The ability to quantitate transfusional
iron overload is crucial for determining the need for and the efficacy of
chelation therapy in patients with long-standing transfusion-dependent anaemias. We evaluated the usefulness of some indirect measures of
iron overload in estimating the
iron concentration in the liver--the most important
iron storage organ--in 26 non-chelated adult non-thalassaemic patients. Liver
iron concentration was determined non-invasively by magnetic resonance imaging (MRI). The standard error of the estimated liver
iron concentration was 80 mumol Fe/g dried liver tissue when using the number of transfused blood units, and 93 mumol Fe/g when using a serum
ferritin assay. Follow-up in 11 patients (12-48 months) revealed that serum
ferritin is a poor measure of the liver
iron concentration during
iron chelation. However, this discrepancy was individually different and seemed to be dependent on the erythropoietic marrow activity. By monitoring the liver
iron concentration by MRI, we compared the efficacy of chelation with
desferrioxamine given either by subcutaneous continuous infusions or by bolus
injections. Depletion of liver
iron stores could be achieved efficiently by both regimens.