Calculation of transfusion iron burden
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Provide a direct quantitative estimate of the body iron burden
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Easy to calculate, inexpensive
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Unreliable in patients with bleeding or chelation therapy
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Serum ferritin level |
Indirect serologic estimation of body iron burden |
Widely available; easy to perform; low-cost; repeatable |
Unreliable in patients with inflammation, liver function deficiency, and ascorbate deficiency |
Serum transferrin saturation |
High sensitivity and specificity in untransfused patients |
Widely available; easy to perform; low-cost; repeatable |
No quantitative correlation to iron burden |
SQUID |
Direct instrumental estimation of hepatic iron concentration |
Noninvasive, repeatable |
Expensive; not widely available; not validated; significant underestimation; not applicable to the heart |
MRI R2 |
Indirect instrumental estimation of tissue iron concentration |
Noninvasive, repeatable; validated in the liver |
Expensive; not widely available; reliable up to LIC of 15mg/gDW; not applicable for cardiac assessment |
MRI T2* |
Indirect instrumental estimation of tissue iron concentration |
Noninvasive; repeatable; validated in the heart; provides cardiac functional information |
Expensive; not widely available; complex, requires skilled radiologist |
Liver biopsy |
Provides a direct estimation of iron overload |
Validated and quantitative method to estimate hepatic iron concentration (gold standard) |
Invasive (cannot be employed in many patients with hematologic malignancies) |
Non-transferrin bound iron (NTBI)1 |
Research tool at present |
Noninvasive method; estimates generation of the toxic iron fraction |
Not validated and not widely available. Not currently useful in clinical practice |
Serum hepcidin level |
Research tool at present |
Noninvasive method that identifies patients at high risk of iron loading |
Not widely available. Not currently useful in clinical practice |