An accurate determination of the total amount and distribution of body
iron stores is essential for prognostic purposes and to evaluate the efficacy of
chelation therapy. In the clinical setting, a rough estimate of the total body
iron burden may be obtained in patients with transfusion-dependent
anemias by calculating the amount of blood administered plus the amount absorbed by the gastrointestinal route, which is influenced by the level of Hb and by bone marrow activity. An increase in serum
iron and a decrease in total
iron binding capacity are early indicators of
iron overload, but their sensitivity and specificity are not very high. In normal individuals, serum
ferritin correlates well with
iron stores, as measured by phlebotomy, and with directly measured liver
iron. However, plasma
ferritin, being an
acute phase reactant, is increased in cases of
chronic disease, disseminated
malignancy, or inflammatory disorders. Non-
transferrin bound
iron, i.e.
iron that circulates in plasma unbound to
transferrin, is potentially toxic since it is capable of taking part in
free radical-mediated reactions that result in irreversible tissue damage. This
iron can be measured with a HPLC based assay. At present the most accurate way of estimating the
iron burden is by direct measurement of
iron concentration in tissues. The liver is the most accessible. The measurement is done by atomic absorption spectrometry on ashed or lyophilized samples obtained by needle biopsy, and correlates well with the total amount of blood transfused and with the extent of hepatic
fibrosis.(ABSTRACT TRUNCATED AT 250 WORDS)