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.

Erythrocyte and plasma ferritin in normal subjects, blood donors and iron deficiency anemia patients.

Ferritin concentration has been determined with an immunoradiometric assay in plasma and washed sedimented erythrocytes after hypotonic lysis. There was a gradual decrease of plasma ferritin in the sequence normal males, normal females, blood donors and patients with iron deficiency anemia. Erythrocyte ferritin remained unchanged in normal males and females and in blood donors, but dropped significantly in the anemic patients. Correspondingly, the ratio of erythrocyte to plasma ferritin rose from less than 2 in healthy males up to 8 in persons with iron deficiency. Little, if any effect on plasma and erythrocyte ferritin was observed in 12 male and female volunteers when taking iron for 4 weeks. In 2 patients with iron deficiency anemia the blood counts were normalized within 2-3 months during oral iron substitution, accompanied by a drastic increase of the erythrocyte ferritin concentration to values far above normal. In contrast, the plasma ferritin concentration remained below normal. Thus, in iron deficiency erythrocyte ferritin is synthesized with priority in the presence of iron and, in addition to plasma ferritin, appears to be a useful parameter of the iron status.