Evaluation of myocardial iron by magnetic resonance imaging during iron chelation therapy with deferrioxamine: indication of close relation between myocardial iron content and chelatable iron pool

Αlpha-thalassemia: A practical overview

α-Thalassemia is an inherited blood disorder characterized by decreased synthesis of α-globin chains that results in an imbalance of α and β globin and thus varying degrees of ineffective erythropoiesis, decreased red blood cell (RBC) survival, chronic hemolytic anemia, and subsequent comorbidities. Clinical presentation varies depending on the genotype, ranging from a silent or mild carrier state to severe, transfusion-dependent or lethal disease. Management of patients with α-thalassemia is primarily supportive, addressing either symptoms (eg, RBC transfusions for anemia), complications of the disease, or its transfusion-dependence (eg, chelation therapy for iron overload). Several novel therapies are also in development, including curative gene manipulation techniques and disease modifying agents that target ineffective erythropoiesis and chronic hemolytic anemia. This review of α-thalassemia and its various manifestations provides practical information for clinicians who practice beyond those regions where it is found with high frequency.

Real-world complication burden and disease management paradigms in transfusion-related β-thalassaemia in Greece: Results from ULYSSES, an epidemiological, multicentre, retrospective cross-sectional study

Patients with transfusion-dependent beta (β)-thalassaemia experience a broad range of complications. ULYSSES, an epidemiological, multicentre, retrospective cross-sectional study, aimed to assess the prevalence and severity of treatment and disease complications, capture disease management and identify predictors of complications in patients with transfusion-dependent β-thalassaemia, treated in routine settings in Greece. Eligible patients were adults diagnosed with β-thalassaemia ≥12 months before enrolment and having received ≥6 red blood cell (RBC) units (excluding elective surgery) with no transfusion-free period ≥35 days in the 24 weeks before enrolment. Primary data were collected at a single visit and through chart review. Between Oct 21, 2019, and Jun 15, 2020, 201 eligible patients [median (interquartile range, IQR) age 45.7 (40.2-50.5) years; 75.6% > 40 years old; 64.2% female] were enrolled, a mean (standard deviation) of 42.9 (7.8) years after diagnosis. Median (IQR) age at diagnosis and RBC transfusion initiation were 0.8 (0.4-2.8) and 1.3 (1.0-5.0) years, respectively. From diagnosis to enrolment, patients had developed a median of six (range: 1-55) complications; 19.6% were grade ≥3. The most represented complications were endocrine/metabolic/nutrition disorders (91.5%), surgical/medical procedures (67.7%) and blood/lymphatic system disorders (64.7%). Real-world data generated by ULYSSES underscore the substantial complication burden of transfusion-dependent β-thalassaemia patients, routinely managed in Greece.

Dual gradient echo in-phase and out of phase sequences in assessment of hepatic iron overload in patients with beta-thalassemia, would be better?

PURPOSE

To evaluate the diagnostic accuracy of the dual gradient-echo (GRE) in- and out-of-phase sequences as a quantitative tool for hepatic iron overload in comparison with MRI R2* relaxometry in paediatric patients with beta-thalassemia.

METHOD

Sixty-three patients with beta-thalassemia major (transfusion-dependent) or beta-thalassemia intermedia (transfusion- and non-transfusion-dependent) were referred from the paediatric department (haematology unit) to the radiology department at a university hospital. The paediatrician conducted a clinical examination for the studied group, assessed their laboratory data, conducted R2* relaxometry and dual gradient echo sequences to calculate R2* and relative signal intensity index at the axial mid-section of the liver, and studied their correlation. A 1.5 Tesla MR scanner was used (Achieva; Philips Medical Systems, the Netherlands). Data were fed to the computer and analysed using the IBM SPSS software package version 20.0 (Armonk, NY: IBM Corp). The Kolmogorov-Smirnov test was used to verify the normality of distribution. The significance of the results was determined at the 5% level. The Chi-square, Fisher's exact correction, Pearson coefficient, and Bland-Altman tests were used.

RESULTS

Dual gradient-echo in- and out-of-phase sequences using visual assessment accurately assessed 93.65% of our patient group with hepatic iron overload. A significant correlation was found between the relative signal intensity index and hepatic MRI R2* relaxometry (p < 0.001, r = 0.861).

CONCLUSIONS

Dual gradient-echo in and out-of-phase sequences are good imaging tools for hepatic iron detection and quantification. These sequences showed good correlation with R2* relaxometry (r = 0.861, p < 0.001).

Novel Application for Activated Carbon Pharmaceutical Formulation as an Efficient Adsorbent of Iron (III) from Contaminated Canned Food

Additional medical indication has been realized for the active carbon commercialized in pharmaceutical stores for the first time. In this study, the active carbon was used to remove iron (III) from real canned food samples contaminated with iron by an adsorption process, in a new approach. Different parameters affecting the adsorption behavior of active carbon towards iron (III) have been optimized. Under the optimized conditions, namely, pH 4, 5 h contact time, 40 ppm iron initial concentration, and 2 g carbon, the study was applied to some of the real canned food samples. Black olive and green bean canned food samples containing relatively high iron levels of 698.0 and 1168 mg kg-1, respectively, have been selected for this study due to their levels which were above the maximum permitted levels 48 mg kg-1 according to the Joint FAO/WHO Expert Committee on Food Additives (JECFA). These samples were digested and treated, and their iron concentration was determined using ICP-AES under the specified optimum conditions. The removal percentage of the real samples was ~91%. In a novel approach, this study simulates the adsorption behavior of active carbon towards iron (III) in the human stomach when canned food with relatively high iron levels has been digested, since the pH value of the human stomach (~3) comes in good agreement with the adsorption optimized pH range (2-4). Moreover, the overall tolerability and safety of active carbon are worldwide known and traditionally documented. These application studies realize the applicability of utilizing active carbon commercially available in pharmaceutical stores to eliminate the toxicity of canned food contaminated by high levels of the investigated elements.

Biopsy-based optimization and calibration of a signal-intensity-ratio-based MRI method (1.5 Tesla) in a dextran-iron loaded mini-pig model, enabling estimation of very high liver iron concentrations

Objective

Magnetic resonance imaging (MRI)-based techniques for non-invasive assessing liver iron concentration (LIC) in patients with iron overload have a limited upper measuring range around 35 mg/g dry weight, caused by signal loss from accelerated T1-, T2-, T2* shortening with increasing LIC. Expansion of this range is necessary to allow evaluation of patients with very high LIC.

Aim

To assess measuring range of a gradient-echo R2* method and a T1-weighted spin-echo (SE), signal intensity ratio (SIR)-based method (TE = 25 ms, TR = 560 ms), and to extend the upper measuring range of the SIR method by optimizing echo time (TE) and repetition time (TR) in iron-loaded minipigs.

Methods

Thirteen mini pigs were followed up during dextran-iron loading with repeated percutaneous liver biopsies for chemical LIC measurement and MRIs for parallel non-invasive estimation of LIC (81 examinations) using different TEs and TRs.

Results

SIR and R2* method had similar upper measuring range around 34 mg/g and similar method agreement. Using TE = 12 ms and TR = 1200 ms extended the upper measuring range to 115 mg/g and yielded good method of agreement.

Discussion

The wider measuring range is likely caused by lesser sensitivity of the SE sequence to iron, due to shorter TE, leading to later signal loss at high LIC, allowing evaluation of most severe hepatic iron overload. Validation in iron-loaded patients is necessary.

Pancreatic MR imaging and endocrine complications in patients with beta-thalassemia: a single-center experience

Iron deposition in various organs can cause endocrine complications in patients with transfusion-dependent beta-thalassemia. The aim was to investigate the relationship between endocrine complications and pancreatic iron overload using magnetic resonance imaging (MRI). Forty patients with transfusion-dependent thalassemia (TDT) were enrolled in the study. The magnetic resonance imagings of the patients were performed using a 1.5 Tesla Philips MRI scanner. Two out of three patients had at least one clinical endocrine complication. The rate of iron deposition was 62.5% in liver, and 45% in pancreas tissue, and was 12.5% in heart tissue. Pancreatic T2* and hepatic T2* values were significantly positively correlated (p = 0.006). Pancreatic T2* and ferritin were significantly negatively correlated (p = 0.03). Cardiac T2* values were negatively correlated with fasting blood glucose (p = 0.03). Patients with short stature had significantly higher cardiac iron burden (22.3 vs. 36.6 T2*ms; p 0.01), and patients with hypothyroidism had higher liver iron concentrations (9.9 vs. 6.4 LIC mg/g; p = 0.05). The ferritin level of 841 ng/mL and liver iron concentration (LIC) value of 8.7 mg/g were detected as the threshold level for severe pancreatic iron burden (AUC 70%, p:0.04, AUC 80%, p = 0.002, respectively). Moreover, males were found to have decreased pancreas T2* values compared with the values in females (T2* 19.3 vs. 29.9, p = 0.05). Patients with higher ferritin levels over than 840 ng/mL should be closely monitored for pancreatic iron deposition, and patients with endocrine complications should be assessed in terms of cardiac iron burden.

Correlation Between Serum Ferritin and Viral Hepatitis in Thalassemia Patients

Serum ferritin is an acute phase protein; importantly, its level is noticeably increased in response to iron overload and systemic inflammation. The iron overload status in thalassemia patients has been recognized as a potential way to measure liver iron concentration (LIC) levels using magnetic resonance imaging (MRI). The aim of this study was to investigate the effect of chronic viral hepatitis on the level of serum ferritin in patients with thalassemia. A cross-sectional study was conducted involving chronic viral hepatitis infection. Mean serum ferritin and LIC levels were recorded. The LIC values were used to divide the patients into two groups; a higher LIC group (>5 mg Fe/g) and a lower LIC group (<5 mg Fe/g). Mean serum ferritin levels were then compared between the two LIC groups. We identified 32 thalassemia patients comprising of 13 chronic viral hepatitis patients, seven patients with hepatitis B virus (HBV), and six patients with hepatitis C virus (HCV). With regard to the group with higher LIC values, the mean serum ferritin levels in the hepatitis group were significantly higher than for those in the non hepatitis group (1776 ± 488 vs. 967 ± 860 ng/mL, p = 0.03). Furthermore, the linear correlation between the mean serum ferritin levels and the viral load in the non transfusion-dependent thalassemia (NTDT) group were found to be significantly correlated (r = 0.7, p = 0.04). Chronic viral hepatitis was determined to be a possible casualty of disproportionately high ferritin levels in the NTDT group.

Iron overload-induced oxidative stress in myelodysplastic syndromes and its cellular sequelae

The myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders. MDS patients often require red blood cell transfusions, resulting in iron overload (IOL). IOL increases production of reactive oxygen species (ROS), oxygen free radicals. We review and illustrate how IOL-induced ROS influence cellular activities relevant to MDS pathophysiology. ROS damage lipids, nucleic acids in mitochondrial and nuclear DNA, structural proteins, transcription factors and enzymes. Cellular consequences include decreased metabolism and tissue and organ dysfunction. In hematopoietic stem cells (HSC), consequences of ROS include decreased glycolysis, shifting the cell from anaerobic to aerobic metabolism and causing HSC to exit the quiescent state, leading to HSC exhaustion or senescence. ROS oxidizes DNA bases, resulting in accumulation of mutations. Membrane oxidation alters fluidity and permeability. In summary, evidence indicates that IOL-induced ROS alters cellular signaling pathways resulting in toxicity to organs and hematopoietic cells, in keeping with adverse clinical outcomes in MDS.

In vivo calibration of the T2* cardiovascular magnetic resonance method at 1.5 T for estimation of cardiac iron in a minipig model of transfusional iron overload

BACKGROUND

Non-invasive estimation of the cardiac iron concentration (CIC) by T2* cardiovascular magnetic resonance (CMR) has been validated repeatedly and is in widespread clinical use. However, calibration data are limited, and mostly from post-mortem studies. In the present study, we performed an in vivo calibration in a dextran-iron loaded minipig model.

METHODS

R2* (= 1/T2*) was assessed in vivo by 1.5 T CMR in the cardiac septum. Chemical CIC was assessed by inductively coupled plasma-optical emission spectroscopy in endomyocardial catheter biopsies (EMBs) from cardiac septum taken during follow up of 11 minipigs on dextran-iron loading, and also in full-wall biopsies from cardiac septum, taken post-mortem in another 16  minipigs, after completed iron loading.

RESULTS

A strong correlation could be demonstrated between chemical CIC in 55 EMBs and parallel cardiac T2* (Spearman rank correlation coefficient 0.72, P < 0.001). Regression analysis led to [CIC] = (R2* - 17.16)/41.12 for the calibration equation with CIC in mg/g dry weight and R2* in Hz. An even stronger correlation was found, when chemical CIC was measured by full-wall biopsies from cardiac septum, taken immediately after euthanasia, in connection with the last CMR session after finished iron loading (Spearman rank correlation coefficient 0.95 (P < 0.001). Regression analysis led to the calibration equation [CIC] = (R2* - 17.2)/31.8.

CONCLUSIONS

Calibration of cardiac T2* by EMBs is possible in the minipig model but is less accurate than by full-wall biopsies. Likely explanations are sampling error, variable content of non-iron containing tissue and smaller biopsies, when using catheter biopsies. The results further validate the CMR T2* technique for estimation of cardiac iron in conditions with iron overload and add to the limited calibration data published earlier.

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.

T1 and T2∗ relaxation time in the parcellated myocardium of healthy Taiwanese participants: A single center study

Background

Quantitative maps from cardiac MRI provide objective information for myocardial tissue. The study aimed to report the T1 and T2∗ relaxation time and its relationship with clinical parameters in healthy Taiwanese participants.

Methods

Ninety-three participants were enrolled between 2014 and 2016 (Males/Females: 43/50; age: 49.7 ± 11.3/49.9 ± 10.3). T1 and T2∗ weighted images were obtained by MOLLI recovery and 3D fully flow compensated gradient echo sequences with a 3T MR scanner, respectively. The T1 map of the myocardium was parcellated into 16 partitions from the American Heart Association. The septal part of basal, mid-cavity, and apical view was selected for the T2∗ map. The difference of quantitative map by sex and age groups were evaluated by Student's TTEST and ANOVA, respectively. The relationship between T1, T2∗ map, and clinical parameters, such as ejection fraction, pulse rate, and blood pressures, were evaluated with partial correlation by controlling BMI and age.

Results

Male participants decreased T1 relaxation time in partitions which located in the mid-cavity and apical before 55 years old compared with females (Male/Female: 1143.1.4 ± 72.0–1191.1 ± 37.0/1180.1 ± 54.5–1326.1 ± 113.3 msec, p < 0.01). For female participants, T1 relaxation time was correlated negatively with systolic pressure (p < 0.01) and pulse rate (p < 0.01) before 45 years old. Besides, T1 and T2∗ relaxation time were positively and negatively correlated with ejection fraction and pulse rate after 45 years old in male participants, respectively. Decreased T2∗ relaxation time could be noticed in participants after 45 years old compared with youngers (26.0 ± 6.5/21.9 ± 8.0 msec; 25.2 ± 5.0/21.6 ± 7.2 msec, p < 0.05).

Conclusion

Reference T1 and T2∗ relaxation time from cardiac MRI in healthy Taiwanese participants were provided with sex and age-dependent manners. The relationship between clinical parameters and T1 or T2∗ relaxation time was also established and could be further investigated for its potential application in healthy/sub-healthy participants.

Consequences of parenteral iron-dextran loading investigated in minipigs. A new model of transfusional iron overload

Patients with blood transfusion-dependent anemias develop transfusional iron overload (TIO), which may cause cardiosiderosis. In patients with an ineffective erythropoiesis, such as thalassemia major, common transfusion regimes aim at suppression of erythropoiesis and of enteral iron loading. Recent data suggest that maintaining residual, ineffective erythropoiesis may protect from cardiosiderosis. We investigated the common consequences of TIO, including cardiosiderosis, in a minipig model of iron overload with normal erythropoiesis. TIO was mimicked by long-term, weekly iron-dextran injections. Iron-dextran loading for around one year induced very high liver iron concentrations, but extrahepatic iron loading, and iron-induced toxicities were mild and did not include fibrosis. Iron deposits were primarily in reticuloendothelial cells, and parenchymal cardiac iron loading was mild. Compared to non-thalassemic patients with TIO, comparable cardiosiderosis in minipigs required about 4-fold greater body iron loads. It is suggested that this resistance against extrahepatic iron loading and toxicity in minipigs may at least in part be explained by a protective effect of the normal erythropoiesis, and additionally by a larger total iron storage capacity of RES than in patients with TIO. Parenteral iron-dextran loading of minipigs is a promising and feasible large-animal model of iron overload, that may mimic TIO in non-thalassemic patients.

Prevalence and Risk Factors for Cardiac and Liver Iron Overload in Adults with Thalassemia in Malaysia

We explored the severity and risk factors for cardiac and liver iron overload (IOL) in 69 thalassemia patients who underwent T2* magnetic resonance imaging (T2* MRI) in a Malaysian tertiary hospital from 2011 to 2015. Fifty-three patients (76.8%) had transfusion-dependent thalassemia (TDT) and 16 (23.2%) had non transfusion-dependent thalassemia (NTDT). Median serum ferritin prior to T2* MRI was 3848.0 μg/L (TDT) and 3971.0 μg/L (NTDT). Cardiac IOL was present in 16 (30.2%) TDT patients and two (12.5%) NTDT patients, in whom severe cardiac IOL defined as T2* <10 ms affected six (11.3%) TDT patients. Liver IOL was present in 51 (96.2%) TDT and 16 (100%) NTDT patients, 37 (69.8%) TDT and 13 (81.3%) NTDT patients were in the most severe category (>15 mgFe/gm dry weight). Serum ferritin showed a significantly strong negative correlation with liver T2* in both TDT (rs = -0.507, p = 0.001) and NTDT (r = -0.762, p = 0.002) but no correlation to cardiac T2* in TDT (r = -0.252, p = 0.099) as well as NTDT (r = -0.457, p = 0.100). For the TDT group, regression analysis showed that cardiac IOL was more severe in males (p = 0.022) and liver IOL was more severe in the Malay ethnic group (p = 0.028) and those with higher serum ferritin levels (p = 0.030). The high prevalence of IOL in our study and the poor correlation between serum ferritin and cardiac T2* underline the need to routinely screen thalassemia patients using T2* MRI to enable the early detection of cardiac IOL.

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.

Association between genotype and disease complications in Egyptian patients with beta thalassemia: A Cross-sectional study

In beta thalassemia, the degree of globin chain imbalance is determined by the nature of the mutation of the β-gene. β° refers to the complete absence of production of β-globin on the affected allele. β⁺ refers to alleles with some residual production of β-globin. The homozygous state results in severe anemia that necessitates regular blood transfusion. On the other hand, frequent blood transfusion can lead to iron overload resulting in progressive dysfunction of the heart, Liver as well as multiple endocrinopathies. We studied the impact of genotype on the development of disease complications in patients with β thalassemia. A Cross sectional study was carried on 73 patients with beta thalassemia. Genotyping was determined by DNA sequencing technique. Routine investigations as well as MRI liver and heart were performed to assess iron overload. We found that β⁺β⁺ was the most common genotype in our patients followed by β°β° and β°β⁺. Mean Liver iron content (LIC) was significantly higher in β°β° compared to β°β⁺ and β⁺β⁺ genotypes and mean cardiac T2* was significantly lower in β°β° compared to β°β⁺ and β⁺β⁺ genotypes. Hepatic complications, hepatitis C, cardiac complications and some endocrinopathies were significantly higher in patients with β°β° genotype compared to other genotypes which explain the role of the underlying genetic defect in thalassemia patients in development of disease complications.

Jadenu® Substituting Exjade® in Iron Overloaded β-Thalassemia Major (BTM) Patients: A Preliminary Report of the Effects on the Tolerability, Serum Ferritin Level, Liver Iron Concentration and Biochemical Profiles

Introduction

Due to the chronic nature of chelation therapy and the adverse consequences of iron overload, patient adherence to therapy is an important issue. Jadenu ^® is a new oral formulation of deferasirox (Exjade ^®) tablets for oral suspension. While Exjade^® is a dispersible tablet that must be mixed in liquid and taken on an empty stomach, Jadenu ^® can be taken in a single step, with or without a light meal, simplifying administration for the treatment of patients with chronic iron overload. This may significantly improve the compliance to treatment of patients with β-thalassemia major (BMT). The aim of this study was to evaluate the drug tolerability and the effects of chelation therapy on serum ferritin concentration, liver iron concentration (LIC) and biochemical profiles in patients with BMT and iron overload.

Patients and Methods

Twelve selected adult patients BMT (mean age: 29 years; range:15–34 years) were enrolled in the study. All patients were on monthly regular red cell transfusion therapy to keep their pre-transfusional hemoglobin (Hb) level not less than 9 g/dL. They were on Exjade^® therapy (30 mg/kg per day) for two years or more before starting Jadenu® therapy (14–28 mg/kg/day). The reason for shifting from Deferasirox^® to Jadenu^® therapy was lack of tolerability, as described by patients, such as nausea, vomiting, diarrhea, stomach pain. Most of them also reported that Deferasirox^® was not palatable. Lab investigations included monthly urine analysis and measurement of their serum concentrations of creatinine, fasting blood glucose (FBG), serum ferritin, alkaline phosphatase (ALP), alanine transferase (ALT), aspartate transferase (AST) and albumin concentrations. LIC was measured using FerriScan ^®. Thyroid function, vitamin D and serum parathormone, before and one year after starting Jadenu ^® therapy, were also assessed.

Results

Apart from some minor gastrointestinal complaints reported in 3 BMT patients that did not require discontinuation of therapy, other side effects were not registered during the treatment. Subjectively, patients reported an improvement in the palatability of Jadenu^® compared to Exjade^® therapy in 8 out of 12 BMT patients. A non-significant decrease in LIC measured by FerriScan^® and serum ferritin levels was observed after one year of treatment with Jadenu^®. A significant positive correlation was found between serum ferritin level and LIC measured by the FerriScan^® method. LIC and serum ferritin level correlated significantly with ALT level (r = 0.31 and 0.45 respectively, p < 0.05). No significant correlation was detected between LIC and other biochemical or hormonal parameters.

Conclusions

Our study shows that short-term treatment with Jadenu ^® is safe but is associated with a non-significant decrease in LIC and serum ferritin levels. Therefore, there is an urgent need for adequately-powered and high-quality trials to assess the clinical efficacy and the longterm outcomes of new deferasirox formulation.

Iron overload in myelodysplastic syndromes: Evidence based guidelines from the Canadian consortium on MDS

In 2008 the first evidence-based Canadian consensus guideline addressing the diagnosis, monitoring and management of transfusional iron overload in patients with myelodysplastic syndromes (MDS) was published. The Canadian Consortium on MDS, comprised of hematologists from across Canada with a clinical and academic interest in MDS, reconvened to update these guidelines. A literature search was updated in 2017; topics reviewed include mechanisms of iron overload induced cellular damage, evidence for clinical endpoints impacted by iron overload including organ dysfunction, infections, marrow failure, overall survival, acute myeloid leukemia progression, and endpoints around hematopoietic stem-cell transplant. Evidence for an impact of iron reduction on the same endpoints is discussed, guidelines are updated, and areas identified where evidence is suboptimal. The guidelines address common questions around the diagnosis, workup and management of iron overload in clinical practice, and take the approach of who, when, why and how to treat iron overload in MDS. Practical recommendations for treatment and monitoring are made. Evidence levels and grading of recommendations are provided for all clinical endpoints examined.

Improvement of chronic hepatitis B by iron chelation therapy in a patient with iron overload: A case report

RATIONALE

This report describes seroconversion of hepatitis B surface antigen (HBsAg) in a patient with marked iron overload caused by chronic hepatitis B (CHB) after receiving iron chelation therapy and discusses the role of iron chelation therapy in CHB.

PATIENT CONCERNS

Increased serum ferritin level for 2 months.

DIAGNOSIS

Secondary iron overload and CHB.

INTERVENTION

To relieve iron load of the body, the patient underwent regular phlebotomy therapy and deferoxamine (DFO) therapy. During the therapy, serum ferritin and hepatitis B virus (HBV) were monitored and the iron concentration of the liver and heart were followed by T2* of magnetic resonance imaging (MRI) scan.

OUTCOMES

Serum ferritin gradually decreased. Approximately 1 year after the therapy, HBsAg turned persistently negative.

LESSONS

Iron chelation therapy may attenuate HBV infection.

MRI for the measurement of liver iron content, and for the diagnosis and follow-up of iron overload disorders

MRI is now the reference method for detecting and quantifying hepatic and extrahepatic iron overload, regardless of its cause. The decrease of the hepatic signal is proportional to the amount of iron in the tissues. It is more pronounced with T2*-weighted gradient echo sequences. It increases proportionally with the strength of the magnetic field. Thus a 3-T MRI is be more sensitive and probably more accurate to detect a slight iron overload, as seen in dysmetabolic hepatosiderosis. Conversely, a 1.5-T MRI better estimates a high overload. Quantification can be done with the calculation of T2* (or R2*) or by using the liver to muscle signal intensity ratio (SIR). Today with a single multi-echo gradient-echo sequence, obtained in a unique apnea, the two methods can be used simultaneously. An associated quantification of steatosis is also obtained. This same type of sequence is proposed for quantification of iron in other tissues and in particular for the myocardium.

Toxicity of iron overload and iron overload reduction in the setting of hematopoietic stem cell transplantation for hematologic malignancies

Iron is an essential element for key cellular metabolic processes. However, transfusional iron overload (IOL) may result in significant cellular toxicity. IOL occurs in transfusion dependent hematologic malignancies (HM), may lead to pathological clinical outcomes, and IOL reduction may improve outcomes. In hematopoietic stem cell transplantation (SCT) for HM, IOL may have clinical importance; endpoints examined regarding an impact of IOL and IOL reduction include transplant-related mortality, organ function, infection, relapse risk, and survival. Here we review the clinical consequences of IOL and effects of IOL reduction before, during and following SCT for HM. IOL pathophysiology is discussed as well as available tests for IOL quantification including transfusion history, serum ferritin level, transferrin saturation, hepcidin, labile plasma iron and other parameters of iron-catalyzed oxygen free radicals, and organ IOL by imaging. Data-based recommendations for IOL measurement, monitoring and reduction before, during and following SCT for HM are made.

Myelodysplastic Syndromes in the Elderly: Treatment Options and Personalized Management

Myelodysplastic syndromes (MDS) are typical diseases of the elderly, with a median age of 68-75 years at initial diagnosis. Demographic changes producing an increased proportion of elderly in our societies mean the incidence of MDS will rise dramatically. Considering the increasing number of treatment options, ranging from best supportive care to hematopoietic stem cell transplantation (HSCT), decision making is rather complex in this cohort of patients. Moreover, aspects of the aging process also have to be considered in therapy planning. Treatment of elderly MDS patients is dependent on the patient's individual risk and prognosis. Comorbidities play an essential role as predictors of survival and therapy tolerance. Age-adjusted models and the use of geriatric assessment scores are described as a basis for individualized treatment algorithms. Specific treatment recommendations for the different groups of patients are given. Currently available therapeutic agents, including supportive care, erythropoiesis-stimulating agents (ESAs), immune-modulating agents, hypomethylating agents, and HSCT are described in detail and discussed with a special focus on elderly MDS patients. The inclusion of elderly patients in clinical trials is of utmost importance to obtain data on efficacy and safety in this particular group of patients. Endpoints relevant for the elderly should be integrated, including maintenance of quality of life and functional activities as well as evaluation of use of healthcare resources.

Value of severe liver iron overload for assessing heart iron levels in thalassemia major patients

PURPOSE

The relationship between severe liver iron overload (LIO) and heart iron overload (HIO) in transfusion-dependent patients with thalassemia major (TM) is uncertain. Whether severe LIO can serve as an index for assessing heart iron deposition has vital clinical significance. Therefore, our aim is to determine if a close relationship exists between severe LIO and HIO.

MATERIALS AND METHODS

We examined 110 TM patients who underwent T2* measurement in the liver and heart on a 1.5 Tesla MRI scanner. Various statistical analysis methods were used to assess the relationship.

RESULTS

Most of these patients suffered from severe LIO (58.18%, liver T2* < 1.4 ms). Both Pearson's and Spearman's tests showed a significant correlation between liver T2* and heart T2* values (with a correlation coefficient of 0.408 and 0.550, respectively, both P < 0.0001). A nonlinear model, with the equation of Heart T2* = 37.974-17.684 / Liver T2*, was found to be the best model to indicate the relationship between liver T2* and heart T2*. Receiver operating characteristic (ROC) analysis showed the area under the ROC curve of liver T2* and serum ferritin for predicting HIO was 0.812 (95% confidence interval [CI]: 0.731-0.892; P < 0.0001) and 0.69 (95% CI: 0.585-0.795; P = 0.001), respectively.

CONCLUSION

Our preliminary data suggest the existence of a close relationship between severe LIO and HIO. High liver iron levels appear to increase the risk of heart iron deposition. This further supports the concept of critical liver iron concentration, above which elevated heart iron is present. J. MAGN. RESON. IMAGING 2016;44:880-889.

Glutathione S-transferase gene polymorphism: Relation to cardiac iron overload in Egyptian patients with Beta Thalassemia Major

OBJECTIVES

Estimating the prevalence of glutathione S-transferase gene polymorphism (GSTM1) null genotype among patients with beta thalassemia major (β-TM) in relation to myocardial status assessed by tissue Doppler and cardiac siderosis assessed by cardiac magnetic resonance imaging (MRI) T2*.

METHODS

Hundred patients with β-TM and 100 healthy controls were enrolled. Complete blood count (CBC), mean serum ferritin and GSTM1 genotyping, echocardiography, tissue Doppler, and cardiac MRI T2* were done.

RESULTS

Serum ferritin ranged from 1200 to 8000 ng/ml, and mean T2* value was 27.10 ± 11.20 ms. Of patients, 68 (68%) had no cardiac siderosis, while 24 (24%) with mild to moderate, and 8 (8%) with sever cardiac siderosis. T2* values were not correlated with serum ferritin (r = -0.09, P = 0.50). GSTM1 null genotype was prevalent in 46% of patients and 40% of controls (P = 0.69). Patients with null genotype had significantly shorter T2* (P = 0.001), higher left ventricular end-diastolic diameter (P = 0.002), and shorter ejection time (P = 0.005) with no significant relation to serum ferritin (P = 0.122). GSTM1 null genotype was the only predictor for cardiac iron overload (P = 0.002).

DISCUSSION

Serum ferritin concentrations have been shown to correlate poorly with all stages of cardiac dysfunction. Low cardiac MRI T2* values occur in patients with β-TM despite good chelation therapy, suggesting a possible role of genetic factors in cardiac siderosis.

CONCLUSION

GSTM1 null genotype is significantly associated with cardiac iron overload independent of serum ferritin in Egyptian patients with β-TM.

The pathophysiology of transfusional iron overload

The pathophysiologic consequences of transfusional iron overload (TIO) as well as the benefits of iron chelation therapy are best described in thalassemia major, although TIO is increasingly seen in other clinical settings. These consequences broadly reflect the levels and distribution of excess storage iron in the heart, endocrine tissues, and liver. TIO also increases the risk of infection, due to increased availability of labile iron to microorganisms. The authors suggest that extrahepatic iron distribution, and hence toxicity, is influenced by balance between generation of nontransferrin-bound iron from red cell catabolism and the utilization of transferrin iron by the erythron.

Guidelines for quantifying iron overload

Both primary and secondary iron overload are increasingly prevalent in the United States because of immigration from the Far East, increasing transfusion therapy in sickle cell disease, and improved survivorship of hematologic malignancies. This chapter describes the use of historical data, serological measures, and MRI to estimate somatic iron burden. Before chelation therapy, transfusional volume is an accurate method for estimating liver iron burden, whereas transferrin saturation reflects the risk of extrahepatic iron deposition. In chronically transfused patients, trends in serum ferritin are helpful, inexpensive guides to relative changes in somatic iron stores. However, intersubject variability is quite high and ferritin values may change disparately from trends in total body iron load over periods of several years. Liver biopsy was once used to anchor trends in serum ferritin, but it is invasive and plagued by sampling variability. As a result, we recommend annual liver iron concentration measurements by MRI for all patients on chronic transfusion therapy. Furthermore, it is important to measure cardiac T2* by MRI every 6-24 months depending on the clinical risk of cardiac iron deposition. Recent validation data for pancreas and pituitary iron assessments are also presented, but further confirmatory data are suggested before these techniques can be recommended for routine clinical use.

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

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

Use of magnetic resonance imaging to monitor iron overload

Treatment of iron overload requires robust estimates of total-body iron burden and its response to iron chelation therapy. Compliance with chelation therapy varies considerably among patients, and individual reporting is notoriously unreliable. Even with perfect compliance, intersubject variability in chelator effectiveness is extremely high, necessitating reliable iron estimates to guide dose titration. In addition, each chelator has a unique profile with respect to clearing iron stores from different organs. This article presents the tools available to clinicians to monitor their patients, focusing on noninvasive magnetic resonance imaging methods because they have become the de facto standard of care.

Cardiac iron overload in sickle-cell disease

Chronically transfused sickle cell disease (SCD) patients have lower risk of myocardial iron overload (MIO) than comparably transfused thalassemia major (TM) patients. However, cardioprotection is incomplete. We present the clinical characteristics of six patients who have prospectively developed MIO, to identify potential risk factors for cardiac iron accumulation. From 2002 to 2011, cardiac, hepatic, and pancreatic iron overload were assessed by R2 and R2 * magnetic resonance imaging techniques in 201 chronic transfused SCD patients as part of their clinical care. At the time, they developed MIO, five of six patients had been on chronic transfusion for more than 11 years; only one was on exchange transfusion. The time to MIO was correlated with reticulocyte and hemoglobin S percentages. All patients had qualitatively poor chelation compliance (<50%). All patients had serum ferritin levels >4600 ng/ml and liver iron concentration >22 mg/g. Pancreatic R2 * was >100 Hz in every patient studied (5/6). Cardiac iron rose proportionally to pancreas R2 *, with all patients having pancreas R2 *>100 Hz when cardiac iron was present. MIO had a threshold relationship with liver iron that was higher than observed in TM patients. In conclusion, MIO occurs in a small percentage of chronically transfused SCD patients and is only associated with exceptionally poor control of total body iron stores. Duration of chronic transfusion is clearly important but other factors, such as levels of effective erythropoiesis, appear to contribute to cardiac risk. Pancreas R2 * can serve as a valuable screening tool for cardiac iron in SCD patients.

Myelodysplastic syndromes

Myelodysplastic syndromes are clonal marrow stem-cell disorders, characterised by ineffective haemopoiesis leading to blood cytopenias, and by progression to acute myeloid leukaemia in a third of patients. 15% of cases occur after chemotherapy or radiotherapy for a previous cancer; the syndromes are most common in elderly people. The pathophysiology involves cytogenetic changes with or without gene mutations and widespread gene hypermethylation at advanced stages. Clinical manifestations result from cytopenias (anaemia, infection, and bleeding). Diagnosis is based on examination of blood and bone marrow showing blood cytopenias and hypercellular marrow with dysplasia, with or without excess of blasts. Prognosis depends largely on the marrow blast percentage, number and extent of cytopenias, and cytogenetic abnormalities. Treatment of patients with lower-risk myelodysplastic syndromes, especially for anaemia, includes growth factors, lenalidomide, and transfusions. Treatment of higher-risk patients is with hypomethylating agents and, whenever possible, allogeneic stem-cell transplantation.

Biopsy-based calibration of T2* magnetic resonance for estimation of liver iron concentration and comparison with R2 Ferriscan

BACKGROUND

There is a need to standardise non-invasive measurements of liver iron concentrations (LIC) so clear inferences can be drawn about body iron levels that are associated with hepatic and extra-hepatic complications of iron overload. Since the first demonstration of an inverse relationship between biopsy LIC and liver magnetic resonance (MR) using a proof-of-concept T2* sequence, MR technology has advanced dramatically with a shorter minimum echo-time, closer inter-echo spacing and constant repetition time. These important advances allow more accurate calculation of liver T2* especially in patients with high LIC.

METHODS

Here, we used an optimised liver T2* sequence calibrated against 50 liver biopsy samples on 25 patients with transfusional haemosiderosis using ordinary least squares linear regression, and assessed the method reproducibility in 96 scans over an LIC range up to 42 mg/g dry weight (dw) using Bland-Altman plots. Using mixed model linear regression we compared the new T2*-LIC with R2-LIC (Ferriscan) on 92 scans in 54 patients with transfusional haemosiderosis and examined method agreement using Bland-Altman approach.

RESULTS

Strong linear correlation between ln(T2*) and ln(LIC) led to the calibration equation LIC = 31.94(T2*)-1.014. This yielded LIC values approximately 2.2 times higher than the proof-of-concept T2* method. Comparing this new T2*-LIC with the R2-LIC (Ferriscan) technique in 92 scans, we observed a close relationship between the two methods for values up to 10 mg/g dw, however the method agreement was poor.

CONCLUSIONS

New calibration of T2* against liver biopsy estimates LIC in a reproducible way, correcting the proof-of-concept calibration by 2.2 times. Due to poor agreement, both methods should be used separately to diagnose or rule out liver iron overload in patients with increased ferritin.

When should iron chelation therapy be considered in patients with myelodysplasia and other bone marrow failure syndromes with iron overload?

Despite the absence of a robust evidence base, there is growing consensus that effective treatment of iron overload leads to decreased morbidity and premature mortality in patients with good prognosis myelodysplastic syndromes (MDSs). Furthermore, new treatment modalities, including disease-modifying therapies (lenalidamide and azacytidine) and reduced intensity conditioning therapies for allogeneic blood stem cell transplants, are offering the prospect of longer survival for patients with traditionally less favourable prognosis MDS, who might also benefit from iron chelation. This article proposes assessment of patients with MDS and related bone marrow failure syndromes to determine suitability for iron chelation. Iron chelation therapy options and monitoring are discussed.

Myelodysplastic syndromes: clinical practice guidelines in oncology

The myelodysplastic syndromes (MDS) represent a heterogeneous group of clonal hematopoietic disorders characterized by cytopenias, dysplasia in one or more myeloid lineages, and the potential for development of acute myeloid leukemia. These disorders primarily affect older adults. The NCCN Clinical Practice Guidelines in Oncology for MDS provide recommendations on the diagnostic evaluation and classification of MDS, risk evaluation according to established prognostic assessment tools (including the new revised International Prognostic Scoring System), treatment options according to risk categories, and management of related anemia.

Cardiovascular function and treatment in β-thalassemia major: a consensus statement from the American Heart Association

This aim of this statement is to report an expert consensus on the diagnosis and treatment of cardiac dysfunction in β-thalassemia major (TM). This consensus statement does not cover other hemoglobinopathies, including thalassemia intermedia and sickle cell anemia, in which a different spectrum of cardiovascular complications is typical. There are considerable uncertainties in this field, with a few randomized controlled trials relating to treatment of chronic myocardial siderosis but none relating to treatment of acute heart failure. The principles of diagnosis and treatment of cardiac iron loading in TM are directly relevant to other iron-overload conditions, including in particular Diamond-Blackfan anemia, sideroblastic anemia, and hereditary hemochromatosis. Heart failure is the most common cause of death in TM and primarily results from cardiac iron accumulation. The diagnosis of ventricular dysfunction in TM patients differs from that in nonanemic patients because of the cardiovascular adaptation to chronic anemia in non-cardiac-loaded TM patients, which includes resting tachycardia, low blood pressure, enlarged end-diastolic volume, high ejection fraction, and high cardiac output. Chronic anemia also leads to background symptomatology such as dyspnea, which can mask the clinical diagnosis of cardiac dysfunction. Central to early identification of cardiac iron overload in TM is the estimation of cardiac iron by cardiac T2* magnetic resonance. Cardiac T2* <10 ms is the most important predictor of development of heart failure. Serum ferritin and liver iron concentration are not adequate surrogates for cardiac iron measurement. Assessment of cardiac function by noninvasive techniques can also be valuable clinically, but serial measurements to establish trends are usually required because interpretation of single absolute values is complicated by the abnormal cardiovascular hemodynamics in TM and measurement imprecision. Acute decompensated heart failure is a medical emergency and requires urgent consultation with a center with expertise in its management. The first principle of management of acute heart failure is control of cardiac toxicity related to free iron by urgent commencement of a continuous, uninterrupted infusion of high-dose intravenous deferoxamine, augmented by oral deferiprone. Considerable care is required to not exacerbate cardiovascular problems from overuse of diuretics or inotropes because of the unusual loading conditions in TM. The current knowledge on the efficacy of removal of cardiac iron by the 3 commercially available iron chelators is summarized for cardiac iron overload without overt cardiac dysfunction. Evidence from well-conducted randomized controlled trials shows superior efficacy of deferiprone versus deferoxamine, the superiority of combined deferiprone with deferoxamine versus deferoxamine alone, and the equivalence of deferasirox versus deferoxamine.

Management of the thalassemias

During the last 30 years, in addition to the considerable progress made in control and prevention of thalassemias(3), there have also been major advances in their symptomatic management, at least in wealthier countries where appropriate facilities are available. Remarkable improvements in survival in the severe forms of thalassemia have followed the more judicious use of blood transfusion and, in particular, the ability to manage the iron accumulation resulting from transfusion with its severe and ultimately lethal effects on endocrine and cardiac function.

How we treat lower-risk myelodysplastic syndromes

Lower-risk myelodysplastic syndromes (MDSs) are defined as having low or intermediate 1 risk by the International Prognostic Scoring System and are characterized mainly by anemia in most cases. Supportive care--primarily red blood cell transfusions--remains an important component of their treatment, but exposes patients to insufficient correction of anemia, alloimmunization, and organ iron overload (for which the role of iron chelation remains debated). Treatment aimed at preventing anemia recurrence should therefore be used whenever possible. Erythropoiesis stimulating agents remain the first-line treatment of anemia in most lower-risk MDS without del(5q), whereas anemia of low-risk MDS with del 5q responds to lenalidomide in two-thirds of the cases, but this drug should be used cautiously because profound cytopenias may occur initially. Treatment after failure of those first-line therapies are disappointing overall, with many patients eventually requiring long-term transfusions, but encouraging results have been reported with hypomethylating agents and lenalidomide. Selected patients respond to antithymocyte globulins, and thrombopoietin receptor agonists are under investigation in lower-risk MDS with thrombocytopenia. Some patients, while remaining at a "lower risk" MDS level, have severe cytopenias and/or poor prognostic factors, found using newer prognostic parameters, or resistance to treatment, making them urgent candidates for more intensive approaches, including allogeneic stem cell transplantation.

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

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

Magnetic resonance imaging in the evaluation of iron overload: a comparison of MRI, echocardiography and serum ferritin level in patients with β-thalassemia major

PURPOSE

This study aimed to evaluate iron levels in cardiac and hepatic tissues using magnetic resonance imaging (MRI) T2*.

METHODS

Cardiac and hepatic MRI was performed for 93 patients with β-thalassemia major.

RESULTS

Cardiac T2* was in the range of 2.9-56.6 ms. Myocardial siderosis was detected in 44% of patients; 25 patients had moderate and severe siderosis with serum ferritin level (SFL) of 576-10,284 ng/ml. There was a significant correlation between SFL and cardiac T2* (p<.001).

CONCLUSIONS

The effective role of MRI as a noninvasive producible method in measurement of iron concentration in tissues is not accessible with conventional techniques.

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

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