Albertine Donker

IRIDA: a Heterogeneous Disease 191 4 Plasma iron clearance and red cell iron incorporation were determined after injection of 59 Fe bound to transferrin. This labeled 59 Fe was prepared by incubating autologous plasma with ferrous citrate after which 59 Fe not bound to transferrin was removed by passing the mixture through an anion exchange resin column. 15 Results Intestinal iron uptake and red cell incorporation studies in patient 3, 14 and 15 indicate that mucosal absorption, intestinal mucosal transport of iron into the circulation and iron retention 14 days after oral iron administration are inadequately low for the relatively low body iron status of these patients ( Supplemental Table 9 ). As shown for patient 3, plasma iron clearance and red cell iron uptake after administration of iv iron coupled to transferrin are both normal, illustrating that IRIDA is a defect of cellular iron release and that erythroblast iron uptake from the circulation and incorporation occurs fast and without restrictions.