Non-invasive assessment of tissue iron overload

Iron deposition in ovarian endometriosis evaluated by magnetic resonance imaging R2* correlates with ovarian function

RESEARCH QUESTION

Does iron overload in patients with endometriosis affect ovarian function? Can a method be developed to visually reflect this?

DESIGN

Magnetic resonance imaging (MRI) R2* was used to evaluate the correlation between iron deposition of ovarian and anti-Müllerian hormone (AMH) in patients with endometriosis. All patients underwent T2* MRI scanning. Serum AMH levels were measured preoperatively. The area of focal iron deposition, iron content of the cystic fluid and AMH levels between the endometriosis and control groups were compared using non-parametric tests. The effects of iron overload on AMH secretion in mouse ovarian granulosa cells were investigated by adding different concentrations of ferric citrate to the medium.

RESULTS

A significant difference was found between endometriosis and control groups in area of iron deposition (P < 0.0001), cystic fluid iron content (P < 0.0001), R2* of lesions (P < 0.0001) and R2* of the cystic fluid (P < 0.0001). Negative correlations were found between serum AMH levels and R2* of cystic lesions in patients with endometriosis aged 18-35 years (rs = -0.6484, P < 0.0001), and between serum AMH levels and R2* of cystic fluid (rs = -0.5074, P = 0.0050). Transcription level (P < 0.0005) and secretion level (P < 0.005) of AMH significantly decreased with the increase in iron exposure.

CONCLUSION

Iron deposits can impair ovarian function, which is reflected in MRI R2*. Serum AMH levels and R2* of cystic lesions or fluid in patients aged 18-35 years had a negative correlation with endometriosis. R2* can be used to reflect the changes of ovarian function caused by iron deposition.

Maternal hemoglobin and iron status in early pregnancy and risk of respiratory tract infections in childhood: A population-based prospective cohort study

BACKGROUND

Maternal hemoglobin and iron status measures during pregnancy might affect the developing fetal respiratory system leading to adverse respiratory conditions. Our aim was to assess the associations of maternal hemoglobin and iron status measures during pregnancy with the risk of respiratory tract infections in children until 10 years of age.

METHODS

In a population-based cohort study among 5134 mother-child pairs, maternal hemoglobin and iron status including ferritin, transferrin, and transferrin saturation were measured during early pregnancy. In children, physician-attended respiratory tract infections from age 6 months until 10 years were assessed by questionnaires. Confounder-adjusted generalized estimating equation modeling was applied.

RESULTS

After taking multiple testing into account, high maternal ferritin concentrations and low maternal transferrin saturation during pregnancy were associated with an overall increased risk of upper, not lower, respiratory tract infections until age 10 years of the child [OR (95% CI: 1.23 (1.10, 1.38) and 1.28 (1.12, 1.47), respectively)]. High maternal transferrin saturation during pregnancy was associated with a decreased and increased risk of upper respiratory tract infections at 1 and 6 years, respectively, [OR (95% CI: 0.60 (0.44, 0.83) and 1.54 (1.17, 2.02))]. Observed associations were suggested to be U-shaped (p-values for non-linearity ≤.001). Maternal hemoglobin and iron status measures during pregnancy were not consistently associated with child's gastroenteritis and urinary tract infections, as proxies for general infection effects.

CONCLUSION

High maternal ferritin and low transferrin saturation concentrations during early pregnancy were most consistently associated with an overall increased risk of child's upper, not lower, respiratory tract infections.

Criticality of Surface Characteristics of Intravenous Iron-Carbohydrate Nanoparticle Complexes: Implications for Pharmacokinetics and Pharmacodynamics

Un-complexed polynuclear ferric oxyhydroxide cannot be administered safely or effectively to patients. When polynuclear iron cores are formed with carbohydrates of various structures, stable complexes with surface carbohydrates driven by multiple interacting sites and forces are formed. These complexes deliver iron in a usable form to the body while avoiding the serious adverse effects of un-complexed forms of iron, such as polynuclear ferric oxyhydroxide. The rate and extent of plasma clearance and tissue biodistribution is variable among the commercially available iron–carbohydrate complexes and is driven principally by the surface characteristics of the complexes which dictate macrophage opsonization. The surface chemistry differences between the iron–carbohydrate complexes results in significant differences in in vivo pharmacokinetic and pharmacodynamic profiles as well as adverse event profiles, demonstrating that the entire iron–carbohydrate complex furnishes the pharmacologic action for these complex products. Currently available physicochemical characterization methods have limitations in biorelevant matrices resulting in challenges in defining critical quality attributes for surface characteristics for this class of complex nanomedicines.

The Superiority of T2*MRI Over Serum Ferritin in the Evaluation of Secondary Iron Overload in a Chronic Kidney Disease Patient: A Case Report

Secondary iron overload is increasingly encountered in chronic kidney disease (CKD) patients because of the frequent use of parenteral iron products, especially in hemodialysis patients. Serum ferritin has been commonly used to monitor iron overload in these patients; however, other conditions can be associated with the high serum ferritin, like infections and inflammatory conditions. Currently, T2*MRI of the heart and liver is the preferred investigation for evaluating liver iron concentration (LIC) and cardiac iron concentration, which reflect the state of iron overload. Few studies observe a positive correlation between serum iron and LIC in CKD patients and postulate that serum ferritin exceeding 290 mcg/L should indicate significant iron overload and necessitates further MRI evaluation. However, here, we present a patient with a history of ESRD for which she underwent renal transplantation twice referred to our clinic due to persistent elevation in serum ferritin level (>1000 mcg/L) for several years. T2*MRI of the heart and liver revealed the absence of iron overload. Our objective of this case is to demonstrate the accuracy of T2*MRI over serum ferritin in evaluating iron overload and questioning the positive correlation between serum ferritin and LIC in CKD patients.

Outcome of iron reduction therapy in ex-thalassemics

There is limited data on iron reduction therapy (IRT) after successful allogeneic haematopoietic stem cell transplantation (aHSCT) for patients with thalassemia major (TM). We present the long term outcome of IRT in 149 patients with TM who underwent aHSCT during January, 2001-December, 2012. The median age was 7 years (range:1–18) and 92 (61.7%) belonged to Pesaro class 3 with a median ferritin at aHSCT of 2480ng/ml (range:866–8921). IRT was reinitiated post-aHSCT at a median of 14 months (range:5–53) post aHSCT with phlebotomy alone in 10 (6.7%) patients or iron chelation alone in 60 (40.3%) patients while 79 (53%) were treated with the combination. Reduction in serum ferritin/month [absolute quantity (ng/ml/month) was as follows: 87 (range:33–195), 130 (range:17–1012) and 147 (range:27.7–1427) in the phlebotomy, chelation and combination therapy groups, respectively (p = 0.038). With a median follow up of 80 months (range:37–182), target ferritin level of <300ng/ml was achieved in 59(40%) while a level <500ng/ml was achieved in 88 patients (59%) in a median duration of 41 months of IRT (range: 3–136). Patients in class III risk category and higher starting serum ferritin levels (>2500ng/ml) were associated with delayed responses to IRT. Our data shows that IRT may be needed for very long periods in ex-thalassaemics to achieve target ferritin levels and should therefore be carefully planned and initiated as soon as possible after aHSCT. A combination of phlebotomy and iron chelators is more effective in reducing iron overload.

Hepatic and cardiac iron load as determined by MRI T2* in patients with congenital dyserythropoietic anemia type I

Iron overload comprises one of the main complications of congenital dyserythropoietic anemia type I (CDA-I). When analyzing magnetic resonance imaging T2* (MRI T2*) results in CDA patients, two previous studies reported discordant results regarding iron load in these patients. To further understand iron loading pattern in this group of patients, we analyzed MRI T2* findings in 46 CDA-I patients. Mild to moderate hepatic iron overload was detected in 28/46 (60.8%) patients. A significant correlation was found between serum ferritin and liver iron concentration (LIC). A significant correlation (p value = 0.02) was also found between the patient's age and LIC, reflecting increased iron loading over time, even in the absence of transfusion therapy. Notably, no cardiac iron overload was detected in any patient. Transfusion-naive patients had better LIC and better cardiac T2* values. These results demonstrate that a high percentage of CDA-I patients have liver iron concentration above the normal values, risking them with significant morbidity and mortality, and emphasize the importance of periodic MRI T2* studies for direct assessment of tissue iron concentration in these patients, taking age and transfusional burden into consideration.

Room Temperature Magnetoelectric Sensor Arrays For Application of Detecting Iron Profiles in Organs

Noninvasive measurement of liver iron concentration (LIC) is clinically important. Yet, at the present time, it can only be achieved with SQUID technology. However, SQUID based BLS suffers high costs and cumbersome cryogenic requirements that prevent SQUID BLS from being adopted by clinical applications. Recently, we demonstrated that a single channel ME sensor with piezo-single crystals could detect LIC from only 3cc of mouse liver tissue without any magnetic field shielding. The results demonstrated not only the sensitivity of ME sensor system for LIC but also the feasibility for mapping LIC profiles spatially. This investigation further developed ME sensor arrays, exploiting the compact size and room temperature operation. A Dual-Channel 1-D ME sensor array along the vertical, Z-direction, was developed and shown to be sensitive to the skin-liver distance change which can be utilized to calibrate and eliminate the inter-subject variability of the LIC measurement due to skin-liver distance. With phantom having spatially dependent iron concentrations, the 1-D ME sensor array was capable of mapping the one-dimensional profile of the iron concentration in the horizontal X- and Y-directions. The results of the prototype sensor devices show the feasibility of an array ME-sensors for imaging iron profile.

Quantification of Liver Iron Overload: Correlation of MRI and Liver Tissue Biopsy in Pediatric Thalassemia Major Patients Undergoing Bone Marrow Transplant

Determination of the magnitude of body iron stores helps to identify individuals at risk of iron-induced organ damage in Thalassemia patients. The most direct clinical method of measuring liver iron concentration (LIC) is through chemical analysis of needle biopsy specimens. Here we present a noninvasive method for the measurement of LIC in vivo using magnetic resonance imaging (MRI). Twenty-three pediatric Thalassemia major patients undergoing bone marrow transplantation at our centre were studied. All 23 patients had MRI T2* and R2* decay time for evaluation of LIC on a 1.5 Tesla MRI system followed by liver tissue biopsy for the assessment of iron concentration using an atomic absorption spectrometry. Simultaneously, serum ferritin levels were measured by enzymatic assay. We have correlated biopsy LIC with liver T2* and serum ferritin values with liver R2*. Of the 23 patients 11 were males, the mean age was 8.3 ± 3.7 years. The study results showed a significant correlation between biopsy LIC and liver T2* MRI (r = 0.768; p < 0.001). Also, there was a significant correlation between serum ferritin levels and liver R2* MRI (r = 0.5647; p < 0.01). Two patients had high variance in serum ferritin levels (2100 and 4100 mg/g) while their LIC was around 24 mg/g, whereas the difference was not seen in T2* MRI. Hence, the liver T2* MRI is a better modality for assessing LIC. Serum ferritin is less reliable than quantitative MRI. The liver T2* MRI is a safe, reliable, feasible and cost-effective method compared to liver tissue biopsy for LIC assessment.

Supportive care during pediatric hematopoietic stem cell transplantation: beyond infectious diseases. A report from workshops on supportive care of the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Hematopoietic stem cell transplantation (HSCT) is currently the standard of care for many malignant and nonmalignant blood diseases. As several treatment-emerging acute toxicities are expected, optimal supportive measurements critically affect HSCT outcomes. The paucity of good clinical studies in supportive practices gives rise to the establishment of heterogeneous guidelines across the different centers, which hampers direct clinical comparison in multicentric studies. Aiming to harmonize the supportive care provided during the pediatric HSCT in Europe, the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT) promoted dedicated workshops during the years 2017 and 2018. The present paper describes the resulting consensus on the management of sinusoidal obstructive syndrome, mucositis, enteral and parenteral nutrition, iron overload, and emesis during HSCT.

Susceptibility based multiparametric quantification of liver disease: Non-invasive evaluation of steatosis and iron overload

PURPOSE

To evaluate if single-voxel MR spectroscopy (MRS) of iron and fat correlates with biopsy results of hepatic steatosis and iron overload, and to compare MR-measurements with room-temperature susceptometer (RTS), ultrasound, controlled attenuation parameter (CAP) and serum ferritin.

MATERIAL AND METHODS

In this prospective study, a set of 42 patients out of 47 screened patients with several chronic liver diseases underwent MRI-examination at 1.5 T including R2-measurements by single-voxel high-speed T2-corrected multiecho spectroscopy, additional liver biopsy, abdominal ultrasound, CAP, and RTS. Routine blood and serum parameters were determined, including ferritin. Atomic absorption spectroscopy (AAS) and histologically confirmed extent of hepatic steatosis from liver biopsy were used as reference standard. For correlation of R2, RTS, CAP, ferritin, and ultrasound with results of AAS and histologically determined fat fraction of liver biopsy specimen, Spearman's and Pearson's correlation as well as receiver operating characteristics curve (ROC) analysis with cut-off values determined by maximizing Youden index was used.

RESULTS

MRS iron assessment correlated best with AAS, with a Pearson correlation coefficient of 0.715 (p < 0.001), followed by RTS 0.520 (p < 0.001), and serum ferritin 0.213 (p = 0.088, not significant). MRS fat quantification correlated best with the histological confirmed extent of steatosis hepatis with a Spearman correlation coefficient of 0.836 (p < 0.001), followed by CAP 0.604 (p < 0.001) and sonographically diagnosed steatosis 0.358 (p = 0.013).

CONCLUSION

MRS by T2-corrected multiecho single-voxel spectroscopy correlated best with histological results of hepatic fat and iron content compared to RTS, CAP, abdominal ultrasound, and ferritin. Non-invasive methods to assess hepatic fat and iron are of clinical interest for follow-up examinations of patients with chronic liver diseases, where repeated biopsy is not indicated.

Cardiac and hepatic siderosis in myelodysplastic syndrome, thalassemia and diverse causes of transfusion-dependent anemia: the TIMES study

Supplemental Digital Content is available in the text

The significant morbidity and mortality associated with iron overload can be reduced by effective iron chelation. Magnetic resonance imaging (MRI) provides accurate and reproducible iron load assessment. The aim of this epidemiological study was to assess the prevalence and severity of cardiac and hepatic siderosis by MRI and to evaluate the impact of MRI on clinical management in patients with transfusion-dependent anemia and non-transfusion-dependent thalassemia (NTDT). We enrolled 243 patients with myelodysplastic syndromes (MDS), thalassemia major (TM), NTDT or other chronic anemia. Overall, 10% and 48% had cardiac and hepatic siderosis, respectively. Mean liver iron concentration (LIC) was above target range in all groups; mean myocardial T2^∗ was normal. Hepatic siderosis was more prevalent than myocardial siderosis in patients with MDS, occurring in 54.4% and 4.4% of patients, respectively. As also observed in patients with NTDT or other anemia, hepatic siderosis was present in a large proportion of MDS patients who were chelation naïve (57.7%), as well as in patients receiving iron chelation therapy (ICT) (52.4%), despite a lower transfusion load compared with TM. Correlation between LIC and serum ferritin was observed across diseases; however, not all patients requiring ICT could be identified with serum ferritin alone, as serum ferritin underestimated LIC in 4.4% and overestimated LIC in 7.5% of patients. Exploratory analyses showed serum ferritin thresholds for liver siderosis detected by MRI at approximately 300 ng/mL higher in MDS than in TM. Most patients reported low–medium adherence to ICT; MRI assessment led to change in ICT in 46% of evaluable patients, including 52% of MDS patients. Accurate organ iron monitoring by MRI facilitated appropriate initiation of chelation, dose optimization and clinical decision making.

Trial registration: ClinicalTrials.gov: NCT01736540.

Measurement of the liver iron concentration in transfusional iron overload by MRI R2* and by high-transition-temperature superconducting magnetic susceptometry

PURPOSE

To compare measurement of the liver iron concentration in patients with transfusional iron overload by magnetic resonance imaging (MRI), using R2*, and by magnetic susceptometry, using a new high-transitiontemperature (high-Tc; operating at 77 K, cooled by liquid nitrogen) superconducting magnetic susceptometer.

METHODS

In 28 patients with transfusional iron overload, 43 measurements of the liver iron concentration were made by both R2* and high-Tc magnetic susceptometry.

RESULTS

Measurements of the liver iron concentration by R2* and high-Tc magnetic susceptometry were significantly correlated when comparing all patients (Pearson's r = 0.91, p < 0.0001) and those with results by susceptometry >7 mg Fe/g liver, dry weight (r = 0.93, p = 0.006). In lower ranges of liver iron, no significant correlations between the two methods were found (0 to <3.2 mg Fe/g liver, dry weight: r = 0.2, p = 0.37; 3.2 to 7 mg Fe/g liver, dry weight: r = 0.41; p = 0.14).

CONCLUSION

The lack of linear correlation between R2* and magnetic susceptibility measurements of the liver iron concentration with minimal or modest iron overload may be due to the effects of fibrosis and other cellular pathology that interfere with R2* but do not appreciably alter magnetic susceptibility.

Imaging endogenous macrophage iron deposits reveals a metabolic biomarker of polarized tumor macrophage infiltration and response to CSF1R breast cancer immunotherapy

Iron deposits are a phenotypic trait of tumor-associated macrophages (TAMs). Histological iron imaging and contrast-agent free magnetic resonance imaging (MRI) can detect these deposits, but their presence  in human cancer, and correlation with immunotherapeutic response is largely untested. Here, primarily using these iron imaging approaches, we evaluated the spatial distribution of polarized macrophage populations containing high endogenous levels of iron in preclinical murine models and human breast cancer, and used them as metabolic biomarkers to correlate TAM infiltration with response to immunotherapy in preclinical trials. Macrophage-targeted inhibition of the colony stimulating factor 1 receptor (CSF1R) by immunotherapy was confirmed to inhibit macrophage accumulation and slow mammary tumor growth in mouse models while also reducing hemosiderin iron-laden TAM accumulation as measured by both iron histology and in vivo iron MRI (FeMRI). Spatial profiling of TAM iron deposit infiltration defined regions of maximal accumulation and response to the CSF1R inhibitor, and revealed differences between microenvironments of human cancer according to levels of polarized macrophage iron accumulation in stromal margins. We therefore demonstrate that iron deposition serves as an endogenous metabolic imaging biomarker of TAM infiltration in breast cancer that has high translational potential for evaluation of immunotherapeutic response.

Relationship between liver iron concentration determined by R2-MRI, serum ferritin, and liver enzymes in patients with thalassemia intermedia

Background

Iron overload is a risk factor affecting all patients with thalassemia intermedia (TI). We aimed to determine whether there is a relationship of serum ferritin (SF) and alanine aminotransferase (ALT) with liver iron concentration (LIC) determined by R2 magnetic resonance imaging (R2-MRI), to estimate the most relevant degree of iron overload and best time to chelate in patients with TI.

Methods

In this cross-sectional study, 119 patients with TI (mean age years) were randomly selected and compared with 120 patients who had a diagnosis of thalassemia major (TM). Correlations of LIC, as determined by R2-MRI, with SF and ALT levels, were assessed in all participants. A P-value <0.05 was considered statistically significant.

Results

SF and LIC levels were lower in patients with TI than in those with TM; only ferritin values were significant. We found a statistically significant relationship between SF and LIC, with cut-off estimates of SF in patients with TI who had splenectomy and those who entered puberty spontaneously (916 and 940 ng/mL, respectively) with LIC >5 mg Fe/g dry weight (P<0.0001). A significant relationship was also found for patients with TI who had elevated ALT level (63.5 U/L), of 3.15 times the upper normal laboratory limit, using a cut-off for LIC ≥5 mg Fe/g dry weight.

Conclusion

We determined the cut-off values for ALT and SF indicating the best time to start iron chelation therapy in patients with TI, and found significant correlations among iron overload, SF, and ALT.

Modern approaches to noninvasive diagnosis of malignant transformation of endometriosis

Endometriosis-associated ovarian cancer (EAOC) is a rare entity and has highly variable morphological presentations. Mural nodules can be seen in EAOC and benign ovarian endometrioma (OE), which causes a diagnostic dilemma. The differential diagnosis between early-stage EAOC with predominantly cystic appearances and benign OE remains a challenge for physicians. This study will summarize recent knowledge of diagnosis of malignant transformation of endometriosis that have been studied through an innovative approach based on a wide array of novel technologies. Using PubMed database, we focused on the biochemical and technical advancement in the differential diagnosis of benign and malignant endometriosis. Compared with the subjects with benign OE, cyst fluid hemoglobin and iron-related compounds levels were significantly lower in patients with EAOC. This observation opens up the possibility of early diagnosis before morphological variations are captured through ultrasonographic and magnetic resonance (MR) imaging diagnosis. The metallobiology technology offers one solution to this challenge. We discuss the noninvasive diagnosis of EAOC via various imaging methods, including electronic absorption spectroscopy, near infrared approach and MR transverse relaxometry. Special emphasis is given to recent advances in the noninvasive imaging modalities.

Quantification of Nanoparticle Enhancement in Polarized Breast Tumor Macrophage Deposits by Spatial Analysis of MRI and Histological Iron Contrast Using Computer Vision

Magnetic resonance imaging applications utilizing nanoparticle agents for polarized macrophage detection are conventionally analyzed according to iron-dependent parameters averaged over large regions of interest (ROI). However, contributions from macrophage iron deposits are usually obscured in these analyses due to their lower spatial frequency and smaller population size compared with the bulk of the tumor tissue. We hypothesized that, by addressing MRI and histological pixel contrast heterogeneity using computer vision image analysis approaches rather than statistical ROI distribution averages, we could enhance our ability to characterize deposits of polarized tumor-associated macrophages (TAMs). We tested this approach using in vivo iron MRI (FeMRI) and histological detection of macrophage iron in control and ultrasmall superparamagnetic iron oxide (USPIO) enhanced mouse models of breast cancer. Automated spatial profiling of the number and size of iron-containing macrophage deposits according to localized high-iron FeMRI or Prussian blue pixel clustering performed better than using distribution averages to evaluate the effects of contrast agent injections. This analysis was extended to characterize subpixel contributions to the localized FeMRI measurements with histology that confirmed the association of endogenous and nanoparticle-enhanced iron deposits with macrophages in vascular regions and further allowed us to define the polarization status of the macrophage iron deposits detected by MRI. These imaging studies demonstrate that characterization of TAMs in breast cancer models can be improved by focusing on spatial distributions of iron deposits rather than ROI averages and indicate that nanoparticle uptake is dependent on the polarization status of the macrophage populations. These findings have broad implications for nanoparticle-enhanced biomedical imaging especially in cancer.

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.

Monitoring Iron Overload: Relationship between R2* Relaxometry of the Liver and Serum Ferritin under Different Therapies

Objective:

The objective of this study was to evaluate the relationship between hepatic magnetic resonance imaging (MRI) with R2* relaxometry and serum ferritin in therapy monitoring of patients with iron overload. Further, a possible influence of the chosen therapy (phlebotomy or chelation) was assessed.

Materials and Methods:

We retrospectively evaluated 42 patients with baseline and follow-up R2* relaxometry and determination of serum ferritin before and during therapeutic phlebotomy or iron chelation therapy or watchful waiting, respectively. Linear regression analysis was used to analyze the correlation between changes of R2* and serum ferritin. Regression lines for different groups were compared with analysis of covariance.

Results:

We found a moderate positive statistical correlation (r = 0.509) between serum ferritin and R2*, a moderate positive correlation between absolute R2* changes and serum ferritin changes (r = 0.497), and a strong correlation for percentage changes (r = 0.712). The correlation analysis between relative changes of R2* and serum ferritin for the different therapies resulted in a strong correlation between phlebotomy and chelation (r = 0.855/0.727) and a moderate for no applied therapy (r = 0.536). In 22/92 paired examinations, a discordance of R2* and ferritin was found, particularly involving patients under chelation.

Conclusions:

Despite the good correlation between serum ferritin and R2* relaxometry in monitoring iron overload, treatment response may be misinterpreted when only serum ferritin is considered. Although ferritin is an acceptable and far cheaper tool for monitoring, MRI should be performed for confirmation, especially in case of unexpected ferritin changes, particularly under chelation therapy.

Relationship between T2* magnetic resonance imaging-derived liver and heart iron content and serum ferritin levels in transfusion-dependent thalassemic children

CONTEXT:

T2* magnetic resonance imaging (MRI) is being increasingly used for the assessment of organ iron content in thalassemics, but cost is a major prohibitive factor for repeated measurements. If serum ferritin correlates well with the T2* MRI liver and heart, it will be economical and more simple tool to assess organ iron deposition.

AIMS:

The aim of this study was to find out the relationship between serum ferritin level and T2* MRI-derived liver and heart iron content in transfusion-dependent thalassemic children

SETTINGS:

Thalassemia day-care center of a teaching hospital

DESIGN:

This was a cross-sectional study

SUBJECTS AND METHODS:

Seventy-three transfusion-dependent beta thalassemic children belonging to 2–18 years of age were subjected to T2* MRI of heart and liver to assess their iron content. Values obtained here were related to serum ferritin.

STATISTICAL ANALYSIS USED:

Keeping the correlation between serum ferritin and T2* MRI as primary outcome, spearman's correlation coefficient was calculated.

RESULTS:

We found poor (negative) correlation between serum ferritin level and T2* MRI liver (r = -0.448, P = 0.000) but no correlation between serum ferritin and T2*MRI heart (r = -0.221, P = 0.060).

Conclusions:

Serum ferritin cannot reliably predict the liver and heart iron content in Indian children with β thalassemia.

A Novel Magnetoelectric Biomagnetic Susceptometer on Iron Level Detection with Mice Tissue in Vitro

Iron plays a vital role in human body. Liver Iron Concentration (LIC) is directly correlated to total body iron and can be an important indicator to a variety of pathologies. Non-invasive methods to quantitatively assess tissue iron with low cost and high sensitivity have drawn vast interests and investments. Among various methods, the magnetoelectric (ME) sensor based biomagnetic liver susceptometer (BLS) is of great promise because it operates at room temperature but with the same principle as that of the well-developed SQUID (Superconducting Quantum Interference Device). Here, we report a magnetoelectric (ME) sensor based BLS system exploiting the recently developed PIN-PMN-PT piezoelectric single crystal. The newly developed ME BLS, which employs the horizontal scanning mechanism with a water bath interface to automatically eliminate the diamagnetic background of the tissues and irregular shape of torso, exhibits an overall sensitivity advancement (300X) to the sensor system previously reported. A linear correlation (R2 = 0.97) found between the system measurements and the biopsy data demonstrates the validity of the system. The ability to detect signals from only 3cc of mouse liver tissue samples suggests a high spatial resolution which could be used for finer scanning and enable magnetic distribution image and profiling.

Iatrogenic iron overload and its potential consequences in patients on hemodialysis

Iron overload was considered rare in hemodialysis patients until recently, but its clinical frequency is now increasingly recognized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosiderosis and genetic hemochromatosis. Magnetic resonance imaging (MRI) is now the gold standard method for estimating and monitoring LIC. Studies of LIC in hemodialysis patients by magnetic susceptometry thirteen years ago and recently by quantitative MRI have demonstrated a relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Moreover, three recent long-term observational studies suggested that excessive IV iron doses might be associated with an increased risk of cardiovascular events and death in hemodialysis patients. It has been hypothesized that iatrogenic iron overload in the era of erythropoiesis-stimulating agents might silently increase complications in dialysis patients without creating obvious, clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It has been postulated that the main pathophysiological pathway leading to these events might involve the pleiotropic master hormone hepcidin, which regulates iron metabolism, leading to activation of macrophages in atherosclerotic plaques and then to clinical cardiovascular events. Thus, the potential iron overload toxicity linked to chronic administration of IV iron therapy is now becoming one of the most controversial topics in the management of anemia in hemodialysis patients.

Iron deposition is associated with differential macrophage infiltration and therapeutic response to iron chelation in prostate cancer

Immune cells such as macrophages are drivers and biomarkers of most cancers. Scoring macrophage infiltration in tumor tissue provides a prognostic assessment that is correlated with disease outcome and therapeutic response, but generally requires invasive biopsy. Routine detection of hemosiderin iron aggregates in macrophages in other settings histologically and in vivo by MRI suggests that similar assessments in cancer can bridge a gap in our ability to assess tumor macrophage infiltration. Quantitative histological and in vivo MRI assessments of non-heme cellular iron revealed that preclinical prostate tumor models could be differentiated according to hemosiderin iron accumulation-both in tumors and systemically. Monitoring cellular iron levels during "off-label" administration of the FDA-approved iron chelator deferiprone evidenced significant reductions in tumor size without extensive perturbation to these iron deposits. Spatial profiling of the iron-laden infiltrates further demonstrated that higher numbers of infiltrating macrophage iron deposits was associated with lower anti-tumor chelation therapy response. Imaging macrophages according to their innate iron status provides a new phenotypic window into the immune tumor landscape and reveals a prognostic biomarker associated with macrophage infiltration and therapeutic outcome.

Sensitive and non-invasive assessment of hepatocellular iron using a novel room-temperature susceptometer

BACKGROUND & AIMS

Liver iron accumulates in various chronic liver diseases where it is an independent factor for survival and carcinogenesis. We tested a novel room-temperature susceptometer (RTS) to non-invasively assess liver iron concentration (LIC).

METHODS

Two hundred and sixty-four patients with or without signs of iron overload or liver disease were prospectively enrolled. Thirty-five patients underwent liver biopsy with semiquantitative iron determination (Prussian Blue staining), atomic absorption spectroscopy (AAS, n=33), or magnetic resonance imaging (MRI, n=15).

RESULTS

In vitro studies demonstrated a highly linear (r²=0.998) association between RTS-signal and iron concentration, with a detection limit of 0.3mM. Using an optimized algorithm, accounting for the skin-to-liver capsule distance, valid measurements could be obtained in 84% of cases. LIC-RTS showed a significant correlation with LIC-AAS (r=0.74, p<0.001), LIC-MRI (r=0.64, p<0.001) and hepatocellular iron (r=0.58, p<0.01), but not with macrophage iron (r=0.32, p=0.30). Normal LIC-RTS was 1.4mg/g dry weight. Besides hereditary and transfusional iron overload, LIC-RTS was also significantly elevated in patients with alcoholic liver disease. The areas under the receiver operating characteristic curve (AUROC) for grade 1, 2 and 3 hepatocellular iron overload were 0.72, 0.89 and 0.97, respectively, with cut-off values of 2.0, 4.0 and 5.0mg/g dry weight. Notably, the positive and negative predictive values, sensitivity, specificity and accuracy of severe hepatic iron overload (HIO) (grade ≥2) detection, were equal to AAS and superior to all serum iron markers. Depletion of hepatic iron could be efficiently monitored upon phlebotomy.

CONCLUSIONS

RTS allows for the rapid and non-invasive measurement of LIC. In comparison to MRI, it could be a cost-effective bedside method for LIC screening. Lay summary: Novel room-temperature susceptometer (RTS) allows for the rapid, sensitive, and non-invasive measurement of liver iron concentration. In comparison to MRI, it could be a cost-effective bedside method for liver iron concentration screening.

Iatrogenic Iron Overload in Dialysis Patients at the Beginning of the 21st Century

Iron overload used to be considered rare in hemodialysis patients but its clinical frequency is now increasingly realized. The liver is the main site of iron storage and the liver iron concentration (LIC) is closely correlated with total iron stores in patients with secondary hemosideroses and genetic hemochromatosis. Magnetic resonance imaging is now the gold standard method for LIC estimation and monitoring in non-renal patients. Studies of LIC in hemodialysis patients by quantitative magnetic resonance imaging and magnetic susceptometry have demonstrated a strong relation between the risk of iron overload and the use of intravenous (IV) iron products prescribed at doses determined by the iron biomarker cutoffs contained in current anemia management guidelines. These findings have challenged the validity of both iron biomarker cutoffs and current clinical guidelines, especially with respect to recommended IV iron doses. Three long-term observational studies have recently suggested that excessive IV iron doses may be associated with an increased risk of cardiovascular events and death in hemodialysis patients. We postulate that iatrogenic iron overload in the era of erythropoiesis-stimulating agents may silently increase complications in dialysis patients without creating frank clinical signs and symptoms. High hepcidin-25 levels were recently linked to fatal and nonfatal cardiovascular events in dialysis patients. It is therefore tempting to postulate that the main pathophysiological pathway leading to these events may involve the pleiotropic master hormone hepcidin (synergized by fibroblast growth factor 23), which regulates iron metabolism. Oxidative stress as a result of IV iron infusions and iron overload, by releasing labile non-transferrin-bound iron, might represent a ‘second hit’ on the vascular bed. Finally, iron deposition in the myocardium of patients with severe iron overload might also play a role in the pathogenesis of sudden death in some patients.

Comparison of Tissue Elastography With Magnetic Resonance Imaging T2* and Serum Ferritin Quantification in Detecting Liver Iron Overload in Patients With Thalassemia Major

BACKGROUND & AIMS

We investigated whether tissue elastography (TE) can be used as an alternative to magnetic resonance imaging (MRI) T2* analysis to determine the degree of iron overload in patients with thalassemia major.

METHODS

We conducted a prospective study of 154 patients (99 male; mean age, 12 ± 3.6 years) with thalassemia major requiring chronic blood transfusion and on iron chelator therapy. The study was performed at a tertiary hospital in India from January 2015 through June 2015. We performed routine blood sample analyses, measurements of serum levels of ferritin, and TE within 1 month of MRI T2* analysis of the liver. The Spearman correlation test and linear regression analysis were used to evaluate the correlation between TE liver stiffness measurements and R2* MRI results or serum ferritin levels.

RESULTS

The subjects' mean total serum levels of bilirubin, alanine aminotransferase, aspartate aminotransferase, and albumin were 1.4 ± 0.6 mg/dL, 65.0 ± 51.8 IU/L, 62.9 ± 44 IU/L, and 4.2 ± 0.2 g/d, respectively. Mean liver stiffness measurement, MRI T2* (3 T), corresponding MRI R2* (3 T), and ferritin values were 8.2 ± 4.4 kPa, 3.18 ± 2.6 milliseconds, 617.3 ± 549 Hz, and 4712 ± 3301 ng/mL, respectively. On the basis of MRI analysis, 67 patients (43.5%) had mild iron overload, 49 patients (31.8%) had moderate iron overload, and 22 patients (14.3%) had severe iron overload. Fibroscan liver stiffness measurements correlated with MRI R2* values (r = 0.85; P < .001). TE results identified the patients with severe, moderate, and mild iron overload with area under the receiver operating characteristic curve values of 94.8%, 84.5%, and 84.7%, respectively. Liver stiffness measurements greater than 13.5, 7.8, and 5.5 kPa identified patients with severe, moderate, and mild iron overload, respectively; the sensitivity and specificity values were 92% and 93% for severe overload, 82% and 82% for moderate overload, and 73% and 75% for mild overload. No correlation was found between TE results and serum level of ferritin (r = 0.19; P = .11).

CONCLUSIONS

Results of TE correlate with those from MRI T2* analysis. TE is cheaper and more available than MRI and might be used to estimate hepatic iron overload, especially moderate to severe overload in patients with thalassemia major who require chronic transfusion.

Assessing the Association between Serum Ferritin, Transferrin Saturation, and C-Reactive Protein in Northern Territory Indigenous Australian Patients with High Serum Ferritin on Maintenance Haemodialysis

Objective. To determine the significance of high serum ferritin observed in Indigenous Australian patients on maintenance haemodialysis in the Northern Territory, we assessed the relationship between ferritin and transferrin saturation (TSAT) as measures of iron status and ferritin and C-reactive protein (CRP) as markers of inflammation. Methods. We performed a retrospective cohort analysis of data from adult patients (≥18 years) on maintenance haemodialysis (>3 months) from 2004 to 2011. Results. There were 1568 patients. The mean age was 53.9 (11.9) years. 1244 (79.3%) were Indigenous. 44.2% (n = 693) were male. Indigenous patients were younger (mean age [52.3 (11.1) versus 57.4 (15.2), p < 0.001]) and had higher CRP [14.7 mg/l (7–35) versus 5.9 mg/l (1.9–17.5), p < 0.001], higher median serum ferritin [1069 µg/l (668–1522) versus 794.9 µg/l (558.5–1252.0), p < 0.001], but similar transferrin saturation [26% (19–37) versus 28% (20–38), p = 0.516]. We observed a small positive correlation between ferritin and TSAT (r² = 0.11, p < 0.001), no correlation between ferritin and CRP (r² = 0.001, p < 0.001), and positive association between high serum ferritin and TSAT (p < 0.001), Indigenous ethnicity (p < 0.001), urea reduction ratio (p = 0.001), and gender (p < 0.001) after adjustment in mixed regression analysis. Conclusion. Serum ferritin and TSAT may inadequately reflect iron status in this population. The high ferritin was poorly explained by inflammation.

Liver stiffness assessed by transient elastography in patients with β thalassaemia major

RATIONALE FOR THE STUDY

This cross-sectional multicenter study was conducted to investigate any difference in liver stiffness measurements (LSM), evaluated by transient elastography, between patients affected by β thalassaemia major, with and without hepatitis C virus (HCV) infection, and healthy blood donors (controls). Secondary aim was to assess any correlation between transient elastography and serum ferritin, liver magnetic resonance imaging (MRI) T2* or superconductive quantum interference device (SQUID) liver susceptometry values.

MATERIALS AND METHODS

The study involved three centers. Transient elastography and MRI T2* examinations were performed in all centers. SQUID liver susceptometry was performed in center1 and center2. T-test for independent data or Mann-Whitney U test was used to analyse differences between two groups. Univariate Pearson's r coefficient was used to test correlations between liver stiffness measurements and all other variables.

RESULTS

In a study with 119 patients and 183 controls, patients who had never been infected with HCV showed significantly higher LSMs than controls [5.7 (95% CI, 5.2-6.2) kPa vs. 4.3 (95% CI, 4.1-4.4) kPa, p < 0.0001]. A moderate correlation between LSMs and ferritin values, adjusted for gender and age, was found in patients (r = 0.49, p < 0.0001) but not in controls (r = -0.22, p = 0.6). No correlation between LSMs and MRI T2* or SQUID liver susceptometry values was observed. In conclusion, compared to controls β thalassaemia major patients had a significant increase in LSMs independently from HCV infection.

Limitations of serum ferritin to predict liver iron concentration responses to deferasirox therapy in patients with transfusion-dependent thalassaemia

BACKGROUND

In transfusion-dependent anaemias, while absolute serum ferritin levels broadly correlate with liver iron concentration (LIC), relationships between trends in these variables are unclear. These relationships are important because serum ferritin changes are often used to adjust or switch chelation regimens when liver magnetic resonance imaging (MRI) is unavailable.

OBJECTIVES AND METHODS

This post hoc analysis of the EPIC study compared serum ferritin and LIC in 317 patients with transfusion-dependent thalassaemia before and after 1 yr of deferasirox.

RESULTS

Serum ferritin responses (decreases) occurred in 73% of patients, 80% of whom also have decreased LIC. However, 52% of patients without a serum ferritin response did decrease LIC and by >1 mg Fe/g dw (median 3.9) in 77% of cases. Absolute serum ferritin and LIC values correlated significantly only when serum ferritin was <4000 ng/mL (r = 0.59; P < 0.0001) and not at higher levels (≥4000 ng/mL; r = 0.19). Serum ferritin response was accompanied by decreased LIC in 89% and 70% of cases when serum ferritin was <4000 or ≥4000 ng/mL, respectively.

CONCLUSIONS

As serum ferritin non-response was associated with LIC decrease in over half of patients, use of liver MRI may be particularly useful for differentiating true from apparent non-responders to deferasirox based on serum ferritin trends alone.

Hepatocellular carcinoma as an emerging morbidity in the thalassemia syndromes: A comprehensive review

The incidence of hepatocellular carcinoma (HCC) in patients with thalassemia is on the rise. The 2 well recognized HCC risk factors in thalassemia are iron overload and chronic viral infection with hepatitis C. The carcinogenicity of iron is related to its induction of oxidative damage, which results in genotoxicity, and to immunologic dysregulation, which attenuates cancer immune surveillance. Chronic hepatitis B and C infections lead to necroinflammation, which can prompt progression to HCC, but an independent role of hepatitis B virus in hepatic carcinogenesis among patients with thalassemia has not been demonstrated. Screening patients who have thalassemia using magnetic resonance imaging-based liver iron concentration measurement and liver ultrasound is recommended for early detection of iron overload and HCC, respectively. Prevention primarily resides in hepatitis B vaccination, donor blood screening, hepatitis treatment, and iron chelation. Although solid data is lacking on the outcomes of HCC treatment in patients with thalassemia, a personalized approach tailored to the individual patient's comorbidities remains necessary for treatment success. Treatment modalities for HCC include surgical resection, chemoembolization, and liver transplantation, among others. Multicenter studies are needed to better explore therapeutic targets that can improve the prognosis of these patients. Cancer 2017;123:751-58. © 2016 American Cancer Society.

Myocardial and liver iron overload, assessed using T2* magnetic resonance imaging with an excel spreadsheet for post processing in Tunisian thalassemia major patients

Thalassemia is a common genetic disorder in Tunisia. Early iron concentration assessment is a crucial and challenging issue. Most of annual deaths due to iron overload occurred in underdeveloped regions of the world. Limited access to liver and heart MRI monitoring might partially explain these poor prognostic results. Standard software programs are not available in Tunisia. This study is the first to evaluate iron overload in heart and liver using the MRI T2* with excel spreadsheet for post processing. Association of this MRI tool results to serum ferritin level, and echocardiography was also investigated. One hundred Tunisian-transfused thalassemia patients older than 10 years (16.1 ± 5.2) were enrolled in the study. The mean myocardial iron concentration (MIC) was 1.26 ± 1.65 mg/g dw (0.06-8.32). Cardiac T2* (CT2*) was under 20 ms in 30 % of patients and under 10 ms in 21 % of patients. Left ventricular ejection function was significantly lower in patients with CT2* <10 ms. Abnormal liver iron concentration (LIC >3 mg/g dw) was found in 95 % of patients. LIC was over 15 mg/g dw in 25 % of patients. MIC was more correlated than CT2* to LIC and serum ferritin. Among patients with SF <1000 μg/l, 13 % had CT2* <20 ms. Our data showed that 30 % of the Tunisian thalassemia major patients enrolled in this cohort had myocardial iron overload despite being treated by iron chelators. SF could not reliably predict iron overload in all thalassemia patients. MRI T2* using excel spreadsheet for routine follow-up of iron overload might improve the prognosis of thalassemia major patients in developing countries, such as Tunisia, where standard MRI tools are not available or expensive.

An Ultrasensitive Magnetoelectric Sensor System For the Quantitative Detection of Liver Iron

Ultrasensitive magnetoelectric (ME) sensors have been developed using magnetostrictive/piezoelectric laminate heterostructures. This paper discusses a highly interdisciplinary design of a room temperature biomagnetic liver susceptometry system (BLS) based on the ME sensors. The ME-sensor based BLS maintains the ultrahigh sensitivity to detect the weak AC biomagnetic signals and introduces a low equivalent magnetic noise. The results reveal a "turning point" and successfully indicate the output signals to be linearly responsive to iron concentrations from normal iron level (0.05 mg_Fe/g_{liver phantom}) to 5 mg_Fe/g_{liver phantom} iron overload level (100X overdose). Further, the introduction of the water-bag technique shows the promise on the automatic deduction of the background (tissue) signal, enabling an even higher sensitivity and better signal-to-noise (SNR). With these improvements, it becomes feasible to get improved characterization flexibility and the field distribution mapping potential via signal processing from the correlations of multiple sensors in the system. Considering the wide presence of biomagnetic signals in human organs, the potential impact of such biomagnetic devices on medicine and health care could be enormous and far-reaching.

MRI Measurements of Iron Load in Transfusion-Dependent Patients: Implementation, Challenges, and Pitfalls

Magnetic resonance imaging (MRI) has played a key role in studies of iron overload in transfusion-dependent patients, providing insights into the relations among liver and cardiac iron loading, iron chelator dose, and morbidity. Currently, there is rapid uptake of these methods into routine clinical practice as part of the management strategy for iron overload in regularly transfused patients. Given the manifold methods of data acquisition and analysis, there are several potential pitfalls that may result in inappropriate decision making. Herein, we review the challenges of establishing suitable MRI techniques for tissue iron measurement in regularly transfused patients.

Safety concerns about intravenous iron therapy in patients with chronic kidney disease

Anaemia in chronic kidney disease (CKD) is managed primarily with erythropoiesis-stimulating agents (ESAs) and iron therapy. Following concerns around ESA therapy, intravenous (IV) iron is being administered more and more worldwide. However, it is still unclear whether this approach is safe at very high doses or in the presence of very high ferritin levels. Some observational studies have shown a relationship between either high ferritin level or high iron dose and increased risk of death, cardiovascular events, hospitalization or infection. Others have not been able to confirm these findings. However, they suffer from indication biases. On the other hand, the majority of randomized clinical trials have only a very short follow-up (and thus drug exposure) and are inadequate to assess the mortality risk. None of them have tested the role of different iron doses on hard end points. With the lack of clear evidence coming from well-designed and large-scale studies, several data suggest that excessive iron therapy may be toxic in several aspects, ranging from iron overload to tissue damage from labile iron. A number of experimental and clinical data suggest that either excessive iron therapy or iron overload may be a possible culprit of atherogenesis. The process seems to be mediated by oxidative stress. Iron therapy should also be used cautiously in the presence of active infections, since iron is essential for bacterial growth. Recently, the European Medicines Agency officially raised concerns about rare hypersensitivity reactions following IV iron administration. The balance has been in favour of benefits. In several European countries, this has created a lot of confusion and somewhat slowed the run towards excessive use. Altogether, IV iron remains a mainstay of anaemia treatment in CKD patients. However, in our opinion, its excessive use should be avoided, especially in patients with high ferritin levels and when ESA agents are not contraindicated.

Erythrocytapheresis is a valid and safe therapeutic option in dysmetabolic iron overload syndrome

Dysmetabolic iron overload syndrome is a rare event causing hepatic impairment with serious long-term side effects. Here, we describe a case of metabolic syndrome-related hepatic iron overload that showed a rapid, effective, and safe response to erythrocytapheresis. J. Clin. Apheresis 31:443-447, 2016. © 2015 Wiley Periodicals, Inc.

Serum Ferritin Levels Correlation With Heart and Liver MRI and LIC in Patients With Transfusion-Dependent Thalassemia

BACKGROUND

Iron-loaded cardiac complication is the essential cause of mortality in patients with thalassemia. Early detection and treatment of cardiac over-load can reduce mortality.

OBJECTIVES

The current study aimed to evaluate the relationship between serum ferritin levels and T2* magnetic resonance imaging (MRI) of heart and liver and liver iron concentration (LIC) to diagnose iron over load in countries with limited access.

PATIENTS AND METHODS

In the current cross-sectional study, 85 Iranian patients with thalassemia with the mean age of 22.7 ± 7 years were randomly selected. All patients were on regular blood transfusion. Echocardiography of heart and liver T2* MRI, determination of serum ferritin levels, and LIC were performed in all subjects at the same time. The correlation of serum ferritin levels with T2*MRI of heart and liver, and LIC was assessed. P value < 0.05 was considered statistically significant.

RESULTS

Abnormal myocardial iron load (T2* MRI < 20 ms) was detected in 58% of the patients and among whom, 36% had severe myocardial iron load (T2* MRI < 10 ms). Median and interquartile range of serum ferritin levels were 1434 and 2702 respectively in patients with thalassemia. Serum ferritin levels showed a statistically significant positive correlation with LIC (rs = 0.718, P < 0.001) and significant negative correlation with T2* Heart (rs = -0.329, P = 0.002), and T2* Liver (rs = -0.698, P < 0.001). However, Ejection fraction was not significantly correlated with serum ferritin levels in the patients (P = 0.399).

CONCLUSIONS

Serum ferritin levels can be used to diagnose iron over-load in patients with thalassemiaas an alternative method in areas where T2* MRI is not available.

Clinical pharmacology of deferasirox

Iron accumulation is a consequence of regular red cell transfusions, and can occur as a result of ineffective erythropoiesis secondary to increased intestinal iron absorption, in patients with various anemias. Without appropriate treatment, iron overload can lead to increased morbidity and mortality. Deferasirox is an oral iron chelator effective for reduction of body iron in iron-overloaded patients with transfusion-dependent anemias and non-transfusion-dependent thalassemia, with a well-established safety profile. This review summarizes the clinical pharmacokinetics, pharmacodynamics, and drug-drug interaction profile of deferasirox, and the claims supporting once-daily dosing for effective chelation. Sustained labile plasma iron suppression is observed with no rebound between doses, protecting organs from potential tissue damage. Increased iron excretion positively correlates with increased deferasirox exposure; to optimize iron removal transfusional iron intake, body iron burden and safety parameters should also be considered. Deferasirox dispersible tablets should be taken ≥30 min before food due to an effect of food on bioavailability. Dosing is consistent across pediatric and adult patients and there is no ethnic sensitivity. Dose adjustment is required for patients with hepatic impairment and may be considered upon coadministration with strong uridine diphosphate glucuronosyltransferase inducers or bile acid sequestrants (coadministration should be avoided where possible), and patients should be monitored upon coadministration with cytochrome P450 (CYP) 3A4/5, CYP2C8, or CYP1A2 substrates. Coadministration with hydroxyurea, a fetal hemoglobin modulator, does not appear to impact deferasirox pharmacokinetics. In summary, a substantial body of clinical and pharmacokinetic data are available for deferasirox to guide its optimal use in multiple patient populations and clinical circumstances.

Pancreatic iron and fat assessment by MRI-R2* in patients with iron overload diseases

BACKGROUND

To determine the pancreatic iron (R2*) and fat content (FC) in comparison to hepatic and cardiac R2* in patients with iron overload disorders like β-thalassemia major (TM), Diamond-Blackfan anemia (DBA) or hereditary hemochromatosis.

METHODS

R2* rates were assessed in the liver, heart and pancreas of 42 patients with TM, 29 subjects with other iron overload diseases, and 10 controls using an ECG-gated breathhold sequence (12 echo time [TE] = 1.3-25.7 ms, readout repetition time [TR] = 244 ms). Pancreatic R2* and FC were assessed from TE dependent region of interest based signal intensities performing water-fat chemical shift relaxometry and were compared with laboratory parameters (glucose, HbA1c, amylase and lipase).

RESULTS

A pancreatic iron gradient from tail (R2* = 122 s(-1) ) to head (R2* = 114 s(-1) , P < 10(-4) ) was found. The close association between cardiac and pancreatic R2* was also confirmed in patients with TM and other iron overload diseases (rs  = 0.64, P < 10(-4) ). Receiver operator characteristic analysis (area: 0.89, P < 10(-4) ) identified patients with elevated cardiac iron at a pancreatic R2* cut-off level of 131s(-1) (sensitivity = specificity at 81%). Highest pancreatic R2* (211s(-1) ) and FC (36%) were found in the tail region of diabetic patients with TM.

CONCLUSION

Pancreatic tail showed highest R2* rates and fat contents, especially in patients with thalassemia. Besides iron accumulation fatty degeneration might be an additional risk factor for the development of diabetes in β-thalassemia major, but this hypothesis needs further studies in prediabetic patients.

Characterization of transfusion-derived iron deposition in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) receiving packed red blood cell (PRBC) transfusions may have increased risk for vital organ iron deposition causing serious late effects.

METHODS

This cross-sectional cohort study of a CCS cohort quantified organ iron content by magnetic resonance imaging. Iron status by serum markers and hemochromatosis gene mutation status were assessed.

RESULTS

Seventy-five patients who had received a range (0-392 mL/kg) of cumulative PRBC transfusion volumes were enrolled (median age 14 years, range 8-25.6 years at evaluation). Median follow-up time was 4.4 years, and median time since last transfusion was 4.9 years. Cancer diagnoses included acute lymphoblastic or myelogenous leukemia (ALL/AML; n = 33) and solid tumors (n = 42). Liver and pancreatic iron concentrations were elevated in 36 of 73 (49.3%) and 19 of 72 (26.4%) subjects, respectively. Cardiac iron concentration was not increased in this cohort. In multivariate analysis, cumulative PRBC volume (P < 0.0001) and older age at diagnosis (P < 0.0001) predicted elevated liver iron concentration.

CONCLUSIONS

Iron overload (IO) may occur in children and adolescents/young adults treated for cancer and is associated with cumulative PRBC transfusion volume and age at diagnosis.

IMPACT

These findings have implications for development of monitoring and management guidelines for cancer patients and survivors at risk for IO, exploration of the additive risk of liver/pancreatic damage from chemotherapeutic exposures, and health education to minimize further liver/pancreatic damage from exposures such as excessive alcohol intake and hepatotoxic medications.

Impact of iron overload and potential benefit from iron chelation in low-risk myelodysplastic syndrome

Myelodysplastic syndromes (MDSs) are a group of heterogeneous clonal bone marrow disorders characterized by ineffective hematopoiesis, peripheral blood cytopenias, and potential for malignant transformation. Lower/intermediate-risk MDSs are associated with longer survival and high red blood cell (RBC) transfusion requirements resulting in secondary iron overload. Recent data suggest that markers of iron overload portend a relatively poor prognosis, and retrospective analysis demonstrates that iron chelation therapy is associated with prolonged survival in transfusion-dependent MDS patients. New data provide concrete evidence of iron's adverse effects on erythroid precursors in vitro and in vivo. Renewed interest in the iron field was heralded by the discovery of hepcidin, the main serum peptide hormone negative regulator of body iron. Evidence from β-thalassemia suggests that regulation of hepcidin by erythropoiesis dominates regulation by iron. Because iron overload develops in some MDS patients who do not require RBC transfusions, the suppressive effect of ineffective erythropoiesis on hepcidin may also play a role in iron overload. We anticipate that additional novel tools for measuring iron overload and a molecular-mechanism-driven description of MDS subtypes will provide a deeper understanding of how iron metabolism and erythropoiesis intersect in MDSs and improve clinical management of this patient population.

Ferritin trends do not predict changes in total body iron in patients with transfusional iron overload

Ferritin levels and trends are widely used to manage iron overload and assess the efficacy of prescribed iron chelation in patients with transfusional iron loading. A retrospective cohort study was conducted in 134 patients with transfusion-dependent anemia, over a period of up to 9 years. To determine whether the trends in ferritin adequately reflect the changes in total body iron, changes in ferritin between consecutive liver iron measurements by magnetic resonance imaging (MRI) were compared to changes in liver iron concentrations (LIC), a measure of total body iron. The time period between two consecutive LIC measurements was defined as a segment. Trends in ferritin were considered to predict the change in LIC within a segment if the change in one parameter was less than twofold that of the other, and was in the same direction. Using the exclusion criteria detailed in methods, the trends in ferritin were compared to changes in LIC in 358 segments. An agreement between ferritin trends and LIC changes was found in only 38% of the 358 segments examined. Furthermore, the change in ferritin was in opposite direction to that of LIC in 26% of the segments. Trends in ferritin were a worse predictor of changes in LIC in sickle cell disease than in thalassemia (P < 0.01). While ferritin is a convenient measure of iron status; ferritin trends were unable to predict changes in LIC in individual patients. Ferritin trends need to be interpreted with caution and confirmed by direct measurement of LIC.

Interpretation of iron studies

Iron plays a vital role in the human body in oxygen transport, mitochondrial oxidative energy production, inactivation of drugs and toxins, and DNA synthesis (Munoz et al, 2011).

Deferasirox for the treatment of iron overload in non-transfusion-dependent thalassemia

Non-transfusion-dependent thalassemia (NTDT) defines a group of patients who do not require regular transfusions for survival, but are at significant risk of iron accumulation from underlying disease-related mechanisms distinct from transfusional iron overload. Management of iron overload in NTDT has received little attention compared with that of β-thalassemia major, despite evidence of significant iron-induced complications with advancing age. The efficacy and safety of the iron chelator deferasirox in NTDT has been evaluated in two pilot studies and the first prospective, randomized, placebo-controlled study (THALASSA) of any chelator in NTDT. Treatment with deferasirox for up to 2 years yielded a sustained reduction in iron burden, with a clinically manageable safety profile. Following these trial data, deferasirox is the first iron chelator approved for use in NTDT patients, and with NTDT guidelines now available, physicians are better equipped to achieve effective monitoring and management of iron burden in NTDT.

Magnetic susceptibility as a B0 field strength independent MRI biomarker of liver iron overload

PURPOSE

MR-based quantification of liver magnetic susceptibility may enable field strength-independent measurement of liver iron concentration (LIC). However, susceptibility quantification is challenging, due to nonlocal effects of susceptibility on the B0 field. The purpose of this work is to demonstrate feasibility of susceptibility-based LIC quantification using a fat-referenced approach.

METHODS

Phantoms consisting of vials with increasing iron concentrations immersed between oil/water layers, and 27 subjects (9 controls/18 subjects with liver iron overload) were scanned. Ferriscan (1.5 T) provided R2-based reference LIC. Multiecho three-dimensional-SPGR (1.5 T/3 T) enabled fat-water, B0- and R2*-mapping. Phantom iron concentration (mg Fe L(-1)) was estimated from B0 differences (ΔB0) between vials and neighboring oil. Liver susceptibility and LIC (mg Fe g(-1) dry tissue) was estimated from ΔB0 between the lateral right lobe of the liver and adjacent subcutaneous adipose tissue.

RESULTS

Estimated phantom iron concentrations had good correlation with true iron concentrations (1.5 T:slope = 0.86, intercept = 0.72, r(2) = 0.98; 3 T:slope = 0.85, intercept = 1.73, r(2) = 0.98). In liver, ΔB0 correlated strongly with R2* (1.5 T:r(2) = 0.86; 3 T:r(2) = 0.93) and B0-LIC had good agreement with Ferriscan-LIC (slopes/intercepts nearly 1.0/0.0, 1.5 T:r(2) = 0.67, slope = 0.93 ± 0.13, P ≈ 0.50, intercept = 1.93 ± 0.78, P ≈ 0.02; 3 T:r(2) = 0.84, slope = 1.01 ± 0.09, P ≈ 0.90, intercept = 0.23 ± 0.52, P ≈ 0.68).

DISCUSSION

Fat-referenced, susceptibility-based LIC estimation is feasible at both field strengths. This approach may enable improved susceptibility mapping in the abdomen.

The importance of spleen, spleen iron, and splenectomy for determining total body iron load, ferrikinetics, and iron toxicity in thalassemia major patients

The importance of spleen, spleen iron and splenectomy has been investigated in 28 male and 19 female β-thalassemia major (β-ΤΜ), adult patients. In one study, an increase from about five (615 g; 19.5 × 11.0 × 6.0 cm) to twenty (2030 g; 25.0 × 17.5 × 12.0 cm) times higher than the normal size and weight of spleen has been observed in twenty patients following splenectomy. In a second study, the mean size for the liver (19.4 cm, range 13.5-26.0 cm) and spleen (15.6 cm, range 7.0-21.0 cm) measured by magnetic resonance imaging (MRI) and by ultrasound imaging for spleen (15.1 cm, range 9.0-21.0 cm) of 16 patients indicated that on average the spleen is about 80% of the size of the liver. In the third study, comparison of the iron load using MRI T(2)* and iron grading of stained biopsies indicated that substantial but variable amounts of excess iron are stored in the spleen (0-40%) in addition to that in the liver. Following splenectomy, total body iron storage capacity is reduced, whereas serum ferritin (p = 0.0085) and iron concentration in other organs appears to increase despite the reduction in the rate of transfusions (p = 0.0001) and maintenance of hemoglobin levels (p = 0.1748). Spleen iron seems to be cleared faster than liver iron using effective chelation protocols. Spleen iron is a major constituent of the total body iron load in β-ΤΜ patients and should be regularly monitored and targeted for chelation. Normalization of the body iron stores at an early age could maintain the spleen in near normal capacity and secondary effects such as cardiac and other complications could be avoided.

Assessment and management of iron overload in β-thalassaemia major patients during the 21st century: a real-life experience from the Italian WEBTHAL project

We conducted a cross-sectional study on 924 β-thalassaemia major patients (mean age 30·1 years) treated at nine Italian centres using the WEBTHAL software, to evaluate real-life application of iron overload assessment and management standards. Serum ferritin <2500 ng/ml was a risk factor for never having liver iron concentration (LIC) measurement, while absence of cardiac disease and siderosis were risk factors for a delay in LIC measurement >2 years. Patients who never had a cardiac MRI (CMR) T2* measurement were <18 years, had iron intake ≤0·4 mg/kg per day, or a serum ferritin <2500 ng/ml. A history of normal CMR T2* was the main risk factor for a delay in subsequent assessment of >2 years. Deferoxamine (22·8%) was more commonly used in patients with Hepatitis C Virus or high serum creatinine. Deferiprone (20·6%) was less commonly prescribed in patients with elevated alanine aminotransferase; while a deferoxamine + deferiprone combination (17·9%) was more commonly used in patients with serum ferritin >2500 ng/ml or CMR T2* <20 ms. Deferasirox (38·3%) was more commonly prescribed in patients <18 years, but less commonly used in those with heart disease or high iron intake. These observations largely echoed guidelines at the time, although some practices are expected to change in light of evolving evidence.

Hemodialysis-associated hemosiderosis in the era of erythropoiesis-stimulating agents: a MRI study

BACKGROUND

Most dialysis patients receiving erythropoesis-stimulating agents (ESA) also receive parenteral iron supplementation. There are few data on the risk of hemosiderosis in this setting.

METHODS

We prospectively measured liver iron concentration by means of T1 and T2* contrast magnetic resonance imaging (MRI) without gadolinium, in a cohort of 119 fit hemodialysis patients receiving both parenteral iron and ESA, in keeping with current guidelines.

RESULTS

Mild to severe hepatic iron overload was observed in 100 patients (84%; confidence interval, [CI] 76%-90%), of whom 36% (CI, 27%-46%) had severe hepatic iron overload (liver iron concentration >201 μmol/g of dry weight). In the cross-sectional study, infused iron, hepcidin, and C-reactive protein values correlated with hepatic iron stores in both univariate analysis (P<.05, Spearman test) and binary logistic regression (P <.05). In 11 patients who were monitored closely during parenteral iron therapy, the iron dose infused per month correlated strongly with both the overall increase and the monthly increase in liver iron concentration (respectively, rho=0.66, P=.0306 and rho=0.85, P=0.0015, Spearman test). In the 33 patients with iron overload, iron stores fell significantly after iron withdrawal or after a major reduction in the iron dose (first MRI: 220 μmol/g (range: 60-340); last MRI: 50 μmol/g (range: 5-210); P <.0001, Wilcoxon's paired test).

CONCLUSIONS

Most hemodialysis patients receiving ESA and intravenous iron supplementation have hepatic iron overload on MRI. These findings call for a revision of guidelines on iron therapy in this setting, especially regarding the amount of iron infused and noninvasive methods for monitoring iron stores.

Iron metabolism and the polycystic ovary syndrome

The polycystic ovary syndrome (PCOS) is associated with insulin resistance and abnormal glucose tolerance. Iron overload may lead also to insulin resistance and diabetes. Serum ferritin levels are increased in PCOS, especially when glucose tolerance is abnormal, suggesting mild iron overload. Factors contributing to potential iron overload in PCOS include the iron sparing effect of chronic menstrual dysfunction, insulin resistance, and a decrease in hepcidin leading to increased iron absorption. Enhancement of erythropoiesis by androgen excess is unlikely, because soluble transferrin receptor levels are not increased in PCOS. Future venues of research should address the long-term effects of PCOS treatment on iron overload and, conversely, the possible effects of iron lowering strategies on the glucose tolerance of patients with PCOS.

MRI evaluation of hepatic iron overload: Recent advances

Many studies show that hepatic iron overload has a close association with hepatitis, hepatic fibrosis, cirrhosis, and hepatic tumors. Methods currently used for detection of hepatic iron overload, such as plasma ferritin detection, liver biopsy, and superconducting quantum interface device, have some limitations. Improvement in software and hardware has enabled MRI to become a safe, noninvasive and accurate method for detecting hepatic iron overload. This article aims to summarize the performance and application of MRI in the evaluation of hepatic iron overload.