Ferritin in erythrocytes and plasma of patients with iron overload.

Erythrocyte and plasma ferritin was followed in 13 patients with iron overload undergoing phlebotomies for at least 6 months in comparison with untreated patients and normal males. Plasma ferritin was widely scattered with an average of only twice the normal, whereas erythrocyte ferritin was highly elevated to about twelve times the normal (p less than 0.0001). - The time course of plasma and erythrocyte ferritin during phlebotomy therapy was analyzed in 3 patients with idiopathic hemochromatosis. Three stages were established: 1. plasma ferritin dropped gradually into the normal range while erythrocyte ferritin remained high, 2. appropriate phlebotomies maintained normal plasma ferritin and high erythrocyte ferritin, and indicated a monthly uptake of dietary iron of 150-200 mg at a steady state, 3. at low plasma ferritin levels, erythrocyte ferritin was rapidly decreased by further intensive phlebotomy therapy. Based on the presumed net removal of iron, 1 microgram/l plasma ferritin was equivalent to 3-6 mg of body iron and 1 microgram/l erythrocyte ferritin to somewhat less than 1 mg of body iron. - An elevated erythrocyte ferritin during phlebotomy therapy in iron overload not only depends on body iron stores like plasma ferritin but may also be regulated by the activity of erythropoiesis.