Iron removal by desferrioxamine in patients on chronic hemodialysis--kinetic study and long-term results.

Serum ferritin levels, cumulative number of administered blood transfusions, number of monthly transfused blood units and total months on hemodialysis (HD) treatment differed significantly in 7 patients on hemodialysis with clinical, biochemical and histological evidence of hemosiderosis, when compared to 37 controls (p less than 0.001 for all parameters). As a new treatment method desferrioxamine (DFO) therapy was introduced for iron detoxification in these hemosiderotic chronically hemodialyzed patients. Hence, to maximize the biological half-time, 30 mg/kg body weight DFO were given after the end of HD in the iron-loaded patients. Iron removal during the subsequent HD and the increase of iron excretion by the stool after DFO was measured by atomic absorption spectroscopy. Iron removal by the artificial kidney was calculated by investigating the function (QDi + QF)CDo over the duration of HD treatment, which equals the total amount of iron removal during HD. Using numerical integration of measured data this removal was found to be 21.8 +/- 6.9 mg whereas cumulative iron loss via the feces was found to be 36.5 +/- 14.6 mg. Therefore, total iron elimination was calculated to be on average 50-60 mg after administration of a single dose of DFO. Furthermore, long-term treatment of 5 patients resulted in a significant decrease of serum ferritin levels from 2,309 +/- 295 to 715 +/- 177 ng WHO/ml (p less than 0.001) after a period of 36 +/- 5 months. We conclude, that DFO in a dosage of 30 mg/kg body weight given at the end of HD is able to remove more than 500 mg iron/month if it is administered following each HD. Long-term results indicate negative iron balance without significant change of transfusion frequency if not more than 2 U of blood (500 mg iron) are administered within 1 month. This treatment schedule might be superior compared to the previously used methods of administration where DFO was given at the beginning or throughout HD.