Evaluation of iron overload

MR Imaging-based Biomarker Development in Hemorrhagic Stroke Patients Including Brain Iron Quantification, Diffusion Tensor Imaging, and Phenomenon of Ultra-early Erythrolysis

This review article discusses the role of MR imaging-based biomarkers in understanding and managing hemorrhagic strokes, focusing on intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage. ICH is a severe type of stroke with high mortality and morbidity rates, primarily caused by the rupture of small blood vessels in the brain, resulting in hematoma formation. MR imaging-based biomarkers, including brain iron quantification, ultra-early erythrolysis detection, and diffusion tensor imaging, offer valuable insights for hemorrhagic stroke management. These biomarkers could improve early diagnosis, risk stratification, treatment monitoring, and patient outcomes in the future, revolutionizing our approach to hemorrhagic strokes.

Iron Overload in Children With Leukemia; Identification of a Cutoff Value for Serum Ferritin Level

OBJECTIVE

To determine the prevalence of iron overload in children with acute lymphoblastic leukemia (ALL) after treatment cessation and establish a cutoff value for serum ferritin level as an indicator of iron overload.

BACKGROUND

Early detection and monitoring of iron overload in patients with leukemia is crucial.

METHODS

In this prospective cohort study, 66 pediatric patients with ALL who were treated at a tertiary referral center affiliated with Shiraz University of Medical Sciences in Shiraz, Southern Iran, were investigated from July 2020 to December 2022. Serum ferritin levels were measured 6 months after treatment completion. T2* magnetic resonance imaging of the liver and heart was done for all patients. The receiver operating characteristic curve was used to illustrate the area under the receiver operating characteristic curve to assess the diagnostic value of serum ferritin level and total transfusion volume.

RESULTS

A total of 24 patients (36.4%) had iron overload in the heart or liver based on T2 magnetic resonance imaging findings. Serum ferritin level was a highly accurate diagnostic marker for iron overload in pediatric patients with ALL, with a sensitivity of 95.8%, and specificity of 85.7% for a cutoff value of 238.5 ng/mL. Also, blood transfusion was a good predictor of iron overload a sensitivity of 75% and specificity of 81% for a cutoff value of 28.3 mL/kg.

CONCLUSION

We identified specific cutoff values for serum ferritin and blood transfusion volume to predict iron overload with high sensitivity and specificity. These markers offer a cost-effective and accessible approach for periodic screening of iron deposition, particularly in resource-constrained settings.

Susceptibility of acute myeloid leukemia cells to ferroptosis and evasion strategies

Acute myeloid leukemia (AML) is a highly aggressive hematologic malignancy with a 5-year survival rate of less than 30%. Continuous updating of diagnostic and therapeutic strategies has not been effective in improving the clinical benefit of AML. AML cells are prone to iron metabolism imbalance due to their unique pathological characteristics, and ferroptosis is a novel cell death mode that is dominated by three cellular biological processes: iron metabolism, oxidative stress and lipid metabolism. An in-depth exploration of the unique ferroptosis mechanism in AML can provide new insights for the diagnosis and treatment of this disease. This study summarizes recent studies on ferroptosis in AML cells and suggests that the metabolic characteristics, gene mutation patterns, and dependence on mitochondria of AML cells greatly increase their susceptibility to ferroptosis. In addition, this study suggests that AML cells can establish a variety of strategies to evade ferroptosis to maintain their survival during the process of occurrence and development, and summarizes the related drugs targeting ferroptosis pathway in AML treatment, which provides development directions for the subsequent mechanism research and clinical treatment of AML.

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.

Iron-dependent ferroptosis participated in benzene-induced anemia of inflammation through IRP1-DHODH-ALOX12 axis

Benzene, a widely existing environmental pollutant, gives huge harm to the hematopoietic system. Iron is one of the raw materials for the creation of blood cells, but the role of iron in the blood toxicity of benzene is still unknown. Here, we examined the role of iron homeostasis in benzene-induced toxicity both in vivo and in vitro. In this study, mice exposed to benzene at 50 ppm for 8 weeks demonstrated the anemia of inflammation, mainly manifested as the decreased serum Fe²⁺, increased serum ferritin and inflammation factors (TNF-α, IL6, IL1β) in the plasma of mice. Furthermore, we found that iron maldistribution in the spleen and bone marrow is accompanied by inflammation reaction and ferroptosis. In the vitro study, benzene metabolite 1,4-BQ stimulated the obvious ROS production and ferroptosis activation in the normal B lymphocytes cells. Meanwhile, from the molecular perspective, the combined proteomics and transcriptome enriched the ferroptosis pathway, and we further confirmed the increased expression of iron regulator IRP1, ferroptosis-regulator DHODH, and fatty acids metabolism enzyme ALOX12 were the crucial participators in regulating benzene-mediated iron metabolism imbalance and ferroptosis. Particularly, the targeted and un-targeted metabolomics in the vivo and vitro study further emphasized the importance of DHODH in benzene-induced ferroptosis. In conclusion, this study revealed that iron-dependent ferroptosis participated in benzene-induced anemia of inflammation and provided a constructive perspective on targeting ferroptosis for the prevention and control of benzene toxicity.

Association of the Liver and Spleen Signal Intensity on MRI with Anemia in Gynecological Cancer

OBJECTIVE

This study is to investigate the association of the liver and spleen signal intensity on MRI with anemia in patients with gynecologic cancer.

METHODS

332 patients with gynecological cancer and 78 healthy women underwent MRI examination. Liver and spleen MRI parameters and laboratory tests were obtained within 1 week. The signal intensity ratios of liver and spleen to the paraspinous muscle were calculated on gradient echo T1-weighted images (T1WI) and T2-weighted images (T2WI) in both patients and healthy women, respectively.

RESULTS

The ratios of liver and spleen to paraspinous muscle on T1WI and T2WI were lower in patients than in the healthy women, respectively (all P<0.0001). The ratios of the liver and spleen to paraspinous muscle on T1WI and T2WI decreased with the increasing stage of anemia and decreasing of the hemoglobin levels (all P<0.001). The ratios of the liver to paraspinous muscle on T1WI, spleen to paraspinous muscle on T1WI, and the liver and spleen to paraspinous muscle on T2WI could predict anemia stage≥1 (AUC=0.576, 0.643, 0.688, and 0.756, respectively), ≥2 (AUC=0.743, 0.714, 0.891, and 0.922, respectively) and 3 (AUC=0.851, 0.822, 0.854, and 0.949, respectively).

CONCLUSION

T2WI-based spleen signal intensity ratios showed the highest potential for noninvasive evaluation of anemia in gynecological cancer.

Pathogenesis, Diagnosis, and Clinical Implications of Hereditary Hemochromatosis-The Cardiological Point of View

Hereditary hemochromatosis (HH) is a genetic disease leading to excessive iron absorption, its accumulation, and oxidative stress induction causing different organ damage, including the heart. The process of cardiac involvement is slow and lasts for years. Cardiac pathology manifests as an impaired diastolic function and cardiac hypertrophy at first and as dilatative cardiomyopathy and heart failure with time. From the moment of heart failure appearance, the prognosis is poor. Therefore, it is crucial to prevent those lesions by upfront therapy at the preclinical phase of the disease. The most useful diagnostic tool for detecting cardiac involvement is echocardiography. However, during an early phase of the disease, when patients do not present severe abnormalities in serum iron parameters and severe symptoms of other organ involvement, heart damage may be overlooked due to the lack of evident signs of cardiac dysfunction. Considerable advancement in echocardiography, with particular attention to speckle tracking echocardiography, allows detecting discrete myocardial abnormalities and planning strategy for further clinical management before the occurrence of substantial heart damage. The review aims to present the current state of knowledge concerning cardiac involvement in HH. In addition, it could help cardiologists and other physicians in their everyday practice with HH patients.

Iron Overload Resulting from the Chronic Oral Administration of Ferric Citrate Impairs Intestinal Immune and Barrier in Mice

Ferric citrate (FC) is an iron-containing phosphate binder used as a food additive for iron supplementation. To explore the potential effect of ferric citrate on intestinal epithelial function, in the present study, we administered the mice orally for 16 weeks with different doses of iron citrate (2.5 mg/day (1.25%), 5 mg/day (2.5%), and 10 mg/day (5.0%)). We found that the iron levels of serum and tissue significantly increased, which caused the body to be in an iron overload state; meanwhile, the villus height, the ratio of villus height to crypt depth, and the number of intraepithelial lymphocytes and goblet cells in jejunum all decreased. Iron overload upregulated the pro-inflammatory cytokines (IL-1β, IL-2, IL-6, TNF-ɑ), while downregulated the anti-inflammatory cytokines (IL-4, IL-10) and sIgA. Moreover, iron overload increased serum D-lactate (D-LA) levels and decreased tight junction proteins (claudin-1, occludin, and ZO-1), MUC-2, and TFF3. In addition, iron overload upregulated the content of MDA and protein carbonyl, while downregulated the activity and content of T-AOC, GSH-PX, SOD, CAT, and GSH. To sum up, the present results showed that long-term oral administration of FC resulted in iron overload, which consequently impaired intestinal immune and barrier function in mice. Meanwhile, the effect on intestinal damage may be highly related to the increase of oxidative stress in the jejunum.

The Clinical Significance of Iron Overload and Iron Metabolism in Myelodysplastic Syndrome and Acute Myeloid Leukemia

Myelodysplasticsyndrome (MDS) and acute myeloid leukemia (AML) are clonal hematopoietic stem cell diseases leading to an insufficient formation of functional blood cells. Disease-immanent factors as insufficient erythropoiesis and treatment-related factors as recurrent treatment with red blood cell transfusions frequently lead to systemic iron overload in MDS and AML patients. In addition, alterations of function and expression of proteins associated with iron metabolism are increasingly recognized to be pathogenetic factors and potential vulnerabilities of these diseases. Iron is known to be involved in multiple intracellular and extracellular processes. It is essential for cell metabolism as well as for cell proliferation and closely linked to the formation of reactive oxygen species. Therefore, iron can influence the course of clonal myeloid disorders, the leukemic environment and the occurrence as well as the defense of infections. Imbalances of iron homeostasis may induce cell death of normal but also of malignant cells. New potential treatment strategies utilizing the importance of the iron homeostasis include iron chelation, modulation of proteins involved in iron metabolism, induction of leukemic cell death via ferroptosis and exploitation of iron proteins for the delivery of antileukemic drugs. Here, we provide an overview of some of the latest findings about the function, the prognostic impact and potential treatment strategies of iron in patients with MDS and AML.

A role of PIEZO1 in iron metabolism in mice and humans

Iron overload causes progressive organ damage and is associated with arthritis, liver damage, and heart failure. Elevated iron levels are present in 1%-5% of individuals; however, iron overload is undermonitored and underdiagnosed. Genetic factors affecting iron homeostasis are emerging. Individuals with hereditary xerocytosis, a rare disorder with gain-of-function (GOF) mutations in mechanosensitive PIEZO1 ion channel, develop age-onset iron overload. We show that constitutive or macrophage expression of a GOF Piezo1 allele in mice disrupts levels of the iron regulator hepcidin and causes iron overload. We further show that PIEZO1 is a key regulator of macrophage phagocytic activity and subsequent erythrocyte turnover. Strikingly, we find that E756del, a mild GOF PIEZO1 allele present in one-third of individuals of African descent, is strongly associated with increased plasma iron. Our study links macrophage mechanotransduction to iron metabolism and identifies a genetic risk factor for increased iron levels in African Americans.

Role of CYP1A1, ABCG2, CYP24A1 and VDR gene polymorphisms on the evaluation of cardiac iron overload in thalassaemia patients

OBJECTIVES

Iron-burden-induced arrhythmia and heart failure are among the leading causes of morbidity and mortality in β-thalassaemia major patients. T2* cardiac magnetic resonance remains the only reliable noninvasive method for the heart iron excess assessment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity and in deferasirox (DFX) metabolism on cardiac iron burden.

PATIENTS AND METHODS

One hundred and five β-thalassaemia patients, treated with DFX, were enrolled in the present study. Drug plasma Ctrough was measured by a high-performance liquid chromatography-ultraviolet method. Allelic discrimination was carried out using the real-time PCR.

RESULTS

CYP1A1*1189 CC, ABCG2 421 GA, CYP24A1 8620 GG and VDR TaqI CC single nucleotide polymorphisms influenced T2* values. Age, serum ferritin, ABCG2 421 GA, ABCG2 1194 +928 TC/CC, CYP24A1 22776 TT and VDR TaqI TC/CC were retained in linear regression model.

CONCLUSION

Our results suggested, for the first time, the role of DFX and vitamin D pharmacogenetics on cardiac iron overload.

The effect of vitamin D pathway genes and deferasirox pharmacogenetics on liver iron in thalassaemia major patients

Monitoring and treating iron overload is crucial in transfusion-dependent thalassaemia patients. Liver stiffness measurement by transient elastography and T2* magnetic resonance imaging represent non-invasive ways to evaluate the adequacy of the iron chelation treatment. We explored the role of single nucleotide polymorphisms involved in vitamin D metabolism, transport and activity, and in deferasirox metabolism on liver iron burden parameters. One-hundred and five beta-thalassaemia patients, treated with deferasirox, have been enrolled. Drug plasma C_trough and AUC were measured by a HPLC-UV method. Allelic discrimination was performed by real-time PCR. Age, UGT1A1-364 CT/TT and CYP27B1 -1260 GT/TT positively predicted liver stiffness values. Deferasirox dose and serum ferritin negatively predicted T2* data, whereas age and CYP2D6 1457 GG genotype positively influenced these values. The discoveries of this research may be useful for personalized medicine and the proposed method could be applied in patients with hereditary hemochromatosis and myelodysplastic syndromes.

Effect of pharmacogenetic markers of vitamin D pathway on deferasirox pharmacokinetics in children

OBJECTIVES

Patients with β-thalassemia major have extremely low vitamin D levels, owing to reduced intestinal absorption, subicteric tint, and/or iron-induced higher pigmentation. We investigated whether some polymorphisms within the VDR, CYP24A1, CYP27B1, and GC genes could play a role in deferasirox pharmacokinetics in a cohort of pediatric patients.

PATIENTS AND METHODS

Eighteen children with β-thalassemia were enrolled. Drug plasma concentrations at the end of dosing interval (Ctrough) and after 0, 2, 4, 6, and 24 h of drug administration were measured by a HPLC-UV method. Allelic discrimination for VDR (TaqI, FokI, BsmI, Cdx2, and ApaI), CYP24A1 (22776, 3999 and 8620), CYP27B1 (2838 and -1260), and GC (1296) single nucleotide polymorphisms was performed by real-time PCR.

RESULTS

CYP24A1 8620 AG/GG group negatively predicted Ctrough in regression analysis (P=0.012). ApaI AA genotype resulted as a negative predictor of Ctrough (P=0.025) and area under the concentration curve (P=0.007); FoKI CC genotype remained as area under the concentration curve positive predictor (P=0.008) and TC/CC group as half-life (t1/2) (P=0.003) and volume of distribution (Vd) (P=0.011) negative one; TaqI TC/CC was retained as a negative predictor of drug maximum concentration (Cmax) (P=0.004). Moreover, GC 1296 TG/GG seemed able to predict lower time to reach drug maximum concentration (Tmax) (P=0.033).

CONCLUSION

Our preliminary experience suggested the potential usefulness of vitamin D pharmacogenetic to better understand deferasirox interindividual variability, also in pediatric patients.

Quantitative susceptibility mapping (QSM) minimizes interference from cellular pathology in R2* estimation of liver iron concentration

BACKGROUND

A challenge for R2 and R2* methods in measuring liver iron concentration (LIC) is that fibrosis, fat, and other hepatic cellular pathology contribute to R2 and R2* and interfere with LIC estimation.

PURPOSE

To examine the interfering effects of fibrosis, fat, and other lesions on R2* LIC estimation and to use quantitative susceptibility mapping (QSM) to reduce these distortions.

STUDY TYPE

Prospective.

PHANTOMS, SUBJECTS

Water phantoms with various concentrations of gadolinium (Gd), collagen (Cl, modeling fibrosis), and fat; nine healthy controls with no known hepatic disease, nine patients with known or suspected hepatic iron overload, and nine patients with focal liver lesions.

FIELD STRENGTH/SEQUENCE

The phantoms and human subjects were imaged using a 3D multiecho gradient-echo on clinical 1.5T and 3T MRI systems.

ASSESSMENT

QSM and R2* images were postprocessed from the same gradient-echo data. Fat contributions to susceptibility and R2* were corrected in signal models for LIC estimation.

STATISTICAL TESTS

Polynomial regression analyses were performed to examine relations among susceptibility, R2* and true [Gd] and [Cl] in phantoms, and among susceptibility and R2* in patient livers.

RESULTS

In phantoms, R2* had a strong nonlinear dependency on [Cl], [fat], and [Gd], while susceptibility was linearly dependent (R²  > 0.98). In patients, R2* was highly sensitive to liver pathological changes, including fat, fibrosis, and tumors, while QSM was relatively insensitive to these abnormalities (P = 0.015). With moderate iron overload, liver susceptibility and R2* were not linearly correlated over a common R2* range [0, 100] sec^-1 (P = 0.35).

DATA CONCLUSION

R2* estimation of LIC is prone to substantial nonlinear interference from fat, fibrosis, and other lesions. QSM processing of the same gradient echo MRI data can effectively minimize the effects of cellular pathology.

LEVEL OF EVIDENCE

1 Technical Efficacy: Stage 1 J. Magn. Reson. Imaging 2018;48:1069-1079.

Role of CYP24A1, VDR and GC gene polymorphisms on deferasirox pharmacokinetics and clinical outcomes

β-Thalassemia patients develop deficiency in vitamin D absorption and liver hydroxylation, resulting in extremely low calcitriol levels. We explored the role of single-nucleotide polymorphisms (SNPs) involved in vitamin D metabolism, transport and activity on deferasirox pharmacokinetics and outcomes (effectiveness trough levels (C_trough) and the area under the curve (AUC) cutoffs of 20 μg ml^-1 and 360 μg ml^-1 h^-1, respectively; nonresponse AUC limit of 250 μg ml^-1 h^-1). Ninety-nine β-thalassemic patients were enrolled. Drug plasma C_trough and AUC were measured by the high-performance liquid chromatography system coupled with an ultraviolet determination method. Allelic discrimination for VDR, CYP24A1, CYP27B1 and GC gene SNPs was performed by real-time PCR. CYP24A1 22776 TT significantly influenced C_min and negatively predicted it in regression analysis. CYP24A1 3999 CC was associated with C_trough and C_min and was a negative predictor of T_max, whereas CYP24A1 8620 GG seemed to have a role in C_trough, AUC, t_1/2 and C_min, and was an AUC negative predictor factor. Considering treatment outcome, Cdx2 and GC 1296 were retained in regression analysis as AUC efficacy cutoff negative predictors.

Deferasirox pharmacogenetic influence on pharmacokinetic, efficacy and toxicity in a cohort of pediatric patients

AIM

We aimed to evaluate the influence of genetic polymorphisms involved in deferasirox metabolism and transport on its pharmacokinetics and treatment toxicity, in a cohort of β-thalassaemic children.

PATIENTS & METHODS

Drug plasma concentrations were measured by a HPLC-UV method. Allelic discrimination for UGT1A1, UGT1A3, CYP1A1, CYP1A2, CYP2D6, MRP2 and BCRP1 polymorphisms was performed by real-time PCR.

RESULTS

CYP1A1 rs2606345AA influenced C_trough (p = 0.001) and t_1/2 (p = 0.042), CYP1A1 rs4646903TC/CC (p = 0.005) and BCRP1 rs2231142GA/AA (p = 0.005) influenced T_max and CYP2D6 rs1135840CG/GG influenced C_max (p = 0.044). UGT1A1 rs887829TT (p = 0.002) and CYP1A2 rs762551CC (p = 0.019) resulted as predictive factor of ferritin levels and CYP1A1 rs2606345CA/AA (p = 0.021) and CYP1A2 rs762551AC/CC (p = 0.027) of liver iron concentration.

CONCLUSION

Our data suggest the usefulness of deferasirox pharmacogenetics in pediatric treatment optimization.

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.

CONIFER - Non-Interventional Study to Evaluate Therapy Monitoring During Deferasirox Treatment of Iron Toxicity in Myelodysplastic Syndrome Patients with Transfusional Iron Overload

BACKGROUND

The non-interventional study CONIFER was designed to assess the safety and clinical practicability of deferasirox for the treatment of transfusional iron overload in myelodysplastic syndrome (MDS) patients.

METHODS

Patients included in the study were diagnosed with MDS and received at least 1 treatment with deferasirox. The observation period covered the time from the initial visit until the last follow-up.

RESULTS

The data of 99 patients with MDS scored mainly as International Prognostic Scoring System (IPSS) low and intermediate 1 were evaluated. The mean age of the participants was 75 years and 58% of the patients were male. Iron overload was assessed by serum ferritin level (mean baseline serum ferritin 2,080 ± 1,244 µg/l). Patients were treated for a mean duration of 16 months (mean daily dose at baseline 11.8 ± 7.0 mg/kg). Stratification of serum ferritin levels by deferasirox dose showed a reduction at the higher but no reduction at the lower dose (< 15 mg/kg vs. ≥ 15 mg/kg and < 20 mg/kg vs. ≥ 20 mg/kg). The majority of patients (81%) were affected by at least 1 adverse event, with decreased renal creatinine clearance being the most frequent.

CONCLUSION

Higher doses (≥ 15 mg/kg) of deferasirox effectively and safely reduced serum ferritin levels in MDS patients with transfusional iron overload.

Increased Hepatic Iron Content Predicts Poor Survival in Patients With Iron Overload Who Underwent Allogeneic Hematopoietic Stem Cell Transplantation

AIM

Iron overload results in increased infection, venous-oclusive disease and hepatic dysfunction in allogeneic hematopoietic stem cell transplant (alloHSCT) recipients. Liver is one of the most common sites of iron overload.

PATIENTS AND METHODS

A total of 50 alloHSCT recipients that underwent liver biopsy in Erciyes Stem Cell Transplantation Hospital, Erciyes University, between 2004 and 2011 were enrolled in the study. The liver biopsy specimens have been obtained from the archives of Erciyes University, Department of Pathology and stainned for iron content.

RESULTS

The mean age was found 34 ± 11 years. For median overall survival (OS); 53 months (min-max: 41-65) in patients with grade 0, 55 months (min-max: 47-64) in patients with grade 1, in patients with grade 2 patients 25.4 months (11.5-39.4 ), grade 3 patients 29.3 months (min-max: 12.3-46.3) and grade 4 patients 2.6 months (min-max: 2.0-3.3). Overall survival was correlated with the degree of liver iron content and it was statistically significant in Kaplan-Meier analysis (P < .001). Disease-free survival was found (DFS); grade 0 patients 47.1 months (min-max: 32.0-62.0), grade 1 patients 36.9 months (min-max: 21.0-65.0), grade 2 patients 23.5 months (min-max: 12.0-59.0), grade 3 patients 27.4 months (min-max: 5.3-59.3) and grade 4 patients 2.6 months (min-max: 2.0-3.0). For DFS; it was negatively correlated with the degree of liver iron content nevertheless; it was not was statistically significant in Kaplan-Meier analysis (P = .093).Hepatic iron overload might be associated with poor survival in patients with transfusional iron overload that underwent alloHSCT.

CONCLUSION

Hepatic iron content might be associated with poorer prognosis in patients with iron overload that underwent alloHSCT.

A Room Temperature Ultrasensitive Magnetoelectric Susceptometer for Quantitative Tissue Iron Detection

Iron is a trace mineral that plays a vital role in the human body. However, absorbing and accumulating excessive iron in body organs (iron overload) can damage or even destroy an organ. Even after many decades of research, progress on the development of noninvasive and low-cost tissue iron detection methods is very limited. Here we report a recent advance in a room-temperature ultrasensitive biomagnetic susceptometer for quantitative tissue iron detection. The biomagnetic susceptometer exploits recent advances in the magnetoelectric (ME) composite sensors that exhibit an ultrahigh AC magnetic sensitivity under the presence of a strong DC magnetic field. The first order gradiometer based on piezoelectric and magnetostrictive laminate (ME composite) structure shows an equivalent magnetic noise of 0.99 nT/rt Hz at 1 Hz in the presence of a DC magnetic field of 0.1 Tesla and a great common mode noise rejection ability. A prototype magnetoelectric liver susceptometry has been demonstrated with liver phantoms. The results indicate its output signals to be linearly responsive to iron concentrations from normal iron dose (0.05 mg Fe/g liver phantom) to 5 mg Fe/g liver phantom iron overload (100X overdose). The results here open up many innovative possibilities for compact-size, portable, cost-affordable, and room-temperature operated medical systems for quantitative determinations of tissue iron.

Comparison between different software programs and post-processing techniques for the MRI quantification of liver iron concentration in thalassemia patients

PURPOSE

In magnetic resonance imaging (MRI) relaxometry, various software programs are available to perform R2* measurements and to estimate the liver iron concentration (LIC). The main objective of our study was to compare R2* LIC values, obtained with three different software programs based on specific decay models and calibration curves, with LIC estimates provided by R2-relaxometry (FerriScan).

METHODS

This retrospective study included 15 patients with 15 baseline MRIs and 34 serial examinations. R2* LIC estimates were calculated using the FuncTool, CMRtools/Thalassemia Tools and Quanta Hematology programs. Longitudinal LIC changes (ΔLIC) were calculated using the subset of 34 serial MRIs.

RESULTS

After Bland-Altman analysis on baseline data, Quanta Hematology, which employs the monoexponential-plus-constant fit, produced the lowest mean difference [0.01 ± 0.14 log(mg/gdw)] with the closest limits of agreement. In the longitudinal setting, Quanta Hematology again gave the lowest mean difference between R2 and R2* LIC (0.1 ± 2.6 mg/gdw). Using FerriScan as reference, the value of concordant directional ΔLIC changes was the same for all programs (27/34, 85.7 %).

CONCLUSIONS

R2* LICs are higher than R2 LICs at iron levels <7 mg/gdw, while R2 LIC averages higher than R2* LIC with increasing iron load. The monoexponential-plus-constant model provided the best agreement with R2 LIC estimates.

Electrocardiographic Presentation, Cardiac Arrhythmias, and Their Management in β-Thalassemia Major Patients

Beta-thalassemia major (β-TM) is a genetic hemoglobin disorder characterized by an absent synthesis of globin chains that are essential for hemoglobin formation, causing chronic hemolytic anemia. Clinical management of thalassemia major consists in regular long-life red blood cell transfusions and iron chelation therapy to remove iron introduced in excess with transfusions. Iron deposition in combination with inflammatory and immunogenic factors is involved in the pathophysiology of cardiac dysfunction in these patients. Heart failure and arrhythmias, caused by myocardial siderosis, are the most important life-limiting complications of iron overload in beta-thalassemia patients. Cardiac complications are responsible for 71% of global death in the beta-thalassemia major patients. The aim of this review was to describe the most frequent electrocardiographic abnormalities and arrhythmias observed in β-TM patients, analyzing their prognostic impact and current treatment strategies.

Iron chelation monotherapy in transfusion-dependent beta-thalassemia major patients: a comparative study of deferasirox and deferoxamine

Introduction

Iron overload is the primary cause of mortality and morbidity in thalassemia major (TM) despite advances in chelation therapy. The aim of this study was to compare the effectiveness and safety of deferasirox (DFX) and deferoxamine (DFO) as iron-chelating agents in patients with transfusion-dependent β-thalassemia major.

Methods

This prospective randomized study included 60 patients with transfusion-dependent β-TM during the period from September 2014 to September 2015. Their ages were ≥ 6 years, and they had serum ferritin above 1500 μg/L and were on irregular DFO therapy. Patients had regular packed red cell transfusion in a dose of 10 mL/kg/session. They were randomized to receive DFX (single oral daily dose of 20–40 mg/kg/day) or DFO (20–50 mg/kg/day via subcutaneous infusion over 8–10 hours, 5 days a week). Iron overload was determined by serum ferritin level. The primary endpoint was decrease of serum ferritin level below 1500 μg/L. The secondary endpoint was drug safety.

Results

Both drugs significantly reduced serum ferritin (p < 0.001). At the end of follow-up, there were no significant differences between the two groups in serum ferritin levels (p = 0.673) and in percent reduction of ferritin (p = 0.315). There were no significant differences between the two groups in the total amount of blood transfusion (p = 0.166) and average iron intake (p = 0.227). There were no mortalities or any serious adverse effects, neutropenia, arthropathy, or pulmonary toxicity. Gastrointestinal upset and skin rash occurred more frequently with DFX than with DFO (p = 0.254 and 0.095, respectively).

Conclusion

With appropriate dosing and compliance with drugs, both DFX and DFO are generally well tolerated, safe, and effective in reducing serum ferritin levels in iron-overloaded, regularly-transfused thalassemia major patients. Therefore, oral DFX is recommended for more convenience and adherence to the treatment regimen.

Role of pharmacogenetics on deferasirox AUC and efficacy

AIM

We evaluated deferasirox pharmacokinetic according to SNPs in genes involved in its metabolism and elimination. Moreover, we defined a plasma area under the curve cut-off value predicting therapy response.

PATIENTS & METHODS

Allelic discrimination was performed by real-time PCR. Drug plasma concentrations were measured by a high performance liquid chromatography system coupled with an ultraviolet method.

RESULTS

Pharmacokinetic parameters were significantly influenced by UGT1A1 rs887829C>T, UGT1A3 rs1983023C>T and rs3806596A>G SNPs. Area under the curve cut-off values of 360 μg/ml/h for efficacy were here defined and 250 μg/ml/h for nonresponse was reported. UGT1A3 rs3806596GG and ABCG2 rs13120400CC genotypes were factors able to predict efficacy, whereas UGT1A3 rs3806596GG was a nonresponse predictor.

CONCLUSION

These data show how screening patient's genetic profile may help clinicians to optimize iron chelation therapy with deferasirox.

Hepatic veno-occlusive disease may develop in secondary iron overloaded mice after allogeneic hematopoietic stem cell transplantation with total body irradiation

BACKGROUND

The outcome of hematopoietic stem cell transplantation (HSCT) is poor in patients with secondary iron overload (SIO). We evaluated the relationship between SIO and veno-occlusive disease (VOD) in an animal model with radiation for HSCT.

METHODS

We used a 6-week-old female BDF1 (H-2(b/d)) and a male C57/BL6 (H-2(b)) as recipient and donor, respectively. Recipient mice were injected intraperitoneally with 10 mg of iron dextran (cumulative doses of 50 mg, 100 mg, and 200 mg). All mice received total body irradiation for HSCT. We obtained peripheral blood for alanine transaminase (ALT) and liver for pathologic findings, lipid hyperoxide (LH) as reactive oxygen species (ROS), and liver iron content (LIC) on post-HSCT day 1 and day 7. The VOD score was assessed by pathologic findings.

RESULTS

ALT levels increased depending on cumulative iron dose, with significant differences between days 1 and 7 for mice loaded with 200 mg of iron (P<0.01). LH levels significantly increased in mice loaded with 200 mg of iron compared to those in other groups (P<0.01). For mice loaded with 100 mg of iron, the LH level depended on the radiation dose (P<0.01). There was a statistically significant relationship among ALT, LH, and LIC parameters (P<0.05). Pathologic scores for VOD correlated with LIC (P<0.01).

CONCLUSION

Livers with SIO showed high ROS levels depending on cumulative iron dose, and correlations with elevated liver enzyme and LIC. The pathologic score for VOD was associated with the LIC. Our results suggest that SIO may induce VOD after HSCT with irradiation.

Efficacy of hepatic T2* MRI values and serum ferritin concentration in predicting thalassemia major classification for hematopoietic stem cell transplantation

Liver biopsy has been performed for many decades for classifying the patients with TM. Meanwhile, using non-invasive methods such as T2* MRI technique has been recently much more considered to determine the hepatic iron overload. Ninety-three pediatric HSCT candidates with TM who underwent liver biopsy were included in this study. Hepatic T2* MRI values and serum ferritin concentrations were assessed to investigate and determine the useful method in detection of patients with TM class III whom received different conditioning regimens, in comparison with class I and II. Twenty (21.5%) patients were categorized as class III. Hepatic T2* MRI could detect TM class III patients with 60% sensitivity and 87.67% specificity (LR+: 4.867, accuracy: 81.72%), while predictive feature of ferritin values for distinguishing patients with TM class III was not statistically significant (p-value >0.01). Combination of T2*MRI with age (T2*-age) could detect TM class III with 85% sensitivity and 72.6% specificity (LR+: 3.1, accuracy: 75.27%).T2*-age may be considered as an alternative and non-invasive method to liver biopsy for differentiation and classification of patients with TM before transplantation.

Prevalence and distribution of iron overload in patients with transfusion-dependent anemias differs across geographic regions: results from the CORDELIA study

OBJECTIVES

The randomized comparison of deferasirox to deferoxamine for myocardial iron removal in patients with transfusion-dependent anemias (CORDELIA) gave the opportunity to assess relative prevalence and body distribution of iron overload in screened patients.

METHODS

Patients aged ≥ 10 yr with transfusion-dependent anemias from 11 countries were screened. Data were summarized descriptively, overall and across regions.

RESULTS

Among 925 patients (99.1% with β-thalassemia major; 98.5% receiving prior chelation; mean age 19.2 yr), 36.7% had myocardial iron overload (myocardial T2* ≤ 20 ms), 12.1% had low left ventricular ejection fraction. Liver iron concentration (LIC) (mean 25.8 mg Fe/g dw) and serum ferritin (median 3702 ng/mL) were high. Fewer patients in the Middle East (ME; 28.5%) had myocardial T2* ≤ 20 ms vs. patients in the West (45.9%) and Far East (FE, 40.9%). Patients in the West had highest myocardial iron burden, but lowest LIC (26.9% with LIC < 7 mg Fe/g dw) and serum ferritin. Among patients with normal myocardial iron, a higher proportion of patients from the ME and FE had LIC ≥ 15 than < 7 mg Fe/g dw (ME, 56.7% vs. 17.2%; FE, 78.6% vs. 7.8%, respectively), a trend which was less evident in the West (44.6% vs. 33.9%, respectively). Transfusion and chelation practices differed between regions.

CONCLUSIONS

Evidence of substantial myocardial and liver iron burden across regions revealed a need for optimization of effective, convenient iron chelation regimens. Significant regional variation exists in myocardial and liver iron loading that are not well explained; improved understanding of factors contributing to differences in body iron distribution may be of clinical benefit.

Influence of single-nucleotide polymorphisms on deferasirox C trough levels and effectiveness

Deferasirox (DFX) is the only once-daily oral chelator for iron overload and its pharmacokinetic has been related with response to therapy. Our aim was to evaluate DFX plasma concentrations according to single-nucleotide polymorphisms in genes involved in its metabolism (UGT1A1, UGT1A3, CYP1A1, CYP1A2 and CYP2D6) and elimination (MRP2 and BCRP1). Further aim was to define a plasma concentration cutoff value predicting an adequate response to therapy. Plasma concentrations were determined at the end of dosing interval (C trough) using an high-performance liquid chromatography-ultraviolet method. Allelic discrimination was performed by real-time PCR. C trough levels were influenced by UGT1A1C>T rs887829, CYP1A1C>A rs2606345, CYP1A2A>C rs762551, CYP1A2C>T rs2470890 and MRP2G>A rs2273697 polymorphisms. A DFX plasma efficacy cutoff value of 20,000 ng ml(-1) was identified; CYP1A1C>A rs2606345 AA and CYP1A2C>T rs2470890 TT genotypes may predict this value, suggesting a negative predictive role in therapy efficacy. Our data suggest the feasibility of a pharmacogenetic-based DFX dose personalization.

Comparison of tissue Doppler imaging with MRI t2* and 24-hour rhythm holter heart rate variability for diagnosing early cardiac impairment in thalassemia major patients

OBJECTIVES

Cardiology follow up is important in thalassemia major patients. The object of this study is to define parameters which can be used in the early detection of cardiac impairment.

MATERIAL AND METHODS

Forty seven beta thalassemia major patients (mean age 16.3 ± 4.47 years; 22 boys, 25 girls) whose left ventricular systolic functions were normal and a healthy control group of fifty age and gender matched children were included in the study. M-mode echocardiographic measurements, systolic and diastolic functions with PW and tissue Doppler and heart rate variabilities (HRVs) were compared between the two groups. The patients were also grouped according to MRT2*, ferritin and left ventricular diastolic diameters (LVDds) to compare the echocardiographic and Holter parameters among them.

RESULTS

None of the children in the study group had symptomatic congestive heart failure. PW Doppler late diastolic forward flow in pulmonary artery was higher in the thalassemia group when compared with the control group (P = 0.01) indicating decreased compliance of the right ventricle. While the systolic and diastolic functions were normal, all the HRV parameters in the thalassemia group were significantly lower than the control group (P = 0.005).

CONCLUSIONS

Significant decrease in HRV and increase in PW late diastolic forward flow in pulmonary artery in the absence of systolic or diastolic dysfunction, points out that these parameters can be useful in detection of early cardiac impairment.

MR characterization of hepatic storage iron in transfusional iron overload

PURPOSE

To quantify the two principal forms of hepatic storage iron, diffuse, soluble iron (primarily ferritin), and aggregated, insoluble iron (primarily hemosiderin) using a new MRI method in patients with transfusional iron overload.

MATERIALS AND METHODS

Six healthy volunteers and 20 patients with transfusion-dependent thalassemia syndromes and iron overload were examined. Ferritin- and hemosiderin-like iron were determined based on the measurement of two distinct relaxation parameters: the "reduced" transverse relaxation rate, RR2 , and the "aggregation index," A, using three sets of Carr-Purcell-Meiboom-Gill (CPMG) datasets with different interecho spacings. Agarose phantoms, simulating the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron, were used for validation.

RESULTS

Both phantom and in vivo human data confirmed that transverse relaxation components associated with the dispersed and aggregated iron could be separated using the two-parameter (RR2 , A) method. The MRI-determined total hepatic storage iron was highly correlated (r = 0.95) with measurements derived from biopsy or biosusceptometry. As total hepatic storage iron increased, the proportion stored as aggregated iron became greater.

CONCLUSION

This method provides a new means for noninvasive MRI determination of the partition of hepatic storage iron between ferritin and hemosiderin in iron overload disorders.

Iranian hereditary hemochromatosis patients: baseline characteristics, laboratory data and gene mutations

BACKGROUND

Hereditary hemochromatosis (HH) is the most common autosomal recessive disorder in white people, characterized by highly abnormal uptake of iron from the gastrointestinal tracts. Recently, mutation studies have focused to detect the genes responsible for HH.

MATERIAL/METHODS

In this cross-sectional study, 12 HH patients were recruited, who were referred to Firoozgar Hospital, Tehran, Iran. In addition to the clinical assessments, a complete laboratory evaluation, imaging modalities, histopathologic assessment, atomic absorption spectrophotometry and gene mutation study were performed. The genetic study for HFE gene mutation was examined for all of the patients since 2006, while non-HFE mutation was conducted since December 2010 (only for 1 of them).

RESULTS

Twelve patients were evaluated consisting of 11 men and 1 woman, with the mean age of 39.58±12.68 yr. The average of atomic iron loads was 13.25±4.83-fold higher than normal standards. Four patients had heterozygotic mutation of H63D (33.3%). There was no significant difference in either the iron load of liver (P=0.927) and heart (P=0.164) or serum concentration of ferritin (P=0.907) and TIBC (P=0.937) between the HFE-mutant and without HFE mutation HH cases.

CONCLUSIONS

In contrast to other studies, C282Y mutation was not detected in any of our Iranian HH patients. Heterozygotic mutations of H63D (HFE) and TFR2 (non-HFE) genes were found to be more common in these patients. Similar to previous reports, these mutations were not found to be significantly associated with severity of presentation in HH patients.

Measurement and correction of stimulated echo contamination in T2-based iron quantification

The purpose of this study was to characterize the effects of stimulated echo contamination on MR-based iron measurement derived from quantitative T2 images and develop a method for retrospective correction. Two multiple spin-echo (MSE) pulse sequences were implemented with different amounts of stimulated echo contamination. Agarose-based phantoms were constructed that simulate the relaxation and susceptibility properties of tissue with different concentrations of dispersed (ferritin-like) and aggregated (hemosiderin-like) iron. Additionally, myocardial iron was assessed in nine human subjects with transfusion iron overload. These data were used to determine the influence of stimulated echoes on iron measurements made by an MR-based iron quantification model that can separately measure dispersed and aggregated iron. The study found that stimulated echo contamination caused an underestimation of dispersed (ferritin-like) iron and an overestimation of aggregated (hemosiderin-like) iron when applying this model. The relationship between the measurements made with and without stimulated echo appears to be linear. The findings suggest that while it is important to use MSE sequences with minimal stimulated echo in T2-based iron quantification, it appears that data acquired with sub-optimal sequences can be retrospectively corrected using the methodology described here.

Evidence for a novel mechanism independent of myocardial iron in β-thalassemia cardiac pathogenesis

Human β-thalassemia major is one of the most prevalent genetic diseases characterized by decrease/absence of β-globin chain production with reduction of erythrocyte number. The main cause of death of treated β-thalassemia major patients with chronic blood transfusion is early cardiac complications that have been attributed to secondary iron overload despite optimal chelation. Herein, we investigated pathophysiological mechanisms of cardiovascular dysfunction in a severe murine model of β-thalassemia from 6 to 15-months of age in the absence of confounding effects related to transfusion. Our longitudinal echocardiography analysis showed that β-thalassemic mice first display a significant increase of cardiac output in response to limited oxygen-carrying erythrocytes that progressed rapidly to left ventricular hypertrophy and structural remodeling. Following this compensated hypertrophy, β-thalassemic mice developed age-dependent deterioration of left ventricular contractility and dysfunction that led toward decompensated heart failure. Consistently, murine β-thalassemic hearts histopathology revealed cardiac remodeling with increased interstitial fibrosis but virtual absence of myocardial iron deposits. Importantly, development of thalassemic cardiac hypertrophy and dysfunction independently of iron overload has uncoupled these cardiopathogenic processes. Altogether our study on β-thalassemia major hemoglobinopathy points to two successive phases resulting from severe chronic anemia and from secondarily induced mechanisms as pathophysiologic contributors to thalassemic cardiopathy.

Imaging of miscellaneous pancreatic pathology (trauma, transplant, infections, and deposition)

In this article's coverage of miscellaneous pancreatic topics, a brief review of pancreatic trauma; pancreatic transplantation; rare infections, such as tuberculosis; deposition disorders, including fatty replacement and hemochromatosis; cystic fibrosis; and others are discussed with pertinent case examples.

MR prediction of liver fibrosis using a liver-specific contrast agent: Superparamagnetic iron oxide versus Gd-EOB-DTPA

PURPOSE

To examine whether the uptake of a liver-specific contrast agent in the liver parenchyma was correlated with the degree of liver fibrosis.

MATERIALS AND METHODS

This retrospective study included 54 and 63 patients who underwent superparamagnetic iron oxide (SPIO)- and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI before liver surgery, respectively. For each patient, we calculated ΔR2* and ΔR2, which represent differences in R2* and R2 values of the liver parenchyma before and after administration of SPIO; and the increase rate of liver-to-spleen signal intensity ratio (LSR) on the hepatobiliary phase compared with the precontrast image. The correlation of each MR parameter with the degree of liver fibrosis (F0 to F4) was assessed using Spearman's rank correlation test.

RESULTS

The increase rate of LSR was best correlated with the degree of liver fibrosis and significantly decreased as the liver fibrosis progressed (rho = -0.641; P < 0.0001). It showed sensitivity of 76.9% and specificity of 83.3% in differentiating F3 or greater fibrosis when 1.126 or less was set up as a cut-off value. No significant correlation was obtained between ΔR2* or ΔR2 and the degree of liver fibrosis.

CONCLUSION

The uptake of Gd-EOB-DTPA in the liver parenchyma decreased as the liver fibrosis progressed. J. Magn. Reson. Imaging 2012;36:664-671. © 2012 Wiley Periodicals, Inc.

Evaluation of hepatic iron overload in Chinese children with β-thalassemia major

Patients with β-thalassemia major require long-term blood transfusions, resulting in hepatic iron overload. Thirty-five Chinese children with β-thalassemia major were recruited in the present studies. Hepatic iron overload was evaluated by histological grading. The relationships between hepatic iron overload and both serum biochemical markers and magnetic resonance imaging (MRI) examination were studied. The majority of the patients showed high degrees of hepatic iron overload by histological study. The degree of hepatic iron overload was correlated with serum ferritin (r = .70, P < .01), hyaluronic acid (r = .58, P = .011), and type III precollagen (r = .55, P = .035). Moreover, hepatic iron overload showed a negative correlation with liver to muscle signal intensity ratio (r = -.44, P = .012), and a positive correlation with red marrow area percentage (r = .52, P < .01). These results indicated that hepatic iron overload might be assessed by serum biochemical markers and MRI examination.

Reduced transverse relaxation rate (RR2) for improved sensitivity in monitoring myocardial iron in thalassemia

PURPOSE

To evaluate the reduced transverse relaxation rate (RR2), a new relaxation index which has been shown recently to be primarily sensitive to intracellular ferritin iron, as a means of detecting short-term changes in myocardial storage iron produced by iron-chelating therapy in transfusion-dependent thalassemia patients.

MATERIALS AND METHODS

A single-breathhold multi-echo fast spin-echo sequence was implemented at 3 Tesla (T) to estimate RR2 by acquiring signal decays with interecho times of 5, 9 and 13 ms. Transfusion-dependent thalassemia patients (N = 8) were examined immediately before suspending iron-chelating therapy for 1 week (Day 0), after a 1-week suspension of chelation (Day 7), and after a 1-week resumption of chelation (Day 14).

RESULTS

The mean percent changes in RR2, R2, and R2* off chelation (between Day 0 and 7) were 11.9 ± 8.9%, 5.4 ± 7.7% and -4.4 ± 25.0%; and, after resuming chelation (between Day 7 and 14), -10.6 ± 13.9%, -8.9 ± 8.0% and -8.5 ± 24.3%, respectively. Significant differences in R2 and RR2 were observed between Day 0 and 7, and between Day 7 and 14, with the greatest proportional changes in RR2. No significant differences in R2* were found.

CONCLUSION

These initial results demonstrate that significant differences in RR2 are detectable after a single week of changes in iron-chelating therapy, likely as a result of superior sensitivity to soluble ferritin iron, which is in close equilibrium with the chelatable cytosolic iron pool. RR2 measurement may provide a new means of monitoring the short-term effectiveness of iron-chelating agents in patients with myocardial iron overload.