diabetes was associated with greater age, male sex, MP joint hypertrophy, greater blood neutrophil counts, and MetS.

A Dormant Microbial Component in the Development of Preeclampsia

Preeclampsia (PE) is a complex, multisystem disorder that remains a leading cause of morbidity and mortality in pregnancy. Four main classes of dysregulation accompany PE and are widely considered to contribute to its severity. These are abnormal trophoblast invasion of the placenta, anti-angiogenic responses, oxidative stress, and inflammation. What is lacking, however, is an explanation of how these themselves are caused. We here develop the unifying idea, and the considerable evidence for it, that the originating cause of PE (and of the four classes of dysregulation) is, in fact, microbial infection, that most such microbes are dormant and hence resist detection by conventional (replication-dependent) microbiology, and that by occasional resuscitation and growth it is they that are responsible for all the observable sequelae, including the continuing, chronic inflammation. In particular, bacterial products such as lipopolysaccharide (LPS), also known as endotoxin, are well known as highly inflammagenic and stimulate an innate (and possibly trained) immune response that exacerbates the inflammation further. The known need of microbes for free iron can explain the iron dysregulation that accompanies PE. We describe the main routes of infection (gut, oral, and urinary tract infection) and the regularly observed presence of microbes in placental and other tissues in PE. Every known proteomic biomarker of "preeclampsia" that we assessed has, in fact, also been shown to be raised in response to infection. An infectious component to PE fulfills the Bradford Hill criteria for ascribing a disease to an environmental cause and suggests a number of treatments, some of which have, in fact, been shown to be successful. PE was classically referred to as endotoxemia or toxemia of pregnancy, and it is ironic that it seems that LPS and other microbial endotoxins really are involved. Overall, the recognition of an infectious component in the etiology of PE mirrors that for ulcers and other diseases that were previously considered to lack one.

Autoimmune Conditions in 235 Hemochromatosis Probands with HFE C282Y Homozygosity and Their First-Degree Relatives

We performed a retrospective study of autoimmune conditions (ACs) in 235 hemochromatosis probands at diagnosis by analyzing age, sex, ACs, history of first-degree family members with ACs (FH), diabetes, heavy ethanol consumption, elevated serum ALT/AST, nonalcoholic fatty liver disease, viral hepatitis, cirrhosis, iron removed to achieve iron depletion (QFe), and positivity for human leukocyte antigen (HLA) haplotypes A^∗01, B^∗08; A^∗02, B^∗44; A^∗03, B^∗07; A^∗03, B^∗14; and A^∗29, B^∗44. There were 138 men (58.7%). Median followup was 19.6 y. One or more of 19 ACs were diagnosed in each of 35 probands (14.9%). Prevalences of Hashimoto's thyroiditis, rheumatoid arthritis, and ankylosing spondylitis were 8.1% (95% CI: [5.1, 12.5]), 1.7% [0.6, 4.6], and 0.0085 [0.0015, 0.0337], respectively. Eighteen probands (7.7%) had a FH. Eight probands with ACs had 9 family members with ACs. In a logistic regression, ACs were less likely in men (odds ratio (OR) 0.3 [0.1, 0.6]) and more likely in probands with a FH (OR 4.1 [1.4, 11.8]). Overall ACs risk was not significantly associated with QFe or HLA haplotypes. Estimated survival of probands with and without ACs did not differ significantly. We conclude that ACs are common in hemochromatosis probands, especially women and probands with a FH.

Quantitative R2* MRI of the liver with rician noise models for evaluation of hepatic iron overload: Simulation, phantom, and early clinical experience

PURPOSE

To compare Rician and non-Rician noise models for quantitative R2 * magnetic resonance imaging (MRI), in a simulation, phantom, and human study.

MATERIALS AND METHODS

Synthetic 12-echo spoiled GRE (SGRE) datasets were generated with various R2 * rates (0-2000 sec(-1) ) at a signal-to-noise ratio (SNR) of 50, 20, 10, and 5. Phantoms of different MnCl2 concentrations (0-25 mM) were constructed and imaged using a 12-echo 3D SGRE sequence at 1.5T. Increasing levels of synthetic noise was added to the original data to simulate sequentially lower SNR conditions. Sixteen patients with suspected or known iron overload were imaged using 12-echo 3D SGRE at 1.5T. Various R2 * quantification methods, based on Rician and non-Rician noise models, were compared in the simulation, phantom, and human datasets.

RESULTS

Non-Rician R2 * estimates were variably inaccurate in the high R2 * range (>500 sec(-1) ), with SNR-dependent linear goodness-of-fit statistic (R(2) ) of 0.373-0.999. Rician R2 * estimates were accurate even in the high R2 * range, with high R(2) of 0.940-0.999 regardless of SNR. Non-Rician R2 * estimates were variably nonlinear at high MnCl2 concentrations, with SNR-dependent R(2) of 0.345-0.994. Rician R2 * estimates were linear even at high MnCl2 concentrations, with high R(2) of 0.923-0.994 regardless of SNR. Between-method agreement of the R2 * estimates was excellent in patients with low ferritin but poor in patients with high ferritin. Rician R2 * estimates had excellent correlation with ferritin (r = 0.966 P < 0.001).

CONCLUSION

Rician R2 * estimates were most consistent in the high R2 * conditions and under varying SNR, and may be more reliable when high iron load is suspected.

Pre-treatment blood inflammatory markers as predictors of systemic infection during induction chemotherapy: results of an exploratory study in patients with acute myeloid leukemia

PURPOSE

The purpose of this study is to evaluate the role of C-reactive protein (CRP) and ferritin blood levels in predicting the incidence of systemic infection among adult patients with acute myeloid leukemia (AML) treated with induction chemotherapy.

METHODS

Adult patients with newly diagnosed AML who were initially treated with conventional 3 + 7 induction chemotherapy within 5 days of their diagnosis were included. Patients with previous cytotoxic chemotherapy <3 years, acute promyelocytic leukemia diagnosis, human immunodeficiency virus infection, or significant systemic infection at the time of diagnosis were excluded. Patients were treated with an institutional policy of substantial identity with negligible differences regarding supportive care.

RESULTS

Among 110 patients (median age 54.5 years), 39 infectious events in 38 patients were reported, along with 21 episodes of infectious treatment-related mortality (TRM; 19.1%). Elevated pre-treatment CRP (p = 0.032) and ferritin (p = 0.002) were related to the incidence of systemic infection. The degree of increase of blood CRP and ferritin level was correlated with the extent of leukocytosis. However, patients with elevated inflammatory markers above normal range had increased risk of infection irrespective of whether they had leukocytosis or not, suggesting that expansion of leukemic blast is another factor affecting the elevation of the markers independent to infection propensity and therefore the magnitude of the elevation does not quantitatively predict the risk of infection.

CONCLUSIONS

Modest elevation of baseline blood inflammatory markers above the normal range could be an indicator for predicting the incidence of systemic infection in patients with AML.

Quantification of ferritin bound iron in human serum using species-specific isotope dilution mass spectrometry

Ferritin is a hollow sphere protein composed of 24 subunits that can store up to 4500 iron atoms in its inner cavity. It is mainly found in the liver and spleen but also in serum at trace levels. Serum ferritin is considered as the best single indicator in assessing body iron stores except liver or bone marrow biopsy. However, it is confounded by other disease conditions. Ferritin bound iron (FBI) and ferritin saturation have been suggested as more robust biomarkers. The current techniques for FBI determination are limited by low antibody specificity, low instrument sensitivity and possible analyte losses during sample preparation. The need for a highly sensitive and reliable method is widely recognized. Here we describe a novel technique to detect serum FBI using species-specific isotope dilution mass spectrometry (SS-IDMS). [(57)Fe]-ferritin was produced by biosynthesis and in vitro labeling with the (57)Fe spike in the form of [(57)Fe]-citrate after cell lysis and heat treatment. [(57)Fe]-ferritin for sample spiking was further purified by fast liquid protein chromatography. Serum ferritin and added [(57)Fe]-ferritin were separated from other iron species by ultrafiltration followed by isotopic analysis of FBI using negative thermal ionization mass spectrometry. Repeatability of our assay is 8% with an absolute detection limit of 18 ng FBI in the sample. As compared to other speciation techniques, SS-IDMS offers maximum control over sample losses and species conversion during analysis. The described technique may therefore serve as a reference technique for clinical applications of FBI as a new biomarker for assessing body iron status.

Diagnostic morphology: biophysical indicators for iron-driven inflammatory diseases

Most non-communicable diseases involve inflammatory changes in one or more vascular systems, and there is considerable evidence that unliganded iron plays major roles in this. Most studies concentrate on biochemical changes, but there are important biophysical correlates. Here we summarize recent microscopy-based observations to the effect that iron can have major effects on erythrocyte morphology, on erythrocyte deformability and on both fibrinogen polymerization and the consequent structure of the fibrin clots formed, each of which contributes significantly and negatively to such diseases. We highlight in particular type 2 diabetes mellitus, ischemic thrombotic stroke, systemic lupus erythematosus, hereditary hemochromatosis and Alzheimer's disease, while recognizing that many other diseases have co-morbidities (and similar causes). Inflammatory biomarkers such as ferritin and fibrinogen are themselves inflammatory, creating a positive feedback that exacerbates disease progression. The biophysical correlates we describe may provide novel, inexpensive and useful biomarkers of the therapeutic benefits of successful treatments.

Serum ferritin, insulin resistance, and metabolic syndrome: clinical and laboratory associations in 769 non-hispanic whites without diabetes mellitus in the HEIRS study

BACKGROUND

In some reports, serum ferritin (SF) has been associated with insulin resistance and metabolic syndrome.

METHODS

We studied non-Hispanic whites without diabetes mellitus in a postscreening examination. Participants included cases [HFE C282Y homozygosity; and transferrin saturation (TS) >50% and SF >300 μg/L (males) and TS >45% and SF >200 μg/dL (females), regardless of HFE genotype] and controls [HFE wild-type (wt/wt) and TS/SF 25th-75th percentiles]. We excluded participants with overnight fasts <8 hr, cirrhosis, hepatitis B or C, pregnancy, or missing data. Observations were age, sex, C282Y homozygosity, body mass index (BMI), systolic and diastolic blood pressures (SBP, DBP), lymphocytes, alanine aminotransferase (ALT), aspartate aminotransferase (AST), C-reactive protein (CRP), TS, SF, and glucose/insulin. Insulin resistance was defined as homeostasis model assessment of insulin resistance (HOMA-IR) 4th quartile (≥2.70).

RESULTS

A total of 407 women and 362 men (mean age 54 years) included 188 C282Y homozygotes and 371 wt/wt. Significant trends across HOMA-IR quartiles included age, male sex, BMI, SBP, DBP, lymphocytes, ALT, CRP >0.5 mg/dL (positive), and TS (negative). Multiple regression on HOMA-IR revealed significant associations with male sex, BMI, SBP, lymphocytes, ALT, CRP>0.5 mg/dL (positive), and DBP and SF (negative). Logistic regression on HOMA-IR 4th quartile revealed significant positive associations with age, male sex, BMI, and lymphocytes. Metabolic syndrome occurred in 53 participants (6.9%). Logistic regression on metabolic syndrome revealed these odds ratios: HOMA-IR 4th quartile [9.1 (4.8, 17.3)] and CRP >0.5 mg/dL [2.9 (1.6, 5.4)].

CONCLUSIONS

Age, male sex, BMI, and lymphocytes were positively associated with HOMA-IR after correction for other factors. HOMA-IR 4th quartile and CRP >0.5 mg/dL predicted metabolic syndrome.

Serum ferritin is an important inflammatory disease marker, as it is mainly a leakage product from damaged cells

"Serum ferritin" presents a paradox, as the iron storage protein ferritin is not synthesised in serum yet is to be found there. Serum ferritin is also a well known inflammatory marker, but it is unclear whether serum ferritin reflects or causes inflammation, or whether it is involved in an inflammatory cycle. We argue here that serum ferritin arises from damaged cells, and is thus a marker of cellular damage. The protein in serum ferritin is considered benign, but it has lost (i.e. dumped) most of its normal complement of iron which when unliganded is highly toxic. The facts that serum ferritin levels can correlate with both disease and with body iron stores are thus expected on simple chemical kinetic grounds. Serum ferritin levels also correlate with other phenotypic readouts such as erythrocyte morphology. Overall, this systems approach serves to explain a number of apparent paradoxes of serum ferritin, including (i) why it correlates with biomarkers of cell damage, (ii) why it correlates with biomarkers of hydroxyl radical formation (and oxidative stress) and (iii) therefore why it correlates with the presence and/or severity of numerous diseases. This leads to suggestions for how one might exploit the corollaries of the recognition that serum ferritin levels mainly represent a consequence of cell stress and damage.

Quantitative susceptibility mapping in the abdomen as an imaging biomarker of hepatic iron overload

PURPOSE

The purpose of this work was to develop and demonstrate feasibility and initial clinical validation of quantitative susceptibility mapping (QSM) in the abdomen as an imaging biomarker of hepatic iron overload.

THEORY AND METHODS

In general, QSM is faced with the challenges of background field removal and dipole inversion. Respiratory motion, the presence of fat, and severe iron overload further complicate QSM in the abdomen. We propose a technique for QSM in the abdomen that addresses these challenges. Data were acquired from 10 subjects without hepatic iron overload and 33 subjects with known or suspected iron overload. The proposed technique was used to estimate the susceptibility map in the abdomen, from which hepatic iron overload was measured. As a reference, spin-echo data were acquired for R2-based LIC estimation. Liver R2* was measured for correlation with liver susceptibility estimates.

RESULTS

Correlation between susceptibility and R2-based LIC estimation was R(2) = 0.76 at 1.5 Tesla (T) and R(2) = 0.83 at 3T. Furthermore, high correlation between liver susceptibility and liver R2* (R(2) = 0.94 at 1.5T; R(2) = 0.93 at 3T) was observed.

CONCLUSION

We have developed and demonstrated initial validation of QSM in the abdomen as an imaging biomarker of hepatic iron overload.

Spin density projection-assisted R2 magnetic resonance imaging of the liver in the management of body iron stores in patients receiving multiple red blood cell transfusions: an audit and retrospective study in South Australia

AIM

To assess the impact of non-invasive monitoring of liver iron concentration (LIC) on management of body iron stores in patients receiving multiple blood transfusions.

METHOD

A retrospective audit was conducted on clinical data from 40 consecutive subjects with haemolytic anaemias or ineffective haematopoiesis who had been monitored non-invasively for LIC over a period of at least 1 year. LIC was measured with spin density projection-assisted proton transverse relaxation rate-magnetic resonance imaging.

RESULTS

Nineteen clinical decisions were explicitly documented in the case notes as being based on LIC results. Decisions comprised initiation of chelation therapy, increasing chelator dose, decreasing chelator dose and change of mode of delivery of deferioxamine from subcutaneous to intravenous. The geometrical mean LIC for the cohort dropped significantly (P= 0.008) from 6.8 mg Fe/g dry tissue at initial measurement to 4.8 mg Fe/g dry tissue at final measurement. The proportion of subjects with LIC in the range associated with greatly increased risk of cardiac disease and death (>15 mg Fe/g dry tissue) dropped significantly (P= 0.01) from 14 of 40 subjects at initial measurement to 5 of 40 subjects at final measurement. No significant changes in the geometrical mean of serum ferritin or the proportion of subjects with serum ferritin above 2500 or 1500 µg/L were observed.

CONCLUSIONS

The data are consistent with previous observations that introduction of non-invasive monitoring of LIC can contribute to a decreased body iron burden through improved clinical decision making and improved feedback to patients and hence improved adherence to chelation therapy.

Profound morphological changes in the erythrocytes and fibrin networks of patients with hemochromatosis or with hyperferritinemia, and their normalization by iron chelators and other agents

It is well-known that individuals with increased iron levels are more prone to thrombotic diseases, mainly due to the presence of unliganded iron, and thereby the increased production of hydroxyl radicals. It is also known that erythrocytes (RBCs) may play an important role during thrombotic events. Therefore the purpose of the current study was to assess whether RBCs had an altered morphology in individuals with hereditary hemochromatosis (HH), as well as some who displayed hyperferritinemia (HF). Using scanning electron microscopy, we also assessed means by which the RBC and fibrin morphology might be normalized. An important objective was to test the hypothesis that the altered RBC morphology was due to the presence of excess unliganded iron by removing it through chelation. Very striking differences were observed, in that the erythrocytes from HH and HF individuals were distorted and had a much greater axial ratio compared to that accompanying the discoid appearance seen in the normal samples. The response to thrombin, and the appearance of a platelet-rich plasma smear, were also markedly different. These differences could largely be reversed by the iron chelator desferal and to some degree by the iron chelator clioquinol, or by the free radical trapping agents salicylate or selenite (that may themselves also be iron chelators). These findings are consistent with the view that the aberrant morphology of the HH and HF erythrocytes is caused, at least in part, by unliganded (‘free’) iron, whether derived directly via raised ferritin levels or otherwise, and that lowering it or affecting the consequences of its action may be of therapeutic benefit. The findings also bear on the question of the extent to which accepting blood donations from HH individuals may be desirable or otherwise.

T2* MRI in regularly transfused children with thalassemia intermedia: serum ferritin does not reflect liver iron stores

Nontransfused patients with thalassemia intermedia (TI) accumulate iron due to increased gastrointestinal absorption of iron. Recent studies using T2* MRI revealed that serum ferritin does not reflect the severity of iron overload in nontransfused TI patients. We evaluated the iron overload status in TI children on monthly transfusion. Based on serum ferritin levels, 11 such patients (mean age 13.18 ± 4.09 years), were classified into two groups, group 1 (six patients) and group 2 (five patients) with serum ferritin levels below and above 1000 ng/mL, respectively. T2* MRI assessments were done for evaluation of hepatic and cardiac iron status. Group 1 and group 2 had mean serum ferritin levels of 817.300 ± 244.690 ng/mL and 1983.80 ± 662.862 ng/mL, respectively (P = .003). T2* MRI showed comparable moderate to severe hepatic iron overload status in both. None of the patients had myocardial iron deposition. We conclude that serum ferritin does not reflect the hepatic iron overload status in our patients with TI on regular transfusion.

Ferritin upregulates hepatic expression of bone morphogenetic protein 6 and hepcidin in mice

Hepcidin is a hepatocellular hormone that inhibits the release of iron from certain cell populations, including enterocytes and reticuloendothelial cells. The regulation of hepcidin (HAMP) gene expression by iron status is mediated in part by the signaling molecule bone morphogenetic protein 6 (BMP6). We took advantage of the low iron status of juvenile mice to characterize the regulation of Bmp6 and Hamp1 expression by iron administered in three forms: 1) ferri-transferrin (Fe-Tf), 2) ferric ammonium citrate (FAC), and 3) liver ferritin. Each of these forms of iron enters cells by distinct mechanisms and chemical forms. Iron was parenterally administered to 10-day-old mice, and hepatic expression of Bmp6 and Hamp1 mRNAs was measured 6 h later. We observed that hepatic Bmp6 expression increased in response to ferritin but was unchanged by Fe-Tf or FAC. Hepatic Hamp1 expression likewise increased in response to ferritin and Fe-Tf but was decreased by FAC. Exogenous ferritin increased Bmp6 and Hamp1 expression in older mice as well. Removing iron from ferritin markedly decreased its effect on Bmp6 expression. Exogenously administered ferritin and the derived iron localized in the liver primarily to sinusoidal lining cells. Moreover, expression of Bmp6 mRNA in isolated adult rodent liver cells was much higher in sinusoidal lining cells than hepatocytes (endothelial >> stellate > Kupffer). We conclude that exogenous iron-containing ferritin upregulates hepatic Bmp6 expression, and we speculate that liver ferritin contributes to regulation of Bmp6 and, thus, Hamp1 genes.

Do toxic heavy metals affect antioxidant defense mechanisms in humans?

The aim of this study was to prove whether anthropogenic pollution affects antioxidant defense mechanisms such as superoxide dismutase (SOD) and catalase (CAT) activity, ferritin (FRT) concentration and total antioxidant status (TAS) in human serum. The study area involves polluted and salted environment (Kujawy region; northern-middle Poland) and Tuchola Forestry (unpolluted control area). We investigated 79 blood samples of volunteers from polluted area and 82 from the control in 2008 and 2009. Lead, cadmium and iron concentrations were measured in whole blood by the ICP-MS method. SOD and CAT activities were measured in serum using SOD and CAT Assay Kits by the standardized colorimetric method. Serum TAS was measured spectrophotometrically by the modified Benzie and Strain (1996) method and FRT concentration-by the immunonefelometric method. Pb and Cd levels and SOD activity were higher in volunteers from polluted area as compared with those from the control (0.0236 mg l(-1) vs. 0.014 mg l(-1); 0.0008 mg l(-1) vs. 0.0005 mg l(-1); 0.137 Um l(-1) vs. 0.055 Um l(-1), respectively). Fe level, CAT activity and TAS were lower in serum of volunteers from polluted area (0.442 g l(-1) vs. 0.476 gl(-1); 3.336 nmol min(-1)ml(-1) vs. 6.017 nmol min(-1)ml(-1); 0.731 Trolox-equivalents vs. 0.936 Trolox-equivalents, respectively), whilst differences in FRT concentration were not significant (66.109 μg l(-1) vs. 37.667 μg l(-1), p=0.3972). Positive correlations between Pb (r=0.206), Cd (r=0.602) and SOD in the inhabitants of polluted area, and between Cd and SOD in the control (r=0.639) were shown. In volunteers from both studied environments TAS-FRT (polluted: r=0.625 vs. control: r=0.837) and Fe-FRT (polluted area: r=0.831 vs. control: r=0.407) correlations, and Pb-FRT (r=0.360) and Pb-TAS (r=0.283) in the control were stated. The higher lead and cadmium concentrations in blood cause an increase of SOD activity. It suggests that this is one of the defense mechanisms of an organism against oxidative stress caused by environmental factors, whilst non-enzymatic mechanisms marked by TAS are the main antioxidant defense system in relation with Pb concentration in humans from unpolluted area. Simultaneously, the higher CAT activity and TAS can indicate that these mechanisms play a key role in the antioxidant protection in non-stressed environments.

Electrocardiographic consequences of cardiac iron overload in thalassemia major

Iron cardiomyopathy is a leading cause of death in transfusion-dependent thalassemia major (TM) patients and MRI (T2*) can recognize preclinical cardiac iron overload, but, is unavailable to many centers. We evaluated the ability of 12-lead electrocardiography to predict cardiac iron loading in TM. 12-lead electrocardiogram and cardiac T2* measurements were performed prospectively, with a detectable cardiac iron cutoff of T2*less than 20 ms. Patients with and without cardiac iron were compared using two-sample statistics and against population norms using age and gender-matched Z-scores. 45/78 patients had detectable cardiac iron. Patients having cardiac iron were older and more likely female but had comparable liver iron burdens and serum ferritin. Increased heart rate (HR) and prolonged corrected QT interval (QT(c)) were present, regardless of cardiac iron status. Repolarization abnormalities were the strongest predictors of cardiac iron, including QT/QT(c) prolongation, left shift of T-wave axis, and interpretation of ST/T-wave morphology. Recursive partitioning of the data for females using T-axis and HR and for males using QT, HR, and T-axis produced algorithms with AUROC's of 88.3 and 87.1, respectively. Bradycardia and repolarization abnormalities on 12-lead electrocardiography were the most specific markers for cardiac iron in thalassemia major. Changes in these variables may be helpful to stratify cardiac risk when cardiac MRI is unavailable. However, diagnostic algorithms need to be vetted on larger and more diverse patient populations and longitudinal studies are necessary to determine reversibility of the observed abnormalities.

The relationship between cardiac and liver iron evaluated by MR imaging in haematological malignancies and chronic liver disease

Although iron overload is clinically significant, only limited data have been published on iron overload in haematological diseases. We investigated cardiac and liver iron accumulation by magnetic resonance imaging (MRI) in a cohort of 87 subjects who did not receive chelation, including 59 haematological patients. M-HIC (MRI-based hepatic iron concentration, normal values <36 μmol/g) is a non-invasive, liver biopsy-calibrated method to analyse iron concentration. This method, calibrated to R2 (transverse relaxation rate), was used as a reference standard (M-HIC(R2)). Transfusions and ferritin were evaluated. Mean M-HIC(R2) and cardiac R^* of all patients were 142 μmol/g (95% CI, 114–170) and 36.4 1/s (95% CI, 34.2–38.5), respectively. M-HIC(R2) was higher in haematological patients than in patients with chronic liver disease or normal controls (P<0.001). Clearly elevated cardiac R2^* was found in two myelodysplastic syndrome (MDS) patients with severe liver iron overload. A poor correlation was found between liver and cardiac iron (n=82, r=0.322, P=0.003), in contrast to a stronger correlation in MDS (n=7, r=0.905, P=0.005). In addition to transfusions, MDS seemed to be an independent factor in iron accumulation. In conclusion, the risk for cardiac iron overload in haematological diseases other than MDS is very low, despite the frequently found liver iron overload.