Iron overload in Brazilian thalassemic patients

Magnetic resonance imaging T2* of the pancreas value using an online software tool and correlate with T2* value of myocardium and liver among patients with transfusion-dependent thalassemia major

Objective

Patients with thalassemia major do require lifetime blood transfusions that eventually result in iron accumulation in different organs. We described the usefulness of using magnetic resonance imaging (MRI) T2^*imaging values for the evaluation of pancreatic iron load in these patients, and we correlated it with MRI T2^* haemosiderosis of the myocardium and liver that has been recognized as a non-invasive assessment of iron overload among patients with thalassemia major.

Materials and methods

We conducted a cross-sectional study on 39 patients with thalassemia major in one of the tertiary university hospitals for a 1-year period. Demographic data were collected from the patient's history. MRI T2^* of the pancreas, liver, and heart were executed on all patients in the same setting. Objective values of iron overload in these organs were obtained using the MRI post-processing software from online software.

Results

A total of 32 (82.1%) patients had pancreatic iron overload including 2 patients (5.1%) with severe iron overload and 15 patients (38.5%) with moderate and mild iron overload, respectively. Nine patients (23.1%) had myocardial iron overload, which included 3 patients (7.7%) who had severe cardiac haemosiderosis. Notably, 37 patients (94.9%) had liver iron overload, which included 15 patients (38.5%) who had severe liver haemosiderosis. There was a moderate positive correlation between the relaxation time of the pancreas and heart haemosiderosis (r = 0.504, P < 0.001). No significant correlation was found between the relaxation time of the pancreas with the liver and the heart with the liver.

Conclusion

Pancreatic haemosiderosis precedes cardiac haemosiderosis, which establishes a basis for initiating earlier iron chelation therapy to patients with thalassemia major.

Cardiovascular magnetic resonance native T2 and T2* quantitative values for cardiomyopathies and heart transplantations: a systematic review and meta-analysis

BACKGROUND

The clinical application of cardiovascular magnetic resonance (CMR) T2 and T2* mapping is currently limited as ranges for healthy and cardiac diseases are poorly defined. In this meta-analysis we aimed to determine the weighted mean of T2 and T2* mapping values in patients with myocardial infarction (MI), heart transplantation, non-ischemic cardiomyopathies (NICM) and hypertension, and the standardized mean difference (SMD) of each population with healthy controls. Additionally, the variation of mapping outcomes between studies was investigated.

METHODS

The PRISMA guidelines were followed after literature searches on PubMed and Embase. Studies reporting CMR T2 or T2* values measured in patients were included. The SMD was calculated using a random effects model and a meta-regression analysis was performed for populations with sufficient published data.

RESULTS

One hundred fifty-four studies, including 13,804 patient and 4392 control measurements, were included. T2 values were higher in patients with MI, heart transplantation, sarcoidosis, systemic lupus erythematosus, amyloidosis, hypertrophic cardiomyopathy (HCM), dilated cardiomyopathy (DCM) and myocarditis (SMD of 2.17, 1.05, 0.87, 1.39, 1.62, 1.95, 1.90 and 1.33, respectively, P <  0.01) compared with controls. T2 values in iron overload patients (SMD = - 0.54, P = 0.30) and Anderson-Fabry disease patients (SMD = 0.52, P = 0.17) did both not differ from controls. T2* values were lower in patients with MI and iron overload (SMD of - 1.99 and - 2.39, respectively, P <  0.01) compared with controls. T2* values in HCM patients (SMD = - 0.61, P = 0.22), DCM patients (SMD = - 0.54, P = 0.06) and hypertension patients (SMD = - 1.46, P = 0.10) did not differ from controls. Multiple CMR acquisition and patient demographic factors were assessed as significant covariates, thereby influencing the mapping outcomes and causing variation between studies.

CONCLUSIONS

The clinical utility of T2 and T2* mapping to distinguish affected myocardium in patients with cardiomyopathies or heart transplantation from healthy myocardium seemed to be confirmed based on this meta-analysis. Nevertheless, variation of mapping values between studies complicates comparison with external values and therefore require local healthy reference values to clinically interpret quantitative values. Furthermore, disease differentiation seems limited, since changes in T2 and T2* values of most cardiomyopathies are similar.

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

CONTEXT:

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

AIMS:

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

SETTINGS:

Thalassemia day-care center of a teaching hospital

DESIGN:

This was a cross-sectional study

SUBJECTS AND METHODS:

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

STATISTICAL ANALYSIS USED:

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

RESULTS:

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

Conclusions:

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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