Hyperferritinemia and liver iron content determined with MRI: Reintroduction of the liver iron index

BACKGROUND

Hyperferritinemia is found in around 12 % of the general population. Analyzing the cause can be difficult. In case of doubt about the presence of major iron overload most guidelines advice to perform a MRI as a reliable non-invasive marker to measure liver iron concentration (LIC). In general, a LIC of ≥ 36 µmol/g dw is considered the be elevated however in hyperferritinemia associated with, for example, obesity or alcohol (over)consumption the LIC can be ≥ 36 µmol/g dw in abscence of major iron overload. So, unfortunately a clear cut-off value to differentiate iron overload from normal iron content is lacking. Previously the liver iron index (LII) (LIC measured in liver biopsy (LIC-b)/age (years)), was introduced to differentiate between patients with major (LII ≥ 2) and minor or no iron overload (LII < 2). Based on the good correlation between the LIC-b and LIC determined with MRI (LIC-MRI), our goal was to investigate whether a LII_MRI ≥ 2 is a good indicator of major iron overload, reflected by a significantly higher amount of iron needed to be mobilized to reach iron depletion.

METHODS

We compared the amount of mobilized iron to reach depletion and inflammation-related characteristics in two groups: LII-MRI ≥ 2 versus LII-MRI <2 in 92 hyperferritinemia patients who underwent HFE genotyping and MRI-LIC determination.

RESULTS

Significantly more iron needed to be mobilized to reach iron depletion in the LII ≥ 2 group (mean 4741, SD ± 4135 mg) versus the LII-MRI <2 group (mean 1340, SD ± 533 mg), P < 0.001. Furthermore, hyperferritinemia in LII-MRI < 2 patients was more often related to components of the metabolic syndrome while hyperferritinemia in LII-MRI ≥ 2 patients was more often related to HFE mutations. ROC curve analysis showed good performance of LII =2 as cut-off value. However the calculations showed that the optimal cut-off for the LII = 3.4.

CONCLUSION

The LII-MRI with a cut-off value of 2 is an effective method to differentiate major from minor iron overload in patients with hyperferritinemia. But the LII-MRI = 3.4 seems a more promising diagnostic test for major iron overload.

A multicenter study on the quantification of liver iron concentration in thalassemia patients by means of the MRI T2* technique

Objective

To investigate the feasibility and accuracy of quantifying liver iron concentration (LIC) in patients with thalassemia (TM) using 1.5T and 3T T₂^* MRI.

Methods

1.5T MRI T₂^* values were measured in 391 TM patients from three medical centers: the T₂^* values of the test group were combined with the LIC (LIC_F) provided by FerriScan to construct the curve equation. In addition, the liver 3T MRI liver T₂^* data of 55 TM patients were measured as the 3T group: the curve equation of 3T T₂^* value and LIC_F was constructed.

Results

Based on the test group LIC_F (0.6-43 mg/g dw) and the corresponding 1.5T T₂^* value, the equation was LIC_F = 37.393T2*∧(-1.22) (R² = 0.971; P < 0.001). There was no significant difference between LIC_{e - 1.5T} and LIC_F in each validation group (Z = -1.269, -0.977, -1.197; P = 0.204, 0.328, 0.231). There was significant consistency (Kendall's W = 0.991, 0.985, 0.980; all P < 0.001) and high correlation (r_s = 0.983, 0.971, 0.960; all P < 0.001) between the two methods. There was no significant difference between the clinical grading results of LIC_{e - 1.5T} and LIC_F in each validation group (χ² = 3.0, 4.0, 2.0; P = 0.083, 0.135, 0.157), and there was significant consistency between the clinical grading results (Kappa's K = 0.943, 0.891, 0.953; P < 0.001). There was no statistical correlation between the LIC_F (≥14 mg/g dw) and the 3T T₂^* value of severe iron overload (P = 0.085). The LIC_F (2-14 mg/g dw) in mild and moderate iron overload was significantly correlated with the corresponding T₂^* value (r_s = -0.940; P < 0.001). The curve equation constructed from LIC_F and corresponding 3T T₂^* values in this range is LIC_F = 18.463T₂^*∧^(-1.142) (R² = 0.889; P < 0.001). There was no significant difference between LIC_F and LIC_{e - 3T} in the mild to moderate range (Z = -0.523; P = 0.601), and there was a significant correlation (r_s = 0.940; P < 0.001) and significant consistency (Kendall's W = 0.970; P = 0.008) between them. LIC_{e - 3T} had high diagnostic efficiency in the diagnosis of severe, moderate, and mild liver iron overload (specificity = 1.000, 0.909; sensitivity = 0.972, 1.000).

Conclusion

The liver iron concentration can be accurately quantified based on the 1.5T T₂^* value of the liver and the specific LIC-T₂^* curve equation. 3T T₂^* technology can accurately quantify mild-to-moderate LIC, but it is not recommended to use 3T T₂^* technology to quantify higher iron concentrations.

Deferasirox versus deferoxamine in managing iron overload in patients with Sickle Cell Anaemia: a systematic review and meta-analysis

OBJECTIVES

To examine the efficacy of deferasirox (DFX) by comparison with deferoxamine (DFO) in managing iron overload in patients with sickle cell anaemia (SCA).

METHODS

Online databases were systematically searched for studies published from January 2007 to July 2022 that had investigated the efficacy of DFX compared with DFO in managing iron overload in patients with SCA.

RESULTS

Of the 316 articles identified, three randomized clinical trials met the inclusion criteria. Meta-analysis of liver tissue iron concentration (LIC) showed that iron overload was not significantly higher in the DFX group compared with DFO group (WMD, -1.61 mg Fe/g dw (95% CI -4.42 to 1.21). However, iron overload as measured by serum ferritin was significantly lower in DFO compared with DFX group (WMD, 278.13 µg/l (95% CI 36.69 to 519.57). Although meta-analysis was not performed on myocardial iron concentration due to incomplete data, the original report found no significant difference between DFX and DFO.

CONCLUSION

While limited by the number of studies included in this meta-analysis, overall, the results tend to show that DFX was as effective as DFO in managing iron overload in patients with SCA.

Rate of Change of Liver Iron Content by MR Imaging Methods: A Comparison Study

Objective: Magnetic resonance imaging (MRI) can accurately quantify liver iron concentration (LIC), eliminating the need for an invasive liver biopsy. Currently, the most widely used relaxometry methods for iron quantification are R2 and R2*, which are based on T2 and T2* acquisition sequences, respectively. We compared the rate of change of LIC as measured by the R2-based, FDA-approved commercially available third-party software with the rate of change of LIC measured by in-house analysis using R2*-relaxometry-based MR imaging in patients undergoing follow-up MRI scans for liver iron estimation. Methods: We retrospectively included patients who had undergone serial MRIs for liver iron estimation. The MR studies were performed on a 1.5T scanner; standard multi-slice, multi-echo T2- and T2*-based sequences were acquired, and LIC was estimated. The comparison between the rate of change of LIC by R2 and R2* values was performed via correlation coefficients and Bland−Altman difference plots. Results: One hundred and eighty-nine MR abdomen studies for liver iron evaluation from 81 patients (male: 38; female: 43) were included in the study. Fifty-nine patients had two serial scans, eighteen patients had three serial scans, three patients had four serial scans, and one patient had five serial scans. The average time interval between the first and last scans for each patient was 13.3 months. The average rates of change of LIC via R2 and R2* methods were −0.0043 ± 0.0214 and −0.0047 ± 0.012 mg/g per month, respectively. There was no significant difference in the rate of change of LIC observed between the two methods. Linearity between the rate of change of LIC measured by R2 (LIC R2) and R2* (LIC R2*) was strong, showing a correlation coefficient of r = 0.72, p < 0.01. A Bland−Altman plot between the rate of change of the two methods showed that the majority of the plotted variables were between two standard deviations. Conclusion: There was no significant difference in the rate of change of LIC detected between the R2 method and the R2* method that uses a gradient echo (GRE) sequence acquired with breath-hold. Since R2* is relatively faster and less prone to motion artifacts, R2*-derived LIC is recommended for iron homeostasis follow-up in patients with liver iron overload.

Estimation of iron overload with T2*MRI in children treated for hematological malignancies

Iron overload may contribute to long-term complications in childhood cancer survivors. There are limited reports of assessment of tissue iron overload in childhood leukemia by magnetic resonance imaging (MRI). A cross-sectional, observational study in children treated for hematological malignancy was undertaken. Patients ≥6 months from the end of therapy who had received ≥5 red-cell transfusions were included. Iron overload was estimated by serum ferritin (SF) and T2*MRI. Forty-five survivors were enrolled among 431 treated for hematological malignancies. The median age at diagnosis was 7-years. A median of 8 red-cell units was transfused. The median duration from the end of treatment was 15 months. An elevated SF (>1,000 ng/ml), elevated liver iron concentration (LIC) and myocardial iron concentration (MIC) were observed in 5 (11.1%), 20 (45.4%), and 2 (4.5%) patients, respectively. All survivors with SF >1,000 ng/ml had elevated LIC. The LIC correlated with SF (p < 0.001). MIC lacked correlation with SF or LIC. Factors including the number of red-cell units transfused and duration from the last transfusion were associated with elevated SF (p = 0.001, 0.002) and elevated LIC (p = 0.012, 0.005) in multiple linear regression. SF >595 ng/ml predicted elevated LIC with a sensitivity of 85% and specificity of 91.6% (AUC 91.2%). A cutoff >9 units of red cell transfusions had poor sensitivity and specificity of 70% and 75% (AUC 76.6%) to predict abnormal LIC. SF >600 ng/ml is a robust tool to predict iron overload, and T2*MRI should be considered in childhood cancer survivors with SF exceeding 600 ng/ml.

Spectroscopy-based multi-parametric quantification in subjects with liver iron overload at 1.5T and 3T

PURPOSE

To evaluate the precision profile (repeatability and reproducibility) of quantitative STEAM-MRS and to determine the relationships between multiple MR biomarkers of chronic liver disease in subjects with iron overload at both 1.5 Tesla (T) and 3T.

METHODS

MRS data were acquired in patients with known or suspected liver iron overload. Two STEAM-MRS sequences (multi-TE and multi-TE-TR) were acquired at both 1.5T and 3T (same day), including test-retest acquisition. Each acquisition enabled estimation of R1, R2, and FWHM (each separately for water and fat); and proton density fat fraction. The test-retest repeatability and reproducibility across acquisition modes (multi-TE vs. multi-TE-TR) of the estimates were evaluated using intraclass correlation coefficients, linear regression, and Bland-Altman analyses. Multi-parametric relationships between parameters at each field strength, across field strengths, and with liver iron concentration were also evaluated using linear and nonlinear regression.

RESULTS

Fifty-six (n = 56) subjects (10 to 73 years, 37 males/19 females) were successfully recruited. Both STEAM-MRS sequences demonstrated good-to-excellent precision (intraclass correlation coefficient ≥ 0.81) for the quantification of R1_water , R2_water , FWHM_water , and proton density fat fraction at both 1.5T and 3T. Additionally, several moderate (R² = 0.50 to 0.69) to high (R² ≥ 0.70) correlations were observed between biomarkers, across field strengths, and with liver iron concentration.

CONCLUSIONS

Over a broad range of liver iron concentration, STEAM-MRS enables rapid and precise measurement of multiple biomarkers of chronic liver disease. By evaluating the multi-parametric relationships between biomarkers, this work may advance the comprehensive MRS-based assessment of chronic liver disease and may help establish biomarkers of chronic liver disease.

The serum ferritin levels and liver iron concentrations in patients with alphathalassemia is there a good correlation?

INTRODUCTION

Liver iron overload is common in patients with thalassemia. In patients with beta-thalassemia, the correlation between serum ferritin and liver iron concentration is well established. The correlation between serum ferritin levels and liver iron concentrations in patients with alpha-thalassemia remains limited.

METHODS

This is a cross-sectional study in patients with alpha-thalassemia aged ≥ 18 years old at Srinagarind Hospital, Khon Kaen University, Thailand. Liver iron concentration (LIC) was evaluated by the MRI-T2* technique. Linear logistic regression analysis was used to determine the correlation between serum ferritin levels and liver iron concentrations.

RESULTS

One hundred and thirty-one of the MRI-T2* measurements from 65 patients with alpha-thalassemia were evaluated. Patients with non-deletional alpha-thalassemia had higher LIC compared to patients with deletional alpha-thalassemia. The serum ferritin levels were relatively low at the same levels of LIC in patients with non-deletional alpha-thalassemia compared to deletional alpha-thalassemia.

CONCLUSIONS

The correlation of serum ferritin levels and LIC was modest and different among alpha-thalassemia genotypes. A different serum ferritin threshold is needed to guide iron chelation therapy in patients with alpha-thalassemia. Evaluation of liver iron concentration is necessary for patients with alpha-thalassemia, especially in patients with non-deletional alpha-thalassemia.

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.

R2 Star MRI in Hemoglobinopathies

Background: Non-invasive determination of liver iron concentration (LIC) is a valuable tool that guides iron chelation therapy in transfusion-dependent patients. Multiple methods have been utilized to measure LIC by MRI. The purpose of this study was to compare free breathing R2* (1/T2*) to whole-liver Ferriscan R2 method for estimation of LIC in a pediatric and young adult population who predominantly have hemoglobinopathies. Methods: Clinical liver and cardiac MRI scans from April 2016 to May 2018 on a Phillips 1.5 T scanner were reviewed. Free breathing T2 and T2* weighted images were acquired on each patient. For T2, multi-slice spin echo sequences were obtained. For T2*, a single mid-liver slice fast gradient echo was performed starting at 0.6 ms with 1.2 ms increments with signal averaging. R2 measurements were performed by Ferriscan analysis. R2* measurements were performed by quantitative T2* map analysis. Results: 107 patients underwent liver scans with the following diagnoses: 76 sickle cell anemia, 20 Thalassemia, 9 malignancies and 2 Blackfan Diamond anemia. Mean age was 12.5 ± 4.5 years. Average scan time for R2 sequences was 10 min, while R2* sequence time was 20 s. R2* estimation of LIC correlated closely with R2 with a correlation coefficient of 0.94. Agreement was strongest for LIC < 15 mg Fe/g dry weight. Overall bias from Bland–Altman plot was 0.66 with a standard deviation of 2.8 and 95% limits of agreement −4.8 to 6.1. Conclusion: LIC estimation by R2* correlates well with R2-Ferriscan in the pediatric age group. Due to the very short scan time of R2*, it allows imaging without sedation or anesthesia. Cardiac involvement was uncommon in this cohort.

Iatrogenic Iron Overload in a Patient With Chronic Kidney Disease: Is There a Correlation Between Serum Ferritin and Liver Iron Concentration Determined by MRI T2*?

Secondary iron overload in patients with chronic kidney disease (CKD) due to iatrogenic iron replacement is an emerging medical challenge. There are limited options to manage secondary iron overload in patients with CKD as most iron chelators are contraindicated due to low creatinine clearance. In addition to that, accuracy of serum ferritin in monitoring is questionable since it is affected by different variables including inflammation and liver disease. Moreover, correlation of serum ferritin with liver iron concentration (LIC) and heart iron concentration is not well studied in CKD patients. There is no established cut-off value in the current guidelines, and this warrants further investigation with more accurate methods.

There are few studies that evaluated the relationship between serum ferritin and LIC determined by different MRI protocols. Limited data in the literature concluded that a positive correlation exists between serum ferritin and LIC determined by MRI T2* and that serum ferritin more than 290 mcg/L is equivalent to severe iron overload on MRI T2*. However, we had a different observation of a patient with CKD on a prolonged course of iron replacement who was monitored with serum ferritin, and despite having a serum ferritin level of more than 1,000 mcg/L, LIC determined by MRI T2* was 5.3 mg/g of liver dry tissue, which is equivalent to mild iron overload. 

This observation opens the door for further studies to examine the correlation between serum ferritin and LIC determined by MRI and to establish a safe cut-off value of serum ferritin so that further investigation would be indicated in patients with CKD.

The value of magnetic resonance imaging in evaluation of myocardial and liver iron overload in a thalassaemia endemic population: a report from Northeastern Thailand

Purpose

Patients with chronic haemolytic anaemia, such as in thalassaemia, require repeated blood transfusions, which leads to iron overload and cellular damage, especially in the heart and liver. Classically, serum ferritin and liver biopsy have been used to monitor patient response to chelation therapy. Magnetic resonance imaging (MRI) has proven to be effective in detecting and quantifying iron in the heart and liver. The aim of the paper is to evaluate the accuracy of the MRI T2* procedure in the assessment of liver iron concentration and myocardial iron overload.

Material and methods

In 210 cases of monthly transfused patients, hepatic and myocardial iron overload was measured by multi-breath-hold MRI T2* and compared to serum ferritin (a traditional marker of iron overload).

Results

No significant correlation was observed between serum ferritin level and cardiac T2* MRI (p = 0.68, r = 0.06). However, a significant correlation was observed between serum ferritin and liver iron concentration evaluated by MRI (p = 0.04, r = 0.68).

Conclusion

Routine evaluation of liver and heart iron content using MRI T2* is suggested to better evaluate the haemosiderosis status in thalassaemic patients.

Inter-method reproducibility of biexponential R2 MR relaxometry for estimation of liver iron concentration

PURPOSE

To assess the reproducibility of biexponential R₂ -relaxometry MRI for estimation of liver iron concentration (LIC) between proprietary and nonproprietary analysis methods.

METHODS

This single-center retrospective study, approved by investigational review board and compliant with the Health Insurance Portability and Accountability Act, included 40 liver MRI exams in 38 subjects with suspected or known iron overload. From spin-echo images of the liver, acquired at 5 different echo times (TE = 6-18 ms), biexponential R₂ maps were calculated using 1 proprietary (FerriScan, Resonance Health Ltd., Claremont WA, Australia) and 3 nonproprietary (simulated annealing, nonlinear least squares, dictionary search) analysis methods. Each subject's average liver R₂ value was converted to LIC using a previously validated calibration curve. Inter-method reproducibility for liver R₂ and LIC were assessed for linearity using linear regression analysis and absolute agreement using intraclass correlation and Bland-Altman analysis. For point estimates, 95% confidence intervals were calculated; P values < 0.05 were considered statistically significant.

RESULTS

Linearity between the proprietary and nonproprietary methods was excellent across the observed range for R₂ (20-312 s^-1 ) and LIC (0.4-52.2 mg/g), with all coefficients of determination (R² ) ≥ 0.95. No statistically significant bias was found (slope estimates ∼ 1; intercept estimates ∼ 0; P values > 0.05). Agreement between the 4 methods was excellent for both liver R₂ and LIC (intraclass correlations ≥ 0.97). Bland-Altman 95% limits of agreement in % difference between the proprietary and nonproprietary methods were ≤ 9% and ≤ 16% for R₂ and LIC, respectively.

CONCLUSION

Biexponential R₂ -relaxometry MRI for LIC estimation is reproducible between proprietary and nonproprietary analysis methods.

Assessment of MR-based R2* and quantitative susceptibility mapping for the quantification of liver iron concentration in a mouse model at 7T

PURPOSE

To assess the feasibility of quantifying liver iron concentration (LIC) using R2* and quantitative susceptibility mapping (QSM) at a high field strength of 7 Tesla (T).

METHODS

Five different concentrations of Fe-dextran were injected into 12 mice to produce various degrees of liver iron overload. After mice were sacrificed, blood and liver samples were harvested. Ferritin enzyme-linked immunosorbent assay (ELISA) and inductively coupled plasma mass spectrometry were performed to quantify serum ferritin concentration and LIC. Multiecho gradient echo MRI was conducted to estimate R2* and the magnetic susceptibility of each liver sample through complex nonlinear least squares fitting and a morphology enabled dipole inversion method, respectively.

RESULTS

Average estimates of serum ferritin concentration, LIC, R2*, and susceptibility all show good linear correlations with injected Fe-dextran concentration; however, the standard deviations in the estimates of R2* and susceptibility increase with injected Fe-dextran concentration. Both R2* and susceptibility measurements also show good linear correlations with LIC (R²  = 0.78 and R²  = 0.91, respectively), and a susceptibility-to-LIC conversion factor of 0.829 ppm/(mg/g wet) is derived.

CONCLUSION

The feasibility of quantifying LIC using MR-based  R2* and QSM at a high field strength of 7T is demonstrated. Susceptibility quantification, which is an intrinsic property of tissues and benefits from being field-strength independent, is more robust than R2* quantification in this ex vivo study. A susceptibility-to-LIC conversion factor is presented that agrees relatively well with previously published QSM derived results obtained at 1.5T and 3T.

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.

Iron Overload and Chelation Therapy in Non-Transfusion Dependent Thalassemia

Iron overload (IOL) due to increased intestinal iron absorption constitutes a major clinical problem in patients with non-transfusion-dependent thalassemia (NTDT), which is a cumulative process with advancing age. Current models for iron metabolism in patients with NTDT suggest that suppression of serum hepcidin leads to an increase in iron absorption and subsequent release of iron from the reticuloendothelial system, leading to depletion of macrophage iron, relatively low levels of serum ferritin, and liver iron loading. The consequences of IOL in patients with NTDT are multiple and multifactorial. Accurate and reliable methods of diagnosis and monitoring of body iron levels are essential, and the method of choice for measuring iron accumulation will depend on the patient's needs and on the available facilities. Iron chelation therapy (ICT) remains the backbone of NTDT management and is one of the most effective and practical ways of decreasing morbidity and mortality. The aim of this review is to describe the mechanism of IOL in NTDT, and the clinical complications that can develop as a result, in addition to the current and future therapeutic options available for the management of IOL in NTDT.

Correlation of serum ferritin levels with hepatic MRI T2 and liver iron concentration in nontransfusion beta-thalassemia intermediate patients: A contemporary issue

BACKGROUND

Beta-thalassemia intermediate is a genetic disease that is milder than beta-thalassemia major. The T2^* magnetic resonance imaging (MRI) technique is currently the gold standard for iron load detection. However, it is expensive and needs an expert radiologist to report findings. Therefore, we conducted this study to determine an optimal cut-off value of ferritin in proportion to T2 MRI of liver and measurement of liver iron concentration for early detection of hepatic iron overload in Beta-thalassemia intermediate patients.

METHODS

This cross-sectional study was conducted on 108 patients with Beta-thalassemia intermediate who referred to tertiary hospital, Shiraz, Iran. Serum ferritin, hepatic T2 MRI, and liver iron concentration were assessed. Receiver operator characteristic was used to determine the sensitivity and specificity of cut-off value.

RESULTS

Serum ferritin levels showed a statistically significant negative correlation with T2 hepatic MRI (r = -0.290, p value =.003) and positive correlation with liver iron concentration (r = 0.426, p value <.001) in the patients with Beta-thalassemia intermediate. According to the receiver operator characteristic, the best cut-off value for ferritin to show early diagnosis of liver iron overload was 412 ng/mL. Calculated sensitivities and specificities were 0.78 and 0.82 for T2 MRI and 0.76 and 0.86 for liver iron concentration, respectively.

CONCLUSION

Serum ferritin levels of around 450 ng/mL might be considered as a cut-off point to evaluate hepatic iron overload before using expensive, not readily available T2 MRI. This level of serum ferritin could be considered for starting iron chelation therapy in patients with Beta-thalassemia intermediate in areas where T2 MRI is not available.

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.

Reducing the iron burden and improving survival in transfusion-dependent thalassemia patients: current perspectives

Hypertransfusion regimens for thalassemic patients revolutionized the management of severe thalassemia; transforming a disease which previously led to early infant death into a chronic condition. The devastating effect of the accrued iron from chronic blood transfusions necessitates a more finely tuned approach to limit the complications of the disease, as well as its treatment. A comprehensive approach including carefully tailored transfusion protocol, continuous monitoring and assessment of total body iron levels, and iron chelation are currently the mainstay in treating iron overload. There are also indications for ancillary treatments, such as splenectomy and fetal hemoglobin induction. The main cause of death in iron overload continues to be related to cardiac complications. However, since the widespread use of iron chelation started in the 1970s, there has been a general improvement in survival in these patients.

Liver iron concentration is not raised in patients with dysmetabolic hyperferritinemia

Background &amp;amp;amp;amp; aims. Hyperferritinemia (HF) is frequently present in patients with metabolic syndrome (MS). MS associated with HF is named dysmetabolic hyperferritinemia (DH). There are some publications that propose that DH is associated with a raised liveriron concentration (LIC). We studied the LIC in patients referred for HF to a secondary hospital to determine if there are differences between patients with or without MS.

MATERIAL AND METHODS

We conducted a prospective study of 132 consecutive patients with HF from January to December 2010. The MS was defined by the International Diabetes Federation criteria (2005). LIC was determined by Magnetic resonance imaging (MRI).

RESULTS

The number of patients for which there was enough data to determine MS was 97, out of which 54 had MS and 43 had no MS (NMS). In 54/97 patients, MRI for LIC determination was performed. From the MS group, 44 were men (27 underwent MRI) and 10 women (9 MRI). The mean LIC was 27.83 ± 20.90 ?mol/g for the MS group. In the NMS group, 36 were men (13 MRI), and 7 women (5 MRI). In 18 patients from the NMS group, LIC was determined by MRI. The mean LIC was 33.16 ± 19.61 ?mol/g in the NMS group. We compared the mean values of LIC from both groups (MS vs. NMS) and no significant differences were found (p = 0.067).

CONCLUSION

Patients with DH present a mean LIC within normal values and their values do not differ from those of patients with HF but without MS.

Defining serum ferritin thresholds to predict clinically relevant liver iron concentrations for guiding deferasirox therapy when MRI is unavailable in patients with non-transfusion-dependent thalassaemia

Liver iron concentration (LIC) assessment by magnetic resonance imaging (MRI) remains the gold standard to diagnose iron overload and guide iron chelation therapy in patients with non-transfusion-dependent thalassaemia (NTDT). However, limited access to MRI technology and expertise worldwide makes it practical to also use serum ferritin assessments. The THALASSA (assessment of Exjade(®) in non-transfusion-dependent THALASSemiA patients) study assessed the efficacy and safety of deferasirox in iron-overloaded NTDT patients and provided a large data set to allow exploration of the relationship between LIC and serum ferritin. Using data from screened patients and those treated with deferasirox for up to 2 years, we identified clinically relevant serum ferritin thresholds (for when MRI is unavailable) for the initiation of chelation therapy (>800 μg/l), as well as thresholds to guide chelator dose interruption (<300 μg/l) and dose escalation (>2000 μg/l). (clinicaltrials.gov identifier: NCT00873041).

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

PURPOSE

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

THEORY AND METHODS

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

RESULTS

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

CONCLUSION

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