Albertine Donker

Chapter 4 158 patients no enteral iron absorption was demonstrated. In the mono-allelic patients, the quantitative results of the IOAT did not predict the severity of the phenotype and the response to oral iron ( Supplemental Files ). Ferrokinetic studies Prior to diagnosis of IRIDA, ferrokinetic studies with radio-active labelled iron were performed in patients 3, 14 and 15 in order to evaluate mucosal iron uptake, transfer, plasma iron clearance, red cell iron incorporation and iron retention. 32-34 The data showed a defect in intestinal iron uptake but adequate iron uptake and incorporation by erythroblasts 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 ( Supplemental Table 9 ). The kinetics of the effect of intravenous iron on blood and serum parameters was studied by administration of 200 mg intravenous iron in patient 14, followed by measurements during the first day and at t= 1 week. Results demonstrated a significant but temporary increase of serum hepcidin on day 1 and a slight increase of Hb, MCV and ferritin after one week. TSAT and the TSAT/hepcidin ratio remained low ( Supplemental Table 10 ).