Uptake of iron by duodenal biopsy specimens from patients with iron-deficiency anaemia and primary haemochromatosis.

Iron uptake by human duodenal mucosa in vitro was considerably higher in iron-deficient patients than in controls. In biopsy specimens taken after treatment with iron, uptake fell to normal levels, although total iron in the mucosa remained low. In iron-overloaded patients with primary haemochromatosis, there was inappropriately high uptake of iron by the biopsy specimens. Kinetic analysis suggested that this was the result of affinity for iron being increased in a carrier in the enterocyte.