Immunoradiometric assay for ferritin in human serum.

A sensitive, specific and precise immunoradiometric assay for ferritin has been developed. Ferritin was measured in the serum of 160 hospital controls, 101 females (118 +/- 9 mug/l) and 59 males (189 +/- 16 mug/l). This difference was statistically significant. In 28 patients with untreated iron deficiency anaemia, serum ferritin concentration (6.1 +/- 0.7 mug/l) was significantly lower than in the controls, but it was within the normal range in 14 cases of polycythaemia vera treated by repeated phlebotomy. In 4 patients with primary haemachromatosis (2884 +/- 56 mug/l), 25 with secondary iron overload states (5702 +/- 1235 mug/l) and 8 with haemolytic anaemia (1612 +/- 605 mug/l), serum ferritin levels were markedly elevated. In 14 cases of transfusional siderosis there was a highly significant correlation between serum ferritin concentration and units of blood transfused. A circadian rhythm in serum ferritin concentration was observed in 7 healthy subjects.