Differential ferrioxamine test in idiopathic haemochromatosis and transfusional haemosiderosis.

The differential ferrioxamine test measures the amount of body iron as ferrioxamine (Fv) chelated by a standard dose of desferrioxamine.Five patients with untreated, uncomplicated idiopathic haemochromatosis and one with transfusion haemosiderosis gave Fv in the range 1,948 to 2,462 mug./kg. (normal 110 to 500). One case of transfusion haemochromatosis with haemolytic anaemia and renal failure gave an Fv value of 8,019 mug./kg. Four patients with idiopathic haemochromatosis after therapeutic venesection gave Fv values of 212 to 885 mug./kg. One relative with a value for Fv of 776 mug./kg. was shown to have early cirrhosis by liver biopsy. Serial Fv measurement after venesection in this patient provided a preliminary assessment of the relationship between Fv values and available iron stores up to about 2,000 mg. iron. This relationship applies only when red cell survival is normal. Approximate figures for the range of available storage iron in 31 healthy men are deduced, namely, 200 mg. to 1,000 mg. (3 to 14 mg./kg.). The test should prove useful in the diagnosis of iron overload, in the screening of relatives for early haemochromatosis, and in the management of iron storage diseases.