How early can myocardial iron overload occur in beta thalassemia major?

Two risk factors for hypozincemia in diabetic β-thalassemia patients: Hepatitis C and deferasirox

BACKGROUND AND AIM

Hypozincemia is a prevalent adverse consequence in diabetes mellitus (DM) and β-Thalassemia patients. We aimed to evaluate the level of serum zinc in β-thalassemia patients with DM and a risk assessment for hypozincemia.

METHODS

The study population included transfusion-dependent thalassemia (TDT) and non-transfusion-dependent thalassemia (NTDT) with overt DM (fasting plasma glucose (FPG) ≥126 mg/dL, and/or 2-h plasma glucose≥200 mg/dL). Serum zinc concentration was measured by the colorimetric method, and the values below 70 μg/dL were defined as hypozincemia. Myocardial and liver T2*-weighted magnetic resonance imaging (MRI T2*, millisecond [ms]) were valued by a free contrast MRI. The demographic, clinical, paraclinical, and laboratory data were also recorded. The data belonged to the period from December 2018 until December 2020.

RESULTS

Of 64 diabetic β-thalassemia patients, 41 cases had zinc data in their medical files (aged 38 ± 9 years, 48.8% female). 78.05% of patients (n = 32) were TDT, and 21.95% were NTDT (n = 9). The mean ± standard deviation of zinc level was 110.2 ± 127.6 μg/dL. The prevalence of hypozincemia was 9.76%, 95% confidence interval [CI] 0.27 to 19.24 (four cases). After controlling age, the odds of hypozincemia for using deferasirox (DFX) was 8.77, 95% CI 0.60 to 127.1. In β-thalassemia patients, the age-adjusted risk of hypozincemia was calculated at 15.85, 95% CI 0.47 to 529.3 for hepatitis C. The adjusted risk of hypozincemia based on age for antacid use was 6.34, 95% CI 0.39 to 102.7.

CONCLUSION

In light of this study, as well as hepatitis C, using DFX and antacids is associated with a high risk of hypozincemia amid diabetic β-thalassemia cases. However, upward bias should be taken into consideration.

Iron overload status in patients with non-transfusion-dependent thalassemia in China

Background:

Iron overload is one of the main factors that increase morbidity and mortality in patients with non-transfusion dependent thalassemia (NTDT).

Aim:

This study aimed at investigating the prevalence and severity of iron overload in Chinese NTDT patients.

Methods:

we analyzed serum ferritin (SF), liver iron concentration (LIC) and cardiac T2* in 178 Chinese NTDT in this cross-sectional study.

Results:

The median SF level was 996.00(27.15–19704.00) ng/ml and the median LIC value was 8.90(0.60–43.00) mg Fe/g dry weight (dw). The youngest patient with liver iron overload was 5 years old with 5.6 mg Fe/g dw in LIC. The median cardiac T2* was 33.06(7.46–75.08) ms. 6 patients had cardiac T2*⩽20ms. The patients with β thalassemia intermedia and HbE/β thalassemia showed a statistically significant lower Hb and higher values of SF and LIC than those of hemoglobin H disease patients. On multivariate logistic regression analysis, patients in ⩾ age 30-year old had a significant higher risk for iron overload (OR: 77.75, 95% CI: 8.76–690.49) in the age group. The detailed analysis of proportions of different LIC indicate in  > 30-year old group, 76.8% patients suffered from moderate and severe LIC.

Conclusion:

Our study provides a strong support for the novel findings that Chinese NTDT patients have a high prevalence of iron overload. The first assessment of MRI LIC should be performed as early as 5 years old. Then, NTDT patients  > 30 years old may suffer with a high burden of iron overload.

Evaluation of electrocardiography, echocardiography and cardiac T2* for cardiac complications in beta thalassemia major

Cardiac complications such as heart failure and arrhythmias caused by "iron-induced" cardiomyopathy are considered as the primary cause of death in the patients with β-thalassemia major. The aim of this study was to evaluate electrocardiography, echocardiography according cardiac T2* and ferritin findings of patients followed-up for β-thalassemia major, and to investigate the importance of these findings for early detection of cardiac complications. The study included 41 patients and 25 healthy individuals with matched age and gender. The cardiac T2* results revealed a cardiac iron load below 20 ms in 12 (29.27%) patients, and above 20 ms in 29 (70.73%) patients. All electrocardiography parameters significantly increased in the patient group when compared to the control group (p < 0.05). All parameters except P wave segment in electrocardiography and T peak-end/QT ratio were significantly higher in the group with cardiac T2* < 20 ms than the group with cardiac T2* > 20 ms (p < 0.05). Intraventricular septum thickness, left ventricular posterior wall thickness, left ventricular mass and left ventricular mass index detected by echocardiography were significantly higher in the group with T2* < 20 ms (p < 0.05). Electrocardiography, echocardiography, cardiac T2* and ferritin findings should be carefully evaluated in these patients in order to detect early signs of cardiac complications.

Assessment of cardiac and liver iron overload by magnetic resonance imaging in patients with thalassemia major: short-term follow-up

Objective

This study was performed to assess cardiac and hepatic iron overload in young patients with thalassemia.

Methods

We reviewed the medical records of patients with thalassemia at a pediatric hematology clinic who had recently undergone cardiac and hepatic magnetic resonance imaging.

Results

Eleven patients underwent cardiac and hepatic T2* imaging at a mean age of 13.9 ± 4.48 (range, 9–21) years. Three patients had cardiac iron overload and all patients had hepatic iron overload according to the magnetic resonance imaging scan. Ten patients underwent control imaging approximately 1 year later. The mean serum ferritin level at the initial imaging examination was 1820.87 ± 1275.22 (range, 634.04–4221.03) ng/mL. There was a strong negative correlation between the ferritin level and cardiac T2* time and between the blood hemoglobin level and hepatic T2* time. Among the 10 patients who underwent control imaging, the average hemoglobin and ferritin levels significantly decreased from the initial to control imaging examinations, but there was no significant increase in the cardiac and hepatic T2*times.

Conclusions

Cardiac and hepatic T2* imaging is a feasible method of assessing cardiac and hepatic iron overload even before complications and clinical signs of iron overload appear.

Cardiac Iron Overload by MRI in Children With B-Thalassemia Major and its Correlation With Cardiac Function by Echocardiography

BACKGROUND

Serial echocardiography is strongly recommended in asymptomatic B-thalassemia major (TM) patients for early detection of subtle cardiac dysfunction. T2*magnetic resonance imaging (MRI) is a noninvasive measurement of myocardial iron burden. Yet, it is not always available in many centers. Our study aimed to evaluate the myocardial function in TM patients using different echocardiographic modalities and to correlate these findings with cardiac T2*MRI.

PATIENTS AND METHODS

This is a cross-sectional study that was carried out on 140 children with a mean age of 10.9±3.7 years. One hundred children with TM and 40 healthy children were matched for age and sex as a control group. Serum ferritin, serum iron, and iron-binding capacity were measured. Cardiac iron overload was assessed by T2*MRI and cardiac function was assessed by echocardiography. The local ethics committee approved the study.

RESULTS

Among 100 children with TM, only 32% had cardiac iron overload of 8.525±5.45 detected by cardiac T2*MRI. Iron deposition correlated significantly with age. Markers of iron overload were significantly correlated with cardiac T2*MRI. There were significantly lower values of myocardial performance index, longitudinal strain, circumferential strain, area strain, and radial strain in TM patients compared with the controls (P<0.001). Only the myocardial performance index was correlated with T2*MRI.

CONCLUSIONS

This study confirms that some parameters measured by tissue Doppler imaging such as the myocardial performance index could be useful for the early detection of cardiac impairment in asymptomatic TM patients when cardiac MRI is lacking. Further studies on a large scale to identify other parameters with high sensitivity are recommended.

Inherited iron overload disorders

Hereditary iron overload includes several disorders characterized by iron accumulation in tissues, organs, or even single cells or subcellular compartments. They are determined by mutations in genes directly involved in hepcidin regulation, cellular iron uptake, management and export, iron transport and storage. Systemic forms are characterized by increased serum ferritin with or without high transferrin saturation, and with or without functional iron deficient anemia. Hemochromatosis includes five different genetic forms all characterized by high transferrin saturation and serum ferritin, but with different penetrance and expression. Mutations in HFE, HFE2, HAMP and TFR2 lead to inadequate or severely reduced hepcidin synthesis that, in turn, induces increased intestinal iron absorption and macrophage iron release leading to tissue iron overload. The severity of hepcidin down-regulation defines the severity of iron overload and clinical complications. Hemochromatosis type 4 is caused by dominant gain-of-function mutations of ferroportin preventing hepcidin-ferroportin binding and leading to hepcidin resistance. Ferroportin disease is due to loss-of-function mutation of SLC40A1 that impairs the iron export efficiency of ferroportin, causes iron retention in reticuloendothelial cell and hyperferritinemia with normal transferrin saturation. Aceruloplasminemia is caused by defective iron release from storage and lead to mild microcytic anemia, low serum iron, and iron retention in several organs including the brain, causing severe neurological manifestations. Atransferrinemia and DMT1 deficiency are characterized by iron deficient erythropoiesis, severe microcytic anemia with high transferrin saturation and parenchymal iron overload due to secondary hepcidin suppression. Diagnosis of the different forms of hereditary iron overload disorders involves a sequential strategy that combines clinical, imaging, biochemical, and genetic data. Management of iron overload relies on two main therapies: blood removal and iron chelators. Specific therapeutic options are indicated in patients with atransferrinemia, DMT1 deficiency and aceruloplasminemia.

Insulin secretion-sensitivity index-2 could be a novel marker in the identification of the role of pancreatic iron deposition on beta-cell function in thalassemia major

The purpose of this study is to evaluate the impact of insulin secretion-sensitivity index-2 (ISSI-2) in the identification of the role of pancreatic iron deposition on beta-cell function in thalassemia major. Tissue iron stores were measured with magnetic resonance imaging (MRI) in the liver (R2), pancreas (R2*), and heart (T2*). ISSI-2 was assessed as a novel oral glucose tolerance test-based measure of beta-cell function. Also, the Stumvoll index showing the insulin sensitivity and Stumvoll index estimating first and second phase insulin secretion were calculated. Fourteen of the 51 Thalassemia Major patients, aged 8-34 (mean 21.1 ± 7.2) years-old, had either an impaired glucose tolerance test (n = 9, 17.6%) or diabetes mellitus (n = 5, 9.8%)-referred to as the glucose dysregulation (GD) group. The median serum ferritin and the mean liver R2 and cardiac T2* values were not significantly different between the GD and normal glucose tolerance (NGT, n = 37) groups whereas pancreas R2* was significantly higher in the GD group compared to the NGT group (p = 0.004). Patients with GD showed significantly lower ISSI-2 index (p < 0.001) as well as the Stumvoll index and Stumvoll first and second phase indices compared to those with NGT (p < 0.001). All patients with GD displayed a pancreas R2* >50 Hz and ISSI-2 <2. In conclusion, Pancreas R2* MRI combined with ISSI-2 index may be valuable parameters to identify patients at the highest risk for developing glucose dysregulation.

Effective method of evaluating myocardial iron concentration in pediatric patients with thalassemia major

Background

The use of T2* magnetic resonance imaging (MRI) has been promoted by recent studies as a noninvasive method for the detection of iron overload in thalassemia major patients. This study aims to estimate the iron load in the heart and liver of thalassemia major patients using T2* MRI and to determine its correlation with the left ventricle ejection fraction and serum ferritin level.

Methods

Forty β-Thalassemia major patients were included in the study. We evaluated the serum ferritin level, echocardiography, cardiac T2*, myocardial iron concentration (MIC), liver iron concentration (LIC) and hepatic T2* in all patients. CMR T2* findings were categorized as normal cardiac T2* (T2* >20 ms) or abnormal cardiac T2* (T2* <20 ms).

Results

The study found that 85% of patients had a normal cardiac T2* value. The median serum ferritin level was 2189. A significant inverse correlation was found between the serum ferritin level and the cardiac T2* (r=−0.381, =0.015); however, the correlations between serum ferritin and the hepatic T2* and liver iron concentration were statistically non-significant (P=0.539 and P=0.637, respectively). Additionally, the LVEF correlation was statistically non-significant with SF, hepatic T2* and cardiac T2*.

Conclusion

Regardless of the serum ferritin level or left ventricle function, a cardiac T2* MRI should be done for all patients with β-Thalassemia major in order to estimate the myocardial iron concentration.

Iron Metabolism and Oxidative Status in Patients with Hb H Disease

To evaluate the iron metabolism and oxidative status in patients with Hb H disease, we investigated 43 patients with Hb H disease, including eight deletional Hb H disease patients and 35 nondeletional Hb H disease patients and 20 healthy controls. The levels of hematological parameters, serum ferritin, hepcidin, superoxide dismutase (SOD), malondialdehyde (MDA) and total antioxidant capacity (TAC), were examined. We found higher serum ferritin levels and lower hepcidin, MDA and TAC levels in Hb H disease patients than in controls. The hepcidin level in Hb H disease patients was positively correlated with MDA and TAC levels but not with serum ferritin and SOD levels. The patients with nondeletional Hb H disease showed higher serum ferritin and Hb H concentrations than those patients with deletional Hb H disease. However, no statistically significant differences in SOD, MDA and TAC levels were found in patients with deletional and nondeletional Hb H disease. Oxidative stress and antioxidant defense were related to hepcidin levels. Our study indicated that hepcidin might be an important parameter for monitoring the iron metabolism and oxidative status of Hb H disease patients.

N-terminal-pro-b-type natriuretic peptide levels and cardiac hemosiderosis in adolescent β-thalassemia major patients

Background:

Iron-induced cardiomyopathy remains the leading cause of mortality in patients with β-thalassemia major. Iron overload cardiomyopathy, which may be reversible through iron chelation, is characterized by early diastolic dysfunction. Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is a sensitive biomarker of diastolic dysfunction.

Aim:

The aim of the study is to evaluate the diagnostic value of NT-proBNP as a surrogate marker of iron overload examined with magnetic resonance imaging T2-star (MRI T2*).

Methods:

Sixty-eight β-thalassemia major patients (10–18 years) with no signs of heart failure underwent NT-proBNP measurement before routine transfusion. All participants prospectively underwent cardiac MRI T2* examination within 3 months (median 19 days). Patients were divided as cardiac hemosiderosis (cardiac MRI T2* <20 ms) and nonhemosiderosis (cardiac MRI T2* >20 ms).

Results:

Of 68 patients, the male-to-female ratio was 1:1.1 and the median age was 14.1 years (range: 10–17.8 years). NT-proBNP levels were not different between hemosiderosis and nonhemosiderosis patients (P = 0.233). Further receiver operating characteristic analysis resulted in no significant correlation of NT-proBNP and MRI T2* (area under the curve 0.393, P = 0.233).

Conclusion:

Measurement of NT-proBNP levels cannot be used for early detection of cardiac iron overload in adolescent with β-thalassemia major.

Cardiac complications and iron overload in beta thalassemia major patients-a systematic review and meta-analysis

Despite the major improvement in therapeutic management of thalassemia major, iron overload is considered a challenging conundrum in these patients and heart disease still remains a major cause of morbidity and mortality in these patients. Therefore, this study aimed to investigate the prevalence of cardiac iron overload and cardiovascular complications in transfusion-dependent thalassemia patients in the worldwide. The following databases were searched: ISI/Web of Science, Embase, PubMed, Scopus, up to February 30, 2018. The quality of the studies was evaluated using the Joanna Briggs Institute Prevalence Critical Appraisal Tool. The random model based on Metaprop was used. One hundred forty-two studies were included. The total number of patients included was 26,893. The mean age of patients was 22.6 (SD = 1.7) years. Based on Metaprop, the overall prevalence of cardiac iron overload/myocardial sidoresis (T2* < 20 ms) and cardiac complications in thalassemia major patients in the worldwide was 25% (95% CI 22-28%) and 42% (95% CI 37-46%), respectively. The results of this study show that the prevalence of cardiac iron overload and cardiovascular complications in patients with thalassemia major is almost high. Therefore, iron chelation and careful monitoring of serum ferritin level will prevent the cardiac iron overload, and interval monitoring of patients with transfusion-dependent thalassemia (TDT) by echocardiography and electrocardiography will help with early detection of cardiovascular complications.

Erythropoiesis and Iron Homeostasis in Non-Transfusion-Dependent Thalassemia Patients with Extramedullary Hematopoiesis

Background

Extramedullary hematopoiesis (EMH) is common in non-transfusion-dependent thalassemia (NTDT) patients. Clinical presentations of EMH vary as MRI screening is not feasible. Hence, serum biomarkers are used to predict the risk of EMH.

Materials and Methods

52 NTDT patients, including 26 EMH (+) and 26 EMH (-), together with 26 healthy controls, were enrolled in this case-control study from 2013 to 2016. EMH was confirmed by computed tomography or MRI. Demographic, transfusion, genetic, laboratory, and liver iron concentration (LIC) data, as well as clinical complications, were analyzed.

Results

EMH (+) patients had significantly higher serum ferritin (SF), growth differentiation factor 15 (GDF15), and erythropoietin (EPO) levels compared with EMH (-) patients and controls. The levels of erythroferrone (ERFE), hepcidin, and sTfR did not differ significantly between EMH (+) and EMH (-) patients (p>0.05). In NTDT patients, serum ERFE was not related to SF, LIC, hepcidin, sTfR, EPO, GDF15, and Hb levels. GDF15, EPO concentrations, and GDF15 to sTfR and GDF15 to EPO ratios are able to determine the presence of EMH with considerable sensitivity and specificity.

Conclusions

GDF15, EPO, and GDF15 to EPO and GDF15 to sTfR ratios are potential biomarkers for the early prediction of NTDT in patients who are at risk for EMH.

Imbalance of erythropoiesis and iron metabolism in patients with thalassemia

Aim: This study aimed to evaluate the imbalance of erythropoiesis and iron metabolism in patients with thalassemia. Methods: 192 patients with non-transfusion-dependent thalassemia (NTDT), 94 patients with transfusion-dependent thalassemia (TDT) and 101 healthy controls were recruited between June 2013 and December 2016 in the Hematology Department, the First Affiliated Hospital of Guangxi Medical University. The groups were compared in terms of levels of erythropoiesis biomarkers [growth differentiation factor 15 (GDF15), erythropoietin (EPO) and soluble transferrin receptor (sTfR)] and of iron overload biomarkers [serum ferritin (SF), liver iron concentration (LIC) and cardiac T2*] and hepcidin. Results: The levels of GDF15, EPO, sTfR, LIC and SF were significantly higher in patients with thalassemia. The levels of GDF15 and EPO were significantly higher in patients with TDT compared to NTDT. Those with iron overload had higher EPO, GDF15, SF and sTfR levels compared with non-iron overload patients. Hepcidin levels and ratios of hepcidin to erythropoietic activity and to iron biomarker levels were lower in patients with β-thalassemia intermedia or hemoglobin (Hb) E/β-thalassemia than in patients with HbH disease. The hepcidin levels were correlated negatively with the levels of EPO, GDF15 and sTfR in patients with NTDT and TDT, but correlated positively with SF and Hb levels only in patients with TDT. Conclusions: Patients with thalassemia showed iron overload, reduced hepcidin levels, and a greater extent of ineffective erythropoiesis. The hepcidin levels were more strongly related to ineffective erythropoiesis compared with iron overload. The imbalance between erythropoiesis and iron metabolism differed across different thalassemia types.

How I manage medical complications of β-thalassemia in adults

The complex pathophysiology in β-thalassemia can translate to multiple morbidities that affect every organ system. Improved survival due to advances in management means that patients are exposed to the harmful effects of ineffective erythropoiesis, anemia, and iron overload for a longer duration, and we started seeing new or more frequent complications in adult compared with younger patients. In this article, we highlight particular aspects of managing adult patients with β-thalassemia, using our own experience in treating such patients. We cover both transfusion-dependent and nontransfusion-dependent forms of the disease and tackle specific morbidities of highest interest.

Renal iron deposition by magnetic resonance imaging in pediatric β-thalassemia major patients: Relation to renal biomarkers, total body iron and chelation therapy

BACKGROUND

The reciprocal of multiecho gradient-echo (ME-GRE) T2* magnetic resonance imaging (MRI) R2*, rises linearly with tissue iron concentration in both heart and liver. Little is known about renal iron deposition in β-thalassemia major (β-TM).

AIM

To assess renal iron overload by MRI and its relation to total body iron and renal function among 50 pediatric patients with β-TM.

METHODS

Serum ferritin, serum cystatin C, urinary albumin creatinine ratio (UACR), and urinary β2-microglobulin (β2 M) were measured with calculation of β2 M/albumin ratio. Quantification of liver, heart and kidney iron overload was done by MRI.

RESULTS

Serum cystatin C, UACR and urinary β2 microglobulin as well as urinary β2m/albumin were significantly higher in β-TM patients than the control group. No significant difference was found as regards renal R2* between Patients with mean serum ferritin above 2500 μg/L and those with lower serum cutoff. Renal R2* was higher in patients with poor compliance to chelation therapy and positively correlated to indirect bilirubin, LDH, cystatin C and LIC but inversely correlated to cardiac T2*.

CONCLUSION

kidney iron deposition impairs renal glomerular and tubular functions in pediatric patients with β-TM and is related to hemolysis, total body iron overload and poor compliance to chelation.

The Correlation of Cardiac and Hepatic Hemosiderosis as Measured by T2*MRI Technique with Ferritin Levels and Hemochromatosis Gene Mutations in Iranian Patients with Beta Thalassemia Major

Objectives

Organ-specific hemosiderosis and iron overload complications are more serious and more frequent in some patients with beta thalassemia major (BTM) compared with others. We investigated whether coinheritance of HFE H63D or C282Y gene mutations in patients with BTM contributes to the phenotypic variation of iron overload complications and assessed the correlation of cardiac and hepatic hemosiderosis with plasma ferritin levels.

Methods

We studied 60 patients with BTM with a mean age of 17.5±9.1 years from the Northwest of Iran. HFE gene mutations were analyzed using the polymerase chain reaction-restriction fragment length polymorphism method. Cardiac and hepatic hemosiderosis was assessed using T2*magnetic resonance imaging (MRI). Ferritin levels were measured using the enzyme immunoassay method.

Results

Ferritin levels showed a strong inverse correlation with hepatic T2*MRI values (r = -0.631, p = 0.001) but a poor correlation with cardiac T2*MRI values (r = -0.297, p = 0.044). The correlation between cardiac T2*MRI values and hepatic T2*MRI values was poor and insignificant (r = 0.287, p = 0.058). Genotype and allele distribution of HFE H63D and C282Y mutation did not differ significantly between patients with and without hepatic or cardiac hemosiderosis (p > 0.050). However, carriers of HFE 63D allele had significantly higher ferritin levels compared with non-carriers (1 903±993 vs. 992±683, p < 0.001).

Conclusions

Cardiac T2*MRI values showed a poor correlation with hepatic T2*MRI values and ferritin levels. Accurate assessment of cardiac iron overload in patients with BTM can only be done using the T2*MRI technique. Additionally, HFE H63D is a significant determinant factor for elevated ferritin levels in BTM patients.

Thalassaemia

Inherited haemoglobin disorders, including thalassaemia and sickle-cell disease, are the most common monogenic diseases worldwide. Several clinical forms of α-thalassaemia and β-thalassaemia, including the co-inheritance of β-thalassaemia with haemoglobin E resulting in haemoglobin E/β-thalassaemia, have been described. The disease hallmarks include imbalance in the α/β-globin chain ratio, ineffective erythropoiesis, chronic haemolytic anaemia, compensatory haemopoietic expansion, hypercoagulability, and increased intestinal iron absorption. The complications of iron overload, arising from transfusions that represent the basis of disease management in most patients with severe thalassaemia, might further complicate the clinical phenotype. These pathophysiological mechanisms lead to an array of clinical manifestations involving numerous organ systems. Conventional management primarily relies on transfusion and iron-chelation therapy, as well as splenectomy in specific cases. An increased understanding of the molecular and pathogenic factors that govern the disease process have suggested routes for the development of new therapeutic approaches that address the underlying chain imbalance, ineffective erythropoiesis, and iron dysregulation, with several agents being evaluated in preclinical models and clinical trials.

Evaluation of cardiac and hepatic iron overload in thalassemia major patients with T2* magnetic resonance imaging

OBJECTIVES

Recent advancements have promoted the use of T2* magnetic resonance imaging (MRI) in the non-invasive detection of iron overload in various organs for thalassemia major patients. This study aims to determine the iron load in the heart and liver of patients with thalassemia major using T2* MRI and to evaluate its correlation with serum ferritin level and iron chelation therapy.

METHODS

This cross-sectional study included 162 subjects diagnosed with thalassemia major, who were classified into acceptable, mild, moderate, or severe cardiac and hepatic iron overload following their T2* MRI results, respectively, and these were correlated to their serum ferritin levels and iron chelation therapy.

RESULTS

The study found that 85.2% of the subjects had normal cardiac iron stores. In contrast, 70.4% of the subjects had severe liver iron overload. A significant but weak correlation (r = -0.28) was found between cardiac T2* MRI and serum ferritin, and a slightly more significant correlation (r = 0.37) was found between liver iron concentration (LIC) and serum ferritin.

DISCUSSION

The findings of this study are consistent with several other studies, which show that patients generally manifest with liver iron overload prior to cardiac iron overload. Moreover, iron accumulation demonstrated by T2* MRI results also show a significant correlation to serum ferritin levels.

CONCLUSION

This is the first study of its kind conducted in Indonesia, which supports the fact that T2* MRI is undoubtedly valuable in the early detection of cardiac and hepatic iron overload in thalassemia major patients.

Prevalence of diabetes mellitus in Chinese children with thalassaemia major

OBJECTIVE

Diabetes mellitus is a common endocrinopathy in patients with β-thalassaemia major (β-TM), which is high prevalent in southern China. This study aimed to determine the cause and prevalence of glycaemic disorders in Chinese children with β-TM.

METHODS

In this prospective study, fasting glucose and insulin (FINS) levels were assessed in 267 β-TM and 80 non-TM control children. Homeostatic model assessment (HOMA) and the quantitative insulin sensitivity check index (QUICKI) were evaluated. Iron overload was assessed by serum ferritin (SF), total units of blood transfused and cardiac T2*.

RESULTS

β-TM had higher FPG (P < 0.001), FINS (P < 0.001) and HOMA-IR (P < 0.05), but lower QUICKI (P < 0.01) than those of controls. The impaired fasting glucose (IFG) was present in 30% of children, whereas 2% had diabetes. The prevalence of IFG in β-TM group was higher in children aged >10 years (OR 6.5; 95% CI 3.7-11.4; P < 0.001), SF of >2500 μg/l (OR 4.8; 95% CI 2.1-11.1; P < 0.01), serum ALT levels of >50 IU/l (OR 2.1; 95% CI 1.2-3.7; P < 0.05) and cardiac T2* of <20 ms (OR 3.3; 95% CI 1.7-6.6; P < 0. 01). The children on deferiprone (DFP) had a reduced incidence of glycaemic aberrations than those on other chelating agents (OR 0.4; 95% CI 0.23-0.8; P < 0.05).

CONCLUSIONS

Our data suggest that IFG occurred in 30% of β TM children, perhaps due to insulin resistance secondary to iron overload. Deferiprone-containing chelating agent may have a protective effect.

Increased mitochondrial DNA deletions and copy number in transfusion-dependent thalassemia

BACKGROUND

Iron overload is the primary cause of morbidity in transfusion-dependent thalassemia. Increase in iron causes mitochondrial dysfunction under experimental conditions, but the occurrence and significance of mitochondrial damage is not understood in patients with thalassemia.

METHODS

Mitochondrial DNA (mtDNA) to nuclear DNA copy number (Mt/N) and frequency of the common 4977-bp mitochondrial deletion (ΔmtDNA⁴⁹⁷⁷) were quantified using a quantitative PCR assay on whole blood samples from 38 subjects with thalassemia who were receiving regular transfusions.

RESULTS

Compared with healthy controls, Mt/N and ΔmtDNA⁴⁹⁷⁷ frequency were elevated in thalassemia (P = 0.038 and P < 0.001, respectively). ΔmtDNA⁴⁹⁷⁷ was increased in the presence of either liver iron concentration > 15 mg/g dry-weight or splenectomy, with the highest levels observed in subjects who had both risk factors (P = 0.003). Myocardial iron (MRI T2* < 20 ms) was present in 0%, 22%, and 46% of subjects with ΔmtDNA⁴⁹⁷⁷ frequency < 20, 20-40, and > 40/1 × 10⁷ mtDNA, respectively (P = 0.025). Subjects with Mt/N values below the group median had significantly lower Matsuda insulin sensitivity index (5.76 ± 0.53) compared with the high Mt/N group (9.11 ± 0.95, P = 0.008).

CONCLUSION

Individuals with transfusion-dependent thalassemia demonstrate age-related increase in mtDNA damage in leukocytes. These changes are markedly amplified by splenectomy and are associated with extrahepatic iron deposition. Elevated mtDNA damage in blood cells may predict the risk of iron-associated organ damage in thalassemia.

Iron overload correlates with serum liver fibrotic markers and liver dysfunction: Potential new methods to predict iron overload-related liver fibrosis in thalassemia patients

BACKGROUND

Early detection of liver fibrosis in thalassemia patients and rapid initiation of treatment to interfere with its progression are extremely important.

OBJECTIVE

This study aimed to find a sensitive, easy-to-detect and noninvasive method other than liver biopsy for early detection of liver fibrosis in thalassemia patients.

METHODS

A total of 244 Chinese Thalassemia patients with non-transfusion-dependent thalassemia (NTDT, n = 105) or thalassemia major (TM, n = 139) and 120 healthy individuals were recruited into the present study, and blood collagen type IV (C IV), precollagen type III (PIIINPC) and hyaluronic acid (HA), aspartate aminotransferase (AST), alanine aminotransferase (ALT) and ferritin were measured. Liver iron concentration was determined by MRI. The correlation of serum markers with liver iron load and liver function was evaluated.

RESULTS

Serum C IV, PIIINPC and HA were significantly elevated in Chinese patients with NTDT and further elevated in TM patients. Moreover, C IV, PIIINPC and HA were also positively correlated to serum ferritin and liver iron concentration and further elevated during the progression to multi-organ damage in NTDT patients. Finally, serum ferritin and liver iron concentration were significantly correlated with liver dysfunction determined by AST and ALT.

CONCLUSION

Taken together, our results indicate that monitoring serum C IV, PIIINPC and HA is a potentially sensitive method to predict the risks for iron overload-related liver fibrosis in Chinese thalassemia patients.

Assessment of Heart and Liver Iron Overload in Thalassemia Major Patients Using T2* Magnetic Resonance Imaging

Accumulation of excess iron in heart can lead to cardiac dysfunction, which is the most common cause of death in thalassemia major patients. Biopsy is an invasive procedure and therefore not an ideal option to assess iron load. However, standard/usual non-invasive methods, such as ferritin measurement, have some limitations and the results show poor correlations with iron load. Magnetic Response Imaging (MRI-T2*), as a non-invasive and reliable method for iron load assessment in organs such as liver and heart, can be suggested as a favorable alternative. This cross-sectional study was implemented in Thalassemia and Hemophilia Clinic Center (Sarvar) affiliated with Mashhad University of Medical Sciences, Mashhad, Iran, from 2012 to 2013. After the approval of the research protocol by the local ethic committee, laboratory tests, including CBC and serum ferritin, were carried out, and echocardiography and heart and liver MRI-T2* were performed. All statistical analysis was done through SPSS software (version 11.5), using independent sample t test and Pearson's correlation coefficient test. A P value ≤0.05 was considered to be significant. 88 patients with the mean (±SD) age of 21.2 (±5.6) years, (range 11-37 years) were observed. Iron load was assessed using MRI-T2* with the following results: Out of 88 patients, 48.9 % had mild to severe cardiac siderosis, and 75.2 % had mild to severe liver siderosis. We demonstrated a correlation between liver MRI-T2* and serum ferritin, and heart MRI-T2* and ejection fraction. However, no correlation between liver and heart MRI-T2* was observed. Heart and liver siderosis is a common and serious problem in thalassemia major patients, and MRI-T2* as a sensitive and non-invasive technique can be used for early/timely detection of siderosis and good therapeutic monitoring in these patients.

Association between vitamin D levels and left ventricular function and NT-proBNP levels among thalassemia major children with iron overload

BACKGROUND

Heart disease is the major cause of death in thalassemia patients. Repeated blood transfusions and hemolysis cause iron overload and also disrupts the hydroxylation and synthesis of vitamin D, causing vitamin D deficiency. Vitamin D deficiency is associated with cardiac dysfunction.

OBJECTIVE

The purpose of this study was to determine the association between vitamin D levels and left ventricular function and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in thalassemia major children with iron overload.

PATIENTS AND METHODS

A cross-sectional study was conducted in March-April 2015 in the thalassemia clinic, Department of Child Health, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia. Thirty-four children with thalassemia were enrolled consecutively. Serum vitamin D and NT-proBNP levels were measured with electrochemiluminescence (ECLIA) method and echocardiography was performed to assess ventricular function.

RESULTS

Significant correlations were found between vitamin D levels and left ventricular ejection fraction (LVEF) (r = 0.399, P = 0.019) and fractional shortening (FS) (r = 0.394, P = 0.021). There was also significant correlation between vitamin D and NT-proBNP levels (r = -0.444, P = 0.008). Chi-square analysis also showed a relationship between vitamin D and NT-proBNP (P = 0.019) levels. There was a difference in NT-proBNP levels among thalassemia major children with iron overload (P = 0.020). Post hoc analysis showed that there was a significant difference in NT-proBNP levels between those with vitamin D deficiency and those with normal vitamin D levels (P = 0.012).

CONCLUSION

There is an association between vitamin D and left ventricular function and NT-proBNP levels in children with thalassemia major and iron overload. Vitamin D can be considered in patients with thalassemia having vitamin D deficiency.

Free-breathing myocardial T2* mapping using GRE-EPI and automatic non-rigid motion correction

BACKGROUND

Measurement of myocardial T2* is becoming widely used in the assessment of patients at risk for cardiac iron overload. The conventional breath-hold, ECG-triggered, segmented, multi-echo gradient echo (MGRE) sequence used for myocardial T2* quantification is very sensitive to respiratory motion and may not be feasible in patients who are unable to breath-hold. We propose a free-breathing myocardial T2* mapping approach that combines a single-shot gradient-echo echo-planar imaging (GRE-EPI) sequence for T2*-weighted image acquisition with automatic non-rigid motion correction (MOCO) of respiratory motion between single-shot images.

METHODS

ECG-triggered T2*-weighted images at different echo times were acquired by a black-blood, single-shot GRE-EPI sequence during free-breathing. A single image at a single TE is acquired in each heartbeat. Automatic non-rigid MOCO was applied to correct for in-plane respiratory motion before pixel-wise T2* mapping. In a total of 117 patients referred for clinical cardiac magnetic resonance exams, the free-breathing MOCO GRE-EPI sequence was compared to the breath-hold segmented MGRE approach. Image quality was scored independently by 2 experienced observers blinded to the particular image acquisition strategy. T2* measurements in the interventricular septum and in the liver were compared for the two methods in all cases with adequate image quality.

RESULTS

T2* maps were acquired in all 117 patients using the breath-hold MGRE and the free-breathing MOCO GRE-EPI approaches, including 8 patients with myocardial iron overload and 25 patients with hepatic iron overload. The mean image quality of the free-breathing MOCO GRE-EPI images was scored significantly higher than that of the breath-hold MGRE images by both reviewers. Out of the 117 studies, 21 breath-hold MGRE studies (17.9% of all the patients) were scored to be less than adequate or very poor by both reviewers, while only 2 free-breathing MOCO GRE-EPI studies were scored to be less than adequate image quality. In a comparative evaluation of the images with at least adequate quality, the intra-class correlation coefficients for myocardial and liver T2* were 0.868 and 0.986 respectively (p < 0.001), indicating that the T2* measured by breath-hold MGRE and free-breathing MOCO GRE-EPI were in close agreement. The coefficient of variation between the breath-hold and free-breathing approaches for myocardial and liver T2* were 9.88% and 9.38% respectively. Bland-Altman plots demonstrated good absolute agreement of T2* in the interventricular septum and the liver from the free-breathing and breath-hold approaches (mean differences -0.03 and 0.16 ms, respectively).

CONCLUSION

The free-breathing approach described for T2* mapping using MOCO GRE-EPI enables accurate myocardial and liver T2* measurements and is insensitive to respiratory motion.

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.

Cost-utility of chelators in transfusion-dependent β-thalassemia major patients: a review of the pharmacoeconomic literature

In the inherited hematologic disorder β-thalassemia major, patients receive regular, lifelong blood transfusions, which carry excess iron that the body is unable to eliminate. Chelation therapy (deferoxamine, deferiprone, deferasirox or deferoxamine-deferiprone combination) is required to reduce iron accumulation in target organs and the associated morbidity and mortality. Each chelation regimen has a distinct safety/efficacy profile and particular costs associated with its use. This review aims to provide an overview of published cost-utility analyses of currently used chelation regimens, and to comment on the potential relevance of their findings in the USA market, where deferiprone has recently been introduced.