HOW SHOULD WE SELECT THE MOST VULNERABLE THALASSEMIC PATIENTS FOR IRON OVERLOAD EVALUATION BY MRI IN A RESOURCE LIMITED COUNTRY?
(Abstract release date: 05/19/16)
EHA Library. Ekwattanakit S. 06/09/16; 135379; LB2268
Dr. Supachai Ekwattanakit
Contributions
Contributions
Abstract
Abstract: LB2268
Type: Eposter Presentation
Background
Serum ferritin (SF) can be used for determination of iron overload (IO), however, it does not perfectly correlate with tissue iron status in transfusion-dependent thalassemia (TDT) and even worst in non-transfusion-dependent thalassemia (NTDT). The magnetic resonance imaging (MRI) for cardiac T2* and liver iron concentration (LIC) is now considered as a gold standard for IO evaluation in thalassemia worldwide. Nevertheless, this tool was not widely available and expensive in Thailand.
Aims
To evaluate the SF cut-off level for diagnosis of severe IO in real-life situation and determine the utility of SF in predicting IO in thalassemic patients and select the most vulnerable patients for further MRI evaluation.
Methods
In this retrospective cross-sectional study, total 1,034 standard MRI (LIC and cardiac T2*) evaluations performed at Siriraj hospital during 2009-2014 and paired clinical data including SF were collected. Regardless of globin genotypes, all 350 thalassemia patients were divided into NTDT (N=108, 162 LIC and 89 cardiac T2* results) and TDT (N=242, 696 LIC and 692 cardiac T2* results). Different SF cut-off values were tested at 100 or 250 ug/l intervals and receiver operating characteristic (ROC) analysis was performed.
Results
Using SF >800 ug/l to predict LIC ≥5 mgFe/g dw, 86.4% of NTDT would be correctly started on iron chelation. However, 42% of patients (42/100) with LIC ≥5 mgFe/g dw had SF between 301-800 ug/l and 62.7% (42/67) of those with SF 301-800 ug/l had LIC ≥5 mgFe/g dw. Using threshold of SF >300ug/l, we could detect IO in 92% (92/100) of those with LIC ≥5 mgFe/g dw. When α-NTDT patients were excluded, ROC analysis found that SF >400 ug/l correctly predict LIC ≥5 mgFe/g dw in 90% of β-NTDT with lower risk of delayed treatment than using SF threshold >800 ug/l (40.6% vs. 61.9%, according to NPV). Of 89 cardiac T2* results in NTDT (SF range of 24-11,668), none had T2* <20ms. For TDT, ROC analysis suggested SF >3,500 ug/l was the best predictive threshold for T2* <20ms (AUC=0.785), while SF >2,500 ug/l was an appropriate cut-off level for LIC ≥15mgFe/g dw (AUC=0.861).
Conclusion
In a resource limited setting for MRI, SF could be used as a predictive marker for selecting severe IO in both TDT and NTDT. In NTDT, MRI for cardiac T2* could be omitted and, once for diagnosis, MRI for LIC should be done in those with SF >300 ug/l. For TDT, the SF cut off of >2,500 and >3,500 ug/l are useful to predict patients with severe LIC and cardiac siderosis, respectively.
Session topic: E-poster
Keyword(s): Ferritin, Iron overload, Magnetic resonance imaging, Thalassemia
Type: Eposter Presentation
Background
Serum ferritin (SF) can be used for determination of iron overload (IO), however, it does not perfectly correlate with tissue iron status in transfusion-dependent thalassemia (TDT) and even worst in non-transfusion-dependent thalassemia (NTDT). The magnetic resonance imaging (MRI) for cardiac T2* and liver iron concentration (LIC) is now considered as a gold standard for IO evaluation in thalassemia worldwide. Nevertheless, this tool was not widely available and expensive in Thailand.
Aims
To evaluate the SF cut-off level for diagnosis of severe IO in real-life situation and determine the utility of SF in predicting IO in thalassemic patients and select the most vulnerable patients for further MRI evaluation.
Methods
In this retrospective cross-sectional study, total 1,034 standard MRI (LIC and cardiac T2*) evaluations performed at Siriraj hospital during 2009-2014 and paired clinical data including SF were collected. Regardless of globin genotypes, all 350 thalassemia patients were divided into NTDT (N=108, 162 LIC and 89 cardiac T2* results) and TDT (N=242, 696 LIC and 692 cardiac T2* results). Different SF cut-off values were tested at 100 or 250 ug/l intervals and receiver operating characteristic (ROC) analysis was performed.
Results
Using SF >800 ug/l to predict LIC ≥5 mgFe/g dw, 86.4% of NTDT would be correctly started on iron chelation. However, 42% of patients (42/100) with LIC ≥5 mgFe/g dw had SF between 301-800 ug/l and 62.7% (42/67) of those with SF 301-800 ug/l had LIC ≥5 mgFe/g dw. Using threshold of SF >300ug/l, we could detect IO in 92% (92/100) of those with LIC ≥5 mgFe/g dw. When α-NTDT patients were excluded, ROC analysis found that SF >400 ug/l correctly predict LIC ≥5 mgFe/g dw in 90% of β-NTDT with lower risk of delayed treatment than using SF threshold >800 ug/l (40.6% vs. 61.9%, according to NPV). Of 89 cardiac T2* results in NTDT (SF range of 24-11,668), none had T2* <20ms. For TDT, ROC analysis suggested SF >3,500 ug/l was the best predictive threshold for T2* <20ms (AUC=0.785), while SF >2,500 ug/l was an appropriate cut-off level for LIC ≥15mgFe/g dw (AUC=0.861).
Conclusion
In a resource limited setting for MRI, SF could be used as a predictive marker for selecting severe IO in both TDT and NTDT. In NTDT, MRI for cardiac T2* could be omitted and, once for diagnosis, MRI for LIC should be done in those with SF >300 ug/l. For TDT, the SF cut off of >2,500 and >3,500 ug/l are useful to predict patients with severe LIC and cardiac siderosis, respectively.
Session topic: E-poster
Keyword(s): Ferritin, Iron overload, Magnetic resonance imaging, Thalassemia
Abstract: LB2268
Type: Eposter Presentation
Background
Serum ferritin (SF) can be used for determination of iron overload (IO), however, it does not perfectly correlate with tissue iron status in transfusion-dependent thalassemia (TDT) and even worst in non-transfusion-dependent thalassemia (NTDT). The magnetic resonance imaging (MRI) for cardiac T2* and liver iron concentration (LIC) is now considered as a gold standard for IO evaluation in thalassemia worldwide. Nevertheless, this tool was not widely available and expensive in Thailand.
Aims
To evaluate the SF cut-off level for diagnosis of severe IO in real-life situation and determine the utility of SF in predicting IO in thalassemic patients and select the most vulnerable patients for further MRI evaluation.
Methods
In this retrospective cross-sectional study, total 1,034 standard MRI (LIC and cardiac T2*) evaluations performed at Siriraj hospital during 2009-2014 and paired clinical data including SF were collected. Regardless of globin genotypes, all 350 thalassemia patients were divided into NTDT (N=108, 162 LIC and 89 cardiac T2* results) and TDT (N=242, 696 LIC and 692 cardiac T2* results). Different SF cut-off values were tested at 100 or 250 ug/l intervals and receiver operating characteristic (ROC) analysis was performed.
Results
Using SF >800 ug/l to predict LIC ≥5 mgFe/g dw, 86.4% of NTDT would be correctly started on iron chelation. However, 42% of patients (42/100) with LIC ≥5 mgFe/g dw had SF between 301-800 ug/l and 62.7% (42/67) of those with SF 301-800 ug/l had LIC ≥5 mgFe/g dw. Using threshold of SF >300ug/l, we could detect IO in 92% (92/100) of those with LIC ≥5 mgFe/g dw. When α-NTDT patients were excluded, ROC analysis found that SF >400 ug/l correctly predict LIC ≥5 mgFe/g dw in 90% of β-NTDT with lower risk of delayed treatment than using SF threshold >800 ug/l (40.6% vs. 61.9%, according to NPV). Of 89 cardiac T2* results in NTDT (SF range of 24-11,668), none had T2* <20ms. For TDT, ROC analysis suggested SF >3,500 ug/l was the best predictive threshold for T2* <20ms (AUC=0.785), while SF >2,500 ug/l was an appropriate cut-off level for LIC ≥15mgFe/g dw (AUC=0.861).
Conclusion
In a resource limited setting for MRI, SF could be used as a predictive marker for selecting severe IO in both TDT and NTDT. In NTDT, MRI for cardiac T2* could be omitted and, once for diagnosis, MRI for LIC should be done in those with SF >300 ug/l. For TDT, the SF cut off of >2,500 and >3,500 ug/l are useful to predict patients with severe LIC and cardiac siderosis, respectively.
Session topic: E-poster
Keyword(s): Ferritin, Iron overload, Magnetic resonance imaging, Thalassemia
Type: Eposter Presentation
Background
Serum ferritin (SF) can be used for determination of iron overload (IO), however, it does not perfectly correlate with tissue iron status in transfusion-dependent thalassemia (TDT) and even worst in non-transfusion-dependent thalassemia (NTDT). The magnetic resonance imaging (MRI) for cardiac T2* and liver iron concentration (LIC) is now considered as a gold standard for IO evaluation in thalassemia worldwide. Nevertheless, this tool was not widely available and expensive in Thailand.
Aims
To evaluate the SF cut-off level for diagnosis of severe IO in real-life situation and determine the utility of SF in predicting IO in thalassemic patients and select the most vulnerable patients for further MRI evaluation.
Methods
In this retrospective cross-sectional study, total 1,034 standard MRI (LIC and cardiac T2*) evaluations performed at Siriraj hospital during 2009-2014 and paired clinical data including SF were collected. Regardless of globin genotypes, all 350 thalassemia patients were divided into NTDT (N=108, 162 LIC and 89 cardiac T2* results) and TDT (N=242, 696 LIC and 692 cardiac T2* results). Different SF cut-off values were tested at 100 or 250 ug/l intervals and receiver operating characteristic (ROC) analysis was performed.
Results
Using SF >800 ug/l to predict LIC ≥5 mgFe/g dw, 86.4% of NTDT would be correctly started on iron chelation. However, 42% of patients (42/100) with LIC ≥5 mgFe/g dw had SF between 301-800 ug/l and 62.7% (42/67) of those with SF 301-800 ug/l had LIC ≥5 mgFe/g dw. Using threshold of SF >300ug/l, we could detect IO in 92% (92/100) of those with LIC ≥5 mgFe/g dw. When α-NTDT patients were excluded, ROC analysis found that SF >400 ug/l correctly predict LIC ≥5 mgFe/g dw in 90% of β-NTDT with lower risk of delayed treatment than using SF threshold >800 ug/l (40.6% vs. 61.9%, according to NPV). Of 89 cardiac T2* results in NTDT (SF range of 24-11,668), none had T2* <20ms. For TDT, ROC analysis suggested SF >3,500 ug/l was the best predictive threshold for T2* <20ms (AUC=0.785), while SF >2,500 ug/l was an appropriate cut-off level for LIC ≥15mgFe/g dw (AUC=0.861).
Conclusion
In a resource limited setting for MRI, SF could be used as a predictive marker for selecting severe IO in both TDT and NTDT. In NTDT, MRI for cardiac T2* could be omitted and, once for diagnosis, MRI for LIC should be done in those with SF >300 ug/l. For TDT, the SF cut off of >2,500 and >3,500 ug/l are useful to predict patients with severe LIC and cardiac siderosis, respectively.
Session topic: E-poster
Keyword(s): Ferritin, Iron overload, Magnetic resonance imaging, Thalassemia
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