Lactoferrin uptake and iron processing into macrophages: a study in familial haemochromatosis.

Various properties of lactoferrin from neutrophils of normal individuals and patients with familial haemochromatosis were compared. No difference was found with respect to (1) the lactoferrin content of neutrophils, the molecular weight and isoelectric point of the protein, the dissociation of its complex with iron at acidic pH, its binding to isolated monocytes, and its uptake by the mouse reticulo-endothelial system. Macrophages from patients and controls were also found to be similar in their ability to bind and ingest lactoferrin and to process the iron provided by the protein. Therefore a defect in the interaction of lactoferrin with the reticulo-endothelial system, related either to the protein itself or to the cells, seems unlikely. A comparison of the lactoferrin- and the transferrin-mediated iron processing by monocytes is finally presented.