Assessment of Body Iron Burden in Thalassemia
| Test . | . | Comments . | Reference . |
|---|---|---|---|
| Indirect: | Most tests widely available | ||
| Serum/plasma ferritin concentration | Noninvasive | 162-169 | |
| Lacks sensitivity and specificity | |||
| Poorly correlated with hepatic iron concentration in individual patients | |||
| Serum transferrin saturation | Lacks sensitivity | 163, 164 | |
| Tests of 24-h deferoxamine-induced urinary iron excretion | Less than half of outpatient aliquots collected correctly | ||
| Ratio of stool:urine iron variable; poorly correlated with hepatic iron concentration | |||
| 51, 52, 67, 163, 164 | |||
| Imaging of tissue iron | |||
| Computed tomography: | Liver | Variable correlation with hepatic iron concentration reported | 170-174 |
| Magnetic resonance: | Liver | Variable correlations with hepatic iron concentration reported | 176-191 |
| Treatment-induced changes confirmed by liver biopsy | 192 | ||
| Heart | Only modality available to image cardiac iron stores; changes observed during chelating therapy are consistent with reduction in cardiac iron | 192, 193 | |
| Anterior pituitary | Only modality available to image pituitary iron; signal moderately well correlated with pituitary reserve | 196-198 | |
| Evaluation of organ function | Most tests lack sensitivity and specificity; may identify established organ dysfunction | 199-207 | |
| Direct: | Most tests not widely available | ||
| Cardiac iron quantitation: Biopsy | Imprecise due to inhomogeneous distribution of cardiac iron | 194, 195 | |
| Hepatic iron quantitation: Biopsy | Reference method; provides direct assessment of body iron burden, severity of fibrosis and inflammation | 161, 208-218 | |
| Safe when performed with ultrasound guidance | 221 | ||
| Superconducting susceptometry (SQUID) | Noninvasive; excellent correlation with biopsy-determined hepatic iron | 209-212 |
| Test . | . | Comments . | Reference . |
|---|---|---|---|
| Indirect: | Most tests widely available | ||
| Serum/plasma ferritin concentration | Noninvasive | 162-169 | |
| Lacks sensitivity and specificity | |||
| Poorly correlated with hepatic iron concentration in individual patients | |||
| Serum transferrin saturation | Lacks sensitivity | 163, 164 | |
| Tests of 24-h deferoxamine-induced urinary iron excretion | Less than half of outpatient aliquots collected correctly | ||
| Ratio of stool:urine iron variable; poorly correlated with hepatic iron concentration | |||
| 51, 52, 67, 163, 164 | |||
| Imaging of tissue iron | |||
| Computed tomography: | Liver | Variable correlation with hepatic iron concentration reported | 170-174 |
| Magnetic resonance: | Liver | Variable correlations with hepatic iron concentration reported | 176-191 |
| Treatment-induced changes confirmed by liver biopsy | 192 | ||
| Heart | Only modality available to image cardiac iron stores; changes observed during chelating therapy are consistent with reduction in cardiac iron | 192, 193 | |
| Anterior pituitary | Only modality available to image pituitary iron; signal moderately well correlated with pituitary reserve | 196-198 | |
| Evaluation of organ function | Most tests lack sensitivity and specificity; may identify established organ dysfunction | 199-207 | |
| Direct: | Most tests not widely available | ||
| Cardiac iron quantitation: Biopsy | Imprecise due to inhomogeneous distribution of cardiac iron | 194, 195 | |
| Hepatic iron quantitation: Biopsy | Reference method; provides direct assessment of body iron burden, severity of fibrosis and inflammation | 161, 208-218 | |
| Safe when performed with ultrasound guidance | 221 | ||
| Superconducting susceptometry (SQUID) | Noninvasive; excellent correlation with biopsy-determined hepatic iron | 209-212 |